Re: [PATCH v2 6/7] misc: bcm-vk: add Broadcom VK driver

[Dan Carpenter]

I'm not sure what git tree you're building on top of.  This patchset
doesn't apply to linux-next which is the only thing I tested...

On Wed, Feb 19, 2020 at 04:48:24PM -0800, Scott Branden wrote:
> Add Broadcom VK driver offload engine.
> This driver interfaces to the VK PCIe offload engine to perform
> should offload functions as video transcoding on multiple streams
> in parallel.  VK device is booted from files loaded using
> request_firmware_into_buf mechanism.  After booted card status is updated
> and messages can then be sent to the card.
> Such messages contain scatter gather list of addresses
> to pull data from the host to perform operations on.
> 
> Signed-off-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
> Signed-off-by: Desmond Yan <desmond.yan@xxxxxxxxxxxx>
> Signed-off-by: James Hu <james.hu@xxxxxxxxxxxx>
> ---
>  drivers/misc/Kconfig             |    1 +
>  drivers/misc/Makefile            |    1 +
>  drivers/misc/bcm-vk/Kconfig      |   42 +
>  drivers/misc/bcm-vk/Makefile     |   11 +
>  drivers/misc/bcm-vk/bcm_vk.h     |  357 ++++++++
>  drivers/misc/bcm-vk/bcm_vk_dev.c | 1197 ++++++++++++++++++++++++++
>  drivers/misc/bcm-vk/bcm_vk_msg.c | 1359 ++++++++++++++++++++++++++++++
>  drivers/misc/bcm-vk/bcm_vk_msg.h |  210 +++++
>  drivers/misc/bcm-vk/bcm_vk_sg.c  |  273 ++++++
>  drivers/misc/bcm-vk/bcm_vk_sg.h  |   60 ++
>  drivers/misc/bcm-vk/bcm_vk_tty.c |  327 +++++++
>  11 files changed, 3838 insertions(+)
>  create mode 100644 drivers/misc/bcm-vk/Kconfig
>  create mode 100644 drivers/misc/bcm-vk/Makefile
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk.h
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_dev.c
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_msg.c
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_msg.h
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_sg.c
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_sg.h
>  create mode 100644 drivers/misc/bcm-vk/bcm_vk_tty.c
> 
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 7f0d48f406e3..39c74ed6a846 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -478,6 +478,7 @@ source "drivers/misc/genwqe/Kconfig"
>  source "drivers/misc/echo/Kconfig"
>  source "drivers/misc/cxl/Kconfig"
>  source "drivers/misc/ocxl/Kconfig"
> +source "drivers/misc/bcm-vk/Kconfig"
>  source "drivers/misc/cardreader/Kconfig"
>  source "drivers/misc/habanalabs/Kconfig"
>  endmenu
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index c1860d35dc7e..d9a3b2791560 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -53,6 +53,7 @@ obj-$(CONFIG_VEXPRESS_SYSCFG)	+= vexpress-syscfg.o
>  obj-$(CONFIG_CXL_BASE)		+= cxl/
>  obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
>  obj-$(CONFIG_OCXL)		+= ocxl/
> +obj-$(CONFIG_BCM_VK)		+= bcm-vk/
>  obj-y				+= cardreader/
>  obj-$(CONFIG_PVPANIC)   	+= pvpanic.o
>  obj-$(CONFIG_HABANA_AI)		+= habanalabs/
> diff --git a/drivers/misc/bcm-vk/Kconfig b/drivers/misc/bcm-vk/Kconfig
> new file mode 100644
> index 000000000000..c75dfb89a38d
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/Kconfig
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Broadcom VK device
> +#
> +config BCM_VK
> +	tristate "Support for Broadcom VK Accelerators"
> +	depends on PCI_MSI
> +	default m
> +	help
> +	  Select this option to enable support for Broadcom
> +	  VK Accelerators.  VK is used for performing
> +	  specific video offload processing.  This driver enables
> +	  userspace programs to access these accelerators via /dev/bcm-vk.N
> +	  devices.
> +
> +	  If unsure, say N.
> +
> +if BCM_VK
> +
> +config BCM_VK_H2VK_VERIFY_AND_RETRY
> +	bool "Host To VK Verifiy Data and Retry"
> +	help
> +	  Turn on to verify the data passed down to VK is good,
> +	  and if not, do a retry until it succeeds.
> +	  This is a debug/workaround on FPGA PCIe timing issues
> +	  but may be found useful for debugging other PCIe hardware issues.
> +	  Small performance loss by enabling this debug config.
> +	  For properly operating PCIe hardware no need to enable this.
> +
> +	  If unsure, say N.
> +
> +config BCM_VK_QSTATS
> +	bool "VK Queue Statistics"
> +	help
> +	  Turn on to enable Queue Statistics.
> +	  These are useful for debugging purposes.
> +	  Some performance loss by enabling this debug config.
> +	  For properly operating PCIe hardware no need to enable this.
> +
> +	  If unsure, say N.
> +
> +endif
> diff --git a/drivers/misc/bcm-vk/Makefile b/drivers/misc/bcm-vk/Makefile
> new file mode 100644
> index 000000000000..05cb213ee826
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/Makefile
> @@ -0,0 +1,11 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Makefile for Broadcom VK driver
> +#
> +
> +obj-$(CONFIG_BCM_VK) += bcm_vk.o
> +bcm_vk-objs := \
> +	bcm_vk_dev.o \
> +	bcm_vk_msg.o \
> +	bcm_vk_sg.o \
> +	bcm_vk_tty.o
> diff --git a/drivers/misc/bcm-vk/bcm_vk.h b/drivers/misc/bcm-vk/bcm_vk.h
> new file mode 100644
> index 000000000000..203ca741bf88
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk.h
> @@ -0,0 +1,357 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#ifndef BCM_VK_H
> +#define BCM_VK_H
> +
> +#include <linux/atomic.h>
> +#include <linux/pci.h>
> +#include <linux/irq.h>
> +#include <linux/miscdevice.h>
> +#include <linux/mutex.h>
> +#include <linux/sched/signal.h>
> +#include <linux/tty.h>
> +#include <linux/uaccess.h>
> +#include <linux/version.h>
> +#include <uapi/linux/misc/bcm_vk.h>
> +
> +#include "bcm_vk_msg.h"
> +
> +#define DRV_MODULE_NAME		"bcm-vk"
> +
> +/*
> + * Load Image is completed in two stages:
> + *
> + * 1) When the VK device boot-up, M7 CPU runs and executes the BootROM.
> + * The Secure Boot Loader (SBL) as part of the BootROM will run
> + * to open up ITCM for host to push BOOT1 image.
> + * SBL will authenticate the image before jumping to BOOT1 image.
> + *
> + * 2) Because BOOT1 image is a secured image, we also called it the
> + * Secure Boot Image (SBI). At second stage, SBI will initialize DDR
> + * and wait for host to push BOOT2 image to DDR.
> + * SBI will authenticate the image before jumping to BOOT2 image.
> + *
> + */
> +/* Location of registers of interest in BAR0 */
> +
> +/* Request register for Secure Boot Loader (SBL) download */
> +#define BAR_CODEPUSH_SBL		0x400
> +/* Start of ITCM */
> +#define CODEPUSH_BOOT1_ENTRY		0x00400000
> +#define CODEPUSH_MASK		        0xFFFFF000
> +#define CODEPUSH_BOOTSTART		BIT(0)
> +
> +/* Boot Status register */
> +#define BAR_BOOT_STATUS			0x404
> +
> +#define SRAM_OPEN			BIT(16)
> +#define DDR_OPEN			BIT(17)
> +
> +/* Firmware loader progress status definitions */
> +#define FW_LOADER_ACK_SEND_MORE_DATA	BIT(18)
> +#define FW_LOADER_ACK_IN_PROGRESS	BIT(19)
> +#define FW_LOADER_ACK_RCVD_ALL_DATA	BIT(20)
> +
> +/* definitions for boot status register */
> +#define BOOT_STATE_MASK			0xFFF3FFFF
> +#define BROM_STATUS_NOT_RUN		0x2
> +#define BROM_NOT_RUN			(SRAM_OPEN | BROM_STATUS_NOT_RUN)
> +#define BROM_STATUS_COMPLETE		0x6
> +#define BROM_RUNNING			(SRAM_OPEN | BROM_STATUS_COMPLETE)
> +#define BOOT1_STATUS_COMPLETE		0x6
> +#define BOOT1_RUNNING			(DDR_OPEN | BOOT1_STATUS_COMPLETE)
> +#define BOOT2_STATUS_COMPLETE		0x6
> +#define BOOT2_RUNNING			(FW_LOADER_ACK_RCVD_ALL_DATA | \
> +					 BOOT2_STATUS_COMPLETE)
> +
> +/* Boot request for Secure Boot Image (SBI) */
> +#define BAR_CODEPUSH_SBI		0x408
> +/* 64M mapped to BAR2 */
> +#define CODEPUSH_BOOT2_ENTRY		0x60000000
> +
> +#define BAR_CARD_STATUS			0x410
> +/* CARD_STATUS definitions */
> +#define CARD_STATUS_TTYVK0_READY	BIT(0)
> +#define CARD_STATUS_TTYVK1_READY	BIT(1)
> +
> +#define BAR_METADATA_VERSION		0x440
> +#define BAR_OS_UPTIME			0x444
> +#define BAR_CHIP_ID			0x448
> +
> +#define BAR_CARD_TEMPERATURE		0x45C
> +/* defines for all temperature sensor */
> +#define BCM_VK_TEMP_FIELD_MASK		0xFF
> +#define BCM_VK_CPU_TEMP_SHIFT		0
> +#define BCM_VK_DDR0_TEMP_SHIFT		8
> +#define BCM_VK_DDR1_TEMP_SHIFT		16
> +
> +#define BAR_CARD_VOLTAGE		0x460
> +/* defines for voltage rail conversion */
> +#define BCM_VK_VOLT_RAIL_MASK		0xFFFF
> +#define BCM_VK_3P3_VOLT_REG_SHIFT	16
> +
> +#define BAR_CARD_ERR_LOG		0x464
> +/* Error log register bit definition - register for error alerts */
> +#define ERR_LOG_UECC			BIT(0)
> +#define ERR_LOG_SSIM_BUSY		BIT(1)
> +#define ERR_LOG_AFBC_BUSY		BIT(2)
> +#define ERR_LOG_HIGH_TEMP_ERR		BIT(3)
> +#define ERR_LOG_WDOG_TIMEOUT		BIT(4)
> +#define ERR_LOG_SYS_FAULT		BIT(5)
> +#define ERR_LOG_MEM_ALLOC_FAIL		BIT(8)
> +#define ERR_LOG_LOW_TEMP_WARN		BIT(9)
> +#define ERR_LOG_ECC			BIT(10)
> +/* Alert bit definitions detectd on host */
> +#define ERR_LOG_HOST_HB_FAIL		BIT(14)
> +#define ERR_LOG_HOST_PCIE_DWN		BIT(15)
> +
> +#define BAR_CARD_ERR_MEM		0x468
> +/* defines for mem err, all fields have same width */
> +#define BCM_VK_MEM_ERR_FIELD_MASK	0xFF
> +#define BCM_VK_ECC_MEM_ERR_SHIFT	0
> +#define BCM_VK_UECC_MEM_ERR_SHIFT	8
> +/* threshold of event occurrence and logs start to come out */
> +#define BCM_VK_ECC_THRESHOLD		10
> +#define BCM_VK_UECC_THRESHOLD		1
> +
> +#define BAR_CARD_PWR_AND_THRE		0x46C
> +/* defines for power and temp threshold, all fields have same width */
> +#define BCM_VK_PWR_AND_THRE_FIELD_MASK	0xFF
> +#define BCM_VK_LOW_TEMP_THRE_SHIFT	0
> +#define BCM_VK_HIGH_TEMP_THRE_SHIFT	8
> +#define BCM_VK_PWR_STATE_SHIFT		16
> +
> +#define BAR_CARD_STATIC_INFO		0x470
> +
> +#define BAR_BOOTSRC_SELECT		0xC78
> +/* BOOTSRC definitions */
> +#define BOOTSRC_SOFT_ENABLE		BIT(14)
> +
> +/* Card OS Firmware version size */
> +#define BAR_FIRMWARE_TAG_SIZE		50
> +#define FIRMWARE_STATUS_PRE_INIT_DONE	0x1F
> +
> +/* VK MSG_ID defines */
> +#define VK_MSG_ID_BITMAP_SIZE		4096
> +#define VK_MSG_ID_BITMAP_MASK		(VK_MSG_ID_BITMAP_SIZE - 1)
> +#define VK_MSG_ID_OVERFLOW		0xFFFF
> +
> +/* VK device supports a maximum of 3 bars */
> +#define MAX_BAR	3
> +
> +/* default number of msg blk for inband SGL */
> +#define BCM_VK_DEF_IB_SGL_BLK_LEN	 16
> +#define BCM_VK_IB_SGL_BLK_MAX		 24
> +
> +enum pci_barno {
> +	BAR_0 = 0,
> +	BAR_1,
> +	BAR_2
> +};
> +
> +#define BCM_VK_NUM_TTY 2
> +
> +struct bcm_vk_tty {
> +	struct tty_port port;
> +	uint32_t to_offset;	/* bar offset to use */
> +	uint32_t to_size;	/* to VK buffer size */
> +	uint32_t wr;		/* write offset shadow */
> +	uint32_t from_offset;	/* bar offset to use */
> +	uint32_t from_size;	/* from VK buffer size */
> +	uint32_t rd;		/* read offset shadow */
> +};
> +
> +/* VK device max power state, supports 3, full, reduced and low */
> +#define MAX_OPP 3
> +#define MAX_CARD_INFO_TAG_SIZE 64
> +
> +struct bcm_vk_card_info {
> +	uint32_t version;
> +	char os_tag[MAX_CARD_INFO_TAG_SIZE];
> +	char cmpt_tag[MAX_CARD_INFO_TAG_SIZE];
> +	uint32_t cpu_freq_mhz;
> +	uint32_t cpu_scale[MAX_OPP];
> +	uint32_t ddr_freq_mhz;
> +	uint32_t ddr_size_MB;
> +	uint32_t video_core_freq_mhz;
> +};
> +
> +/*
> + * Control structure of logging messages from the card.  This
> + * buffer is for logmsg that comes from vk
> + */
> +struct bcm_vk_peer_log {
> +	uint32_t rd_idx;
> +	uint32_t wr_idx;
> +	uint32_t buf_size;
> +	uint32_t mask;
> +	char data[0];
> +};
> +/* max size per line of peer log */
> +#define BCM_VK_PEER_LOG_LINE_MAX  256
> +
> +struct bcm_vk_hb_ctrl {
> +	struct timer_list timer;
> +	uint32_t last_uptime;
> +	uint32_t lost_cnt;
> +};
> +
> +struct bcm_vk_alert {
> +	uint16_t flags;
> +	uint16_t notfs;
> +};
> +
> +/* some alert counters that the driver will keep track */
> +struct bcm_vk_alert_cnts {
> +	uint16_t ecc;
> +	uint16_t uecc;
> +};
> +
> +struct bcm_vk {
> +	struct pci_dev *pdev;
> +	void __iomem *bar[MAX_BAR];
> +	int num_irqs;
> +
> +	struct bcm_vk_card_info card_info;
> +
> +	/* mutex to protect the ioctls */
> +	struct mutex mutex;
> +	struct miscdevice miscdev;
> +	int misc_devid; /* dev id allocated */
> +
> +	struct tty_driver *tty_drv;
> +	struct timer_list serial_timer;
> +	struct bcm_vk_tty tty[BCM_VK_NUM_TTY];
> +
> +	/* Reference-counting to handle file operations */
> +	struct kref kref;
> +
> +	spinlock_t msg_id_lock;
> +	uint16_t msg_id;
> +	DECLARE_BITMAP(bmap, VK_MSG_ID_BITMAP_SIZE);
> +	spinlock_t ctx_lock;
> +	struct bcm_vk_ctx ctx[VK_CMPT_CTX_MAX];
> +	struct bcm_vk_ht_entry pid_ht[VK_PID_HT_SZ];
> +	struct task_struct *reset_ppid; /* process that issue reset */
> +
> +	atomic_t msgq_inited; /* indicate if info has been synced with vk */
> +	struct bcm_vk_msg_chan h2vk_msg_chan;
> +	struct bcm_vk_msg_chan vk2h_msg_chan;

These two names are almost the same except the letters are jumbled up.
Please, figure out better names because the human mind sees them as
exactly the same at first glance.

https://www.mnn.com/lifestyle/arts-culture/stories/why-your-brain-can-read-jumbled-letters


> +
> +	struct workqueue_struct *wq_thread;
> +	struct work_struct wq_work; /* work queue for deferred job */
> +	unsigned long wq_offload[1]; /* various flags on wq requested */
> +	void *tdma_vaddr; /* test dma segment virtual addr */
> +	dma_addr_t tdma_addr; /* test dma segment bus addr */
> +
> +	struct notifier_block panic_nb;
> +	uint32_t ib_sgl_size; /* size allocated for inband sgl insertion */
> +
> +	/* heart beat mechanism control structure */
> +	struct bcm_vk_hb_ctrl hb_ctrl;
> +	/* house-keeping variable of error logs */
> +	spinlock_t host_alert_lock; /* protection to access host_alert struct */
> +	struct bcm_vk_alert host_alert;
> +	struct bcm_vk_alert peer_alert; /* bits set by the card */
> +	struct bcm_vk_alert_cnts alert_cnts;
> +
> +	/* offset of the peer log control in BAR2 */
> +	uint32_t peerlog_off;
> +};
> +
> +/* wq offload work items bits definitions */
> +enum bcm_vk_wq_offload_flags {
> +	BCM_VK_WQ_DWNLD_PEND = 0,
> +	BCM_VK_WQ_DWNLD_AUTO = 1,
> +	BCM_VK_WQ_NOTF_PEND  = 2,
> +};
> +
> +/* a macro to get an individual field with mask and shift */
> +#define BCM_VK_EXTRACT_FIELD(_field, _reg, _mask, _shift) \
> +		(_field = (((_reg) >> (_shift)) & (_mask)))
> +
> +/* structure that is used to faciliate displaying of register content */
> +struct bcm_vk_entry {
> +	const uint32_t mask;
> +	const uint32_t exp_val;
> +	const char *str;
> +};
> +
> +/* alerts that could be generated from peer */
> +#define BCM_VK_PEER_ERR_NUM 9
> +extern struct bcm_vk_entry const bcm_vk_peer_err[BCM_VK_PEER_ERR_NUM];
> +/* alerts detected by the host */
> +#define BCM_VK_HOST_ERR_NUM 2
> +extern struct bcm_vk_entry const bcm_vk_host_err[BCM_VK_HOST_ERR_NUM];
> +
> +/*
> + * check if PCIe interface is down on read.  Use it when it is
> + * certain that _val should never be all ones.
> + */
> +#define BCM_VK_INTF_IS_DOWN(val) ((val) == 0xFFFFFFFF)
> +
> +static inline u32 vkread32(struct bcm_vk *vk,
> +			   enum pci_barno bar,
> +			   uint64_t offset)
> +{
> +	u32 value;
> +
> +	value = ioread32(vk->bar[bar] + offset);
> +	return value;


	return ioread32(vk->bar[bar] + offset);

> +}
> +
> +static inline void vkwrite32(struct bcm_vk *vk,
> +			     u32 value,
> +			     enum pci_barno bar,
> +			     uint64_t offset)
> +{
> +	iowrite32(value, vk->bar[bar] + offset);
> +}
> +
> +static inline u8 vkread8(struct bcm_vk *vk,
> +			 enum pci_barno bar,
> +			 uint64_t offset)
> +{
> +	u8 value;
> +
> +	value = ioread8(vk->bar[bar] + offset);
> +	return value;

	return ioread8(vk->bar[bar] + offset);

> +}
> +
> +static inline void vkwrite8(struct bcm_vk *vk,
> +			    u8 value,
> +			    enum pci_barno bar,
> +			    uint64_t offset)
> +{
> +	iowrite8(value, vk->bar[bar] + offset);
> +}
> +
> +int bcm_vk_open(struct inode *inode, struct file *p_file);
> +ssize_t bcm_vk_read(struct file *p_file, char __user *buf, size_t count,
> +		    loff_t *f_pos);
> +ssize_t bcm_vk_write(struct file *p_file, const char __user *buf,
> +		     size_t count, loff_t *f_pos);
> +int bcm_vk_release(struct inode *inode, struct file *p_file);
> +void bcm_vk_release_data(struct kref *kref);
> +irqreturn_t bcm_vk_msgq_irqhandler(int irq, void *dev_id);
> +irqreturn_t bcm_vk_notf_irqhandler(int irq, void *dev_id);
> +int bcm_vk_msg_init(struct bcm_vk *vk);
> +void bcm_vk_msg_remove(struct bcm_vk *vk);
> +int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync);
> +bool bcm_vk_msgq_marker_valid(struct bcm_vk *vk);
> +void bcm_vk_blk_drv_access(struct bcm_vk *vk);
> +int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, uint32_t shut_type, pid_t pid);
> +void bcm_vk_trigger_reset(struct bcm_vk *vk);
> +void bcm_h2vk_doorbell(struct bcm_vk *vk, uint32_t q_num, uint32_t db_val);
> +int bcm_vk_auto_load_all_images(struct bcm_vk *vk);
> +int bcm_vk_tty_init(struct bcm_vk *vk, char *name);
> +void bcm_vk_tty_exit(struct bcm_vk *vk);
> +void bcm_vk_hb_init(struct bcm_vk *vk);
> +void bcm_vk_hb_deinit(struct bcm_vk *vk);
> +void bcm_vk_handle_notf(struct bcm_vk *vk);
> +bool bcm_vk_drv_access_ok(struct bcm_vk *vk);
> +
> +#endif
> diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c
> new file mode 100644
> index 000000000000..d8f59e898ca8
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_dev.c
> @@ -0,0 +1,1197 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/firmware.h>
> +#include <linux/fs.h>
> +#include <linux/idr.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/pci_regs.h>
> +#include <uapi/linux/misc/bcm_vk.h>
> +
> +#include "bcm_vk.h"
> +
> +#define PCI_DEVICE_ID_VALKYRIE	0x5E87
> +#define PCI_DEVICE_ID_VIPER	0x5E88
> +
> +static DEFINE_IDA(bcm_vk_ida);
> +
> +struct load_image_tab {
> +		const uint32_t image_type;
> +		const char *image_name;

Indented too far.

> +};
> +
> +enum soc_idx {
> +	VALKYRIE = 0,
> +	VIPER
> +};
> +
> +#define NUM_BOOT_STAGES 2
> +const struct load_image_tab image_tab[][NUM_BOOT_STAGES] = {
> +	[VALKYRIE] = {
> +		{VK_IMAGE_TYPE_BOOT1, VK_BOOT1_DEF_VALKYRIE_FILENAME},
> +		{VK_IMAGE_TYPE_BOOT2, VK_BOOT2_DEF_VALKYRIE_FILENAME}
> +	},
> +	[VIPER] = {
> +		{VK_IMAGE_TYPE_BOOT1, VK_BOOT1_DEF_VIPER_FILENAME},
> +		{VK_IMAGE_TYPE_BOOT2, VK_BOOT2_DEF_VIPER_FILENAME}
> +	}
> +};
> +
> +/* Location of memory base addresses of interest in BAR1 */
> +/* Load Boot1 to start of ITCM */
> +#define BAR1_CODEPUSH_BASE_BOOT1	0x100000
> +
> +/* Allow minimum 1s for Load Image timeout responses */
> +#define LOAD_IMAGE_TIMEOUT_MS		(1 * MSEC_PER_SEC)
> +
> +/* Image startup timeouts */
> +#define BOOT1_STARTUP_TIMEOUT_MS	(5 * MSEC_PER_SEC)
> +#define BOOT2_STARTUP_TIMEOUT_MS	(10 * MSEC_PER_SEC)
> +
> +/* 1ms wait for checking the transfer complete status */
> +#define TXFR_COMPLETE_TIMEOUT_MS	1
> +
> +/* MSIX usages */
> +#define VK_MSIX_MSGQ_MAX		3
> +#define VK_MSIX_NOTF_MAX		1
> +#define VK_MSIX_IRQ_MAX			(VK_MSIX_MSGQ_MAX + VK_MSIX_NOTF_MAX)
> +
> +/* Number of bits set in DMA mask*/
> +#define BCM_VK_DMA_BITS			64
> +
> +/* deinit time for the card os after receiving doorbell */
> +#define BCM_VK_DEINIT_TIME_MS		(2 * MSEC_PER_SEC)
> +
> +/*
> + * module parameters
> + */
> +static bool auto_load = true;
> +module_param(auto_load, bool, 0444);
> +MODULE_PARM_DESC(auto_load,
> +		 "Load images automatically at PCIe probe time.\n");
> +static uint nr_scratch_pages = VK_BAR1_SCRATCH_DEF_NR_PAGES;
> +module_param(nr_scratch_pages, uint, 0444);
> +MODULE_PARM_DESC(nr_scratch_pages,
> +		 "Number of pre allocated DMAable coherent pages.\n");
> +static uint nr_ib_sgl_blk = BCM_VK_DEF_IB_SGL_BLK_LEN;
> +module_param(nr_ib_sgl_blk, uint, 0444);
> +MODULE_PARM_DESC(nr_ib_sgl_blk,
> +		 "Number of in-band msg blks for short SGL.\n");
> +
> +/*
> + * alerts that could be generated from peer
> + */
> +struct bcm_vk_entry const bcm_vk_peer_err[BCM_VK_PEER_ERR_NUM] = {
> +	{ERR_LOG_UECC, ERR_LOG_UECC, "uecc"},
> +	{ERR_LOG_SSIM_BUSY, ERR_LOG_SSIM_BUSY, "ssim_busy"},
> +	{ERR_LOG_AFBC_BUSY, ERR_LOG_AFBC_BUSY, "afbc_busy"},
> +	{ERR_LOG_HIGH_TEMP_ERR, ERR_LOG_HIGH_TEMP_ERR, "high_temp"},
> +	{ERR_LOG_WDOG_TIMEOUT, ERR_LOG_WDOG_TIMEOUT, "wdog_timeout"},
> +	{ERR_LOG_SYS_FAULT, ERR_LOG_SYS_FAULT, "sys_fault"},
> +	{ERR_LOG_MEM_ALLOC_FAIL, ERR_LOG_MEM_ALLOC_FAIL, "malloc_fail warn"},
> +	{ERR_LOG_LOW_TEMP_WARN, ERR_LOG_LOW_TEMP_WARN, "low_temp warn"},
> +	{ERR_LOG_ECC, ERR_LOG_ECC, "ecc"},
> +};
> +/* alerts detected by the host */
> +struct bcm_vk_entry const bcm_vk_host_err[BCM_VK_HOST_ERR_NUM] = {
> +	{ERR_LOG_HOST_PCIE_DWN, ERR_LOG_HOST_PCIE_DWN, "PCIe_down"},
> +	{ERR_LOG_HOST_HB_FAIL, ERR_LOG_HOST_HB_FAIL, "hb_fail"},
> +};
> +
> +irqreturn_t bcm_vk_notf_irqhandler(int irq, void *dev_id)
> +{
> +	struct bcm_vk *vk = dev_id;
> +
> +	if (!bcm_vk_drv_access_ok(vk)) {
> +		dev_err(&vk->pdev->dev,
> +			"Interrupt %d received when msgq not inited\n", irq);
> +		goto skip_schedule_work;
> +	}
> +
> +	/* if notification is not pending, set bit and schedule work */
> +	if (test_and_set_bit(BCM_VK_WQ_NOTF_PEND, vk->wq_offload) == 0)
> +		queue_work(vk->wq_thread, &vk->wq_work);
> +
> +skip_schedule_work:
> +	return IRQ_HANDLED;
> +}
> +
> +static void bcm_vk_log_notf(struct bcm_vk *vk,
> +			    struct bcm_vk_alert *alert,
> +			    struct bcm_vk_entry const *entry_tab,
> +			    const uint32_t table_size)
> +{
> +	uint32_t i;
> +	uint32_t masked_val, latched_val;
> +	struct bcm_vk_entry const *entry;
> +	uint32_t reg;
> +	uint16_t ecc_mem_err, uecc_mem_err;
> +	struct device *dev = &vk->pdev->dev;
> +
> +	for (i = 0; i < table_size; i++) {
> +		entry = &entry_tab[i];
> +		masked_val = entry->mask & alert->notfs;
> +		latched_val = entry->mask & alert->flags;
> +
> +		if (masked_val == ERR_LOG_UECC) {
> +			/*
> +			 * if there is difference between stored cnt and it
> +			 * is greater than threshold, log it.
> +			 */
> +			reg = vkread32(vk, BAR_0, BAR_CARD_ERR_MEM);
> +			BCM_VK_EXTRACT_FIELD(uecc_mem_err, reg,
> +					     BCM_VK_MEM_ERR_FIELD_MASK,
> +					     BCM_VK_UECC_MEM_ERR_SHIFT);
> +			if ((uecc_mem_err != vk->alert_cnts.uecc) &&
> +			    (uecc_mem_err >= BCM_VK_UECC_THRESHOLD))
> +				dev_info(dev,
> +					 "ALERT! %s.%d uecc RAISED - ErrCnt %d\n",
> +					 DRV_MODULE_NAME, vk->misc_devid,
> +					 uecc_mem_err);
> +			vk->alert_cnts.uecc = uecc_mem_err;
> +		} else if (masked_val == ERR_LOG_ECC) {
> +			reg = vkread32(vk, BAR_0, BAR_CARD_ERR_MEM);
> +			BCM_VK_EXTRACT_FIELD(ecc_mem_err, reg,
> +					     BCM_VK_MEM_ERR_FIELD_MASK,
> +					     BCM_VK_ECC_MEM_ERR_SHIFT);
> +			if ((ecc_mem_err != vk->alert_cnts.ecc) &&
> +			    (ecc_mem_err >= BCM_VK_ECC_THRESHOLD))
> +				dev_info(dev, "ALERT! %s.%d ecc RAISED - ErrCnt %d\n",
> +					 DRV_MODULE_NAME, vk->misc_devid,
> +					 ecc_mem_err);
> +			vk->alert_cnts.ecc = ecc_mem_err;
> +		} else if (masked_val != latched_val) {
> +			/* print a log as info */
> +			dev_info(dev, "ALERT! %s.%d %s %s\n",
> +				 DRV_MODULE_NAME, vk->misc_devid, entry->str,
> +				 masked_val ? "RAISED" : "CLEARED");
> +		}
> +	}
> +}
> +
> +static void bcm_vk_dump_peer_log(struct bcm_vk *vk)
> +{
> +	struct bcm_vk_peer_log log, *p_ctl;
> +	char loc_buf[BCM_VK_PEER_LOG_LINE_MAX];
> +	int cnt;
> +	struct device *dev = &vk->pdev->dev;
> +	uint data_offset;
> +
> +	p_ctl = vk->bar[BAR_2] + vk->peerlog_off;

Have you tried running Sparse on this driver?

> +	log = *p_ctl;
> +	/* do a rmb() to make sure log is updated */
> +	rmb();
> +
> +	dev_dbg(dev, "Peer PANIC: Size 0x%x(0x%x), [Rd Wr] = [%d %d]\n",
> +		log.buf_size, log.mask, log.rd_idx, log.wr_idx);
> +
> +	cnt = 0;
> +	data_offset = vk->peerlog_off + sizeof(struct bcm_vk_peer_log);
> +	while (log.rd_idx != log.wr_idx) {
> +		loc_buf[cnt] = vkread8(vk, BAR_2, data_offset + log.rd_idx);
> +
> +		if ((loc_buf[cnt] == '\0') ||
> +		    (cnt == (BCM_VK_PEER_LOG_LINE_MAX - 1))) {
> +			dev_err(dev, "%s", loc_buf);
> +			cnt = 0;
> +		} else {
> +			cnt++;
> +		}
> +		log.rd_idx = (log.rd_idx + 1) & log.mask;
> +	}
> +	/* update rd idx at the end */
> +	vkwrite32(vk, log.rd_idx, BAR_2, vk->peerlog_off);
> +}
> +
> +void bcm_vk_handle_notf(struct bcm_vk *vk)
> +{
> +	uint32_t reg;
> +	struct bcm_vk_alert alert;
> +	bool intf_down;
> +	unsigned long flags;
> +
> +	/* handle peer alerts and then locally detected ones */
> +	reg = vkread32(vk, BAR_0, BAR_CARD_ERR_LOG);
> +	intf_down = BCM_VK_INTF_IS_DOWN(reg);
> +	if (!intf_down) {
> +		vk->peer_alert.notfs = reg;
> +		bcm_vk_log_notf(vk, &vk->peer_alert, bcm_vk_peer_err,
> +				ARRAY_SIZE(bcm_vk_peer_err));
> +		vk->peer_alert.flags = vk->peer_alert.notfs;
> +	} else {
> +		/* turn off access */
> +		bcm_vk_blk_drv_access(vk);
> +	}
> +
> +	/* check and make copy of alert with lock and then free lock */
> +	spin_lock_irqsave(&vk->host_alert_lock, flags);
> +	if (intf_down)
> +		vk->host_alert.notfs |= ERR_LOG_HOST_PCIE_DWN;
> +
> +	alert = vk->host_alert;
> +	vk->host_alert.flags = vk->host_alert.notfs;
> +	spin_unlock_irqrestore(&vk->host_alert_lock, flags);
> +
> +	/* call display with copy */
> +	bcm_vk_log_notf(vk, &alert, bcm_vk_host_err,
> +			ARRAY_SIZE(bcm_vk_host_err));
> +
> +	/*
> +	 * If it is a sys fault or heartbeat timeout, we would like extract
> +	 * log msg from the card so that we would know what is the last fault
> +	 */
> +	if ((!intf_down) &&
> +	    ((vk->host_alert.flags & ERR_LOG_HOST_HB_FAIL) ||
> +	     (vk->peer_alert.flags & ERR_LOG_SYS_FAULT)))
> +		bcm_vk_dump_peer_log(vk);
> +}
> +
> +static inline int bcm_vk_wait(struct bcm_vk *vk, enum pci_barno bar,
> +			      uint64_t offset, u32 mask, u32 value,
> +			      unsigned long timeout_ms)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
> +	u32 rd_val;
> +
> +	do {
> +		rd_val = vkread32(vk, bar, offset);
> +		dev_dbg(dev, "BAR%d Offset=0x%llx: 0x%x\n",
> +			bar, offset, rd_val);
> +
> +		if (time_after(jiffies, timeout))
> +			return -ETIMEDOUT;
> +
> +		cpu_relax();
> +		cond_resched();
> +	} while ((rd_val & mask) != value);
> +
> +	return 0;
> +}
> +
> +static void bcm_vk_get_card_info(struct bcm_vk *vk)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	uint32_t offset;
> +	int i;
> +	uint8_t *dst;
> +	struct bcm_vk_card_info *info = &vk->card_info;
> +
> +	/* first read the offset from spare register */
> +	offset = vkread32(vk, BAR_0, BAR_CARD_STATIC_INFO);
> +	offset &= (pci_resource_len(vk->pdev, BAR_2 * 2) - 1);
> +
> +	/* based on the offset, read info to internal card info structure */
> +	dst = (uint8_t *)info;
> +	for (i = 0; i < sizeof(*info); i++)
> +		*dst++ = vkread8(vk, BAR_2, offset++);
> +
> +#define CARD_INFO_LOG_FMT "version   : %x\n" \
> +			  "os_tag    : %s\n" \
> +			  "cmpt_tag  : %s\n" \
> +			  "cpu_freq  : %d MHz\n" \
> +			  "cpu_scale : %d full, %d lowest\n" \
> +			  "ddr_freq  : %d MHz\n" \
> +			  "ddr_size  : %d MB\n" \
> +			  "video_freq: %d MHz\n"
> +	dev_dbg(dev, CARD_INFO_LOG_FMT, info->version, info->os_tag,
> +		info->cmpt_tag, info->cpu_freq_mhz, info->cpu_scale[0],
> +		info->cpu_scale[MAX_OPP - 1], info->ddr_freq_mhz,
> +		info->ddr_size_MB, info->video_core_freq_mhz);
> +
> +	/* get the peer log pointer, only need the offset */
> +	vk->peerlog_off = offset;
> +}
> +
> +static int bcm_vk_sync_card_info(struct bcm_vk *vk)
> +{
> +	uint32_t rdy_marker = vkread32(vk, BAR_1, VK_BAR1_MSGQ_DEF_RDY);
> +
> +	/* check for marker, but allow diags mode to skip sync */
> +	if (!bcm_vk_msgq_marker_valid(vk))
> +		return (rdy_marker == VK_BAR1_DIAG_RDY_MARKER ? 0 : -EINVAL);
> +
> +	/*
> +	 * Write down scratch addr which is used for DMA. For
> +	 * signed part, BAR1 is accessible only after boot2 has come
> +	 * up
> +	 */
> +	if (vk->tdma_addr) {
> +		vkwrite32(vk, vk->tdma_addr >> 32, BAR_1,
> +			  VK_BAR1_SCRATCH_OFF_LO);
> +		vkwrite32(vk, (uint32_t)vk->tdma_addr, BAR_1,
> +			  VK_BAR1_SCRATCH_OFF_HI);
> +		vkwrite32(vk, nr_scratch_pages * PAGE_SIZE, BAR_1,
> +			  VK_BAR1_SCRATCH_SZ_ADDR);
> +	}
> +
> +	/* get static card info, only need to read once */
> +	bcm_vk_get_card_info(vk);
> +
> +	return 0;
> +}
> +
> +void bcm_vk_blk_drv_access(struct bcm_vk *vk)
> +{
> +	int i;
> +
> +	/*
> +	 * kill all the apps except for the process that is resetting.
> +	 * If not called during reset, reset_ppid == NULL, and all will be
> +	 * killed.
> +	 */
> +	spin_lock(&vk->ctx_lock);
> +
> +	/* set msgq_inited to 0 so that all rd/wr will be blocked */
> +	atomic_set(&vk->msgq_inited, 0);
> +
> +	for (i = 0; i < VK_PID_HT_SZ; i++) {
> +		struct bcm_vk_ctx *ctx;
> +
> +		list_for_each_entry(ctx, &vk->pid_ht[i].head, node) {
> +			if (ctx->ppid != vk->reset_ppid) {
> +				dev_dbg(&vk->pdev->dev,
> +					"Send kill signal to pid %d\n",
> +					task_pid_nr(ctx->ppid));
> +				kill_pid(task_pid(ctx->ppid), SIGKILL, 1);
> +			}
> +		}
> +	}
> +	spin_unlock(&vk->ctx_lock);
> +}
> +
> +static void bcm_vk_buf_notify(struct bcm_vk *vk, void *bufp,
> +			      dma_addr_t host_buf_addr, uint32_t buf_size)
> +{
> +	/* update the dma address to the card */
> +	vkwrite32(vk, host_buf_addr >> 32, BAR_1,
> +		  VK_BAR1_DMA_BUF_OFF_HI);
> +	vkwrite32(vk, (uint32_t)host_buf_addr, BAR_1,
> +		  VK_BAR1_DMA_BUF_OFF_LO);
> +	vkwrite32(vk, buf_size, BAR_1, VK_BAR1_DMA_BUF_SZ);
> +}
> +
> +static int bcm_vk_load_image_by_type(struct bcm_vk *vk, u32 load_type,
> +				     const char *filename)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	const struct firmware *fw;
> +	void *bufp;
> +	size_t max_buf;
> +	int ret;
> +	uint64_t offset_codepush;
> +	u32 codepush;
> +	u32 value;
> +	dma_addr_t boot2_dma_addr;
> +
> +	if (load_type == VK_IMAGE_TYPE_BOOT1) {
> +		/*
> +		 * After POR, enable VK soft BOOTSRC so bootrom do not clear
> +		 * the pushed image (the TCM memories).
> +		 */
> +		value = vkread32(vk, BAR_0, BAR_BOOTSRC_SELECT);
> +		value |= BOOTSRC_SOFT_ENABLE;
> +		vkwrite32(vk, value, BAR_0, BAR_BOOTSRC_SELECT);
> +
> +		codepush = CODEPUSH_BOOTSTART + CODEPUSH_BOOT1_ENTRY;
> +		offset_codepush = BAR_CODEPUSH_SBL;
> +
> +		/* Write a 1 to request SRAM open bit */
> +		vkwrite32(vk, CODEPUSH_BOOTSTART, BAR_0, offset_codepush);
> +
> +		/* Wait for VK to respond */
> +		ret = bcm_vk_wait(vk, BAR_0, BAR_BOOT_STATUS, SRAM_OPEN,
> +				  SRAM_OPEN, LOAD_IMAGE_TIMEOUT_MS);
> +		if (ret < 0) {
> +			dev_err(dev, "boot1 timeout\n");
> +			goto err_out;
> +		}
> +
> +		bufp = vk->bar[BAR_1] + BAR1_CODEPUSH_BASE_BOOT1;
> +		max_buf = SZ_256K;
> +	} else if (load_type == VK_IMAGE_TYPE_BOOT2) {
> +		codepush = CODEPUSH_BOOT2_ENTRY;
> +		offset_codepush = BAR_CODEPUSH_SBI;
> +
> +		/* Wait for VK to respond */
> +		ret = bcm_vk_wait(vk, BAR_0, BAR_BOOT_STATUS, DDR_OPEN,
> +				  DDR_OPEN, LOAD_IMAGE_TIMEOUT_MS);
> +		if (ret < 0) {
> +			dev_err(dev, "boot2 timeout\n");
> +			goto err_out;
> +		}
> +
> +		max_buf = SZ_4M;
> +		bufp = dma_alloc_coherent(dev,
> +					  max_buf,
> +					  &boot2_dma_addr, GFP_KERNEL);
> +		if (!bufp) {
> +			dev_err(dev, "Error allocating 0x%zx\n", max_buf);
> +			ret = -ENOMEM;
> +			goto err_out;
> +		}
> +
> +		bcm_vk_buf_notify(vk, bufp, boot2_dma_addr, max_buf);
> +	} else {
> +		dev_err(dev, "Error invalid image type 0x%x\n", load_type);
> +		ret = -EINVAL;
> +		goto err_out;
> +	}
> +
> +	ret = request_firmware_into_buf(&fw, filename, dev,
> +					bufp, max_buf, 0,
> +					KERNEL_PREAD_FLAG_PART);
> +	if (ret) {
> +		dev_err(dev, "Error %d requesting firmware file: %s\n",
> +			ret, filename);
> +		goto err_out;
> +	}
> +	dev_dbg(dev, "size=0x%zx\n", fw->size);
> +
> +	dev_dbg(dev, "Signaling 0x%x to 0x%llx\n", codepush, offset_codepush);
> +	vkwrite32(vk, codepush, BAR_0, offset_codepush);
> +
> +	if (load_type == VK_IMAGE_TYPE_BOOT1) {
> +		/* wait until done */
> +		ret = bcm_vk_wait(vk, BAR_0, BAR_BOOT_STATUS,
> +				  BOOT1_RUNNING,
> +				  BOOT1_RUNNING,
> +				  BOOT1_STARTUP_TIMEOUT_MS);
> +		if (ret) {
> +			dev_err(dev,
> +				"Timeout %ld ms waiting for boot1 to come up\n",
> +				BOOT1_STARTUP_TIMEOUT_MS);
> +			goto err_firmware_out;
> +		}
> +	} else if (load_type == VK_IMAGE_TYPE_BOOT2) {
> +		unsigned long timeout = jiffies + msecs_to_jiffies(
> +					LOAD_IMAGE_TIMEOUT_MS);
> +
> +		/* To send more data to VK than max_buf allowed at a time */
> +		do {
> +			/*
> +			 * Check for ack from card. when Ack is received,
> +			 * it means all the data is received by card.
> +			 * Exit the loop after ack is received.
> +			 */
> +			ret = bcm_vk_wait(vk, BAR_0, BAR_BOOT_STATUS,
> +					  FW_LOADER_ACK_RCVD_ALL_DATA,
> +					  FW_LOADER_ACK_RCVD_ALL_DATA,
> +					  TXFR_COMPLETE_TIMEOUT_MS);
> +			if (ret == 0) {
> +				dev_info(dev, "Exit boot2 download\n");
> +				break;
> +			}
> +
> +			/* exit the loop, if there is no response from card */
> +			if (time_after(jiffies, timeout)) {
> +				dev_err(dev, "Error. No reply from card\n");
> +				ret = -ETIMEDOUT;
> +				goto err_firmware_out;
> +			}
> +
> +			/* Wait for VK to open BAR space to copy new data */
> +			ret = bcm_vk_wait(vk, BAR_0, offset_codepush,
> +					  codepush, 0,
> +					  TXFR_COMPLETE_TIMEOUT_MS);
> +			if (ret == 0) {
> +				ret = request_firmware_into_buf(
> +							&fw,
> +							filename,
> +							dev, bufp,
> +							max_buf,
> +							fw->size,
> +							KERNEL_PREAD_FLAG_PART);
> +				if (ret) {
> +					dev_err(dev, "Error %d requesting firmware file: %s offset: 0x%zx\n",
> +						ret, filename,
> +						fw->size);
> +					goto err_firmware_out;
> +				}
> +				dev_dbg(dev, "size=0x%zx\n", fw->size);
> +				dev_dbg(dev, "Signaling 0x%x to 0x%llx\n",
> +					codepush, offset_codepush);
> +				vkwrite32(vk, codepush, BAR_0, offset_codepush);
> +				/* reload timeout after every codepush */
> +				timeout = jiffies + msecs_to_jiffies(
> +					  LOAD_IMAGE_TIMEOUT_MS);
> +			}
> +		} while (1);
> +
> +		/* wait for fw status bits to indicate app ready */
> +		ret = bcm_vk_wait(vk, BAR_0, VK_BAR_FWSTS,
> +				  VK_FWSTS_READY,
> +				  VK_FWSTS_READY,
> +				  BOOT2_STARTUP_TIMEOUT_MS);
> +		if (ret < 0) {
> +			dev_err(dev, "Boot2 not ready - timeout\n");
> +			goto err_firmware_out;
> +		}
> +
> +		/*
> +		 * Next, initialize Message Q if we are loading boot2.
> +		 * Do a force sync
> +		 */
> +		ret = bcm_vk_sync_msgq(vk, true);
> +		if (ret) {
> +			dev_err(dev, "Boot2 Error reading comm msg Q info\n");
> +			ret = -EIO;
> +			goto err_firmware_out;
> +		}
> +
> +		/* sync & channel other info */
> +		ret = bcm_vk_sync_card_info(vk);
> +		if (ret) {
> +			dev_err(dev, "Syncing Card Info failure\n");
> +			goto err_firmware_out;
> +		}
> +	}
> +
> +err_firmware_out:
> +	release_firmware(fw);
> +
> +err_out:
> +	if (load_type == VK_IMAGE_TYPE_BOOT2)
> +		dma_free_coherent(dev, max_buf, bufp, boot2_dma_addr);

bufp is uninitialized.  Never use the label name "err" or "out" because
it's always wrong.  This is just a combination of the two.

> +
> +	return ret;
> +}
> +
> +static u32 bcm_vk_next_boot_image(struct bcm_vk *vk)
> +{
> +	uint32_t boot_status;
> +	uint32_t fw_status;
> +	u32 load_type = 0;  /* default for unknown */
> +
> +	boot_status = vkread32(vk, BAR_0, BAR_BOOT_STATUS);
> +	fw_status = vkread32(vk, BAR_0, VK_BAR_FWSTS);
> +
> +	if (!BCM_VK_INTF_IS_DOWN(boot_status) && (boot_status & SRAM_OPEN))
> +		load_type = VK_IMAGE_TYPE_BOOT1;
> +	else if (boot_status == BOOT1_RUNNING)
> +		load_type = VK_IMAGE_TYPE_BOOT2;
> +
> +	/*
> +	 * TO_FIX: For now, like to know what value we get everytime
> +	 *         for debugging.
> +	 */
> +	dev_info(&vk->pdev->dev,
> +		 "boot-status value for next image: 0x%x : fw-status 0x%x\n",
> +		 boot_status, fw_status);
> +
> +	return load_type;
> +}
> +
> +int bcm_vk_auto_load_all_images(struct bcm_vk *vk)
> +{
> +	int i, id, ret = -1;
> +	struct device *dev = &vk->pdev->dev;
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	uint32_t curr_type;
> +	const char *curr_name;
> +
> +	switch (pdev->device) {
> +	case PCI_DEVICE_ID_VALKYRIE:
> +		id = VALKYRIE;
> +		break;
> +
> +	case PCI_DEVICE_ID_VIPER:
> +		id = VIPER;
> +		break;
> +
> +	default:
> +		dev_err(dev, "no images for 0x%x\n", pdev->device);
> +		goto bcm_vk_auto_load_all_exit;
> +	}
> +
> +	/* log a message to know the relative loading order */
> +	dev_info(dev, "Load All for device %d\n", vk->misc_devid);
> +
> +	for (i = 0; i < NUM_BOOT_STAGES; i++) {
> +		curr_type = image_tab[id][i].image_type;
> +		if (bcm_vk_next_boot_image(vk) == curr_type) {
> +			curr_name = image_tab[id][i].image_name;
> +			ret = bcm_vk_load_image_by_type(vk, curr_type,
> +							curr_name);
> +			dev_info(dev, "Auto load %s, ret %d\n",
> +				 curr_name, ret);
> +
> +			if (ret) {
> +				dev_err(dev, "Error loading default %s\n",
> +					curr_name);
> +				goto bcm_vk_auto_load_all_exit;
> +			}
> +		}
> +	}
> +
> +bcm_vk_auto_load_all_exit:
> +	return ret;
> +}
> +
> +static int bcm_vk_trigger_autoload(struct bcm_vk *vk)
> +{
> +	if (test_and_set_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload) != 0)
> +		return -EPERM;
> +
> +	set_bit(BCM_VK_WQ_DWNLD_AUTO, vk->wq_offload);
> +	queue_work(vk->wq_thread, &vk->wq_work);
> +
> +	return 0;
> +}
> +
> +static long bcm_vk_load_image(struct bcm_vk *vk, struct vk_image *arg)
> +{
> +	int ret;
> +	struct device *dev = &vk->pdev->dev;
> +	struct vk_image image;
> +	u32 next_loadable;
> +
> +	if (copy_from_user(&image, arg, sizeof(image))) {
> +		ret = -EACCES;
> +		goto bcm_vk_load_image_exit;
> +	}
> +
> +	/* first check if fw is at the right state for the download */

What does this comment mean?  Just delete it.  The code is clear on
its own.

> +	next_loadable = bcm_vk_next_boot_image(vk);
> +	if (next_loadable != image.type) {
> +		dev_err(dev, "Next expected image %u, Loading %u\n",
> +			next_loadable, image.type);
> +		ret = -EPERM;
> +		goto bcm_vk_load_image_exit;
> +	}
> +
> +	/*
> +	 * if something is pending download already.  This could only happen
> +	 * for now when the driver is being loaded, or if someone has issued
> +	 * another download command in another shell.
> +	 */
> +	if (test_and_set_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload) != 0) {
> +		dev_err(dev, "Download operation already pending.\n");
> +		return -EPERM;

Woohoo for the direct return!  Just make this function use direct
returns everywhere and delete all the do nothing returns.

> +	}
> +
> +	ret = bcm_vk_load_image_by_type(vk, image.type, image.filename);
> +	clear_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload);
> +
> +bcm_vk_load_image_exit:
> +	return ret;
> +}
> +
> +static long bcm_vk_access_bar(struct bcm_vk *vk, struct vk_access *arg)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	struct vk_access access;
> +	long ret = -EINVAL;
> +	u32 value;
> +	long i;
> +	long num;
> +
> +	if (copy_from_user(&access, arg, sizeof(struct vk_access))) {
> +		ret = -EACCES;

		return -EFAULT;

> +		goto err_out;
> +	}
> +
> +	/* do some range checking in the barno and offset */
> +	if (access.barno >= MAX_BAR) {
> +		dev_err(dev, "invalid bar no %d\n", access.barno);
> +		goto err_out;
> +	} else if ((access.offset + access.len) >
> +		   pci_resource_len(vk->pdev, access.barno * 2)) {

There is an arithmatic overlfow.  Also len should be a multiple of
sizeof(u32).

	} else if (access.len % sizeof(u32) ||
		   access.offset + access.len < access.offset ||
		   access.offset + access.len > pci_resource_len(vk->pdev,
							access.barno * 2)) {


> +		dev_err(dev, "invalid bar offset 0x%llx, len 0x%x\n",
> +			access.offset, access.len);
> +		goto err_out;
> +	}
> +
> +	if (access.type == VK_ACCESS_READ) {
> +		dev_dbg(dev, "read barno:%d offset:0x%llx len:0x%x\n",
> +			access.barno, access.offset, access.len);
> +		num = access.len / sizeof(u32);
> +		for (i = 0; i < num; i++) {
> +			value = vkread32(vk, access.barno,
> +					 access.offset + (i * sizeof(u32)));
> +			ret = put_user(value, access.data + i);
> +			if (ret)
> +				goto err_out;
> +
> +			dev_dbg(dev, "0x%x\n", value);
> +		}
> +	} else if (access.type == VK_ACCESS_WRITE) {
> +		dev_dbg(dev, "write barno:%d offset:0x%llx len:0x%x\n",
> +			access.barno, access.offset, access.len);
> +		num = access.len / sizeof(u32);
> +		for (i = 0; i < num; i++) {
> +			ret = get_user(value, access.data + i);
> +			if (ret)
> +				goto err_out;
> +
> +			vkwrite32(vk, value, access.barno,
> +				  access.offset + (i * sizeof(u32)));
> +			dev_dbg(dev, "0x%x\n", value);
> +		}
> +	} else {
> +		dev_dbg(dev, "invalid access type %d\n", access.type);
> +	}
> +err_out:
> +	return ret;
> +}
> +
> +static int bcm_vk_reset_successful(struct bcm_vk *vk)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	u32 fw_status, reset_reason;
> +	int ret = -EAGAIN;
> +
> +	/*
> +	 * Reset could be triggered when the card in several state:
> +	 *   i)   in bootROM
> +	 *   ii)  after boot1
> +	 *   iii) boot2 running
> +	 *
> +	 * i) & ii) - no status bits will be updated.  If vkboot1
> +	 * runs automatically after reset, it  will update the reason
> +	 * to be unknown reason
> +	 * iii) - reboot reason match + deinit done.
> +	 */
> +	fw_status = vkread32(vk, BAR_0, VK_BAR_FWSTS);
> +	/* immediate exit if interface goes down */
> +	if (BCM_VK_INTF_IS_DOWN(fw_status)) {
> +		dev_err(dev, "PCIe Intf Down!\n");
> +		goto bcm_vk_reset_exit;
> +	}
> +
> +	/* initial check on reset reason */

This comment doesn't add anything.

> +	reset_reason = (fw_status & VK_FWSTS_RESET_REASON_MASK);
> +	if ((reset_reason == VK_FWSTS_RESET_MBOX_DB)
> +	     || (reset_reason == VK_FWSTS_RESET_UNKNOWN))
> +		ret = 0;

Please use checkpatch.pl --strict.

	if ((reset_reason == VK_FWSTS_RESET_MBOX_DB) ||
	    (reset_reason == VK_FWSTS_RESET_UNKNOWN))
		ret = 0;


> +
> +	/*
> +	 * if some of the deinit bits are set, but done
> +	 * bit is not, this is a failure if triggered while boot2 is running
> +	 */
> +	if ((fw_status & VK_FWSTS_DEINIT_TRIGGERED)
> +	    && !(fw_status & VK_FWSTS_RESET_DONE))
> +		ret = -EAGAIN;
> +
> +bcm_vk_reset_exit:
> +	dev_dbg(dev, "FW status = 0x%x ret %d\n", fw_status, ret);
> +
> +	return ret;
> +}
> +
> +static long bcm_vk_reset(struct bcm_vk *vk, struct vk_reset *arg)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	struct vk_reset reset;
> +	int ret = 0;
> +
> +	if (copy_from_user(&reset, arg, sizeof(struct vk_reset))) {
> +		ret = -EACCES;


		return -EFAULT;

> +		goto err_out;
> +	}
> +	dev_info(dev, "Issue Reset\n");
> +
> +	/*
> +	 * The following is the sequence of reset:
> +	 * - send card level graceful shut down
> +	 * - wait enough time for VK to handle its business, stopping DMA etc
> +	 * - kill host apps
> +	 * - Trigger interrupt with DB
> +	 */
> +	bcm_vk_send_shutdown_msg(vk, VK_SHUTDOWN_GRACEFUL, 0);
> +
> +	spin_lock(&vk->ctx_lock);
> +	if (!vk->reset_ppid) {
> +		vk->reset_ppid = current;
> +	} else {
> +		dev_err(dev, "Reset already launched by process pid %d\n",
> +			task_pid_nr(vk->reset_ppid));
> +		ret = -EACCES;
> +	}
> +	spin_unlock(&vk->ctx_lock);
> +	if (ret)
> +		goto err_out;
> +
> +	bcm_vk_blk_drv_access(vk);
> +	bcm_vk_trigger_reset(vk);
> +
> +	/*
> +	 * Wait enough time for card os to deinit
> +	 * and populate the reset reason.
> +	 */
> +	msleep(BCM_VK_DEINIT_TIME_MS);
> +
> +	ret = bcm_vk_reset_successful(vk);
> +
> +err_out:
> +	return ret;
> +}
> +
> +static int bcm_vk_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> +	struct bcm_vk_ctx *ctx = file->private_data;
> +	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
> +	unsigned long pg_size;
> +
> +	/* only BAR2 is mmap possible, which is bar num 4 due to 64bit */
> +#define VK_MMAPABLE_BAR 4
> +
> +	pg_size = ((pci_resource_len(vk->pdev, VK_MMAPABLE_BAR) - 1)
> +		    >> PAGE_SHIFT) + 1;
> +	if (vma->vm_pgoff + vma_pages(vma) > pg_size)
> +		return -EINVAL;
> +
> +	vma->vm_pgoff += (pci_resource_start(vk->pdev, VK_MMAPABLE_BAR)
> +			  >> PAGE_SHIFT);
> +	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> +
> +	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
> +				  vma->vm_end - vma->vm_start,
> +				  vma->vm_page_prot);
> +}
> +
> +static long bcm_vk_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> +	long ret = -EINVAL;
> +	struct bcm_vk_ctx *ctx = file->private_data;
> +	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
> +	void __user *argp = (void __user *)arg;
> +
> +	dev_dbg(&vk->pdev->dev,
> +		"ioctl, cmd=0x%02x, arg=0x%02lx\n",
> +		cmd, arg);
> +
> +	mutex_lock(&vk->mutex);
> +
> +	switch (cmd) {
> +	case VK_IOCTL_LOAD_IMAGE:
> +		ret = bcm_vk_load_image(vk, argp);
> +		break;
> +
> +	case VK_IOCTL_ACCESS_BAR:
> +		ret = bcm_vk_access_bar(vk, argp);
> +		break;
> +
> +	case VK_IOCTL_RESET:
> +		ret = bcm_vk_reset(vk, argp);
> +		break;
> +
> +	default:
> +		break;
> +	}
> +
> +	mutex_unlock(&vk->mutex);
> +
> +	return ret;
> +}
> +
> +static const struct file_operations bcm_vk_fops = {
> +	.owner = THIS_MODULE,
> +	.open = bcm_vk_open,
> +	.read = bcm_vk_read,
> +	.write = bcm_vk_write,
> +	.release = bcm_vk_release,
> +	.mmap = bcm_vk_mmap,
> +	.unlocked_ioctl = bcm_vk_ioctl,
> +};
> +
> +static int bcm_vk_on_panic(struct notifier_block *nb,
> +			   unsigned long e, void *p)
> +{
> +	struct bcm_vk *vk = container_of(nb, struct bcm_vk, panic_nb);
> +
> +	bcm_h2vk_doorbell(vk, VK_BAR0_RESET_DB_NUM, VK_BAR0_RESET_DB_HARD);
> +
> +	return 0;
> +}
> +
> +static int bcm_vk_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> +{
> +	int err;
> +	int i;
> +	int id;
> +	int irq;
> +	char name[20];
> +	struct bcm_vk *vk;
> +	struct device *dev = &pdev->dev;
> +	struct miscdevice *misc_device;
> +	uint32_t boot_status;
> +
> +	/* allocate vk structure which is tied to kref for freeing */
> +	vk = kzalloc(sizeof(*vk), GFP_KERNEL);
> +	if (!vk)
> +		return -ENOMEM;
> +
> +	kref_init(&vk->kref);
> +	if (nr_ib_sgl_blk > BCM_VK_IB_SGL_BLK_MAX) {
> +		dev_warn(dev, "Inband SGL blk %d limited to max %d\n",
> +			 nr_ib_sgl_blk, BCM_VK_IB_SGL_BLK_MAX);
> +		nr_ib_sgl_blk = BCM_VK_IB_SGL_BLK_MAX;
> +	}
> +	vk->ib_sgl_size = nr_ib_sgl_blk * VK_MSGQ_BLK_SIZE;
> +	vk->pdev = pdev;
> +	mutex_init(&vk->mutex);
> +
> +	err = pci_enable_device(pdev);
> +	if (err) {
> +		dev_err(dev, "Cannot enable PCI device\n");
> +		return err;
> +	}
> +
> +	err = pci_request_regions(pdev, DRV_MODULE_NAME);
> +	if (err) {
> +		dev_err(dev, "Cannot obtain PCI resources\n");
> +		goto err_disable_pdev;
> +	}
> +
> +	/* make sure DMA is good */
> +	err = dma_set_mask_and_coherent(&pdev->dev,
> +					DMA_BIT_MASK(BCM_VK_DMA_BITS));
> +	if (err) {
> +		dev_err(dev, "failed to set DMA mask\n");
> +		goto err_disable_pdev;
> +	}
> +
> +	/* The tdma is a scratch area for some DMA testings. */
> +	if (nr_scratch_pages) {
> +		vk->tdma_vaddr = dma_alloc_coherent(dev,
> +					 nr_scratch_pages * PAGE_SIZE,
> +					 &vk->tdma_addr, GFP_KERNEL);
> +		if (!vk->tdma_vaddr) {
> +			err = -ENOMEM;
> +			goto err_disable_pdev;
> +		}
> +	}
> +
> +	pci_set_master(pdev);
> +	pci_set_drvdata(pdev, vk);
> +
> +	irq = pci_alloc_irq_vectors(pdev,
> +				    1,
> +				    VK_MSIX_IRQ_MAX,
> +				    PCI_IRQ_MSI | PCI_IRQ_MSIX);
> +
> +	if (irq < VK_MSIX_IRQ_MAX) {
> +		dev_err(dev, "failed to get %d MSIX interrupts, ret(%d)\n",
> +			VK_MSIX_IRQ_MAX, irq);
> +		err = (irq >= 0) ? -EINVAL : irq;
> +		goto err_disable_pdev;
> +	}
> +
> +	dev_info(dev, "Number of IRQs %d allocated.\n", irq);
> +
> +	for (i = 0; i < MAX_BAR; i++) {
> +		/* multiple by 2 for 64 bit BAR mapping */
> +		vk->bar[i] = pci_ioremap_bar(pdev, i * 2);
> +		if (!vk->bar[i]) {
> +			dev_err(dev, "failed to remap BAR%d\n", i);
> +			goto err_iounmap;
> +		}
> +	}
> +
> +	for (vk->num_irqs = 0;
> +	     vk->num_irqs < VK_MSIX_MSGQ_MAX;
> +	     vk->num_irqs++) {
> +		err = devm_request_irq(dev, pci_irq_vector(pdev, vk->num_irqs),
> +				       bcm_vk_msgq_irqhandler,
> +				       IRQF_SHARED, DRV_MODULE_NAME, vk);
> +		if (err) {
> +			dev_err(dev, "failed to request msgq IRQ %d for MSIX %d\n",
> +				pdev->irq + vk->num_irqs, vk->num_irqs + 1);
> +			goto err_irq;
> +		}
> +	}
> +	/* one irq for notification from VK */
> +	err = devm_request_irq(dev, pci_irq_vector(pdev, vk->num_irqs),
> +			       bcm_vk_notf_irqhandler,
> +			       IRQF_SHARED, DRV_MODULE_NAME, vk);
> +	if (err) {
> +		dev_err(dev, "failed to request notf IRQ %d for MSIX %d\n",
> +			pdev->irq + vk->num_irqs, vk->num_irqs + 1);
> +		goto err_irq;
> +	}
> +	vk->num_irqs++;
> +
> +	id = ida_simple_get(&bcm_vk_ida, 0, 0, GFP_KERNEL);
> +	if (id < 0) {
> +		err = id;
> +		dev_err(dev, "unable to get id\n");
> +		goto err_irq;
> +	}
> +
> +	vk->misc_devid = id;
> +	snprintf(name, sizeof(name), DRV_MODULE_NAME ".%d", id);
> +	misc_device = &vk->miscdev;
> +	misc_device->minor = MISC_DYNAMIC_MINOR;
> +	misc_device->name = kstrdup(name, GFP_KERNEL);
> +	if (!misc_device->name) {
> +		err = -ENOMEM;
> +		goto err_ida_remove;
> +	}
> +	misc_device->fops = &bcm_vk_fops,
> +
> +	err = misc_register(misc_device);
> +	if (err) {
> +		dev_err(dev, "failed to register device\n");
> +		goto err_kfree_name;
> +	}
> +
> +	err = bcm_vk_msg_init(vk);
> +	if (err) {
> +		dev_err(dev, "failed to init msg queue info\n");
> +		goto err_misc_deregister;
> +	}
> +
> +	/* sync other info */
> +	bcm_vk_sync_card_info(vk);
> +
> +	/* register for panic notifier */
> +	vk->panic_nb.notifier_call = bcm_vk_on_panic;
> +	atomic_notifier_chain_register(&panic_notifier_list,
> +				       &vk->panic_nb);
> +
> +	snprintf(name, sizeof(name), KBUILD_MODNAME ".%d_ttyVK", id);
> +	err = bcm_vk_tty_init(vk, name);
> +	if (err)
> +		goto err_unregister_panic_notifier;
> +
> +	/*
> +	 * lets trigger an auto download.  We don't want to do it serially here
> +	 * because at probing time, it is not supposed to block for a long time.
> +	 */
> +	boot_status = vkread32(vk, BAR_0, BAR_BOOT_STATUS);
> +	if (auto_load) {
> +		if ((boot_status & BOOT_STATE_MASK) == BROM_RUNNING) {
> +			if (bcm_vk_trigger_autoload(vk))
> +				goto err_bcm_vk_tty_exit;
> +		} else {
> +			dev_info(dev,
> +				 "Auto-load skipped - BROM not in proper state (0x%x)\n",
> +				 boot_status);
> +		}
> +	}
> +
> +	/* enable hb */
> +	bcm_vk_hb_init(vk);
> +
> +	dev_info(dev, "BCM-VK:%u created, 0x%p\n", id, vk);
> +
> +	return 0;
> +
> +err_bcm_vk_tty_exit:
> +	bcm_vk_tty_exit(vk);
> +
> +err_unregister_panic_notifier:
> +	atomic_notifier_chain_unregister(&panic_notifier_list,
> +					 &vk->panic_nb);
> +
> +err_misc_deregister:
> +	misc_deregister(misc_device);
> +
> +err_kfree_name:
> +	kfree(misc_device->name);
> +	misc_device->name = NULL;
> +
> +err_ida_remove:
> +	ida_simple_remove(&bcm_vk_ida, id);
> +
> +err_irq:
> +	for (i = 0; i < vk->num_irqs; i++)
> +		devm_free_irq(dev, pci_irq_vector(pdev, i), vk);
> +
> +	pci_disable_msix(pdev);
> +	pci_disable_msi(pdev);
> +
> +err_iounmap:
> +	for (i = 0; i < MAX_BAR; i++) {
> +		if (vk->bar[i])
> +			pci_iounmap(pdev, vk->bar[i]);
> +	}
> +	pci_release_regions(pdev);
> +
> +err_disable_pdev:
> +	pci_disable_device(pdev);
> +
> +	return err;
> +}
> +
> +void bcm_vk_release_data(struct kref *kref)
> +{
> +	struct bcm_vk *vk = container_of(kref, struct bcm_vk, kref);
> +
> +	/* use raw print, as dev is gone */
> +	pr_info("BCM-VK:%d release data 0x%p\n", vk->misc_devid, vk);
> +	kfree(vk);
> +}
> +
> +static void bcm_vk_remove(struct pci_dev *pdev)
> +{
> +	int i;
> +	struct bcm_vk *vk = pci_get_drvdata(pdev);
> +	struct miscdevice *misc_device = &vk->miscdev;
> +
> +	bcm_vk_hb_deinit(vk);
> +	bcm_vk_tty_exit(vk);
> +
> +	/* unregister panic notifier */
> +	atomic_notifier_chain_unregister(&panic_notifier_list,
> +				       &vk->panic_nb);
> +
> +	bcm_vk_msg_remove(vk);
> +
> +	if (vk->tdma_vaddr)
> +		dma_free_coherent(&pdev->dev, nr_scratch_pages * PAGE_SIZE,
> +				  vk->tdma_vaddr, vk->tdma_addr);
> +
> +	/* remove if name is set which means misc dev registered */
> +	if (misc_device->name) {
> +		misc_deregister(misc_device);
> +		kfree(misc_device->name);
> +		ida_simple_remove(&bcm_vk_ida, vk->misc_devid);
> +	}
> +	for (i = 0; i < vk->num_irqs; i++)
> +		devm_free_irq(&pdev->dev, pci_irq_vector(pdev, i), vk);
> +
> +	pci_disable_msix(pdev);
> +	pci_disable_msi(pdev);
> +
> +	cancel_work_sync(&vk->wq_work);
> +	destroy_workqueue(vk->wq_thread);
> +
> +	for (i = 0; i < MAX_BAR; i++) {
> +		if (vk->bar[i])
> +			pci_iounmap(pdev, vk->bar[i]);
> +	}
> +
> +	dev_info(&pdev->dev, "BCM-VK:%d released\n", vk->misc_devid);
> +
> +	pci_release_regions(pdev);
> +	pci_disable_device(pdev);
> +
> +	kref_put(&vk->kref, bcm_vk_release_data);
> +}
> +
> +static const struct pci_device_id bcm_vk_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, PCI_DEVICE_ID_VALKYRIE), },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, PCI_DEVICE_ID_VIPER), },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(pci, bcm_vk_ids);
> +
> +static struct pci_driver pci_driver = {
> +	.name     = DRV_MODULE_NAME,
> +	.id_table = bcm_vk_ids,
> +	.probe    = bcm_vk_probe,
> +	.remove   = bcm_vk_remove,
> +};
> +module_pci_driver(pci_driver);
> +
> +MODULE_DESCRIPTION("Broadcom VK Host Driver");
> +MODULE_AUTHOR("Scott Branden <scott.branden@xxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_VERSION("1.0");
> diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c
> new file mode 100644
> index 000000000000..651fba2149e2
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c
> @@ -0,0 +1,1359 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/fs.h>
> +#include <linux/hash.h>
> +#include <linux/interrupt.h>
> +#include <linux/list.h>
> +#include <linux/sizes.h>
> +#include <linux/spinlock.h>
> +#include <linux/timer.h>
> +
> +#include "bcm_vk.h"
> +#include "bcm_vk_msg.h"
> +#include "bcm_vk_sg.h"
> +
> +#if defined(CONFIG_BCM_VK_H2VK_VERIFY_AND_RETRY)
> +/*
> + * Turn on the following to verify the data passed down to VK is good, and
> + * if not, do retry.  This is a debug/workaround on FPGA PCIe timing issues
> + * but may be found useful for debugging other PCIe hardware issues.
> + */
> +static void bcm_vk_h2vk_verify_idx(struct device *dev,
> +				   const char *tag,
> +				   volatile uint32_t *idx,
> +				   uint32_t expected)
> +{
> +	unsigned int count = 0;
> +
> +	while (*idx != expected) {
> +		count++;
> +		dev_err(dev, "[%d] %s exp %d idx %d\n",
> +			count, tag, expected, *idx);
> +
> +		/* write again */
> +		*idx = expected;
> +	}
> +}
> +
> +static void bcm_vk_h2vk_verify_blk(struct device *dev,
> +				   const struct vk_msg_blk *src,
> +				   volatile struct vk_msg_blk *dst)
> +
> +{
> +	struct vk_msg_blk rd_bck;
> +	unsigned int count = 0;
> +
> +	rd_bck = *dst;
> +	while (memcmp(&rd_bck, src, sizeof(rd_bck)) != 0) {
> +		count++;
> +		dev_err(dev,
> +			"[%d]Src Blk: [0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x]\n",
> +			count,
> +			src->function_id,
> +			src->size,
> +			src->queue_id,
> +			src->msg_id,
> +			src->context_id,
> +			src->args[0],
> +			src->args[1]);
> +		dev_err(dev,
> +			"[%d]Rdb Blk: [0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x]\n",
> +			count,
> +			rd_bck.function_id,
> +			rd_bck.size,
> +			rd_bck.queue_id,
> +			rd_bck.msg_id,
> +			rd_bck.context_id,
> +			rd_bck.args[0],
> +			rd_bck.args[1]);
> +
> +		*dst = *src;
> +		rd_bck = *dst;
> +	}
> +}
> +#else
> +static void bcm_vk_h2vk_verify_idx(struct device __always_unused *dev,
> +				   const char __always_unused *tag,
> +				   volatile uint32_t __always_unused *idx,
> +				   uint32_t __always_unused expected)
> +{
> +}
> +
> +static void bcm_vk_h2vk_verify_blk
> +		(struct device __always_unused *dev,
> +		 const struct vk_msg_blk __always_unused *src,
> +		 volatile struct vk_msg_blk __always_unused *dst)
> +
> +{
> +}
> +#endif
> +
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +
> +/* Use default value of 20000 rd/wr per update */
> +#if !defined(BCM_VK_QSTATS_ACC_CNT)
> +#define BCM_VK_QSTATS_ACC_CNT 20000
> +#endif
> +
> +void bcm_vk_update_qstats(struct bcm_vk *vk, const char *tag,
> +			  struct bcm_vk_qstats *qstats, uint32_t occupancy)
> +{
> +	struct bcm_vk_qs_cnts *qcnts = &qstats->qcnts;
> +
> +	if (occupancy > qcnts->max_occ) {
> +		qcnts->max_occ = occupancy;
> +		if (occupancy > qcnts->max_abs)
> +			qcnts->max_abs = occupancy;
> +	}
> +
> +	qcnts->acc_sum += occupancy;
> +	if (++qcnts->cnt >= BCM_VK_QSTATS_ACC_CNT) {
> +		/* log average and clear counters */
> +		dev_info(&vk->pdev->dev,
> +			 "%s[%d]: Max: [%3d/%3d] Acc %d num %d, Aver %d\n",
> +			 tag, qstats->q_num,
> +			 qcnts->max_occ, qcnts->max_abs,
> +			 qcnts->acc_sum,
> +			 qcnts->cnt,
> +			 qcnts->acc_sum / qcnts->cnt);
> +
> +		qcnts->cnt = 0;
> +		qcnts->max_occ = 0;
> +		qcnts->acc_sum = 0;
> +	}
> +}
> +#endif
> +
> +/* number of retries when enqueue message fails before returning EAGAIN */
> +#define BCM_VK_H2VK_ENQ_RETRY 10
> +#define BCM_VK_H2VK_ENQ_RETRY_DELAY_MS 50
> +
> +bool bcm_vk_drv_access_ok(struct bcm_vk *vk)
> +{
> +	return (!!atomic_read(&vk->msgq_inited));
> +}
> +
> +static void bcm_vk_set_host_alert(struct bcm_vk *vk, uint32_t bit_mask)
> +{
> +	struct bcm_vk_alert *alert = &vk->host_alert;
> +	unsigned long flags;
> +
> +	/* use irqsave version as this maybe called inside timer interrupt */
> +	spin_lock_irqsave(&vk->host_alert_lock, flags);
> +	alert->notfs |= bit_mask;
> +	spin_unlock_irqrestore(&vk->host_alert_lock, flags);
> +
> +	if (test_and_set_bit(BCM_VK_WQ_NOTF_PEND, vk->wq_offload) == 0)
> +		queue_work(vk->wq_thread, &vk->wq_work);
> +}
> +
> +/*
> + * Heartbeat related defines
> + * The heartbeat from host is a last resort.  If stuck condition happens
> + * on the card, firmware is supposed to detect it.  Therefore, the heartbeat
> + * values used will be more relaxed on the driver, which need to be bigger
> + * than the watchdog timeout on the card.
> + */
> +#define BCM_VK_HB_TIMER_S 3
> +#define BCM_VK_HB_TIMER_VALUE (BCM_VK_HB_TIMER_S * HZ)
> +#define BCM_VK_HB_LOST_MAX 4
> +
> +static void bcm_vk_hb_poll(struct timer_list *t)
> +{
> +	uint32_t uptime_s;
> +	struct bcm_vk_hb_ctrl *hb = container_of(t, struct bcm_vk_hb_ctrl,
> +						 timer);
> +	struct bcm_vk *vk = container_of(hb, struct bcm_vk, hb_ctrl);
> +
> +	if (bcm_vk_drv_access_ok(vk)) {
> +		/* read uptime from register and compare */
> +		uptime_s = vkread32(vk, BAR_0, BAR_OS_UPTIME);
> +
> +		if (uptime_s == hb->last_uptime)
> +			hb->lost_cnt++;
> +
> +		dev_dbg(&vk->pdev->dev, "Last uptime %d current %d, lost %d\n",
> +			hb->last_uptime, uptime_s, hb->lost_cnt);
> +
> +		/*
> +		 * if the interface goes down without any activity, a value
> +		 * of 0xFFFFFFFF will be continuously read, and the detection
> +		 * will be happened eventually.
> +		 */
> +		hb->last_uptime = uptime_s;
> +	} else {
> +		/* reset heart beat lost cnt */
> +		hb->lost_cnt = 0;
> +	}
> +
> +	/* next, check if heartbeat exceeds limit */
> +	if (hb->lost_cnt > BCM_VK_HB_LOST_MAX) {
> +		dev_err(&vk->pdev->dev, "Heartbeat Misses %d times, %d s!\n",
> +			BCM_VK_HB_LOST_MAX,
> +			BCM_VK_HB_LOST_MAX * BCM_VK_HB_TIMER_S);
> +
> +		bcm_vk_blk_drv_access(vk);
> +		bcm_vk_set_host_alert(vk, ERR_LOG_HOST_HB_FAIL);
> +	}
> +	/* re-arm timer */
> +	mod_timer(&hb->timer, jiffies + BCM_VK_HB_TIMER_VALUE);
> +}
> +
> +void bcm_vk_hb_init(struct bcm_vk *vk)
> +{
> +	struct bcm_vk_hb_ctrl *hb = &vk->hb_ctrl;
> +
> +	timer_setup(&hb->timer, bcm_vk_hb_poll, 0);
> +	mod_timer(&hb->timer, jiffies + BCM_VK_HB_TIMER_VALUE);
> +}
> +
> +void bcm_vk_hb_deinit(struct bcm_vk *vk)
> +{
> +	struct bcm_vk_hb_ctrl *hb = &vk->hb_ctrl;
> +
> +	del_timer(&hb->timer);
> +}
> +
> +static void bcm_vk_msgid_bitmap_clear(struct bcm_vk *vk,
> +				      unsigned int start,
> +				      unsigned int nbits)
> +{
> +	spin_lock(&vk->msg_id_lock);
> +	bitmap_clear(vk->bmap, start, nbits);
> +	spin_unlock(&vk->msg_id_lock);
> +}
> +
> +/*
> + * allocate a ctx per file struct
> + */
> +static struct bcm_vk_ctx *bcm_vk_get_ctx(struct bcm_vk *vk,
> +					 struct task_struct *ppid)
> +{
> +	uint32_t i;
> +	struct bcm_vk_ctx *ctx = NULL;
> +	const pid_t pid = task_pid_nr(ppid);
> +	uint32_t hash_idx = hash_32(pid, VK_PID_HT_SHIFT_BIT);
> +
> +	spin_lock(&vk->ctx_lock);
> +
> +	/* check if it is in reset, if so, don't allow */
> +	if (vk->reset_ppid) {
> +		dev_err(&vk->pdev->dev,
> +			"No context allowed during reset by pid %d\n",
> +			task_pid_nr(vk->reset_ppid));
> +
> +		goto in_reset_exit;
> +	}
> +
> +	for (i = 0; i < ARRAY_SIZE(vk->ctx); i++) {
> +		if (!vk->ctx[i].in_use) {
> +			vk->ctx[i].in_use = true;
> +			ctx = &vk->ctx[i];
> +			break;
> +		}
> +	}
> +
> +	if (!ctx) {
> +		dev_err(&vk->pdev->dev, "All context in use\n");
> +
> +		goto all_in_use_exit;
> +	}
> +
> +	/* set the pid and insert it to hash table */
> +	ctx->ppid = ppid;
> +	ctx->hash_idx = hash_idx;
> +	list_add_tail(&ctx->node, &vk->pid_ht[hash_idx].head);
> +
> +	/* increase kref */
> +	kref_get(&vk->kref);
> +
> +	/* clear counter */
> +	ctx->pend_cnt = 0;
> +all_in_use_exit:
> +in_reset_exit:
> +	spin_unlock(&vk->ctx_lock);
> +
> +	return ctx;
> +}
> +
> +static uint16_t bcm_vk_get_msg_id(struct bcm_vk *vk)
> +{
> +	uint16_t rc = VK_MSG_ID_OVERFLOW;
> +	uint16_t test_bit_count = 0;
> +
> +	spin_lock(&vk->msg_id_lock);
> +	while (test_bit_count < VK_MSG_ID_BITMAP_SIZE) {
> +		vk->msg_id++;
> +		vk->msg_id = vk->msg_id & VK_MSG_ID_BITMAP_MASK;
> +		if (test_bit(vk->msg_id, vk->bmap)) {
> +			test_bit_count++;
> +			continue;
> +		}
> +		rc = vk->msg_id;
> +		bitmap_set(vk->bmap, vk->msg_id, 1);
> +		break;
> +	}
> +	spin_unlock(&vk->msg_id_lock);
> +
> +	return rc;
> +}
> +
> +static int bcm_vk_free_ctx(struct bcm_vk *vk, struct bcm_vk_ctx *ctx)
> +{
> +	uint32_t idx;
> +	uint32_t hash_idx;
> +	pid_t pid;
> +	struct bcm_vk_ctx *entry;
> +	int count = 0;
> +
> +	if (ctx == NULL) {
> +		dev_err(&vk->pdev->dev, "NULL context detected\n");
> +		return -EINVAL;
> +	}
> +	idx = ctx->idx;
> +	pid = task_pid_nr(ctx->ppid);
> +
> +	spin_lock(&vk->ctx_lock);
> +
> +	if (!vk->ctx[idx].in_use) {
> +		dev_err(&vk->pdev->dev, "context[%d] not in use!\n", idx);
> +	} else {
> +		vk->ctx[idx].in_use = false;
> +		vk->ctx[idx].miscdev = NULL;
> +
> +		/* Remove it from hash list and see if it is the last one. */
> +		list_del(&ctx->node);
> +		hash_idx = ctx->hash_idx;
> +		list_for_each_entry(entry, &vk->pid_ht[hash_idx].head, node) {
> +			if (task_pid_nr(entry->ppid) == pid)
> +				count++;
> +		}
> +	}
> +
> +	spin_unlock(&vk->ctx_lock);
> +
> +	return count;
> +}
> +
> +static void bcm_vk_free_wkent(struct device *dev, struct bcm_vk_wkent *entry)
> +{
> +	bcm_vk_sg_free(dev, entry->dma, VK_DMA_MAX_ADDRS);
> +
> +	kfree(entry->vk2h_msg);
> +	kfree(entry);
> +}
> +
> +static void bcm_vk_drain_all_pend(struct device *dev,
> +				  struct bcm_vk_msg_chan *chan,
> +				  struct bcm_vk_ctx *ctx)
> +{
> +	uint32_t num;
> +	struct bcm_vk_wkent *entry, *tmp;
> +	struct bcm_vk *vk;
> +	struct list_head del_q;
> +
> +	if (ctx)
> +		vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
> +
> +	INIT_LIST_HEAD(&del_q);
> +	spin_lock(&chan->pendq_lock);
> +	for (num = 0; num < chan->q_nr; num++) {
> +		list_for_each_entry_safe(entry, tmp, &chan->pendq[num], node) {
> +			if (ctx == NULL) {
> +				list_del(&entry->node);
> +				list_add_tail(&entry->node, &del_q);
> +			} else if (entry->ctx->idx == ctx->idx) {
> +				struct vk_msg_blk *msg;
> +				int bit_set;
> +				bool responded;
> +
> +				/* if it is specific ctx, log for any stuck */
> +				msg = entry->h2vk_msg;
> +				bit_set = test_bit(msg->msg_id, vk->bmap);
> +				responded = entry->vk2h_msg ? true : false;
> +				dev_info(dev,
> +					 "Drained: fid %u size %u msg 0x%x(seq-%x) ctx 0x%x[fd-%d] args:[0x%x 0x%x] resp %s, bmap %d\n",
> +					 msg->function_id, msg->size,
> +					 msg->msg_id, entry->seq_num,
> +					 msg->context_id, entry->ctx->idx,
> +					 msg->args[0], msg->args[1],
> +					 responded ? "T" : "F", bit_set);
> +				list_del(&entry->node);
> +				list_add_tail(&entry->node, &del_q);
> +				if (responded)
> +					ctx->pend_cnt--;
> +				else if (bit_set)
> +					bcm_vk_msgid_bitmap_clear(vk,
> +								  msg->msg_id,
> +								  1);
> +			}
> +		}
> +	}
> +	spin_unlock(&chan->pendq_lock);
> +
> +	/* batch clean up */
> +	num = 0;
> +	list_for_each_entry_safe(entry, tmp, &del_q, node) {
> +		list_del(&entry->node);
> +		bcm_vk_free_wkent(dev, entry);
> +		num++;
> +	}
> +	if (num)
> +		dev_info(dev, "Total drained items %d\n", num);
> +}
> +
> +bool bcm_vk_msgq_marker_valid(struct bcm_vk *vk)
> +{
> +	uint32_t rdy_marker = 0;
> +	uint32_t fw_status;
> +
> +	fw_status = vkread32(vk, BAR_0, VK_BAR_FWSTS);
> +
> +	if ((fw_status & VK_FWSTS_READY) == VK_FWSTS_READY)
> +		rdy_marker = vkread32(vk, BAR_1, VK_BAR1_MSGQ_DEF_RDY);
> +
> +	return (rdy_marker == VK_BAR1_MSGQ_RDY_MARKER);
> +}
> +
> +/*
> + * Function to sync up the messages queue info that is provided by BAR1
> + */
> +int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync)
> +{
> +	struct bcm_vk_msgq *msgq = NULL;
> +	struct device *dev = &vk->pdev->dev;
> +	uint32_t msgq_off;
> +	uint32_t num_q;
> +	struct bcm_vk_msg_chan *chan_list[] = {&vk->h2vk_msg_chan,
> +					       &vk->vk2h_msg_chan};
> +	struct bcm_vk_msg_chan *chan = NULL;
> +	int i, j;
> +	int ret = 0;
> +
> +	/*
> +	 * If the driver is loaded at startup where vk OS is not up yet,
> +	 * the msgq-info may not be available until a later time.  In
> +	 * this case, we skip and the sync function is supposed to be
> +	 * called again.
> +	 */
> +	if (!bcm_vk_msgq_marker_valid(vk)) {
> +		dev_info(dev, "BAR1 msgq marker not initialized.\n");
> +		return ret;

This is "return 0;" which seems wrong.

> +	}
> +
> +	msgq_off = vkread32(vk, BAR_1, VK_BAR1_MSGQ_CTRL_OFF);
> +
> +	/* each side is always half the total  */
> +	num_q = vk->h2vk_msg_chan.q_nr = vk->vk2h_msg_chan.q_nr =
> +		vkread32(vk, BAR_1, VK_BAR1_MSGQ_NR) / 2;
> +
> +	/* first msgq location */
> +	msgq = (struct bcm_vk_msgq *)(vk->bar[BAR_1] + msgq_off);
> +
> +	/*
> +	 * if this function is called when it is already inited,
> +	 * something is wrong
> +	 */
> +	if (bcm_vk_drv_access_ok(vk) && (!force_sync)) {

Delete extra parens.

> +		dev_err(dev, "Msgq info already in sync\n");
> +		ret = -EPERM;
> +		goto already_inited;

Please do a direct "return -EPERM;"

> +	}
> +
> +	for (i = 0; i < ARRAY_SIZE(chan_list); i++) {
> +		chan = chan_list[i];
> +		memset(chan->sync_qinfo, 0, sizeof(chan->sync_qinfo));
> +
> +		for (j = 0; j < num_q; j++) {
> +			chan->msgq[j] = msgq;
> +
> +			dev_info(dev,
> +				 "MsgQ[%d] type %d num %d, @ 0x%x, rd_idx %d wr_idx %d, size %d, nxt 0x%x\n",
> +				 j,
> +				 chan->msgq[j]->type,
> +				 chan->msgq[j]->num,
> +				 chan->msgq[j]->start,
> +				 chan->msgq[j]->rd_idx,
> +				 chan->msgq[j]->wr_idx,
> +				 chan->msgq[j]->size,
> +				 chan->msgq[j]->nxt);

It would be shorter to replace chan->msgq[j]->type with msgq->type.

> +
> +			/* formulate and record static info */
> +			chan->sync_qinfo[j].q_start =
> +				vk->bar[BAR_1] + chan->msgq[j]->start;

Maybe set "qinfo = &chan->sync_qinfo[j];" at the start of the loop so
that these fit on one line.

			qinfo->q_start = vk->bar[BAR_1] + msgq->start;

> +			chan->sync_qinfo[j].q_size = chan->msgq[j]->size;
> +			/* set low threshold as 50% or 1/2 */
> +			chan->sync_qinfo[j].q_low =
> +				chan->sync_qinfo[j].q_size >> 1;
> +			chan->sync_qinfo[j].q_mask =
> +				chan->sync_qinfo[j].q_size - 1;
> +
> +			msgq = (struct bcm_vk_msgq *)
> +				((char *)msgq + sizeof(*msgq) + msgq->nxt);
> +
> +			rmb(); /* do a read mb to guarantee */
> +		}
> +	}
> +	atomic_set(&vk->msgq_inited, 1);
> +
> +already_inited:
> +	return ret;
> +}
> +
> +static int bcm_vk_msg_chan_init(struct bcm_vk_msg_chan *chan)
> +{
> +	int rc = 0;
> +	uint32_t i;
> +
> +	mutex_init(&chan->msgq_mutex);
> +	spin_lock_init(&chan->pendq_lock);
> +	for (i = 0; i < VK_MSGQ_MAX_NR; i++) {
> +		INIT_LIST_HEAD(&chan->pendq[i]);
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +		chan->qstats[i].q_num = i;
> +#endif
> +	}
> +
> +	return rc;


	return 0;

> +}
> +
> +static void bcm_vk_append_pendq(struct bcm_vk_msg_chan *chan, uint16_t q_num,
> +				struct bcm_vk_wkent *entry)
> +{
> +	spin_lock(&chan->pendq_lock);
> +	list_add_tail(&entry->node, &chan->pendq[q_num]);
> +	if (entry->vk2h_msg)
> +		entry->ctx->pend_cnt++;
> +	spin_unlock(&chan->pendq_lock);
> +}
> +
> +static uint32_t bcm_vk_append_ib_sgl(struct bcm_vk *vk,
> +				     struct bcm_vk_wkent *entry,
> +				     struct _vk_data *data,
> +				     unsigned int num_planes)
> +{
> +	unsigned int i;
> +	unsigned int item_cnt = 0;
> +	struct device *dev = &vk->pdev->dev;
> +	struct bcm_vk_msg_chan *chan = &vk->h2vk_msg_chan;
> +	struct vk_msg_blk *msg = &entry->h2vk_msg[0];
> +	struct bcm_vk_msgq *msgq;
> +	struct bcm_vk_sync_qinfo *qinfo;
> +	uint32_t ib_sgl_size = 0;
> +	uint8_t *buf = (uint8_t *)&entry->h2vk_msg[entry->h2vk_blks];
> +	uint32_t avail;
> +
> +	/* check if high watermark is hit, and if so, skip */
> +	msgq = chan->msgq[msg->queue_id];
> +	qinfo = &chan->sync_qinfo[msg->queue_id];
> +	avail = VK_MSGQ_AVAIL_SPACE(msgq, qinfo);
> +	if (avail < qinfo->q_low) {
> +		dev_dbg(dev, "Skip inserting inband SGL, [0x%x/0x%x]\n",
> +			avail, qinfo->q_size);
> +		return ib_sgl_size;

		return 0;

> +	}
> +
> +	for (i = 0; i < num_planes; i++) {
> +		if (data[i].address &&
> +		    (ib_sgl_size + data[i].size) <= vk->ib_sgl_size) {
> +
> +			item_cnt++;
> +			memcpy(buf, entry->dma[i].sglist, data[i].size);
> +			ib_sgl_size += data[i].size;
> +			buf += data[i].size;
> +		}
> +	}
> +
> +	dev_dbg(dev, "Num %u sgl items appended, size 0x%x, room 0x%x\n",
> +		item_cnt, ib_sgl_size, vk->ib_sgl_size);
> +
> +	/* round up size */
> +	ib_sgl_size = (ib_sgl_size + VK_MSGQ_BLK_SIZE - 1)
> +		       >> VK_MSGQ_BLK_SZ_SHIFT;
> +
> +	return ib_sgl_size;
> +}
> +
> +void bcm_h2vk_doorbell(struct bcm_vk *vk, uint32_t q_num,
> +			      uint32_t db_val)
> +{
> +	/* press door bell based on q_num */
> +	vkwrite32(vk,
> +		  db_val,
> +		  BAR_0,
> +		  VK_BAR0_REGSEG_DB_BASE + q_num * VK_BAR0_REGSEG_DB_REG_GAP);
> +}
> +
> +static int bcm_h2vk_msg_enqueue(struct bcm_vk *vk, struct bcm_vk_wkent *entry)
> +{
> +	static uint32_t seq_num;
> +	struct bcm_vk_msg_chan *chan = &vk->h2vk_msg_chan;
> +	struct device *dev = &vk->pdev->dev;
> +	struct vk_msg_blk *src = &entry->h2vk_msg[0];
> +
> +	volatile struct vk_msg_blk *dst;
> +	struct bcm_vk_msgq *msgq;
> +	struct bcm_vk_sync_qinfo *qinfo;
> +	uint32_t q_num = src->queue_id;
> +	uint32_t wr_idx; /* local copy */
> +	uint32_t i;
> +	uint32_t avail;
> +	uint32_t retry;
> +
> +	if (entry->h2vk_blks != src->size + 1) {
> +		dev_err(dev, "number of blks %d not matching %d MsgId[0x%x]: func %d ctx 0x%x\n",
> +			entry->h2vk_blks,
> +			src->size + 1,
> +			src->msg_id,
> +			src->function_id,
> +			src->context_id);
> +		return -EMSGSIZE;
> +	}
> +
> +	msgq = chan->msgq[q_num];
> +	qinfo = &chan->sync_qinfo[q_num];
> +
> +	rmb(); /* start with a read barrier */
> +	mutex_lock(&chan->msgq_mutex);
> +
> +	avail = VK_MSGQ_AVAIL_SPACE(msgq, qinfo);
> +
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +	bcm_vk_update_qstats(vk, "h2vk", &chan->qstats[q_num],
> +			     qinfo->q_size - avail);
> +#endif
> +	/* if not enough space, return EAGAIN and let app handles it */
> +	retry = 0;
> +	while ((avail < entry->h2vk_blks)
> +	       && (retry++ < BCM_VK_H2VK_ENQ_RETRY)) {
> +		mutex_unlock(&chan->msgq_mutex);
> +
> +		msleep(BCM_VK_H2VK_ENQ_RETRY_DELAY_MS);
> +		mutex_lock(&chan->msgq_mutex);
> +		avail = VK_MSGQ_AVAIL_SPACE(msgq, qinfo);
> +	}
> +	if (retry > BCM_VK_H2VK_ENQ_RETRY) {
> +		mutex_unlock(&chan->msgq_mutex);
> +		return -EAGAIN;
> +	}
> +
> +	/* at this point, mutex is taken and there is enough space */
> +	entry->seq_num = seq_num++; /* update debug seq number */
> +	wr_idx = msgq->wr_idx;
> +
> +	if (wr_idx >= qinfo->q_size) {
> +		dev_crit(dev, "Invalid wr_idx 0x%x => max 0x%x!",
> +			 wr_idx, qinfo->q_size);
> +		bcm_vk_blk_drv_access(vk);
> +		bcm_vk_set_host_alert(vk, ERR_LOG_HOST_PCIE_DWN);
> +		goto idx_err;
> +	}
> +
> +	dst = VK_MSGQ_BLK_ADDR(qinfo, wr_idx);
> +	for (i = 0; i < entry->h2vk_blks; i++) {
> +		*dst = *src;
> +
> +		bcm_vk_h2vk_verify_blk(dev, src, dst);
> +
> +		src++;
> +		wr_idx = VK_MSGQ_INC(qinfo, wr_idx, 1);
> +		dst = VK_MSGQ_BLK_ADDR(qinfo, wr_idx);
> +	}
> +
> +	/* flush the write pointer */
> +	msgq->wr_idx = wr_idx;
> +	wmb(); /* flush */
> +
> +	bcm_vk_h2vk_verify_idx(dev, "wr_idx", &msgq->wr_idx, wr_idx);
> +
> +	/* log new info for debugging */
> +	dev_dbg(dev,
> +		"MsgQ[%d] [Rd Wr] = [%d %d] blks inserted %d - Q = [u-%d a-%d]/%d\n",
> +		msgq->num,
> +		msgq->rd_idx, msgq->wr_idx, entry->h2vk_blks,
> +		VK_MSGQ_OCCUPIED(msgq, qinfo),
> +		VK_MSGQ_AVAIL_SPACE(msgq, qinfo),
> +		msgq->size);
> +	/*
> +	 * press door bell based on queue number. 1 is added to the wr_idx
> +	 * to avoid the value of 0 appearing on the VK side to distinguish
> +	 * from initial value.
> +	 */
> +	bcm_h2vk_doorbell(vk, q_num, wr_idx + 1);
> +idx_err:
> +	mutex_unlock(&chan->msgq_mutex);
> +	return 0;
> +}
> +
> +int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, uint32_t shut_type,
> +			     pid_t pid)
> +{
> +	int rc = 0;
> +	struct bcm_vk_wkent *entry;
> +	struct device *dev = &vk->pdev->dev;
> +
> +	/*
> +	 * check if the marker is still good.  Sometimes, the PCIe interface may
> +	 * have gone done, and if so and we ship down thing based on broken
> +	 * values, kernel may panic.
> +	 */
> +	if (!bcm_vk_msgq_marker_valid(vk)) {
> +		dev_info(dev, "PCIe comm chan - invalid marker (0x%x)!\n",
> +			 vkread32(vk, BAR_1, VK_BAR1_MSGQ_DEF_RDY));
> +		return -EINVAL;
> +	}
> +
> +	entry = kzalloc(sizeof(struct bcm_vk_wkent) +
> +			sizeof(struct vk_msg_blk), GFP_KERNEL);
> +	if (!entry)
> +		return -ENOMEM;
> +
> +	/* just fill up non-zero data */
> +	entry->h2vk_msg[0].function_id = VK_FID_SHUTDOWN;
> +	entry->h2vk_msg[0].queue_id = 0; /* use highest queue */
> +	entry->h2vk_blks = 1; /* always 1 block */
> +
> +	entry->h2vk_msg[0].args[0] = shut_type;
> +	entry->h2vk_msg[0].args[1] = pid;
> +
> +	rc = bcm_h2vk_msg_enqueue(vk, entry);
> +	if (rc)
> +		dev_err(dev,
> +			"Sending shutdown message to q %d for pid %d fails.\n",
> +			entry->h2vk_msg[0].queue_id, pid);
> +
> +	kfree(entry);
> +
> +	return rc;
> +}
> +
> +int bcm_vk_handle_last_sess(struct bcm_vk *vk, struct task_struct *ppid)
> +{
> +	int rc = 0;
> +	pid_t pid = task_pid_nr(ppid);
> +	struct device *dev = &vk->pdev->dev;
> +
> +	/*
> +	 * don't send down or do anything if message queue is not initialized
> +	 * and if it is the reset session, clear it.
> +	 */
> +	if (!bcm_vk_drv_access_ok(vk)) {
> +
> +		if (vk->reset_ppid == ppid)
> +			vk->reset_ppid = NULL;
> +		return -EPERM;
> +	}
> +
> +	dev_dbg(dev, "No more sessions, shut down pid %d\n", pid);
> +
> +	/* only need to do it if it is not the reset process */
> +	if (vk->reset_ppid != ppid)
> +		rc = bcm_vk_send_shutdown_msg(vk, VK_SHUTDOWN_PID, pid);
> +	else
> +		/* reset the pointer if it is exiting last session */
> +		vk->reset_ppid = NULL;
> +
> +	return rc;
> +}
> +
> +static struct bcm_vk_wkent *bcm_vk_find_pending(struct bcm_vk *vk,
> +						struct bcm_vk_msg_chan *chan,
> +						uint16_t q_num,
> +						uint16_t msg_id)
> +{
> +	bool found = false;
> +	struct bcm_vk_wkent *entry;
> +
> +	spin_lock(&chan->pendq_lock);
> +	list_for_each_entry(entry, &chan->pendq[q_num], node) {
> +
> +		if (entry->h2vk_msg[0].msg_id == msg_id) {
> +			list_del(&entry->node);
> +			found = true;
> +			bcm_vk_msgid_bitmap_clear(vk, msg_id, 1);
> +			break;
> +		}
> +	}
> +	spin_unlock(&chan->pendq_lock);
> +	return ((found) ? entry : NULL);
> +}
> +
> +static uint32_t bcm_vk2h_msg_dequeue(struct bcm_vk *vk)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	struct bcm_vk_msg_chan *chan = &vk->vk2h_msg_chan;
> +	struct vk_msg_blk *data;
> +	volatile struct vk_msg_blk *src;
> +	struct vk_msg_blk *dst;
> +	struct bcm_vk_msgq *msgq;
> +	struct bcm_vk_sync_qinfo *qinfo;
> +	struct bcm_vk_wkent *entry;
> +	uint32_t rd_idx;
> +	uint32_t q_num, j;
> +	uint32_t num_blks;
> +	uint32_t total = 0;
> +
> +	/*
> +	 * drain all the messages from the queues, and find its pending
> +	 * entry in the h2vk queue, based on msg_id & q_num, and move the
> +	 * entry to the vk2h pending queue, waiting for user space
> +	 * program to extract
> +	 */
> +	mutex_lock(&chan->msgq_mutex);
> +	rmb(); /* start with a read barrier */
> +	for (q_num = 0; q_num < chan->q_nr; q_num++) {
> +		msgq = chan->msgq[q_num];
> +		qinfo = &chan->sync_qinfo[q_num];
> +
> +		while (!VK_MSGQ_EMPTY(msgq)) {
> +
> +			/*
> +			 * Make a local copy and get pointer to src blk
> +			 * The rd_idx is masked before getting the pointer to
> +			 * avoid out of bound access in case the interface goes
> +			 * down.  It will end up pointing to the last block in
> +			 * the buffer, but subsequent src->size check would be
> +			 * able to catch this.
> +			 */
> +			rd_idx = msgq->rd_idx;
> +			src = VK_MSGQ_BLK_ADDR(qinfo,
> +					     rd_idx & VK_MSGQ_SIZE_MASK(qinfo));
> +
> +			if ((rd_idx >= qinfo->q_size)
> +			    || (src->size > (qinfo->q_size - 1))) {
> +				dev_crit(dev,
> +					 "Invalid rd_idx 0x%x or size 0x%x => max 0x%x!",
> +					 rd_idx, src->size, qinfo->q_size);
> +				bcm_vk_blk_drv_access(vk);
> +				bcm_vk_set_host_alert(
> +					vk, ERR_LOG_HOST_PCIE_DWN);
> +				goto idx_err;
> +			}
> +
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +			bcm_vk_update_qstats(vk, "vk2h", &chan->qstats[q_num],
> +					     VK_MSGQ_OCCUPIED(msgq, qinfo));
> +#endif
> +			num_blks = src->size + 1;
> +			data = kzalloc(num_blks * VK_MSGQ_BLK_SIZE, GFP_KERNEL);
> +			if (data) {
> +				/* copy messages and linearize it */
> +				dst = data;
> +				for (j = 0; j < num_blks; j++) {
> +					*dst = *src;
> +
> +					dst++;
> +					rd_idx = VK_MSGQ_INC(qinfo, rd_idx, 1);
> +					src = VK_MSGQ_BLK_ADDR(qinfo, rd_idx);
> +				}
> +				total++;
> +			} else {
> +				dev_crit(dev, "Error allocating memory\n");
> +				/* just keep draining..... */
> +				rd_idx = VK_MSGQ_INC(qinfo, rd_idx, num_blks);
> +			}
> +
> +			/* flush rd pointer after a message is dequeued */
> +			msgq->rd_idx = rd_idx;
> +			mb(); /* do both rd/wr as we are extracting data out */
> +
> +			bcm_vk_h2vk_verify_idx(dev, "rd_idx",
> +					       &msgq->rd_idx, rd_idx);
> +
> +			/* log new info for debugging */
> +			dev_dbg(dev,
> +				"MsgQ[%d] [Rd Wr] = [%d %d] blks extracted %d - Q = [u-%d a-%d]/%d\n",
> +				msgq->num,
> +				msgq->rd_idx, msgq->wr_idx, num_blks,
> +				VK_MSGQ_OCCUPIED(msgq, qinfo),
> +				VK_MSGQ_AVAIL_SPACE(msgq, qinfo),
> +				msgq->size);
> +
> +			/*
> +			 * No need to search if it is an autonomous one-way
> +			 * message from driver, as these messages do not bear
> +			 * a h2vk pending item. Currently, only the shutdown
> +			 * message falls into this category.
> +			 */
> +			if (data->function_id == VK_FID_SHUTDOWN) {
> +				kfree(data);
> +				continue;
> +			}
> +
> +			/* lookup original message in h2vk direction */
> +			entry = bcm_vk_find_pending(vk,
> +						    &vk->h2vk_msg_chan,
> +						    q_num,
> +						    data->msg_id);
> +
> +			/*
> +			 * if there is message to does not have prior send,
> +			 * this is the location to add here
> +			 */
> +			if (entry) {
> +				entry->vk2h_blks = num_blks;
> +				entry->vk2h_msg = data;
> +				bcm_vk_append_pendq(&vk->vk2h_msg_chan,
> +						    q_num, entry);
> +
> +			} else {
> +				dev_crit(dev,
> +					 "Could not find MsgId[0x%x] for resp func %d bmap %d\n",
> +					 data->msg_id, data->function_id,
> +					 test_bit(data->msg_id, vk->bmap));
> +				kfree(data);
> +			}
> +
> +		}
> +	}
> +idx_err:
> +	mutex_unlock(&chan->msgq_mutex);
> +	dev_dbg(dev, "total %d drained from queues\n", total);
> +
> +	return total;
> +}
> +
> +/*
> + * deferred work queue for draining and auto download.
> + */
> +static void bcm_vk_wq_handler(struct work_struct *work)
> +{
> +	struct bcm_vk *vk = container_of(work, struct bcm_vk, wq_work);
> +	struct device *dev = &vk->pdev->dev;
> +	uint32_t tot;
> +
> +	/* check wq offload bit map to perform various operations */
> +	if (test_bit(BCM_VK_WQ_NOTF_PEND, vk->wq_offload)) {
> +		/* clear bit right the way for notification */
> +		clear_bit(BCM_VK_WQ_NOTF_PEND, vk->wq_offload);
> +		bcm_vk_handle_notf(vk);
> +	}
> +	if (test_bit(BCM_VK_WQ_DWNLD_AUTO, vk->wq_offload)) {
> +		bcm_vk_auto_load_all_images(vk);
> +
> +		/*
> +		 * at the end of operation, clear AUTO bit and pending
> +		 * bit
> +		 */
> +		clear_bit(BCM_VK_WQ_DWNLD_AUTO, vk->wq_offload);
> +		clear_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload);
> +	}
> +
> +	/* next, try to drain */
> +	tot = bcm_vk2h_msg_dequeue(vk);
> +
> +	if (tot == 0)
> +		dev_dbg(dev, "Spurious trigger for workqueue\n");
> +}
> +
> +/*
> + * init routine for all required data structures
> + */
> +static int bcm_vk_data_init(struct bcm_vk *vk)
> +{
> +	int rc = 0;
> +	int i;
> +
> +	spin_lock_init(&vk->ctx_lock);
> +	for (i = 0; i < ARRAY_SIZE(vk->ctx); i++) {
> +		vk->ctx[i].in_use = false;
> +		vk->ctx[i].idx = i;	/* self identity */
> +		vk->ctx[i].miscdev = NULL;
> +	}
> +	spin_lock_init(&vk->msg_id_lock);
> +	spin_lock_init(&vk->host_alert_lock);
> +	vk->msg_id = 0;
> +
> +	/* initialize hash table */
> +	for (i = 0; i < VK_PID_HT_SZ; i++)
> +		INIT_LIST_HEAD(&vk->pid_ht[i].head);
> +
> +	INIT_WORK(&vk->wq_work, bcm_vk_wq_handler);
> +	return rc;

	return 0;

> +}
> +
> +irqreturn_t bcm_vk_msgq_irqhandler(int irq, void *dev_id)
> +{
> +	struct bcm_vk *vk = dev_id;
> +
> +	if (!bcm_vk_drv_access_ok(vk)) {
> +		dev_err(&vk->pdev->dev,
> +			"Interrupt %d received when msgq not inited\n", irq);
> +		goto skip_schedule_work;
> +	}
> +
> +	queue_work(vk->wq_thread, &vk->wq_work);
> +
> +skip_schedule_work:
> +	return IRQ_HANDLED;
> +}
> +
> +int bcm_vk_open(struct inode *inode, struct file *p_file)
> +{
> +	struct bcm_vk_ctx *ctx;
> +	struct miscdevice *miscdev = (struct miscdevice *)p_file->private_data;
> +	struct bcm_vk *vk = container_of(miscdev, struct bcm_vk, miscdev);
> +	struct device *dev = &vk->pdev->dev;
> +	int    rc = 0;
> +
> +	/* get a context and set it up for file */
> +	ctx = bcm_vk_get_ctx(vk, current);
> +	if (!ctx) {
> +		dev_err(dev, "Error allocating context\n");
> +		rc = -ENOMEM;
> +	} else {
> +
> +		/*
> +		 * set up context and replace private data with context for
> +		 * other methods to use.  Reason for the context is because
> +		 * it is allowed for multiple sessions to open the sysfs, and
> +		 * for each file open, when upper layer query the response,
> +		 * only those that are tied to a specific open should be
> +		 * returned.  The context->idx will be used for such binding
> +		 */
> +		ctx->miscdev = miscdev;
> +		p_file->private_data = ctx;
> +		dev_dbg(dev, "ctx_returned with idx %d, pid %d\n",
> +			ctx->idx, task_pid_nr(ctx->ppid));
> +	}
> +	return rc;
> +}
> +
> +ssize_t bcm_vk_read(struct file *p_file, char __user *buf, size_t count,
> +			   loff_t *f_pos)
> +{
> +	ssize_t rc = -ENOMSG;
> +	struct bcm_vk_ctx *ctx = p_file->private_data;
> +	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk,
> +					 miscdev);
> +	struct device *dev = &vk->pdev->dev;
> +	struct bcm_vk_msg_chan *chan = &vk->vk2h_msg_chan;
> +	struct bcm_vk_wkent *entry = NULL;
> +	uint32_t q_num;
> +	uint32_t rsp_length;
> +	bool found = false;
> +
> +	if (!bcm_vk_drv_access_ok(vk))
> +		return -EPERM;
> +
> +	dev_dbg(dev, "Buf count %ld\n", count);
> +	found = false;
> +
> +	/*
> +	 * search through the pendq on the vk2h chan, and return only those
> +	 * that belongs to the same context.  Search is always from the high to
> +	 * the low priority queues
> +	 */
> +	spin_lock(&chan->pendq_lock);
> +	for (q_num = 0; q_num < chan->q_nr; q_num++) {
> +		list_for_each_entry(entry, &chan->pendq[q_num], node) {
> +			if (entry->ctx->idx == ctx->idx) {
> +				if (count >=
> +				    (entry->vk2h_blks * VK_MSGQ_BLK_SIZE)) {
> +					list_del(&entry->node);
> +					ctx->pend_cnt--;
> +					found = true;
> +				} else {
> +					/* buffer not big enough */
> +					rc = -EMSGSIZE;
> +				}
> +				goto bcm_vk_read_loop_exit;
> +			}
> +		}
> +	}
> + bcm_vk_read_loop_exit:
> +	spin_unlock(&chan->pendq_lock);
> +
> +	if (found) {
> +		/* retrieve the passed down msg_id */
> +		entry->vk2h_msg[0].msg_id = entry->usr_msg_id;
> +		rsp_length = entry->vk2h_blks * VK_MSGQ_BLK_SIZE;
> +		if (copy_to_user(buf, entry->vk2h_msg, rsp_length) == 0)
> +			rc = rsp_length;

The error code should be -EFAULT if this message fails (vs -ENOMSG).


> +
> +		bcm_vk_free_wkent(dev, entry);
> +	} else if (rc == -EMSGSIZE) {
> +		struct vk_msg_blk tmp_msg = entry->vk2h_msg[0];
> +
> +		/*
> +		 * in this case, return just the first block, so
> +		 * that app knows what size it is looking for.
> +		 */
> +		tmp_msg.msg_id = entry->usr_msg_id;
> +		tmp_msg.size = entry->vk2h_blks - 1;
> +		if (copy_to_user(buf, &tmp_msg, VK_MSGQ_BLK_SIZE) != 0) {
> +			dev_err(dev, "Error return 1st block in -EMSGSIZE\n");
> +			rc = -EFAULT;
> +		}
> +	}
> +	return rc;
> +}
> +
> +ssize_t bcm_vk_write(struct file *p_file, const char __user *buf,
> +			    size_t count, loff_t *f_pos)
> +{
> +	ssize_t rc = -EPERM;
> +	struct bcm_vk_ctx *ctx = p_file->private_data;
> +	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk,
> +					 miscdev);
> +	struct bcm_vk_msgq *msgq;
> +	struct device *dev = &vk->pdev->dev;
> +	struct bcm_vk_wkent *entry;
> +	uint32_t sgl_extra_blks;
> +
> +	if (!bcm_vk_drv_access_ok(vk))
> +		return -EPERM;
> +
> +	dev_dbg(dev, "Msg count %ld\n", count);
> +
> +	/* first, do sanity check where count should be multiple of basic blk */
> +	if (count & (VK_MSGQ_BLK_SIZE - 1)) {
> +		dev_err(dev, "Failure with size %ld not multiple of %ld\n",
> +			count, VK_MSGQ_BLK_SIZE);
> +		rc = -EBADR;

#define EBADR           53      /* Invalid request descriptor */

This should just be -EINVAL;


> +		goto bcm_vk_write_err;

These label names are too long.  They don't need the function prefix.

> +	}
> +
> +	/* allocate the work entry + buffer for size count and inband sgl */
> +	entry = kzalloc(sizeof(struct bcm_vk_wkent) + count + vk->ib_sgl_size,
> +			GFP_KERNEL);
> +	if (!entry) {
> +		rc = -ENOMEM;
> +		goto bcm_vk_write_err;
> +	}
> +
> +	/* now copy msg from user space, and then formulate the wk ent */
> +	if (copy_from_user(&entry->h2vk_msg[0], buf, count))
> +		goto bcm_vk_write_free_ent;

This is returning -EPERM instead of -EFAULT.

> +
> +	entry->h2vk_blks = count >> VK_MSGQ_BLK_SZ_SHIFT;
> +	entry->ctx = ctx;
> +
> +	/* do a check on the blk size which could not exceed queue space */
> +	msgq = vk->h2vk_msg_chan.msgq[entry->h2vk_msg[0].queue_id];
> +	if (entry->h2vk_blks + (vk->ib_sgl_size >> VK_MSGQ_BLK_SZ_SHIFT)
> +	    > (msgq->size - 1)) {
> +		dev_err(dev, "Blk size %d exceed max queue size allowed %d\n",
> +			entry->h2vk_blks, msgq->size - 1);
> +		rc = -EOVERFLOW;

This should probably just be -EINVAL as well.


> +		goto bcm_vk_write_free_ent;
> +	}
> +
> +	/* Use internal message id */
> +	entry->usr_msg_id = entry->h2vk_msg[0].msg_id;
> +	rc = bcm_vk_get_msg_id(vk);
> +	if (rc == VK_MSG_ID_OVERFLOW) {
> +		dev_err(dev, "msg_id overflow\n");
> +		rc = -EOVERFLOW;
> +		goto bcm_vk_write_free_ent;
> +	}
> +	entry->h2vk_msg[0].msg_id = rc;
> +
> +	dev_dbg(dev,
> +		"Message ctx id %d, usr_msg_id 0x%x sent msg_id 0x%x\n",
> +		ctx->idx, entry->usr_msg_id,
> +		entry->h2vk_msg[0].msg_id);
> +
> +	/* Convert any pointers to sg list */
> +	if (entry->h2vk_msg[0].function_id == VK_FID_TRANS_BUF) {
> +		unsigned int num_planes;
> +		int dir;
> +		struct _vk_data *data;
> +
> +		/*
> +		 * check if we are in reset, if so, no buffer transfer is
> +		 * allowed and return error.
> +		 */
> +		if (vk->reset_ppid) {
> +			dev_dbg(dev, "No Transfer allowed during reset, pid %d.\n",
> +				task_pid_nr(ctx->ppid));
> +			rc = -EACCES;
> +			goto bcm_vk_write_free_msgid;
> +		}
> +
> +		num_planes = entry->h2vk_msg[0].args[0] & VK_CMD_PLANES_MASK;
> +		if ((entry->h2vk_msg[0].args[0] & VK_CMD_MASK)
> +		    == VK_CMD_DOWNLOAD) {
> +			/* Memory transfer from vk device */

There are a bunch of pretty obvious comments that should just be
deleted.

> +			dir = DMA_FROM_DEVICE;
> +		} else {
> +			/* Memory transfer to vk device */
> +			dir = DMA_TO_DEVICE;
> +		}
> +
> +		/* Calculate vk_data location */
> +		/* Go to end of the message */
> +		data = (struct _vk_data *)
> +			&(entry->h2vk_msg[entry->h2vk_msg[0].size + 1]);
> +		/* Now back up to the start of the pointers */
> +		data -= num_planes;
> +
> +		/* Convert user addresses to DMA SG List */
> +		rc = bcm_vk_sg_alloc(dev, entry->dma, dir, data, num_planes);
> +		if (rc)
> +			goto bcm_vk_write_free_msgid;
> +
> +		/* try to embed inband sgl */
> +		sgl_extra_blks = bcm_vk_append_ib_sgl(vk, entry, data,
> +						      num_planes);
> +		entry->h2vk_blks += sgl_extra_blks;
> +		entry->h2vk_msg[0].size += sgl_extra_blks;
> +	}
> +
> +	/*
> +	 * store wk ent to pending queue until a response is got. This needs to
                 ^^
vk?

> +	 * be done before enqueuing the message
> +	 */
> +	bcm_vk_append_pendq(&vk->h2vk_msg_chan, entry->h2vk_msg[0].queue_id,
> +			    entry);
> +
> +	rc = bcm_h2vk_msg_enqueue(vk, entry);
> +	if (rc) {
> +		dev_err(dev, "Fail to enqueue msg to h2vk queue\n");
> +
> +		/* remove message from pending list */
> +		entry = bcm_vk_find_pending(vk,
> +					    &vk->h2vk_msg_chan,
> +					    entry->h2vk_msg[0].queue_id,
> +					    entry->h2vk_msg[0].msg_id);


Can bcm_vk_find_pending() return NULL here (leading to an Oops when we
do entry->h2vk_msg[0].msg_id and why can't we just use the previous
value of entry?  The comment doesn't help me.

> +		goto bcm_vk_write_free_ent;
> +	}
> +
> +	return count;
> +
> +bcm_vk_write_free_msgid:
> +	bcm_vk_msgid_bitmap_clear(vk, entry->h2vk_msg[0].msg_id, 1);
> +bcm_vk_write_free_ent:
> +	kfree(entry);
> +bcm_vk_write_err:
> +	return rc;
> +}
> +
> +int bcm_vk_release(struct inode *inode, struct file *p_file)
> +{
> +	int ret;
> +	struct bcm_vk_ctx *ctx = p_file->private_data;
> +	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
> +	struct device *dev = &vk->pdev->dev;
> +	struct task_struct *ppid = ctx->ppid;
> +	pid_t pid = task_pid_nr(ppid);
> +
> +	dev_dbg(dev, "Draining with context idx %d pid %d\n",
> +		ctx->idx, pid);
> +
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->h2vk_msg_chan, ctx);
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->vk2h_msg_chan, ctx);
> +
> +	ret = bcm_vk_free_ctx(vk, ctx);

This returns a positive number.

> +	if (ret == 0)
> +		ret = bcm_vk_handle_last_sess(vk, ppid);
> +
> +	/* free memory if it is the last reference */
> +	kref_put(&vk->kref, bcm_vk_release_data);
> +
> +	return ret;

Which we propogate to here.  Probably this should just be "return 0;".

> +}
> +
> +int bcm_vk_msg_init(struct bcm_vk *vk)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +	int err = 0;
> +
> +	if (bcm_vk_data_init(vk)) {
> +		dev_err(dev, "Error initializing internal data structures\n");
> +		err = -EINVAL;
> +		goto err_out;
> +	}
> +
> +	if (bcm_vk_msg_chan_init(&vk->h2vk_msg_chan) ||
> +	    bcm_vk_msg_chan_init(&vk->vk2h_msg_chan)) {
> +		dev_err(dev, "Error initializing communication channel\n");
> +		err = -EIO;
> +		goto err_out;
> +	}
> +
> +	/* create dedicated workqueue */
> +	vk->wq_thread = create_singlethread_workqueue(vk->miscdev.name);
> +	if (!vk->wq_thread) {
> +		dev_err(dev, "Fail to create workqueue thread\n");
> +		err = -ENOMEM;
> +		goto err_out;
> +	}
> +
> +	/* read msgq info */
> +	if (bcm_vk_sync_msgq(vk, false)) {
> +		dev_err(dev, "Error reading comm msg Q info\n");
> +		err = -EIO;
> +		goto err_out;
> +	}
> +
> +err_out:
> +	return err;

This should probably clean up the work queue on error?

> +}
> +
> +void bcm_vk_msg_remove(struct bcm_vk *vk)
> +{
> +	bcm_vk_blk_drv_access(vk);
> +
> +	/* drain all pending items */
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->h2vk_msg_chan, NULL);
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->vk2h_msg_chan, NULL);
> +}
> +
> +void bcm_vk_trigger_reset(struct bcm_vk *vk)
> +{
> +	uint32_t i;
> +	u32 value;
> +
> +	/* clean up before pressing the door bell */
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->h2vk_msg_chan, NULL);
> +	bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->vk2h_msg_chan, NULL);
> +	vkwrite32(vk, 0, BAR_1, VK_BAR1_MSGQ_DEF_RDY);
> +	/* make tag '\0' terminated */
> +	vkwrite32(vk, 0, BAR_1, VK_BAR1_BOOT1_VER_TAG);
> +
> +	for (i = 0; i < VK_BAR1_DAUTH_MAX; i++) {
> +		vkwrite32(vk, 0, BAR_1, VK_BAR1_DAUTH_STORE_ADDR(i));
> +		vkwrite32(vk, 0, BAR_1, VK_BAR1_DAUTH_VALID_ADDR(i));
> +	}
> +	for (i = 0; i < VK_BAR1_SOTP_REVID_MAX; i++)
> +		vkwrite32(vk, 0, BAR_1, VK_BAR1_SOTP_REVID_ADDR(i));
> +
> +	memset(&vk->card_info, 0, sizeof(vk->card_info));
> +	memset(&vk->alert_cnts, 0, sizeof(vk->alert_cnts));
> +
> +	/*
> +	 * When boot request fails, the CODE_PUSH_OFFSET stays persistent.
> +	 * Allowing us to debug the failure. When we call reset,
> +	 * we should clear CODE_PUSH_OFFSET so ROM does not execute
> +	 * boot again (and fails again) and instead waits for a new
> +	 * codepush.
> +	 */
> +	value = vkread32(vk, BAR_0, BAR_CODEPUSH_SBL);
> +	value &= ~CODEPUSH_MASK;
> +	vkwrite32(vk, value, BAR_0, BAR_CODEPUSH_SBL);
> +
> +	/* reset fw_status with proper reason, and press db */
> +	vkwrite32(vk, VK_FWSTS_RESET_MBOX_DB, BAR_0, VK_BAR_FWSTS);
> +	bcm_h2vk_doorbell(vk, VK_BAR0_RESET_DB_NUM, VK_BAR0_RESET_DB_SOFT);
> +
> +	/* clear the uptime register after reset pressed and alert record */
> +	vkwrite32(vk, 0, BAR_0, BAR_OS_UPTIME);
> +	memset(&vk->host_alert, 0, sizeof(vk->host_alert));
> +	memset(&vk->peer_alert, 0, sizeof(vk->peer_alert));
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +	/* clear qstats */
> +	for (i = 0; i < VK_MSGQ_MAX_NR; i++) {
> +		memset(&vk->h2vk_msg_chan.qstats[i].qcnts, 0,
> +		       sizeof(vk->h2vk_msg_chan.qstats[i].qcnts));
> +		memset(&vk->vk2h_msg_chan.qstats[i].qcnts, 0,
> +		       sizeof(vk->vk2h_msg_chan.qstats[i].qcnts));
> +	}
> +#endif
> +	/* clear 4096 bits of bitmap */
> +	bitmap_clear(vk->bmap, 0, VK_MSG_ID_BITMAP_SIZE);
> +}
> diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.h b/drivers/misc/bcm-vk/bcm_vk_msg.h
> new file mode 100644
> index 000000000000..076307b2f1c4
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_msg.h
> @@ -0,0 +1,210 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#ifndef BCM_VK_MSG_H
> +#define BCM_VK_MSG_H
> +
> +#include <uapi/linux/misc/bcm_vk.h>
> +#include "bcm_vk_sg.h"
> +
> +/* Single message queue control structure */
> +struct bcm_vk_msgq {
> +	uint16_t type;	/* queue type */
> +	uint16_t num;	/* queue number */
> +	uint32_t start;	/* offset in BAR1 where the queue memory starts */
> +	volatile uint32_t rd_idx; /* read idx */
> +	volatile uint32_t wr_idx; /* write idx */
> +	uint32_t size;	/*
> +			 * size, which is in number of 16byte blocks,
> +			 * to align with the message data structure.
> +			 */
> +	uint32_t nxt;	/*
> +			 * nxt offset to the next msg queue struct.
> +			 * This is to provide flexibity for alignment purposes.
> +			 */
> +};
> +
> +/*
> + * Structure to record static info from the msgq sync.  We keep local copy
> + * for some of these variables for both performance + checking purpose.
> + */
> +struct bcm_vk_sync_qinfo {
> +	void __iomem *q_start;
> +	uint32_t q_size;
> +	uint32_t q_mask;
> +	uint32_t q_low;
> +};
> +
> +#define VK_MSGQ_MAX_NR 4 /* Maximum number of message queues */
> +
> +/*
> + * some useful message queue macros
> + */
> +
> +/* vk_msg_blk is 16 bytes fixed */
> +#define VK_MSGQ_BLK_SIZE   (sizeof(struct vk_msg_blk))
> +/* shift for fast division of basic msg blk size */
> +#define VK_MSGQ_BLK_SZ_SHIFT 4
> +
> +#define VK_MSGQ_EMPTY(_msgq) ((_msgq)->rd_idx == (_msgq)->wr_idx)
> +
> +#define VK_MSGQ_SIZE_MASK(_qinfo) ((_qinfo)->q_mask)
> +
> +#define VK_MSGQ_INC(_qinfo, _idx, _inc) \
> +	(((_idx) + (_inc)) & VK_MSGQ_SIZE_MASK(_qinfo))
> +
> +#define VK_MSGQ_BLK_ADDR(_qinfo, _idx) \
> +	(volatile struct vk_msg_blk *)((_qinfo)->q_start + \
> +				       (VK_MSGQ_BLK_SIZE * (_idx)))
> +
> +#define VK_MSGQ_OCCUPIED(_msgq, _qinfo) \
> +	(((_msgq)->wr_idx - (_msgq)->rd_idx) & VK_MSGQ_SIZE_MASK(_qinfo))
> +
> +#define VK_MSGQ_AVAIL_SPACE(_msgq, _qinfo) \
> +	((_qinfo)->q_size - VK_MSGQ_OCCUPIED(_msgq, _qinfo) - 1)
> +
> +/* context per session opening of sysfs */
> +struct bcm_vk_ctx {
> +	struct list_head node; /* use for linkage in Hash Table */
> +	uint idx;
> +	bool in_use;
> +	struct task_struct *ppid;
> +	uint32_t hash_idx;
> +	struct miscdevice *miscdev;
> +	int pend_cnt; /* number of items pending to be read from host */
> +};
> +
> +/* pid hash table entry */
> +struct bcm_vk_ht_entry {
> +	struct list_head head;
> +};
> +
> +#define VK_DMA_MAX_ADDRS 4 /* Max 4 DMA Addresses */
> +/* structure for house keeping a single work entry */
> +struct bcm_vk_wkent {
> +
> +	struct list_head node; /* for linking purpose */
> +	struct bcm_vk_ctx *ctx;
> +
> +	/* Store up to 4 dma pointers */
> +	struct bcm_vk_dma dma[VK_DMA_MAX_ADDRS];
> +
> +	uint32_t vk2h_blks; /* response */
> +	struct vk_msg_blk *vk2h_msg;
> +
> +	/*
> +	 * put the h2vk_msg at the end so that we could simply append h2vk msg
> +	 * to the end of the allocated block
> +	 */
> +	uint32_t usr_msg_id;
> +	uint32_t h2vk_blks;
> +	uint32_t seq_num;
> +	struct vk_msg_blk h2vk_msg[0];
> +};
> +
> +/* queue stats counters */
> +struct bcm_vk_qs_cnts {
> +	uint32_t cnt; /* general counter, used to limit output */
> +	uint32_t acc_sum;
> +	uint32_t max_occ; /* max during a sampling period */
> +	uint32_t max_abs; /* the abs max since reset */
> +};
> +
> +/* stats structure */
> +struct bcm_vk_qstats {
> +	uint32_t q_num;
> +	struct bcm_vk_qs_cnts qcnts;
> +};
> +
> +/* control channel structure for either h2vk or vk2h communication */
> +struct bcm_vk_msg_chan {
> +	uint32_t q_nr;
> +	struct mutex msgq_mutex;
> +	/* pointing to BAR locations */
> +	struct bcm_vk_msgq *msgq[VK_MSGQ_MAX_NR];
> +
> +	spinlock_t pendq_lock;
> +	/* for temporary storing pending items, one for each queue */
> +	struct list_head pendq[VK_MSGQ_MAX_NR];
> +	/* static queue info from the sync */
> +	struct bcm_vk_sync_qinfo sync_qinfo[VK_MSGQ_MAX_NR];
> +#if defined(CONFIG_BCM_VK_QSTATS)
> +	/* qstats */
> +	struct bcm_vk_qstats qstats[VK_MSGQ_MAX_NR];
> +#endif
> +};
> +
> +/* total number of supported ctx, 32 ctx each for 5 components */
> +#define VK_CMPT_CTX_MAX		(32 * 5)
> +
> +/* hash table defines to store the opened FDs */
> +#define VK_PID_HT_SHIFT_BIT	7 /* 128 */
> +#define VK_PID_HT_SZ		(1 << VK_PID_HT_SHIFT_BIT)
> +
> +/* The following are offsets of DDR info provided by the vk card */
> +#define VK_BAR0_SEG_SIZE	(4 * SZ_1K) /* segment size for BAR0 */
> +
> +/* shutdown types supported */
> +#define VK_SHUTDOWN_PID		1
> +#define VK_SHUTDOWN_GRACEFUL	2
> +
> +/*
> + * first door bell reg, ie for queue = 0.  Only need the first one, as
> + * we will use the queue number to derive the others
> + */
> +#define VK_BAR0_REGSEG_DB_BASE		0x484
> +#define VK_BAR0_REGSEG_DB_REG_GAP	8 /*
> +					   * DB register gap,
> +					   * DB1 at 0x48c and DB2 at 0x494
> +					   */
> +
> +/* reset register and specific values */
> +#define VK_BAR0_RESET_DB_NUM		3
> +#define VK_BAR0_RESET_DB_SOFT		0xFFFFFFFF
> +#define VK_BAR0_RESET_DB_HARD		0xFFFFFFFD
> +
> +/* BAR1 message q definition */
> +
> +/* indicate if msgq ctrl in BAR1 is populated */
> +#define VK_BAR1_MSGQ_DEF_RDY		0x60c0
> +/* ready marker value for the above location, normal boot2 */
> +#define VK_BAR1_MSGQ_RDY_MARKER		0xbeefcafe
> +/* ready marker value for the above location, normal boot2 */
> +#define VK_BAR1_DIAG_RDY_MARKER		0xdeadcafe
> +/* number of msgqs in BAR1 */
> +#define VK_BAR1_MSGQ_NR			0x60c4
> +/* BAR1 queue control structure offset */
> +#define VK_BAR1_MSGQ_CTRL_OFF		0x60c8
> +/* BAR1 ucode and boot1 version tag */
> +#define VK_BAR1_UCODE_VER_TAG		0x6170
> +#define VK_BAR1_BOOT1_VER_TAG		0x61b0
> +#define VK_BAR1_VER_TAG_SIZE		64
> +/* Memory to hold the DMA buffer memory address allocated for boot2 download */
> +#define VK_BAR1_DMA_BUF_OFF_HI		0x61e0
> +#define VK_BAR1_DMA_BUF_OFF_LO		(VK_BAR1_DMA_BUF_OFF_HI + 4)
> +#define VK_BAR1_DMA_BUF_SZ		(VK_BAR1_DMA_BUF_OFF_HI + 8)
> +/* Scratch memory allocated on host for VK */
> +#define VK_BAR1_SCRATCH_OFF_LO		0x61f0
> +#define VK_BAR1_SCRATCH_OFF_HI		(VK_BAR1_SCRATCH_OFF_LO + 4)
> +#define VK_BAR1_SCRATCH_SZ_ADDR		(VK_BAR1_SCRATCH_OFF_LO + 8)
> +#define VK_BAR1_SCRATCH_DEF_NR_PAGES	32
> +  /* BAR1 SOTP AUTH and REVID info */
> +#define VK_BAR1_DAUTH_BASE_ADDR		0x6200
> +#define VK_BAR1_DAUTH_STORE_SIZE	0x48
> +#define VK_BAR1_DAUTH_VALID_SIZE	0x8
> +#define VK_BAR1_DAUTH_MAX		4
> +#define VK_BAR1_DAUTH_STORE_ADDR(x) \
> +		(VK_BAR1_DAUTH_BASE_ADDR + \
> +		 (x) * (VK_BAR1_DAUTH_STORE_SIZE + VK_BAR1_DAUTH_VALID_SIZE))
> +#define VK_BAR1_DAUTH_VALID_ADDR(x) \
> +		(VK_BAR1_DAUTH_STORE_ADDR(x) + VK_BAR1_DAUTH_STORE_SIZE)
> +
> +#define VK_BAR1_SOTP_REVID_BASE_ADDR	0x6340
> +#define VK_BAR1_SOTP_REVID_SIZE		0x10
> +#define VK_BAR1_SOTP_REVID_MAX		2
> +#define VK_BAR1_SOTP_REVID_ADDR(x) \
> +		(VK_BAR1_SOTP_REVID_BASE_ADDR + (x) * VK_BAR1_SOTP_REVID_SIZE)
> +
> +#endif
> diff --git a/drivers/misc/bcm-vk/bcm_vk_sg.c b/drivers/misc/bcm-vk/bcm_vk_sg.c
> new file mode 100644
> index 000000000000..e5de07958f0b
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_sg.c
> @@ -0,0 +1,273 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +#include <linux/dma-mapping.h>
> +#include <linux/mm.h>
> +#include <linux/pagemap.h>
> +#include <linux/vmalloc.h>
> +
> +#include <asm/page.h>
> +#include <asm/pgtable.h>
> +#include <asm/unaligned.h>
> +
> +#include <uapi/linux/misc/bcm_vk.h>
> +
> +#include "bcm_vk.h"
> +#include "bcm_vk_msg.h"
> +#include "bcm_vk_sg.h"
> +
> +/*
> + * Valkyrie has a hardware limitation of 16M transfer size.
> + * So limit the SGL chunks to 16M.
> + */
> +#define BCM_VK_MAX_SGL_CHUNK SZ_16M
> +
> +static int bcm_vk_dma_alloc(struct device *dev,
> +			    struct bcm_vk_dma *dma,
> +			    int dir,
> +			    struct _vk_data *vkdata);
> +static int bcm_vk_dma_free(struct device *dev, struct bcm_vk_dma *dma);
> +
> +/* Uncomment to dump SGLIST */
> +//#define BCM_VK_DUMP_SGLIST
> +
> +static int bcm_vk_dma_alloc(struct device *dev,
> +			    struct bcm_vk_dma *dma,
> +			    int direction,
> +			    struct _vk_data *vkdata)
> +{
> +	dma_addr_t addr, sg_addr;
> +	int err;
> +	int i;
> +	int offset;
> +	uint32_t size;
> +	uint32_t remaining_size;
> +	uint32_t transfer_size;
> +	uint64_t data;
> +	unsigned long first, last;
> +	struct _vk_data *sgdata;
> +
> +	/* Get 64-bit user address */
> +	data = get_unaligned(&(vkdata->address));

Extra parens.

> +
> +	/* offset into first page */
> +	offset = offset_in_page(data);
> +
> +	/* Calculate number of pages */
> +	first = (data & PAGE_MASK) >> PAGE_SHIFT;
> +	last  = ((data + vkdata->size - 1) & PAGE_MASK) >> PAGE_SHIFT;
> +	dma->nr_pages = last - first + 1;
> +
> +	/* Allocate DMA pages */
> +	dma->pages = kmalloc_array(dma->nr_pages,
> +				   sizeof(struct page *),
> +				   GFP_KERNEL);
> +	if (dma->pages == NULL)
> +		return -ENOMEM;
> +
> +	dev_dbg(dev, "Alloc DMA Pages [0x%llx+0x%x => %d pages]\n",
> +		data, vkdata->size, dma->nr_pages);
> +
> +	dma->direction = direction;
> +
> +	/* Get user pages into memory */
> +	err = get_user_pages_fast(data & PAGE_MASK,
> +				  dma->nr_pages,
> +				  direction == DMA_FROM_DEVICE,
> +				  dma->pages);
> +	if (err != dma->nr_pages) {
> +		dma->nr_pages = (err >= 0) ? err : 0;
> +		dev_err(dev, "get_user_pages_fast, err=%d [%d]\n",
> +			err, dma->nr_pages);
> +		return err < 0 ? err : -EINVAL;
> +	}
> +
> +	/* Max size of sg list is 1 per mapped page + fields at start */
> +	dma->sglen = (dma->nr_pages * sizeof(*sgdata)) +
> +		     (sizeof(uint32_t) * SGLIST_VKDATA_START);
> +
> +	/* Allocate sglist */
> +	dma->sglist = dma_alloc_coherent(dev,
> +					 dma->sglen,
> +					 &dma->handle,
> +					 GFP_KERNEL);


	dma->sglist = dma_alloc_coherent(dev, dma->sglen, &dma->handle,
					 GFP_KERNEL);



> +	if (!dma->sglist)
> +		return -ENOMEM;

No cleanup?

> +
> +	dma->sglist[SGLIST_NUM_SG] = 0;
> +	dma->sglist[SGLIST_TOTALSIZE] = vkdata->size;
> +	remaining_size = vkdata->size;
> +	sgdata = (struct _vk_data *)&(dma->sglist[SGLIST_VKDATA_START]);
> +
> +	/* Map all pages into DMA */
> +	i = 0;

Set but not used.

> +	size = min_t(size_t, PAGE_SIZE - offset, remaining_size);
> +	remaining_size -= size;
> +	sg_addr = dma_map_page(dev,
> +			       dma->pages[0],
> +			       offset,
> +			       size,
> +			       dma->direction);
> +	transfer_size = size;
> +	if (unlikely(dma_mapping_error(dev, sg_addr))) {
> +		__free_page(dma->pages[0]);
> +		return -EIO;
> +	}
> +
> +	for (i = 1; i < dma->nr_pages; i++) {
> +		size = min_t(size_t, PAGE_SIZE, remaining_size);
> +		remaining_size -= size;
> +		addr = dma_map_page(dev,
> +				    dma->pages[i],
> +				    0,
> +				    size,
> +				    dma->direction);
> +		if (unlikely(dma_mapping_error(dev, addr))) {
> +			__free_page(dma->pages[i]);
> +			return -EIO;
> +		}
> +
> +		/*
> +		 * Compress SG list entry when pages are contiguous
> +		 * and transfer size less or equal to BCM_VK_MAX_SGL_CHUNK
> +		 */
> +		if ((addr == (sg_addr + transfer_size)) &&
> +		    ((transfer_size + size) <= BCM_VK_MAX_SGL_CHUNK)) {
> +			/* pages are contiguous, add to same sg entry */
> +			transfer_size += size;
> +		} else {
> +			/* pages are not contiguous, write sg entry */
> +			sgdata->size = transfer_size;
> +			put_unaligned(sg_addr, (uint64_t *)&(sgdata->address));
> +			dma->sglist[SGLIST_NUM_SG]++;
> +
> +			/* start new sg entry */
> +			sgdata++;
> +			sg_addr = addr;
> +			transfer_size = size;
> +		}
> +	}
> +	/* Write last sg list entry */
> +	sgdata->size = transfer_size;
> +	put_unaligned(sg_addr, (uint64_t *)&(sgdata->address));
> +	dma->sglist[SGLIST_NUM_SG]++;
> +
> +	/* Update pointers and size field to point to sglist */
> +	put_unaligned((uint64_t)dma->handle, &(vkdata->address));
> +	vkdata->size = (dma->sglist[SGLIST_NUM_SG] * sizeof(*sgdata)) +
> +		       (sizeof(uint32_t) * SGLIST_VKDATA_START);
> +
> +#ifdef BCM_VK_DUMP_SGLIST
> +	dev_dbg(dev,
> +		"sgl 0x%llx handle 0x%llx, sglen: 0x%x sgsize: 0x%x\n",
> +		(uint64_t)dma->sglist,
> +		dma->handle,
> +		dma->sglen,
> +		vkdata->size);
> +	for (i = 0; i < vkdata->size / sizeof(uint32_t); i++)
> +		dev_dbg(dev, "i:0x%x 0x%x\n", i, dma->sglist[i]);
> +#endif
> +
> +	return 0;
> +}
> +
> +int bcm_vk_sg_alloc(struct device *dev,
> +		    struct bcm_vk_dma *dma,
> +		    int dir,
> +		    struct _vk_data *vkdata,
> +		    int num)
> +{
> +	int i;
> +	int rc = -EINVAL;
> +
> +	/* Convert user addresses to DMA SG List */
> +	for (i = 0; i < num; i++) {
> +		if (vkdata[i].size && vkdata[i].address) {
> +			/*
> +			 * If both size and address are non-zero
> +			 * then DMA alloc.
> +			 */
> +			rc = bcm_vk_dma_alloc(dev,
> +					      &dma[i],
> +					      dir,
> +					      &vkdata[i]);
> +		} else if (vkdata[i].size ||
> +			   vkdata[i].address) {
> +			/*
> +			 * If one of size and address are zero
> +			 * there is a problem.
> +			 */
> +			dev_err(dev,
> +				"Invalid vkdata %x 0x%x 0x%llx\n",
> +				i, vkdata[i].size, vkdata[i].address);
> +			rc = -EINVAL;
> +		} else {
> +			/*
> +			 * If size and address are both zero
> +			 * don't convert, but return success.
> +			 */
> +			rc = 0;
> +		}
> +
> +		if (rc)
> +			goto fail_alloc;
> +	}
> +	return rc;
> +
> +fail_alloc:
> +	while (i > 0) {
> +		i--;
> +		if (dma[i].sglist)
> +			bcm_vk_dma_free(dev, &dma[i]);
> +	}
> +	return rc;
> +}
> +
> +static int bcm_vk_dma_free(struct device *dev, struct bcm_vk_dma *dma)
> +{
> +	dma_addr_t addr;
> +	int i;
> +	int num_sg;
> +	uint32_t size;
> +	struct _vk_data *vkdata;
> +
> +	dev_dbg(dev, "free sglist=%p sglen=0x%x\n",
> +		dma->sglist, dma->sglen);
> +

This fits in 80 characters.

	dev_dbg(dev, "free sglist=%p sglen=0x%x\n", dma->sglist, dma->sglen);


> +	/* Unmap all pages in the sglist */
> +	num_sg = dma->sglist[SGLIST_NUM_SG];
> +	vkdata = (struct _vk_data *)&(dma->sglist[SGLIST_VKDATA_START]);

Extra parens.

> +	for (i = 0; i < num_sg; i++) {
> +		size = vkdata[i].size;
> +		addr = get_unaligned(&(vkdata[i].address));
> +
> +		dma_unmap_page(dev, addr, size, dma->direction);
> +	}
> +
> +	/* Free allocated sglist */
> +	dma_free_coherent(dev, dma->sglen, dma->sglist, dma->handle);
> +
> +	/* Release lock on all pages */
> +	for (i = 0; i < dma->nr_pages; i++)
> +		put_page(dma->pages[i]);
> +
> +	/* Free allocated dma pages */
> +	kfree(dma->pages);
> +	dma->sglist = NULL;
> +
> +	return 0;
> +}
> +
> +int bcm_vk_sg_free(struct device *dev, struct bcm_vk_dma *dma, int num)
> +{
> +	int i;
> +
> +	/* Unmap and free all pages and sglists */
> +	for (i = 0; i < num; i++) {
> +		if (dma[i].sglist)
> +			bcm_vk_dma_free(dev, &dma[i]);
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/misc/bcm-vk/bcm_vk_sg.h b/drivers/misc/bcm-vk/bcm_vk_sg.h
> new file mode 100644
> index 000000000000..df88154e80b7
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_sg.h
> @@ -0,0 +1,60 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#ifndef BCM_VK_SG_H
> +#define BCM_VK_SG_H
> +
> +#include <linux/dma-mapping.h>
> +
> +struct bcm_vk_dma {
> +	/* for userland buffer */
> +	struct page **pages;
> +	int nr_pages;
> +
> +	/* common */
> +	dma_addr_t handle;
> +	/*
> +	 * sglist is of the following LE format
> +	 * [U32] num_sg  = number of sg addresses (N)
> +	 * [U32] totalsize = totalsize of data being transferred in sglist
> +	 * [U32] size[0] = size of data in address0
> +	 * [U32] addr_l[0] = lower 32-bits of address0
> +	 * [U32] addr_h[0] = higher 32-bits of address0
> +	 * ..
> +	 * [U32] size[N-1] = size of data in addressN-1
> +	 * [U32] addr_l[N-1] = lower 32-bits of addressN-1
> +	 * [U32] addr_h[N-1] = higher 32-bits of addressN-1
> +	 */
> +	uint32_t *sglist;
> +#define SGLIST_NUM_SG		0
> +#define SGLIST_TOTALSIZE	1
> +#define SGLIST_VKDATA_START	2
> +
> +	int sglen; /* Length (bytes) of sglist */
> +	int direction;
> +};
> +
> +struct _vk_data {
> +	uint32_t size;    /* data size in bytes */
> +	uint64_t address; /* Pointer to data     */
> +} __packed;
> +
> +/*
> + * Scatter-gather DMA buffer API.
> + *
> + * These functions provide a simple way to create a page list and a
> + * scatter-gather list from userspace address and map the memory
> + * for DMA operation.
> + */
> +int bcm_vk_sg_alloc(struct device *dev,
> +		    struct bcm_vk_dma *dma,
> +		    int dir,
> +		    struct _vk_data *vkdata,
> +		    int num);
> +
> +int bcm_vk_sg_free(struct device *dev, struct bcm_vk_dma *dma, int num);
> +
> +#endif
> +
> diff --git a/drivers/misc/bcm-vk/bcm_vk_tty.c b/drivers/misc/bcm-vk/bcm_vk_tty.c
> new file mode 100644
> index 000000000000..3835218aaec6
> --- /dev/null
> +++ b/drivers/misc/bcm-vk/bcm_vk_tty.c
> @@ -0,0 +1,327 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2020 Broadcom.
> + */
> +
> +#include <linux/tty.h>
> +#include <linux/tty_driver.h>
> +#include <linux/tty_flip.h>
> +
> +#include "bcm_vk.h"
> +
> +/* TTYVK base offset is 0x30000 into BAR1 */
> +#define BAR1_TTYVK_BASE_OFFSET	0x300000
> +/* Each TTYVK channel (TO or FROM) is 0x10000 */
> +#define BAR1_TTYVK_CHAN_OFFSET	0x100000
> +/* Each TTYVK channel has TO and FROM, hence the * 2 */
> +#define BAR1_TTYVK_BASE(index)	(BAR1_TTYVK_BASE_OFFSET + \
> +				 ((index) * BAR1_TTYVK_CHAN_OFFSET * 2))
> +/* TO TTYVK channel base comes before FROM for each index */
> +#define TO_TTYK_BASE(index)	BAR1_TTYVK_BASE(index)
> +#define FROM_TTYK_BASE(index)	(BAR1_TTYVK_BASE(index) + \
> +				 BAR1_TTYVK_CHAN_OFFSET)
> +
> +struct bcm_vk_tty_chan {
> +	uint32_t reserved;
> +	uint32_t size;
> +	uint32_t wr;
> +	uint32_t rd;
> +	uint32_t *data;
> +};
> +
> +#define VK_BAR_CHAN(v, DIR, e)	((v)->DIR##_offset \
> +				 + offsetof(struct bcm_vk_tty_chan, e))
> +#define VK_BAR_CHAN_SIZE(v, DIR)	VK_BAR_CHAN(v, DIR, size)
> +#define VK_BAR_CHAN_WR(v, DIR)		VK_BAR_CHAN(v, DIR, wr)
> +#define VK_BAR_CHAN_RD(v, DIR)		VK_BAR_CHAN(v, DIR, rd)
> +#define VK_BAR_CHAN_DATA(v, DIR, off)	(VK_BAR_CHAN(v, DIR, data) + off)
> +
> +/* Poll every 1/10 of second - temp hack till we use MSI interrupt */
> +#define SERIAL_TIMER_VALUE (HZ / 10)
> +
> +#if defined(BCM_VK_LEGACY_API)
> +
> +/* No support in legacy case, and do a dummy init and exit */
> +int bcm_vk_tty_init(struct bcm_vk *vk, char *name)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +
> +	dev_dbg(dev, "init %s\n", name);
> +	return 0;
> +}
> +
> +void bcm_vk_tty_exit(struct bcm_vk *vk)
> +{
> +	struct device *dev = &vk->pdev->dev;
> +
> +	dev_dbg(dev, "exit\n");
> +}
> +
> +#else
> +
> +static void bcm_vk_tty_poll(struct timer_list *t)
> +{
> +	struct bcm_vk *vk = from_timer(vk, t, serial_timer);
> +	struct bcm_vk_tty *vktty;
> +	int card_status;
> +	int ready_mask;
> +	int count = 0;
> +	unsigned char c;
> +	int i;
> +	int wr;
> +
> +	card_status = vkread32(vk, BAR_0, BAR_CARD_STATUS);
> +
> +	for (i = 0; i < BCM_VK_NUM_TTY; i++) {
> +		/* Check the card status that the tty channel is ready */
> +		ready_mask = BIT(i);
> +		if ((card_status & ready_mask) == 0)

Get rid of ready_mask and use BIT(i) directly.

> +			continue;
> +
> +		vktty = &vk->tty[i];
> +
> +		/* Fetch the wr offset in buffer from VK */
> +		wr = vkread32(vk, BAR_1, VK_BAR_CHAN_WR(vktty, from));
> +		if (wr >= vktty->from_size) {
> +			dev_err(&vk->pdev->dev,
> +				"ERROR: poll ttyVK%d wr:0x%x > 0x%x\n",
> +				i, wr, vktty->from_size);
> +			/* Need to signal and close device in this case */
> +			return;
> +		}
> +
> +		/*
> +		 * Simple read of circular buffer and
> +		 * insert into tty flip buffer
> +		 */
> +		while (vk->tty[i].rd != wr) {
> +			c = vkread8(vk, BAR_1,
> +				    VK_BAR_CHAN_DATA(vktty, from, vktty->rd));
> +			vktty->rd++;
> +			if (vktty->rd >= vktty->from_size)
> +				vktty->rd = 0;
> +			tty_insert_flip_char(&vktty->port, c, TTY_NORMAL);
> +			count++;
> +		}
> +	}
> +
> +	if (count) {
> +		tty_flip_buffer_push(&vktty->port);
> +
> +		/* Update read offset from shadow register to card */
> +		vkwrite32(vk, vktty->rd, BAR_1, VK_BAR_CHAN_RD(vktty, from));
> +	}
> +
> +	mod_timer(&vk->serial_timer, jiffies + SERIAL_TIMER_VALUE);
> +}
> +
> +static int bcm_vk_tty_open(struct tty_struct *tty, struct file *file)
> +{
> +	int card_status;
> +	int ready_mask;
> +	struct bcm_vk *vk;
> +	struct bcm_vk_tty *vktty;
> +	int index;
> +
> +	/* initialize the pointer in case something fails */
> +	tty->driver_data = NULL;
> +
> +	vk = (struct bcm_vk *)dev_get_drvdata(tty->dev);
> +	index = tty->index;
> +
> +	if (index >= BCM_VK_NUM_TTY)
> +		return -EINVAL;
> +
> +	vktty = &vk->tty[index];
> +
> +	vktty->to_offset = TO_TTYK_BASE(index);
> +	vktty->from_offset = FROM_TTYK_BASE(index);
> +
> +	/* Do not allow tty device to be opened if tty on card not ready */
> +	card_status = vkread32(vk, BAR_0, BAR_CARD_STATUS);
> +	if (card_status == -1)
> +		return -1;
> +
> +	ready_mask = BIT(index);
> +	if ((card_status & ready_mask) == 0)
> +		return -1;
> +
> +	/*
> +	 * Get shadow registers of the buffer sizes and the "to" write offset
> +	 * and "from" read offset
> +	 */
> +	vktty->to_size = vkread32(vk, BAR_1, VK_BAR_CHAN_SIZE(vktty, to));
> +	vktty->wr = vkread32(vk, BAR_1,  VK_BAR_CHAN_WR(vktty, to));
> +	vktty->from_size = vkread32(vk, BAR_1, VK_BAR_CHAN_SIZE(vktty, from));
> +	vktty->rd = vkread32(vk, BAR_1,  VK_BAR_CHAN_RD(vktty, from));
> +
> +	if (tty->count == 1) {
> +		timer_setup(&vk->serial_timer, bcm_vk_tty_poll, 0);
> +		mod_timer(&vk->serial_timer, jiffies + SERIAL_TIMER_VALUE);
> +	}
> +	return 0;
> +}
> +
> +static void bcm_vk_tty_close(struct tty_struct *tty, struct file *file)
> +{
> +	struct bcm_vk *vk;
> +
> +	vk = (struct bcm_vk *)dev_get_drvdata(tty->dev);


	struct bcm_vk *vk = dev_get_drvdata(tty->dev);

> +
> +	if (tty->count == 1)
> +		del_timer_sync(&vk->serial_timer);
> +}
> +
> +static int bcm_vk_tty_write(struct tty_struct *tty,
> +			    const unsigned char *buffer,
> +			    int count)
> +{
> +	int index;
> +	struct bcm_vk *vk;
> +	struct bcm_vk_tty *vktty;
> +	int i;
> +	int retval;
> +
> +	index = tty->index;
> +	vk = (struct bcm_vk *)dev_get_drvdata(tty->dev);

The cast is unnecessary.

> +	vktty = &vk->tty[index];
> +
> +	/* Simple write each byte to circular buffer */
> +	for (i = 0; i < count; i++) {
> +		vkwrite8(vk,
> +			 buffer[i],
> +			 BAR_1,
> +			 VK_BAR_CHAN_DATA(vktty, to, vktty->wr));

		vkwrite8(vk, buffer[i], BAR_1,
			 VK_BAR_CHAN_DATA(vktty, to, vktty->wr));


> +		vktty->wr++;
> +		if (vktty->wr >= vktty->to_size)
> +			vktty->wr = 0;
> +	}
> +	/* Update write offset from shadow register to card */
> +	/* TODO: Need to add write to doorbell here */
> +	vkwrite32(vk, vktty->wr, BAR_1, VK_BAR_CHAN_WR(vktty, to));
> +
> +	retval = count;
> +
> +	return retval;

Delete the "retval" variable.

> +}
> +
> +static int bcm_vk_tty_write_room(struct tty_struct *tty)
> +{
> +	int room;
> +	struct bcm_vk *vk;
> +	struct bcm_vk_tty *vktty;
> +
> +	vk = (struct bcm_vk *)dev_get_drvdata(tty->dev);

Delete cast.

> +	vktty = &vk->tty[tty->index];
> +
> +	/*
> +	 * Calculate how much room is left in the device
> +	 * Just return the size -1 of buffer.  We could care about
> +	 * overflow but don't at this point.
> +	 */

This comment raises more questions than it answers.  Why would we care
about overflow and why don't we at this point?  Perhaps just delete the
comment.

> +	room = vktty->to_size - 1;
> +
> +	return room;

Delete the room variable and the vktty variable.

	return vk->tty[tty->index].to_size - 1;


> +}
> +
> +static const struct tty_operations serial_ops = {
> +	.open = bcm_vk_tty_open,
> +	.close = bcm_vk_tty_close,
> +	.write = bcm_vk_tty_write,
> +	.write_room = bcm_vk_tty_write_room,
> +};
> +
> +int bcm_vk_tty_init(struct bcm_vk *vk, char *name)
> +{
> +	int i;
> +	int err;
> +	unsigned long flags;
> +	struct tty_driver *tty_drv;
> +	struct device *dev = &vk->pdev->dev;
> +
> +	/* allocate the tty driver */
> +	flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
> +	tty_drv = tty_alloc_driver(BCM_VK_NUM_TTY, flags);

Delete the flags variable.

> +

Delete this blank line.

> +	if (IS_ERR(tty_drv)) {
> +		err = PTR_ERR(tty_drv);
> +		goto err_exit;


		return PTR_ERR(tty_drv);

> +	}
> +	/* Save struct tty_driver for uninstalling the device */
> +	vk->tty_drv = tty_drv;
> +
> +	/* initialize the tty driver */
> +	tty_drv->driver_name = KBUILD_MODNAME;
> +	tty_drv->name = kstrdup(name, GFP_KERNEL);
> +	if (!tty_drv->name) {
> +		err = -ENOMEM;
> +		goto err_put_tty_driver;
> +	}
> +	tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
> +	tty_drv->subtype = SERIAL_TYPE_NORMAL;
> +	tty_drv->init_termios = tty_std_termios;
> +	tty_set_operations(tty_drv, &serial_ops);
> +
> +	/* register the tty driver */
> +	err = tty_register_driver(tty_drv);
> +	if (err) {
> +		dev_err(dev, "tty_register_driver failed\n");
> +		goto err_kfree_tty_name;
> +	}
> +
> +	for (i = 0; i < BCM_VK_NUM_TTY; i++) {
> +		struct device *tty_dev;
> +
> +		tty_port_init(&vk->tty[i].port);
> +		tty_dev = tty_port_register_device(&vk->tty[i].port,
> +						   tty_drv,
> +						   i,
> +						   dev);

		tty_dev = tty_port_register_device(&vk->tty[i].port, tty_drv,
						   i, dev);


> +		dev_set_drvdata(tty_dev, vk);
> +
> +		if (IS_ERR(tty_dev)) {

Calling dev_set_drvdata() before checking for IS_ERR().

> +			int j;
> +
> +			for (j = 0; j < i; j++)
> +				tty_port_unregister_device(&vk->tty[j].port,
> +							   tty_drv,
> +							   j);
> +			goto err_tty_unregister_driver;

No error code.

> +		}

			if (IS_ERR(tty_dev)) {
				err = PTR_ERR(tty_dev);
				goto unwind;
			}

> +	}
> +
> +	return 0;
> +

unwind:
	while (--i >= 0)
		tty_port_unregister_device(&vk->tty[i].port, tty_drv, i);


> +err_tty_unregister_driver:
> +	tty_unregister_driver(tty_drv);
> +
> +err_kfree_tty_name:
> +	kfree(tty_drv->name);
> +	tty_drv->name = NULL;
> +
> +err_put_tty_driver:
> +	put_tty_driver(tty_drv);
> +
> +err_exit:
> +	return err;
> +}
> +
> +void bcm_vk_tty_exit(struct bcm_vk *vk)
> +{
> +	int i;
> +
> +	del_timer_sync(&vk->serial_timer);
> +	for (i = 0; i < BCM_VK_NUM_TTY; ++i) {
> +		tty_port_unregister_device(&vk->tty[i].port,
> +					   vk->tty_drv,
> +					   i);
> +		tty_port_destroy(&vk->tty[i].port);
> +	}
> +	tty_unregister_driver(vk->tty_drv);
> +	put_tty_driver(vk->tty_drv);
> +
> +	kfree(vk->tty_drv->name);
              ^^^^^^^^^^^

Use after free because of the put_tty_driver().  I think test again
with CONFIG_PAGE_POISONING?

> +	vk->tty_drv->name = NULL;
> +}

regards,
dan carpenter