Re: [PATCH 1/8] cxl/mem: Move some definitions to mem.h

From: Jonathan Cameron
Date: Mon May 10 2021 - 11:18:53 EST


On Fri, 7 May 2021 15:51:20 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:

> In preparation for sharing cxl.h with other generic CXL consumers,
> move / consolidate some of the memory device specifics to mem.h.
>
> The motivation for moving out of cxl.h is to maintain least privilege
> access to memory-device details since cxl.h is used in multiple files.
> The motivation for moving definitions into a new mem.h header is for
> code readability and organization. I.e. minimize implementation details
> when reading data structures and other definitions.
>
> Reviewed-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
I'll do these one by one as not sure if you use automated scripts to pick up
(which get confused by any time people do "for patches 1-4 + 7")
Basically I'm fine with all but patch 5...

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

> ---
> drivers/cxl/cxl.h | 57 ------------------------------------
> drivers/cxl/mem.c | 25 +---------------
> drivers/cxl/mem.h | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 86 insertions(+), 81 deletions(-)
> create mode 100644 drivers/cxl/mem.h
>
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 6f14838c2d25..2e3bdacb32e7 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -34,62 +34,5 @@
> #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
> #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
>
> -/* CXL 2.0 8.2.8.5.1.1 Memory Device Status Register */
> -#define CXLMDEV_STATUS_OFFSET 0x0
> -#define CXLMDEV_DEV_FATAL BIT(0)
> -#define CXLMDEV_FW_HALT BIT(1)
> -#define CXLMDEV_STATUS_MEDIA_STATUS_MASK GENMASK(3, 2)
> -#define CXLMDEV_MS_NOT_READY 0
> -#define CXLMDEV_MS_READY 1
> -#define CXLMDEV_MS_ERROR 2
> -#define CXLMDEV_MS_DISABLED 3
> -#define CXLMDEV_READY(status) \
> - (FIELD_GET(CXLMDEV_STATUS_MEDIA_STATUS_MASK, status) == \
> - CXLMDEV_MS_READY)
> -#define CXLMDEV_MBOX_IF_READY BIT(4)
> -#define CXLMDEV_RESET_NEEDED_MASK GENMASK(7, 5)
> -#define CXLMDEV_RESET_NEEDED_NOT 0
> -#define CXLMDEV_RESET_NEEDED_COLD 1
> -#define CXLMDEV_RESET_NEEDED_WARM 2
> -#define CXLMDEV_RESET_NEEDED_HOT 3
> -#define CXLMDEV_RESET_NEEDED_CXL 4
> -#define CXLMDEV_RESET_NEEDED(status) \
> - (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \
> - CXLMDEV_RESET_NEEDED_NOT)
> -
> -struct cxl_memdev;
> -/**
> - * struct cxl_mem - A CXL memory device
> - * @pdev: The PCI device associated with this CXL device.
> - * @regs: IO mappings to the device's MMIO
> - * @status_regs: CXL 2.0 8.2.8.3 Device Status Registers
> - * @mbox_regs: CXL 2.0 8.2.8.4 Mailbox Registers
> - * @memdev_regs: CXL 2.0 8.2.8.5 Memory Device Registers
> - * @payload_size: Size of space for payload
> - * (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
> - * @mbox_mutex: Mutex to synchronize mailbox access.
> - * @firmware_version: Firmware version for the memory device.
> - * @enabled_commands: Hardware commands found enabled in CEL.
> - * @pmem_range: Persistent memory capacity information.
> - * @ram_range: Volatile memory capacity information.
> - */
> -struct cxl_mem {
> - struct pci_dev *pdev;
> - void __iomem *regs;
> - struct cxl_memdev *cxlmd;
> -
> - void __iomem *status_regs;
> - void __iomem *mbox_regs;
> - void __iomem *memdev_regs;
> -
> - size_t payload_size;
> - struct mutex mbox_mutex; /* Protects device mailbox and firmware */
> - char firmware_version[0x10];
> - unsigned long *enabled_cmds;
> -
> - struct range pmem_range;
> - struct range ram_range;
> -};
> -
> extern struct bus_type cxl_bus_type;
> #endif /* __CXL_H__ */
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index 244cb7d89678..45871ef65152 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -12,6 +12,7 @@
> #include <linux/io-64-nonatomic-lo-hi.h>
> #include "pci.h"
> #include "cxl.h"
> +#include "mem.h"
>
> /**
> * DOC: cxl mem
> @@ -29,12 +30,6 @@
> * - Handle and manage error conditions.
> */
>
> -/*
> - * An entire PCI topology full of devices should be enough for any
> - * config
> - */
> -#define CXL_MEM_MAX_DEVS 65536
> -
> #define cxl_doorbell_busy(cxlm) \
> (readl((cxlm)->mbox_regs + CXLDEV_MBOX_CTRL_OFFSET) & \
> CXLDEV_MBOX_CTRL_DOORBELL)
> @@ -91,24 +86,6 @@ struct mbox_cmd {
> #define CXL_MBOX_SUCCESS 0
> };
>
> -/**
> - * struct cxl_memdev - CXL bus object representing a Type-3 Memory Device
> - * @dev: driver core device object
> - * @cdev: char dev core object for ioctl operations
> - * @cxlm: pointer to the parent device driver data
> - * @ops_active: active user of @cxlm in ops handlers
> - * @ops_dead: completion when all @cxlm ops users have exited
> - * @id: id number of this memdev instance.
> - */
> -struct cxl_memdev {
> - struct device dev;
> - struct cdev cdev;
> - struct cxl_mem *cxlm;
> - struct percpu_ref ops_active;
> - struct completion ops_dead;
> - int id;
> -};
> -
> static int cxl_mem_major;
> static DEFINE_IDA(cxl_memdev_ida);
> static struct dentry *cxl_debugfs;
> diff --git a/drivers/cxl/mem.h b/drivers/cxl/mem.h
> new file mode 100644
> index 000000000000..616bb6fd721f
> --- /dev/null
> +++ b/drivers/cxl/mem.h
> @@ -0,0 +1,85 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* Copyright(c) 2020-2021 Intel Corporation. */
> +#ifndef __CXL_MEM_H__
> +#define __CXL_MEM_H__
> +
> +/* CXL 2.0 8.2.8.5.1.1 Memory Device Status Register */
> +#define CXLMDEV_STATUS_OFFSET 0x0
> +#define CXLMDEV_DEV_FATAL BIT(0)
> +#define CXLMDEV_FW_HALT BIT(1)
> +#define CXLMDEV_STATUS_MEDIA_STATUS_MASK GENMASK(3, 2)
> +#define CXLMDEV_MS_NOT_READY 0
> +#define CXLMDEV_MS_READY 1
> +#define CXLMDEV_MS_ERROR 2
> +#define CXLMDEV_MS_DISABLED 3
> +#define CXLMDEV_READY(status) \
> + (FIELD_GET(CXLMDEV_STATUS_MEDIA_STATUS_MASK, status) == \
> + CXLMDEV_MS_READY)
> +#define CXLMDEV_MBOX_IF_READY BIT(4)
> +#define CXLMDEV_RESET_NEEDED_MASK GENMASK(7, 5)
> +#define CXLMDEV_RESET_NEEDED_NOT 0
> +#define CXLMDEV_RESET_NEEDED_COLD 1
> +#define CXLMDEV_RESET_NEEDED_WARM 2
> +#define CXLMDEV_RESET_NEEDED_HOT 3
> +#define CXLMDEV_RESET_NEEDED_CXL 4
> +#define CXLMDEV_RESET_NEEDED(status) \
> + (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \
> + CXLMDEV_RESET_NEEDED_NOT)
> +
> +/*
> + * An entire PCI topology full of devices should be enough for any
> + * config
> + */
> +#define CXL_MEM_MAX_DEVS 65536
> +
> +/**
> + * struct cxl_memdev - CXL bus object representing a Type-3 Memory Device
> + * @dev: driver core device object
> + * @cdev: char dev core object for ioctl operations
> + * @cxlm: pointer to the parent device driver data
> + * @ops_active: active user of @cxlm in ops handlers
> + * @ops_dead: completion when all @cxlm ops users have exited
> + * @id: id number of this memdev instance.
> + */
> +struct cxl_memdev {
> + struct device dev;
> + struct cdev cdev;
> + struct cxl_mem *cxlm;
> + struct percpu_ref ops_active;
> + struct completion ops_dead;
> + int id;
> +};
> +
> +/**
> + * struct cxl_mem - A CXL memory device
> + * @pdev: The PCI device associated with this CXL device.
> + * @regs: IO mappings to the device's MMIO
> + * @status_regs: CXL 2.0 8.2.8.3 Device Status Registers
> + * @mbox_regs: CXL 2.0 8.2.8.4 Mailbox Registers
> + * @memdev_regs: CXL 2.0 8.2.8.5 Memory Device Registers
> + * @payload_size: Size of space for payload
> + * (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
> + * @mbox_mutex: Mutex to synchronize mailbox access.
> + * @firmware_version: Firmware version for the memory device.
> + * @enabled_cmds: Hardware commands found enabled in CEL.
> + * @pmem_range: Persistent memory capacity information.
> + * @ram_range: Volatile memory capacity information.
> + */
> +struct cxl_mem {
> + struct pci_dev *pdev;
> + void __iomem *regs;
> + struct cxl_memdev *cxlmd;
> +
> + void __iomem *status_regs;
> + void __iomem *mbox_regs;
> + void __iomem *memdev_regs;
> +
> + size_t payload_size;
> + struct mutex mbox_mutex; /* Protects device mailbox and firmware */
> + char firmware_version[0x10];
> + unsigned long *enabled_cmds;
> +
> + struct range pmem_range;
> + struct range ram_range;
> +};
> +#endif /* __CXL_MEM_H__ */
>