Re: [PATCH V11 5/7] dma: qcom_hidma: implement lower level hardware interface
From: Andy Shevchenko
Date: Mon Jan 04 2016 - 14:01:15 EST
On Mon, Jan 4, 2016 at 2:06 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
> This patch implements the hardware hooks for the HIDMA channel driver.
>
> The main functions of interest are:
> - hidma_ll_init
> - hidma_ll_request
> - hidma_ll_queue_request
> - hidma_ll_hw_start
>
> OS layer calls the hidma_ll_init function during probe to set up the
> hardware. At this moment, the number of supported descriptors are also
> given. On each request, a descriptor is allocated from the free pool and
> filled in with the transfer parameters. Multiple requests can be queued
> into the hardware via the OS interface. When client is ready for requests
> to be executed, start method is called.
>
> Completions are delivered via callbacks via tasklet.
Few nitpicks below.
>
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> drivers/dma/qcom/Makefile | 2 +
> drivers/dma/qcom/hidma.h | 2 +-
> drivers/dma/qcom/hidma_ll.c | 927 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 930 insertions(+), 1 deletion(-)
> create mode 100644 drivers/dma/qcom/hidma_ll.c
>
> diff --git a/drivers/dma/qcom/Makefile b/drivers/dma/qcom/Makefile
> index bfea699..6bf9267 100644
> --- a/drivers/dma/qcom/Makefile
> +++ b/drivers/dma/qcom/Makefile
> @@ -1,3 +1,5 @@
> obj-$(CONFIG_QCOM_BAM_DMA) += bam_dma.o
> obj-$(CONFIG_QCOM_HIDMA_MGMT) += hdma_mgmt.o
> hdma_mgmt-objs := hidma_mgmt.o hidma_mgmt_sys.o
> +obj-$(CONFIG_QCOM_HIDMA) += hdma.o
> +hdma-objs := hidma_ll.o hidma.o
> diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
> index 231e306..1e09d7c 100644
> --- a/drivers/dma/qcom/hidma.h
> +++ b/drivers/dma/qcom/hidma.h
> @@ -37,7 +37,7 @@ struct hidma_tre {
> atomic_t allocated; /* if this channel is allocated */
> bool queued; /* flag whether this is pending */
> u16 status; /* status */
> - u32 chidx; /* index of the tre */
> + u32 idx; /* index of the tre */
> u32 dma_sig; /* signature of the tre */
> const char *dev_name; /* name of the device */
> void (*callback)(void *data); /* requester callback */
> diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
> new file mode 100644
> index 0000000..0cd8d70
> --- /dev/null
> +++ b/drivers/dma/qcom/hidma_ll.c
> @@ -0,0 +1,927 @@
> +/*
> + * Qualcomm Technologies HIDMA DMA engine low level code
> + *
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/dmaengine.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/mm.h>
> +#include <linux/highmem.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/delay.h>
> +#include <linux/atomic.h>
> +#include <linux/iopoll.h>
> +#include <linux/kfifo.h>
> +#include <linux/bitops.h>
> +
> +#include "hidma.h"
> +
> +#define EVRE_SIZE 16 /* each EVRE is 16 bytes */
> +
> +#define TRCA_CTRLSTS_OFFSET 0x0
> +#define TRCA_RING_LOW_OFFSET 0x8
> +#define TRCA_RING_HIGH_OFFSET 0xC
> +#define TRCA_RING_LEN_OFFSET 0x10
> +#define TRCA_READ_PTR_OFFSET 0x18
> +#define TRCA_WRITE_PTR_OFFSET 0x20
> +#define TRCA_DOORBELL_OFFSET 0x400
I would rather have same precision for all offsets
like
...CTRLSTS_OFFSET 0x000
and so on
> +
> +#define EVCA_CTRLSTS_OFFSET 0x0
> +#define EVCA_INTCTRL_OFFSET 0x4
> +#define EVCA_RING_LOW_OFFSET 0x8
> +#define EVCA_RING_HIGH_OFFSET 0xC
> +#define EVCA_RING_LEN_OFFSET 0x10
> +#define EVCA_READ_PTR_OFFSET 0x18
> +#define EVCA_WRITE_PTR_OFFSET 0x20
> +#define EVCA_DOORBELL_OFFSET 0x400
Ditto.
> +
> +#define EVCA_IRQ_STAT_OFFSET 0x100
> +#define EVCA_IRQ_CLR_OFFSET 0x108
> +#define EVCA_IRQ_EN_OFFSET 0x110
> +
> +#define EVRE_CFG_IDX 0
> +#define EVRE_LEN_IDX 1
> +#define EVRE_DEST_LOW_IDX 2
> +#define EVRE_DEST_HI_IDX 3
> +
> +#define EVRE_ERRINFO_BIT_POS 24
> +#define EVRE_CODE_BIT_POS 28
> +
> +#define EVRE_ERRINFO_MASK GENMASK(3, 0)
> +#define EVRE_CODE_MASK GENMASK(3, 0)
> +
> +#define CH_CONTROL_MASK GENMASK(7, 0)
> +#define CH_STATE_MASK GENMASK(7, 0)
> +#define CH_STATE_BIT_POS 0x8
> +
> +#define IRQ_EV_CH_EOB_IRQ_BIT_POS 0
> +#define IRQ_EV_CH_WR_RESP_BIT_POS 1
> +#define IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS 9
> +#define IRQ_TR_CH_DATA_RD_ER_BIT_POS 10
> +#define IRQ_TR_CH_DATA_WR_ER_BIT_POS 11
> +#define IRQ_TR_CH_INVALID_TRE_BIT_POS 14
> +
> +#define ENABLE_IRQS (BIT(IRQ_EV_CH_EOB_IRQ_BIT_POS) | \
> + BIT(IRQ_EV_CH_WR_RESP_BIT_POS) | \
> + BIT(IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) | \
> + BIT(IRQ_TR_CH_DATA_RD_ER_BIT_POS) | \
> + BIT(IRQ_TR_CH_DATA_WR_ER_BIT_POS) | \
> + BIT(IRQ_TR_CH_INVALID_TRE_BIT_POS))
> +
> +enum ch_command {
> + CH_DISABLE = 0,
> + CH_ENABLE = 1,
> + CH_SUSPEND = 2,
> + CH_RESET = 9,
> +};
> +
> +enum ch_state {
> + CH_DISABLED = 0,
> + CH_ENABLED = 1,
> + CH_RUNNING = 2,
> + CH_SUSPENDED = 3,
> + CH_STOPPED = 4,
> + CH_ERROR = 5,
> + CH_IN_RESET = 9,
> +};
> +
> +enum tre_type {
> + TRE_MEMCPY = 3,
> + TRE_MEMSET = 4,
> +};
> +
> +enum evre_type {
> + EVRE_DMA_COMPLETE = 0x23,
> + EVRE_IMM_DATA = 0x24,
> +};
> +
> +enum err_code {
> + EVRE_STATUS_COMPLETE = 1,
> + EVRE_STATUS_ERROR = 4,
> +};
> +
> +void hidma_ll_free(struct hidma_lldev *lldev, u32 tre_ch)
> +{
> + struct hidma_tre *tre;
> +
> + if (tre_ch >= lldev->nr_tres) {
> + dev_err(lldev->dev, "invalid TRE number in free:%d", tre_ch);
> + return;
> + }
> +
> + tre = &lldev->trepool[tre_ch];
> + if (atomic_read(&tre->allocated) != true) {
> + dev_err(lldev->dev, "trying to free an unused TRE:%d", tre_ch);
> + return;
> + }
> +
> + atomic_set(&tre->allocated, 0);
> +}
> +
> +int hidma_ll_request(struct hidma_lldev *lldev, u32 dma_sig,
> + const char *dev_name,
> + void (*callback)(void *data), void *data, u32 *tre_ch)
> +{
> + unsigned int i;
> + struct hidma_tre *tre;
> + u32 *tre_local;
> +
> + if (!tre_ch || !lldev)
> + return -EINVAL;
> +
> + /* need to have at least one empty spot in the queue */
> + for (i = 0; i < lldev->nr_tres - 1; i++) {
> + if (atomic_add_unless(&lldev->trepool[i].allocated, 1, 1))
> + break;
> + }
> +
> + if (i == (lldev->nr_tres - 1))
> + return -ENOMEM;
> +
> + tre = &lldev->trepool[i];
> + tre->dma_sig = dma_sig;
> + tre->dev_name = dev_name;
> + tre->callback = callback;
> + tre->data = data;
> + tre->idx = i;
> + tre->status = 0;
> + tre->queued = 0;
> + lldev->tx_status_list[i].err_code = 0;
> + tre->lldev = lldev;
> + tre_local = &tre->tre_local[0];
> + tre_local[TRE_CFG_IDX] = TRE_MEMCPY;
> + tre_local[TRE_CFG_IDX] |= (lldev->chidx & 0xFF) << 8;
> + tre_local[TRE_CFG_IDX] |= BIT(16); /* set IEOB */
> + *tre_ch = i;
> + if (callback)
> + callback(data);
> + return 0;
> +}
> +
> +/*
> + * Multiple TREs may be queued and waiting in the
> + * pending queue.
> + */
> +static void hidma_ll_tre_complete(unsigned long arg)
> +{
> + struct hidma_lldev *lldev = (struct hidma_lldev *)arg;
> + struct hidma_tre *tre;
> +
> + while (kfifo_out(&lldev->handoff_fifo, &tre, 1)) {
> + /* call the user if it has been read by the hardware */
> + if (tre->callback)
> + tre->callback(tre->data);
> + }
> +}
> +
> +/*
> + * Called to handle the interrupt for the channel.
> + * Return a positive number if TRE or EVRE were consumed on this run.
> + * Return a positive number if there are pending TREs or EVREs.
> + * Return 0 if there is nothing to consume or no pending TREs/EVREs found.
> + */
> +static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
> +{
> + struct hidma_tre *tre;
> + u32 evre_write_off;
> + u32 evre_ring_size = lldev->evre_ring_size;
> + u32 tre_ring_size = lldev->tre_ring_size;
> + u32 num_completed = 0, tre_iterator, evre_iterator;
> + unsigned long flags;
> +
> + evre_write_off = readl_relaxed(lldev->evca + EVCA_WRITE_PTR_OFFSET);
> + tre_iterator = lldev->tre_processed_off;
> + evre_iterator = lldev->evre_processed_off;
> +
> + if ((evre_write_off > evre_ring_size) ||
> + ((evre_write_off % EVRE_SIZE) != 0)) {
> + dev_err(lldev->dev, "HW reports invalid EVRE write offset\n");
> + return 0;
> + }
> +
> + /*
> + * By the time control reaches here the number of EVREs and TREs
> + * may not match. Only consume the ones that hardware told us.
> + */
> + while ((evre_iterator != evre_write_off)) {
> + u32 *current_evre = lldev->evre_ring + evre_iterator;
> + u32 cfg;
> + u8 err_info;
> +
> + spin_lock_irqsave(&lldev->lock, flags);
> + tre = lldev->pending_tre_list[tre_iterator / TRE_SIZE];
> + if (!tre) {
> + spin_unlock_irqrestore(&lldev->lock, flags);
> + dev_warn(lldev->dev,
> + "tre_index [%d] and tre out of sync\n",
> + tre_iterator / TRE_SIZE);
> + tre_iterator += TRE_SIZE;
> + if (tre_iterator >= tre_ring_size)
> + tre_iterator -= tre_ring_size;
Could it be refactored to macro
increment_iterator(iter,size,ring_size) ?
> + evre_iterator += EVRE_SIZE;
> + if (evre_iterator >= evre_ring_size)
> + evre_iterator -= evre_ring_size;
Ditto.
> +
> + continue;
> + }
> + lldev->pending_tre_list[tre->tre_index] = NULL;
> +
> + /*
> + * Keep track of pending TREs that SW is expecting to receive
> + * from HW. We got one now. Decrement our counter.
> + */
> + lldev->pending_tre_count--;
> + if (lldev->pending_tre_count < 0) {
> + dev_warn(lldev->dev,
> + "tre count mismatch on completion");
> + lldev->pending_tre_count = 0;
> + }
> +
> + spin_unlock_irqrestore(&lldev->lock, flags);
> +
> + cfg = current_evre[EVRE_CFG_IDX];
> + err_info = cfg >> EVRE_ERRINFO_BIT_POS;
> + err_info &= EVRE_ERRINFO_MASK;
> + lldev->tx_status_list[tre->idx].err_info = err_info;
> + lldev->tx_status_list[tre->idx].err_code =
> + (cfg >> EVRE_CODE_BIT_POS) & EVRE_CODE_MASK;
> + tre->queued = 0;
> +
> + kfifo_put(&lldev->handoff_fifo, tre);
> + tasklet_schedule(&lldev->task);
> +
> + tre_iterator += TRE_SIZE;
> + if (tre_iterator >= tre_ring_size)
> + tre_iterator -= tre_ring_size;
Ditto.
> + evre_iterator += EVRE_SIZE;
> + if (evre_iterator >= evre_ring_size)
> + evre_iterator -= evre_ring_size;
Ditto.
> +
> + /*
> + * Read the new event descriptor written by the HW.
> + * As we are processing the delivered events, other events
> + * get queued to the SW for processing.
> + */
> + evre_write_off =
> + readl_relaxed(lldev->evca + EVCA_WRITE_PTR_OFFSET);
> + num_completed++;
> + }
> +
> + if (num_completed) {
> + u32 evre_read_off = (lldev->evre_processed_off +
> + EVRE_SIZE * num_completed);
> + u32 tre_read_off = (lldev->tre_processed_off +
> + TRE_SIZE * num_completed);
> +
> + evre_read_off = evre_read_off % evre_ring_size;
> + tre_read_off = tre_read_off % tre_ring_size;
> +
> + writel(evre_read_off, lldev->evca + EVCA_DOORBELL_OFFSET);
> +
> + /* record the last processed tre offset */
> + lldev->tre_processed_off = tre_read_off;
> + lldev->evre_processed_off = evre_read_off;
> + }
> +
> + return num_completed;
> +}
> +
> +void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
> + u8 err_code)
> +{
> + u32 tre_iterator;
> + struct hidma_tre *tre;
> + u32 tre_ring_size = lldev->tre_ring_size;
> + int num_completed = 0;
> + u32 tre_read_off;
> + unsigned long flags;
> +
> + tre_iterator = lldev->tre_processed_off;
> + while (lldev->pending_tre_count) {
> + int tre_index = tre_iterator / TRE_SIZE;
> +
> + spin_lock_irqsave(&lldev->lock, flags);
> + tre = lldev->pending_tre_list[tre_index];
> + if (!tre) {
> + spin_unlock_irqrestore(&lldev->lock, flags);
> + tre_iterator += TRE_SIZE;
> + if (tre_iterator >= tre_ring_size)
> + tre_iterator -= tre_ring_size;
Ditto.
> + continue;
> + }
> + lldev->pending_tre_list[tre_index] = NULL;
> + lldev->pending_tre_count--;
> + if (lldev->pending_tre_count < 0) {
> + dev_warn(lldev->dev,
> + "tre count mismatch on completion");
> + lldev->pending_tre_count = 0;
> + }
> + spin_unlock_irqrestore(&lldev->lock, flags);
> +
> + lldev->tx_status_list[tre->idx].err_info = err_info;
> + lldev->tx_status_list[tre->idx].err_code = err_code;
> + tre->queued = 0;
> +
> + kfifo_put(&lldev->handoff_fifo, tre);
> + tasklet_schedule(&lldev->task);
> +
> + tre_iterator += TRE_SIZE;
> + if (tre_iterator >= tre_ring_size)
> + tre_iterator -= tre_ring_size;
Ditto.
> +
> + num_completed++;
> + }
> + tre_read_off = (lldev->tre_processed_off + TRE_SIZE * num_completed);
> +
> + tre_read_off = tre_read_off % tre_ring_size;
> +
> + /* record the last processed tre offset */
> + lldev->tre_processed_off = tre_read_off;
> +}
> +
> +static int hidma_ll_reset(struct hidma_lldev *lldev)
> +{
> + u32 val;
> + int ret;
> +
> + val = readl(lldev->trca + TRCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_RESET << 16;
> + writel(val, lldev->trca + TRCA_CTRLSTS_OFFSET);
> +
> + /*
> + * Delay 10ms after reset to allow DMA logic to quiesce.
> + * Do a polled read up to 1ms and 10ms maximum.
> + */
> + ret = readl_poll_timeout(lldev->trca + TRCA_CTRLSTS_OFFSET, val,
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK) ==
> + CH_DISABLED), 1000, 10000);
> + if (ret) {
> + dev_err(lldev->dev, "transfer channel did not reset\n");
> + return ret;
> + }
> +
> + val = readl(lldev->evca + EVCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_RESET << 16;
> + writel(val, lldev->evca + EVCA_CTRLSTS_OFFSET);
> +
> + /*
> + * Delay 10ms after reset to allow DMA logic to quiesce.
> + * Do a polled read up to 1ms and 10ms maximum.
> + */
> + ret = readl_poll_timeout(lldev->evca + EVCA_CTRLSTS_OFFSET, val,
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK) ==
> + CH_DISABLED), 1000, 10000);
> + if (ret)
> + return ret;
> +
> + lldev->trch_state = CH_DISABLED;
> + lldev->evch_state = CH_DISABLED;
> + return 0;
> +}
> +
> +static void hidma_ll_enable_irq(struct hidma_lldev *lldev, u32 irq_bits)
> +{
> + writel(irq_bits, lldev->evca + EVCA_IRQ_EN_OFFSET);
> +}
> +
> +/*
> + * The interrupt handler for HIDMA will try to consume as many pending
> + * EVRE from the event queue as possible. Each EVRE has an associated
> + * TRE that holds the user interface parameters. EVRE reports the
> + * result of the transaction. Hardware guarantees ordering between EVREs
> + * and TREs. We use last processed offset to figure out which TRE is
> + * associated with which EVRE. If two TREs are consumed by HW, the EVREs
> + * are in order in the event ring.
> + *
> + * This handler will do a one pass for consuming EVREs. Other EVREs may
> + * be delivered while we are working. It will try to consume incoming
> + * EVREs one more time and return.
> + *
> + * For unprocessed EVREs, hardware will trigger another interrupt until
> + * all the interrupt bits are cleared.
> + *
> + * Hardware guarantees that by the time interrupt is observed, all data
> + * transactions in flight are delivered to their respective places and
> + * are visible to the CPU.
> + *
> + * On demand paging for IOMMU is only supported for PCIe via PRI
> + * (Page Request Interface) not for HIDMA. All other hardware instances
> + * including HIDMA work on pinned DMA addresses.
> + *
> + * HIDMA is not aware of IOMMU presence since it follows the DMA API. All
> + * IOMMU latency will be built into the data movement time. By the time
> + * interrupt happens, IOMMU lookups + data movement has already taken place.
> + *
> + * While the first read in a typical PCI endpoint ISR flushes all outstanding
> + * requests traditionally to the destination, this concept does not apply
> + * here for this HW.
> + */
> +static void hidma_ll_int_handler_internal(struct hidma_lldev *lldev)
> +{
> + u32 status;
> + u32 enable;
> + u32 cause;
> + int repeat = 2;
> + unsigned long timeout;
> +
> + /*
> + * Fine tuned for this HW...
> + *
> + * This ISR has been designed for this particular hardware. Relaxed
> + * read and write accessors are used for performance reasons due to
> + * interrupt delivery guarantees. Do not copy this code blindly and
> + * expect that to work.
> + */
> + status = readl_relaxed(lldev->evca + EVCA_IRQ_STAT_OFFSET);
> + enable = readl_relaxed(lldev->evca + EVCA_IRQ_EN_OFFSET);
> + cause = status & enable;
> +
> + if ((cause & (BIT(IRQ_TR_CH_INVALID_TRE_BIT_POS))) ||
> + (cause & BIT(IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS)) ||
> + (cause & BIT(IRQ_EV_CH_WR_RESP_BIT_POS)) ||
> + (cause & BIT(IRQ_TR_CH_DATA_RD_ER_BIT_POS)) ||
> + (cause & BIT(IRQ_TR_CH_DATA_WR_ER_BIT_POS))) {
> + u8 err_code = EVRE_STATUS_ERROR;
> + u8 err_info = 0xFF;
> +
> + /* Clear out pending interrupts */
> + writel(cause, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> +
> + dev_err(lldev->dev, "error 0x%x, resetting...\n", cause);
> +
> + hidma_cleanup_pending_tre(lldev, err_info, err_code);
> +
> + /* reset the channel for recovery */
> + if (hidma_ll_setup(lldev)) {
> + dev_err(lldev->dev,
> + "channel reinitialize failed after error\n");
> + return;
> + }
> + hidma_ll_enable_irq(lldev, ENABLE_IRQS);
> + return;
> + }
> +
> + /*
> + * Try to consume as many EVREs as possible.
> + * skip this loop if the interrupt is spurious.
> + */
> + while (cause && repeat) {
> + unsigned long start = jiffies;
> +
> + /* This timeout should be sufficent for core to finish */
> + timeout = start + msecs_to_jiffies(500);
> +
> + while (lldev->pending_tre_count) {
> + hidma_handle_tre_completion(lldev);
> + if (time_is_before_jiffies(timeout)) {
> + dev_warn(lldev->dev,
> + "ISR timeout %lx-%lx from %lx [%d]\n",
> + jiffies, timeout, start,
> + lldev->pending_tre_count);
> + break;
> + }
> + }
> +
> + /* We consumed TREs or there are pending TREs or EVREs. */
> + writel_relaxed(cause, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> +
> + /*
> + * Another interrupt might have arrived while we are
> + * processing this one. Read the new cause.
> + */
> + status = readl_relaxed(lldev->evca + EVCA_IRQ_STAT_OFFSET);
> + enable = readl_relaxed(lldev->evca + EVCA_IRQ_EN_OFFSET);
> + cause = status & enable;
> +
> + repeat--;
> + }
> +}
> +
> +static int hidma_ll_enable(struct hidma_lldev *lldev)
> +{
> + u32 val;
> + int ret;
> +
> + val = readl(lldev->evca + EVCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_ENABLE << 16;
> + writel(val, lldev->evca + EVCA_CTRLSTS_OFFSET);
> +
> + ret = readl_poll_timeout(lldev->evca + EVCA_CTRLSTS_OFFSET, val,
> + ((((val >> CH_STATE_BIT_POS) & CH_STATE_MASK)
> + == CH_ENABLED)
> + ||
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK)
> + == CH_RUNNING)), 1000, 10000);
> + if (ret) {
> + dev_err(lldev->dev, "event channel did not get enabled\n");
> + return ret;
> + }
> +
> + val = readl(lldev->trca + TRCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_ENABLE << 16;
> + writel(val, lldev->trca + TRCA_CTRLSTS_OFFSET);
> +
> + ret = readl_poll_timeout(lldev->trca + TRCA_CTRLSTS_OFFSET, val,
> + ((((val >> CH_STATE_BIT_POS) & CH_STATE_MASK)
> + == CH_ENABLED)
> + ||
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK)
> + == CH_RUNNING)), 1000, 10000);
u32 val, state;
state = (val >> CH_STATE_BIT_POS) & CH_STATE_MASK;
...
And above.
> + if (ret) {
> + dev_err(lldev->dev, "transfer channel did not get enabled\n");
> + return ret;
> + }
> +
> + lldev->trch_state = CH_ENABLED;
> + lldev->evch_state = CH_ENABLED;
> +
> + return 0;
> +}
> +
> +int hidma_ll_resume(struct hidma_lldev *lldev)
> +{
> + return hidma_ll_enable(lldev);
> +}
> +
> +static void hidma_ll_hw_start(struct hidma_lldev *lldev)
> +{
> + unsigned long irqflags;
> +
> + spin_lock_irqsave(&lldev->lock, irqflags);
> + writel(lldev->tre_write_offset, lldev->trca + TRCA_DOORBELL_OFFSET);
> + spin_unlock_irqrestore(&lldev->lock, irqflags);
> +}
> +
> +bool hidma_ll_isenabled(struct hidma_lldev *lldev)
> +{
> + u32 val;
> +
> + val = readl(lldev->trca + TRCA_CTRLSTS_OFFSET);
> + lldev->trch_state = (val >> CH_STATE_BIT_POS) & CH_STATE_MASK;
> + val = readl(lldev->evca + EVCA_CTRLSTS_OFFSET);
> + lldev->evch_state = (val >> CH_STATE_BIT_POS) & CH_STATE_MASK;
Even macro
#define CH_STATE(v) ...
> +
> + /* both channels have to be enabled before calling this function */
> + if (((lldev->trch_state == CH_ENABLED) ||
> + (lldev->trch_state == CH_RUNNING)) &&
> + ((lldev->evch_state == CH_ENABLED) ||
> + (lldev->evch_state == CH_RUNNING)))
> + return true;
> +
> + return false;
> +}
> +
> +void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch)
> +{
> + struct hidma_tre *tre;
> + unsigned long flags;
> +
> + tre = &lldev->trepool[tre_ch];
> +
> + /* copy the TRE into its location in the TRE ring */
> + spin_lock_irqsave(&lldev->lock, flags);
> + tre->tre_index = lldev->tre_write_offset / TRE_SIZE;
> + lldev->pending_tre_list[tre->tre_index] = tre;
> + memcpy(lldev->tre_ring + lldev->tre_write_offset, &tre->tre_local[0],
> + TRE_SIZE);
> + lldev->tx_status_list[tre->idx].err_code = 0;
> + lldev->tx_status_list[tre->idx].err_info = 0;
> + tre->queued = 1;
> + lldev->pending_tre_count++;
> + lldev->tre_write_offset = (lldev->tre_write_offset + TRE_SIZE)
> + % lldev->tre_ring_size;
> + spin_unlock_irqrestore(&lldev->lock, flags);
> +}
> +
> +void hidma_ll_start(struct hidma_lldev *lldev)
> +{
> + hidma_ll_hw_start(lldev);
> +}
> +
> +/*
> + * Note that even though we stop this channel
> + * if there is a pending transaction in flight
> + * it will complete and follow the callback.
> + * This request will prevent further requests
> + * to be made.
> + */
> +int hidma_ll_pause(struct hidma_lldev *lldev)
> +{
> + u32 val;
> + int ret;
> +
> + val = readl(lldev->evca + EVCA_CTRLSTS_OFFSET);
> + lldev->evch_state = (val >> CH_STATE_BIT_POS) & CH_STATE_MASK;
> + val = readl(lldev->trca + TRCA_CTRLSTS_OFFSET);
> + lldev->trch_state = (val >> CH_STATE_BIT_POS) & CH_STATE_MASK;
Ditto.
> +
> + /* already suspended by this OS */
> + if ((lldev->trch_state == CH_SUSPENDED) ||
> + (lldev->evch_state == CH_SUSPENDED))
> + return 0;
> +
> + /* already stopped by the manager */
> + if ((lldev->trch_state == CH_STOPPED) ||
> + (lldev->evch_state == CH_STOPPED))
> + return 0;
> +
> + val = readl(lldev->trca + TRCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_SUSPEND << 16;
> + writel(val, lldev->trca + TRCA_CTRLSTS_OFFSET);
> +
> + /*
> + * Start the wait right after the suspend is confirmed.
> + * Do a polled read up to 1ms and 10ms maximum.
> + */
> + ret = readl_poll_timeout(lldev->trca + TRCA_CTRLSTS_OFFSET, val,
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK) ==
Ditto. And everywhere else.
> + CH_SUSPENDED), 1000, 10000);
> + if (ret)
> + return ret;
> +
> + val = readl(lldev->evca + EVCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_SUSPEND << 16;
> + writel(val, lldev->evca + EVCA_CTRLSTS_OFFSET);
> +
> + /*
> + * Start the wait right after the suspend is confirmed
> + * Delay up to 10ms after reset to allow DMA logic to quiesce.
> + */
> + ret = readl_poll_timeout(lldev->evca + EVCA_CTRLSTS_OFFSET, val,
> + (((val >> CH_STATE_BIT_POS) & CH_STATE_MASK) ==
> + CH_SUSPENDED), 1000, 10000);
> + if (ret)
> + return ret;
> +
> + lldev->trch_state = CH_SUSPENDED;
> + lldev->evch_state = CH_SUSPENDED;
> + return 0;
> +}
> +
> +void hidma_ll_set_transfer_params(struct hidma_lldev *lldev, u32 tre_ch,
> + dma_addr_t src, dma_addr_t dest, u32 len,
> + u32 flags)
> +{
> + struct hidma_tre *tre;
> + u32 *tre_local;
> +
> + if (tre_ch >= lldev->nr_tres) {
> + dev_err(lldev->dev,
> + "invalid TRE number in transfer params:%d", tre_ch);
> + return;
> + }
> +
> + tre = &lldev->trepool[tre_ch];
> + if (atomic_read(&tre->allocated) != true) {
> + dev_err(lldev->dev,
> + "trying to set params on an unused TRE:%d", tre_ch);
> + return;
> + }
> +
> + tre_local = &tre->tre_local[0];
> + tre_local[TRE_LEN_IDX] = len;
> + tre_local[TRE_SRC_LOW_IDX] = lower_32_bits(src);
> + tre_local[TRE_SRC_HI_IDX] = upper_32_bits(src);
> + tre_local[TRE_DEST_LOW_IDX] = lower_32_bits(dest);
> + tre_local[TRE_DEST_HI_IDX] = upper_32_bits(dest);
> + tre->int_flags = flags;
> +}
> +
> +/*
> + * Called during initialization and after an error condition
> + * to restore hardware state.
> + */
> +int hidma_ll_setup(struct hidma_lldev *lldev)
> +{
> + int rc;
> + u64 addr;
> + u32 val;
> + u32 nr_tres = lldev->nr_tres;
> +
> + lldev->pending_tre_count = 0;
> + lldev->tre_processed_off = 0;
> + lldev->evre_processed_off = 0;
> + lldev->tre_write_offset = 0;
> +
> + /* disable interrupts */
> + hidma_ll_enable_irq(lldev, 0);
> +
> + /* clear all pending interrupts */
> + val = readl(lldev->evca + EVCA_IRQ_STAT_OFFSET);
> + writel(val, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> +
> + rc = hidma_ll_reset(lldev);
> + if (rc)
> + return rc;
> +
> + /*
> + * Clear all pending interrupts again.
> + * Otherwise, we observe reset complete interrupts.
> + */
> + val = readl(lldev->evca + EVCA_IRQ_STAT_OFFSET);
> + writel(val, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> +
> + /* disable interrupts again after reset */
> + hidma_ll_enable_irq(lldev, 0);
> +
> + addr = lldev->tre_ring_handle;
> + writel(lower_32_bits(addr), lldev->trca + TRCA_RING_LOW_OFFSET);
> + writel(upper_32_bits(addr), lldev->trca + TRCA_RING_HIGH_OFFSET);
> + writel(lldev->tre_ring_size, lldev->trca + TRCA_RING_LEN_OFFSET);
> +
> + addr = lldev->evre_ring_handle;
> + writel(lower_32_bits(addr), lldev->evca + EVCA_RING_LOW_OFFSET);
> + writel(upper_32_bits(addr), lldev->evca + EVCA_RING_HIGH_OFFSET);
> + writel(EVRE_SIZE * nr_tres, lldev->evca + EVCA_RING_LEN_OFFSET);
> +
> + /* support IRQ only for now */
> + val = readl(lldev->evca + EVCA_INTCTRL_OFFSET);
> + val &= ~0xF;
> + val |= 0x1;
> + writel(val, lldev->evca + EVCA_INTCTRL_OFFSET);
> +
> + /* clear all pending interrupts and enable them */
> + writel(ENABLE_IRQS, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> + hidma_ll_enable_irq(lldev, ENABLE_IRQS);
> +
> + rc = hidma_ll_enable(lldev);
> + if (rc)
> + return rc;
> +
> + return rc;
> +}
> +
> +struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
> + void __iomem *trca, void __iomem *evca,
> + u8 chidx)
> +{
> + u32 required_bytes;
> + struct hidma_lldev *lldev;
> + int rc;
> +
> + if (!trca || !evca || !dev || !nr_tres)
> + return NULL;
> +
> + /* need at least four TREs */
> + if (nr_tres < 4)
> + return NULL;
> +
> + /* need an extra space */
> + nr_tres += 1;
> +
> + lldev = devm_kzalloc(dev, sizeof(struct hidma_lldev), GFP_KERNEL);
> + if (!lldev)
> + return NULL;
> +
> + lldev->evca = evca;
> + lldev->trca = trca;
> + lldev->dev = dev;
> + required_bytes = sizeof(struct hidma_tre) * nr_tres;
> + lldev->trepool = devm_kzalloc(lldev->dev, required_bytes, GFP_KERNEL);
> + if (!lldev->trepool)
> + return NULL;
> +
> + required_bytes = sizeof(lldev->pending_tre_list[0]) * nr_tres;
> + lldev->pending_tre_list = devm_kzalloc(dev, required_bytes, GFP_KERNEL);
devm_kcalloc for each?
> + if (!lldev->pending_tre_list)
> + return NULL;
> +
> + required_bytes = sizeof(lldev->tx_status_list[0]) * nr_tres;
> + lldev->tx_status_list = devm_kzalloc(dev, required_bytes, GFP_KERNEL);
Ditto.
> + if (!lldev->tx_status_list)
> + return NULL;
> +
> + lldev->tre_ring = dmam_alloc_coherent(dev, (TRE_SIZE + 1) * nr_tres,
> + &lldev->tre_ring_handle,
> + GFP_KERNEL);
> + if (!lldev->tre_ring)
> + return NULL;
> +
> + memset(lldev->tre_ring, 0, (TRE_SIZE + 1) * nr_tres);
> + lldev->tre_ring_size = TRE_SIZE * nr_tres;
> + lldev->nr_tres = nr_tres;
> +
> + /* the TRE ring has to be TRE_SIZE aligned */
> + if (!IS_ALIGNED(lldev->tre_ring_handle, TRE_SIZE)) {
> + u8 tre_ring_shift;
> +
> + tre_ring_shift = lldev->tre_ring_handle % TRE_SIZE;
> + tre_ring_shift = TRE_SIZE - tre_ring_shift;
> + lldev->tre_ring_handle += tre_ring_shift;
> + lldev->tre_ring += tre_ring_shift;
> + }
> +
> + lldev->evre_ring = dmam_alloc_coherent(dev, (EVRE_SIZE + 1) * nr_tres,
> + &lldev->evre_ring_handle,
> + GFP_KERNEL);
> + if (!lldev->evre_ring)
> + return NULL;
> +
> + memset(lldev->evre_ring, 0, (EVRE_SIZE + 1) * nr_tres);
> + lldev->evre_ring_size = EVRE_SIZE * nr_tres;
> +
> + /* the EVRE ring has to be EVRE_SIZE aligned */
> + if (!IS_ALIGNED(lldev->evre_ring_handle, EVRE_SIZE)) {
> + u8 evre_ring_shift;
> +
> + evre_ring_shift = lldev->evre_ring_handle % EVRE_SIZE;
> + evre_ring_shift = EVRE_SIZE - evre_ring_shift;
> + lldev->evre_ring_handle += evre_ring_shift;
> + lldev->evre_ring += evre_ring_shift;
> + }
> + lldev->nr_tres = nr_tres;
> + lldev->chidx = chidx;
> +
> + rc = kfifo_alloc(&lldev->handoff_fifo,
> + nr_tres * sizeof(struct hidma_tre *), GFP_KERNEL);
> + if (rc)
> + return NULL;
> +
> + rc = hidma_ll_setup(lldev);
> + if (rc)
> + return NULL;
> +
> + spin_lock_init(&lldev->lock);
> + tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev);
> + lldev->initialized = 1;
> + hidma_ll_enable_irq(lldev, ENABLE_IRQS);
> + return lldev;
> +}
> +
> +int hidma_ll_uninit(struct hidma_lldev *lldev)
> +{
> + int rc = 0;
> + u32 val;
> +
> + if (!lldev)
> + return -ENODEV;
> +
> + if (lldev->initialized) {
> + u32 required_bytes;
> +
> + lldev->initialized = 0;
> +
> + required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres;
> + tasklet_kill(&lldev->task);
Can this be moved up? Or you afraid of racing?
> + memset(lldev->trepool, 0, required_bytes);
> + lldev->trepool = NULL;
> + lldev->pending_tre_count = 0;
> + lldev->tre_write_offset = 0;
> +
> + rc = hidma_ll_reset(lldev);
> +
> + /*
> + * Clear all pending interrupts again.
> + * Otherwise, we observe reset complete interrupts.
> + */
> + val = readl(lldev->evca + EVCA_IRQ_STAT_OFFSET);
> + writel(val, lldev->evca + EVCA_IRQ_CLR_OFFSET);
> + hidma_ll_enable_irq(lldev, 0);
> + }
> + return rc;
> +}
> +
> +irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
> +{
> + struct hidma_lldev *lldev = arg;
> +
> + hidma_ll_int_handler_internal(lldev);
> + return IRQ_HANDLED;
> +}
> +
> +enum dma_status hidma_ll_status(struct hidma_lldev *lldev, u32 tre_ch)
> +{
> + enum dma_status ret = DMA_ERROR;
> + unsigned long flags;
> + u8 err_code;
> +
> + spin_lock_irqsave(&lldev->lock, flags);
> + err_code = lldev->tx_status_list[tre_ch].err_code;
> +
> + if (err_code & EVRE_STATUS_COMPLETE)
> + ret = DMA_COMPLETE;
> + else if (err_code & EVRE_STATUS_ERROR)
> + ret = DMA_ERROR;
> + else
> + ret = DMA_IN_PROGRESS;
> + spin_unlock_irqrestore(&lldev->lock, flags);
> +
> + return ret;
> +}
> --
> Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>
> --
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--
With Best Regards,
Andy Shevchenko
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