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    Subject[PATCH 3/4] dmaengine: Register as a DMA resource
    Date
    From: Sanjay R Mehta <sanju.mehta@amd.com>

    This Registers the ptdma to Linux dmaengine
    framework as general purpose DMA channels.

    Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
    Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
    Reviewed-by: Rajesh Kumar <Rajesh1.Kumar@amd.com>
    ---
    drivers/dma/ptdma/Kconfig | 1 +
    drivers/dma/ptdma/Makefile | 3 +-
    drivers/dma/ptdma/ptdma-dev.c | 8 +
    drivers/dma/ptdma/ptdma-dmaengine.c | 700 ++++++++++++++++++++++++++++++++++++
    drivers/dma/ptdma/ptdma.h | 43 +++
    5 files changed, 754 insertions(+), 1 deletion(-)
    create mode 100644 drivers/dma/ptdma/ptdma-dmaengine.c

    diff --git a/drivers/dma/ptdma/Kconfig b/drivers/dma/ptdma/Kconfig
    index a373431..3954501 100644
    --- a/drivers/dma/ptdma/Kconfig
    +++ b/drivers/dma/ptdma/Kconfig
    @@ -3,5 +3,6 @@ config AMD_PTDMA
    tristate "AMD Passthru DMA Engine"
    default m
    depends on X86_64 && PCI
    + select DMA_ENGINE
    help
    Provides the support for AMD Passthru DMA engine.
    diff --git a/drivers/dma/ptdma/Makefile b/drivers/dma/ptdma/Makefile
    index a5b4cef..5fc174a 100644
    --- a/drivers/dma/ptdma/Makefile
    +++ b/drivers/dma/ptdma/Makefile
    @@ -6,6 +6,7 @@
    obj-$(CONFIG_AMD_PTDMA) += ptdma.o

    ptdma-objs := ptdma-ops.o \
    - ptdma-dev.o
    + ptdma-dev.o \
    + ptdma-dmaengine.o

    ptdma-$(CONFIG_PCI) += ptdma-pci.o
    diff --git a/drivers/dma/ptdma/ptdma-dev.c b/drivers/dma/ptdma/ptdma-dev.c
    index e69999b..1a7a982 100644
    --- a/drivers/dma/ptdma/ptdma-dev.c
    +++ b/drivers/dma/ptdma/ptdma-dev.c
    @@ -357,6 +357,11 @@ int pt_core_init(struct pt_device *pt)
    /* Put this on the unit list to make it available */
    pt_add_device(pt);

    + /* Register the DMA engine support */
    + ret = pt_dmaengine_register(pt);
    + if (ret)
    + goto e_kthread;
    +
    return 0;


    @@ -382,6 +387,9 @@ void pt_core_destroy(struct pt_device *pt)
    struct pt_cmd_queue *cmd_q = &pt->cmd_q;
    struct pt_cmd *cmd;

    + /* Unregister the DMA engine */
    + pt_dmaengine_unregister(pt);
    +
    /* Remove this device from the list of available units first */
    pt_del_device(pt);

    diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c
    new file mode 100644
    index 0000000..265cdaa
    --- /dev/null
    +++ b/drivers/dma/ptdma/ptdma-dmaengine.c
    @@ -0,0 +1,700 @@
    +// SPDX-License-Identifier: GPL-2.0-only
    +/*
    + * AMD Passthrough DMA device driver
    + *
    + * Copyright (C) 2019 Advanced Micro Devices, Inc.
    + *
    + * Author: Sanjay R Mehta <sanju.mehta@amd.com>
    + *
    + * Based on CCP driver
    + * Original copyright message:
    + *
    + * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
    + *
    + * Author: Gary R Hook <gary.hook@amd.com>
    + */
    +
    +#include "ptdma.h"
    +#include "../dmaengine.h"
    +
    +#define PT_DMA_WIDTH(_mask) \
    +({ \
    + u64 mask = _mask + 1; \
    + (mask == 0) ? 64 : fls64(mask); \
    +})
    +
    +static void pt_free_cmd_resources(struct pt_device *pt,
    + struct list_head *list)
    +{
    + struct pt_dma_cmd *cmd, *ctmp;
    +
    + list_for_each_entry_safe(cmd, ctmp, list, entry) {
    + list_del(&cmd->entry);
    + kmem_cache_free(pt->dma_cmd_cache, cmd);
    + }
    +}
    +
    +static void pt_free_desc_resources(struct pt_device *pt,
    + struct list_head *list)
    +{
    + struct pt_dma_desc *desc, *dtmp;
    +
    + list_for_each_entry_safe(desc, dtmp, list, entry) {
    + pt_free_cmd_resources(pt, &desc->active);
    + pt_free_cmd_resources(pt, &desc->pending);
    +
    + list_del(&desc->entry);
    + kmem_cache_free(pt->dma_desc_cache, desc);
    + }
    +}
    +
    +static void pt_free_chan_resources(struct dma_chan *dma_chan)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + unsigned long flags;
    +
    + dev_dbg(chan->pt->dev, "%s - chan=%p\n", __func__, chan);
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + pt_free_desc_resources(chan->pt, &chan->complete);
    + pt_free_desc_resources(chan->pt, &chan->active);
    + pt_free_desc_resources(chan->pt, &chan->pending);
    + pt_free_desc_resources(chan->pt, &chan->created);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +}
    +
    +static void pt_cleanup_desc_resources(struct pt_device *pt,
    + struct list_head *list)
    +{
    + struct pt_dma_desc *desc, *dtmp;
    +
    + list_for_each_entry_safe_reverse(desc, dtmp, list, entry) {
    + if (!async_tx_test_ack(&desc->tx_desc))
    + continue;
    +
    + dev_dbg(pt->dev, "%s - desc=%p\n", __func__, desc);
    +
    + pt_free_cmd_resources(pt, &desc->active);
    + pt_free_cmd_resources(pt, &desc->pending);
    +
    + list_del(&desc->entry);
    + kmem_cache_free(pt->dma_desc_cache, desc);
    + }
    +}
    +
    +static void pt_do_cleanup(unsigned long data)
    +{
    + struct pt_dma_chan *chan = (struct pt_dma_chan *)data;
    + unsigned long flags;
    +
    + dev_dbg(chan->pt->dev, "%s - chan=%s\n", __func__,
    + dma_chan_name(&chan->dma_chan));
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + pt_cleanup_desc_resources(chan->pt, &chan->complete);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +}
    +
    +static int pt_issue_next_cmd(struct pt_dma_desc *desc)
    +{
    + struct pt_dma_cmd *cmd;
    + int ret;
    +
    + cmd = list_first_entry(&desc->pending, struct pt_dma_cmd, entry);
    + list_move(&cmd->entry, &desc->active);
    +
    + dev_dbg(desc->pt->dev, "%s - tx %d, cmd=%p\n", __func__,
    + desc->tx_desc.cookie, cmd);
    +
    + ret = pt_enqueue_cmd(&cmd->pt_cmd);
    + if (!ret || (ret == -EINPROGRESS) || (ret == -EBUSY))
    + return 0;
    +
    + dev_dbg(desc->pt->dev, "%s - error: ret=%d, tx %d, cmd=%p\n", __func__,
    + ret, desc->tx_desc.cookie, cmd);
    +
    + return ret;
    +}
    +
    +static void pt_free_active_cmd(struct pt_dma_desc *desc)
    +{
    + struct pt_dma_cmd *cmd;
    +
    + cmd = list_first_entry_or_null(&desc->active, struct pt_dma_cmd,
    + entry);
    + if (!cmd)
    + return;
    +
    + dev_dbg(desc->pt->dev, "%s - freeing tx %d cmd=%p\n",
    + __func__, desc->tx_desc.cookie, cmd);
    +
    + list_del(&cmd->entry);
    + kmem_cache_free(desc->pt->dma_cmd_cache, cmd);
    +}
    +
    +static struct pt_dma_desc *__pt_next_dma_desc(struct pt_dma_chan *chan,
    + struct pt_dma_desc *desc)
    +{
    + /* Move current DMA descriptor to the complete list */
    + if (desc)
    + list_move(&desc->entry, &chan->complete);
    +
    + /* Get the next DMA descriptor on the active list */
    + desc = list_first_entry_or_null(&chan->active, struct pt_dma_desc,
    + entry);
    +
    + return desc;
    +}
    +
    +static struct pt_dma_desc *pt_handle_active_desc(struct pt_dma_chan *chan,
    + struct pt_dma_desc *desc)
    +{
    + struct dma_async_tx_descriptor *tx_desc;
    + unsigned long flags;
    +
    + /* Loop over descriptors until one is found with commands */
    + do {
    + if (desc) {
    + /* Remove the DMA command from the list and free it */
    + pt_free_active_cmd(desc);
    +
    + if (!list_empty(&desc->pending)) {
    + /* No errors, keep going */
    + if (desc->status != DMA_ERROR)
    + return desc;
    +
    + /* Error, free remaining commands and move on */
    + pt_free_cmd_resources(desc->pt,
    + &desc->pending);
    + }
    +
    + tx_desc = &desc->tx_desc;
    + } else {
    + tx_desc = NULL;
    + }
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + if (desc) {
    + if (desc->status != DMA_ERROR)
    + desc->status = DMA_COMPLETE;
    +
    + dev_dbg(desc->pt->dev,
    + "%s - tx %d complete, status=%u\n", __func__,
    + desc->tx_desc.cookie, desc->status);
    +
    + dma_cookie_complete(tx_desc);
    + dma_descriptor_unmap(tx_desc);
    + }
    +
    + desc = __pt_next_dma_desc(chan, desc);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +
    + if (tx_desc) {
    + dmaengine_desc_get_callback_invoke(tx_desc, NULL);
    +
    + dma_run_dependencies(tx_desc);
    + }
    + } while (desc);
    +
    + return NULL;
    +}
    +
    +static struct pt_dma_desc *__pt_pending_to_active(struct pt_dma_chan *chan)
    +{
    + struct pt_dma_desc *desc;
    +
    + if (list_empty(&chan->pending))
    + return NULL;
    +
    + desc = list_empty(&chan->active)
    + ? list_first_entry(&chan->pending, struct pt_dma_desc, entry)
    + : NULL;
    +
    + list_splice_tail_init(&chan->pending, &chan->active);
    +
    + return desc;
    +}
    +
    +static void pt_cmd_callback(void *data, int err)
    +{
    + struct pt_dma_desc *desc = data;
    + struct pt_dma_chan *chan;
    + int ret;
    +
    + if (err == -EINPROGRESS)
    + return;
    +
    + chan = container_of(desc->tx_desc.chan, struct pt_dma_chan,
    + dma_chan);
    +
    + dev_dbg(chan->pt->dev, "%s - tx %d callback, err=%d\n",
    + __func__, desc->tx_desc.cookie, err);
    +
    + if (err)
    + desc->status = DMA_ERROR;
    +
    + while (true) {
    + /* Check for DMA descriptor completion */
    + desc = pt_handle_active_desc(chan, desc);
    +
    + /* Don't submit cmd if no descriptor or DMA is paused */
    + if (!desc || (chan->status == DMA_PAUSED))
    + break;
    +
    + ret = pt_issue_next_cmd(desc);
    + if (!ret)
    + break;
    +
    + desc->status = DMA_ERROR;
    + }
    +
    + tasklet_schedule(&chan->cleanup_tasklet);
    +}
    +
    +static dma_cookie_t pt_tx_submit(struct dma_async_tx_descriptor *tx_desc)
    +{
    + struct pt_dma_desc *desc = container_of(tx_desc, struct pt_dma_desc,
    + tx_desc);
    + struct pt_dma_chan *chan;
    + dma_cookie_t cookie;
    + unsigned long flags;
    +
    + chan = container_of(tx_desc->chan, struct pt_dma_chan, dma_chan);
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + cookie = dma_cookie_assign(tx_desc);
    + list_del(&desc->entry);
    + list_add_tail(&desc->entry, &chan->pending);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +
    + dev_dbg(chan->pt->dev, "%s - added tx descriptor %d to pending list\n",
    + __func__, cookie);
    +
    + return cookie;
    +}
    +
    +static struct pt_dma_cmd *pt_alloc_dma_cmd(struct pt_dma_chan *chan)
    +{
    + struct pt_dma_cmd *cmd;
    +
    + cmd = kmem_cache_zalloc(chan->pt->dma_cmd_cache, GFP_NOWAIT);
    +
    + return cmd;
    +}
    +
    +static struct pt_dma_desc *pt_alloc_dma_desc(struct pt_dma_chan *chan,
    + unsigned long flags)
    +{
    + struct pt_dma_desc *desc;
    +
    + desc = kmem_cache_zalloc(chan->pt->dma_desc_cache, GFP_NOWAIT);
    + if (!desc)
    + return NULL;
    +
    + dma_async_tx_descriptor_init(&desc->tx_desc, &chan->dma_chan);
    + desc->tx_desc.flags = flags;
    + desc->tx_desc.tx_submit = pt_tx_submit;
    + desc->pt = chan->pt;
    + INIT_LIST_HEAD(&desc->pending);
    + INIT_LIST_HEAD(&desc->active);
    + desc->status = DMA_IN_PROGRESS;
    +
    + return desc;
    +}
    +
    +static struct pt_dma_desc *pt_create_desc(struct dma_chan *dma_chan,
    + struct scatterlist *dst_sg,
    + unsigned int dst_nents,
    + struct scatterlist *src_sg,
    + unsigned int src_nents,
    + unsigned long flags)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_device *pt = chan->pt;
    + struct pt_dma_desc *desc;
    + struct pt_dma_cmd *cmd;
    + struct pt_cmd *pt_cmd;
    + struct pt_passthru_engine *pt_engine;
    + unsigned int src_offset, src_len;
    + unsigned int dst_offset, dst_len;
    + unsigned int len;
    + unsigned long sflags;
    + size_t total_len;
    +
    + if (!dst_sg || !src_sg)
    + return NULL;
    +
    + if (!dst_nents || !src_nents)
    + return NULL;
    +
    + desc = pt_alloc_dma_desc(chan, flags);
    + if (!desc)
    + return NULL;
    +
    + total_len = 0;
    +
    + src_len = sg_dma_len(src_sg);
    + src_offset = 0;
    +
    + dst_len = sg_dma_len(dst_sg);
    + dst_offset = 0;
    +
    + while (true) {
    + if (!src_len) {
    + src_nents--;
    + if (!src_nents)
    + break;
    +
    + src_sg = sg_next(src_sg);
    + if (!src_sg)
    + break;
    +
    + src_len = sg_dma_len(src_sg);
    + src_offset = 0;
    + continue;
    + }
    +
    + if (!dst_len) {
    + dst_nents--;
    + if (!dst_nents)
    + break;
    +
    + dst_sg = sg_next(dst_sg);
    + if (!dst_sg)
    + break;
    +
    + dst_len = sg_dma_len(dst_sg);
    + dst_offset = 0;
    + continue;
    + }
    +
    + len = min(dst_len, src_len);
    +
    + cmd = pt_alloc_dma_cmd(chan);
    + if (!cmd)
    + goto err;
    +
    + pt_cmd = &cmd->pt_cmd;
    + pt_cmd->pt = chan->pt;
    + pt_engine = &pt_cmd->passthru;
    + pt_cmd->flags = PT_CMD_MAY_BACKLOG;
    + pt_cmd->engine = PT_ENGINE_PASSTHRU;
    + pt_engine->bit_mod = PT_PASSTHRU_BITWISE_NOOP;
    + pt_engine->byte_swap = PT_PASSTHRU_BYTESWAP_NOOP;
    + pt_engine->src_dma = sg_dma_address(src_sg) + src_offset;
    + pt_engine->dst_dma = sg_dma_address(dst_sg) + dst_offset;
    + pt_engine->src_len = len;
    + pt_engine->final = 1;
    + pt_cmd->callback = pt_cmd_callback;
    + pt_cmd->data = desc;
    +
    + list_add_tail(&cmd->entry, &desc->pending);
    +
    + dev_dbg(pt->dev,
    + "%s - cmd=%p, src=%pad, dst=%pad, len=%llu\n", __func__,
    + cmd, &pt_engine->src_dma,
    + &pt_engine->dst_dma, pt_engine->src_len);
    +
    + total_len += len;
    +
    + src_len -= len;
    + src_offset += len;
    +
    + dst_len -= len;
    + dst_offset += len;
    + }
    +
    + desc->len = total_len;
    +
    + if (list_empty(&desc->pending))
    + goto err;
    +
    + dev_dbg(pt->dev, "%s - desc=%p\n", __func__, desc);
    +
    + spin_lock_irqsave(&chan->lock, sflags);
    +
    + list_add_tail(&desc->entry, &chan->created);
    +
    + spin_unlock_irqrestore(&chan->lock, sflags);
    +
    + return desc;
    +
    +err:
    + pt_free_cmd_resources(pt, &desc->pending);
    + kmem_cache_free(pt->dma_desc_cache, desc);
    +
    + return NULL;
    +}
    +
    +static struct dma_async_tx_descriptor *pt_prep_dma_memcpy(
    + struct dma_chan *dma_chan, dma_addr_t dst, dma_addr_t src, size_t len,
    + unsigned long flags)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_dma_desc *desc;
    + struct scatterlist dst_sg, src_sg;
    +
    + dev_dbg(chan->pt->dev,
    + "%s - src=%pad, dst=%pad, len=%zu, flags=%#lx\n",
    + __func__, &src, &dst, len, flags);
    +
    + sg_init_table(&dst_sg, 1);
    + sg_dma_address(&dst_sg) = dst;
    + sg_dma_len(&dst_sg) = len;
    +
    + sg_init_table(&src_sg, 1);
    + sg_dma_address(&src_sg) = src;
    + sg_dma_len(&src_sg) = len;
    +
    + desc = pt_create_desc(dma_chan, &dst_sg, 1, &src_sg, 1, flags);
    + if (!desc)
    + return NULL;
    +
    + return &desc->tx_desc;
    +}
    +
    +static struct dma_async_tx_descriptor *pt_prep_dma_interrupt(
    + struct dma_chan *dma_chan, unsigned long flags)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_dma_desc *desc;
    +
    + desc = pt_alloc_dma_desc(chan, flags);
    + if (!desc)
    + return NULL;
    +
    + return &desc->tx_desc;
    +}
    +
    +static void pt_issue_pending(struct dma_chan *dma_chan)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_dma_desc *desc;
    + unsigned long flags;
    +
    + dev_dbg(chan->pt->dev, "%s\n", __func__);
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + desc = __pt_pending_to_active(chan);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +
    + /* If there was nothing active, start processing */
    + if (desc)
    + pt_cmd_callback(desc, 0);
    +}
    +
    +static enum dma_status pt_tx_status(struct dma_chan *dma_chan,
    + dma_cookie_t cookie,
    + struct dma_tx_state *state)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_dma_desc *desc;
    + enum dma_status ret;
    + unsigned long flags;
    +
    + if (chan->status == DMA_PAUSED) {
    + ret = DMA_PAUSED;
    + goto out;
    + }
    +
    + ret = dma_cookie_status(dma_chan, cookie, state);
    + if (ret == DMA_COMPLETE) {
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + /* Get status from complete chain, if still there */
    + list_for_each_entry(desc, &chan->complete, entry) {
    + if (desc->tx_desc.cookie != cookie)
    + continue;
    +
    + ret = desc->status;
    + break;
    + }
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    + }
    +
    +out:
    + dev_dbg(chan->pt->dev, "%s - %u\n", __func__, ret);
    +
    + return ret;
    +}
    +
    +static int pt_pause(struct dma_chan *dma_chan)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    +
    + chan->status = DMA_PAUSED;
    +
    + /*TODO: Wait for active DMA to complete before returning? */
    +
    + return 0;
    +}
    +
    +static int pt_resume(struct dma_chan *dma_chan)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + struct pt_dma_desc *desc;
    + unsigned long flags;
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + desc = list_first_entry_or_null(&chan->active, struct pt_dma_desc,
    + entry);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +
    + /* Indicate the channel is running again */
    + chan->status = DMA_IN_PROGRESS;
    +
    + /* If there was something active, re-start */
    + if (desc)
    + pt_cmd_callback(desc, 0);
    +
    + return 0;
    +}
    +
    +static int pt_terminate_all(struct dma_chan *dma_chan)
    +{
    + struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
    + dma_chan);
    + unsigned long flags;
    +
    + dev_dbg(chan->pt->dev, "%s\n", __func__);
    +
    + spin_lock_irqsave(&chan->lock, flags);
    +
    + pt_free_desc_resources(chan->pt, &chan->active);
    + pt_free_desc_resources(chan->pt, &chan->pending);
    + pt_free_desc_resources(chan->pt, &chan->created);
    +
    + spin_unlock_irqrestore(&chan->lock, flags);
    +
    + return 0;
    +}
    +
    +int pt_dmaengine_register(struct pt_device *pt)
    +{
    + struct pt_dma_chan *chan;
    + struct dma_device *dma_dev = &pt->dma_dev;
    + struct dma_chan *dma_chan;
    + char *dma_cmd_cache_name;
    + char *dma_desc_cache_name;
    + int ret;
    +
    + pt->pt_dma_chan = devm_kcalloc(pt->dev, 1,
    + sizeof(*(pt->pt_dma_chan)),
    + GFP_KERNEL);
    + if (!pt->pt_dma_chan)
    + return -ENOMEM;
    +
    + dma_cmd_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL,
    + "%s-dmaengine-cmd-cache",
    + pt->name);
    + if (!dma_cmd_cache_name)
    + return -ENOMEM;
    +
    + pt->dma_cmd_cache = kmem_cache_create(dma_cmd_cache_name,
    + sizeof(struct pt_dma_cmd),
    + sizeof(void *),
    + SLAB_HWCACHE_ALIGN, NULL);
    + if (!pt->dma_cmd_cache)
    + return -ENOMEM;
    +
    + dma_desc_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL,
    + "%s-dmaengine-desc-cache",
    + pt->name);
    + if (!dma_desc_cache_name) {
    + ret = -ENOMEM;
    + goto err_cache;
    + }
    +
    + pt->dma_desc_cache = kmem_cache_create(dma_desc_cache_name,
    + sizeof(struct pt_dma_desc),
    + sizeof(void *),
    + SLAB_HWCACHE_ALIGN, NULL);
    + if (!pt->dma_desc_cache) {
    + ret = -ENOMEM;
    + goto err_cache;
    + }
    +
    + dma_dev->dev = pt->dev;
    + dma_dev->src_addr_widths = PT_DMA_WIDTH(dma_get_mask(pt->dev));
    + dma_dev->dst_addr_widths = PT_DMA_WIDTH(dma_get_mask(pt->dev));
    + dma_dev->directions = DMA_MEM_TO_MEM;
    + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
    + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
    + dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
    + dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
    +
    + INIT_LIST_HEAD(&dma_dev->channels);
    +
    + chan = pt->pt_dma_chan;
    + dma_chan = &chan->dma_chan;
    +
    + chan->pt = pt;
    +
    + spin_lock_init(&chan->lock);
    + INIT_LIST_HEAD(&chan->created);
    + INIT_LIST_HEAD(&chan->pending);
    + INIT_LIST_HEAD(&chan->active);
    + INIT_LIST_HEAD(&chan->complete);
    +
    + tasklet_init(&chan->cleanup_tasklet, pt_do_cleanup,
    + (unsigned long)chan);
    +
    + dma_chan->device = dma_dev;
    + dma_cookie_init(dma_chan);
    +
    + list_add_tail(&dma_chan->device_node, &dma_dev->channels);
    +
    + dma_dev->device_free_chan_resources = pt_free_chan_resources;
    + dma_dev->device_prep_dma_memcpy = pt_prep_dma_memcpy;
    + dma_dev->device_prep_dma_interrupt = pt_prep_dma_interrupt;
    + dma_dev->device_issue_pending = pt_issue_pending;
    + dma_dev->device_tx_status = pt_tx_status;
    + dma_dev->device_pause = pt_pause;
    + dma_dev->device_resume = pt_resume;
    + dma_dev->device_terminate_all = pt_terminate_all;
    +
    + ret = dma_async_device_register(dma_dev);
    + if (ret)
    + goto err_reg;
    +
    + return 0;
    +
    +err_reg:
    + kmem_cache_destroy(pt->dma_desc_cache);
    +
    +err_cache:
    + kmem_cache_destroy(pt->dma_cmd_cache);
    +
    + return ret;
    +}
    +
    +void pt_dmaengine_unregister(struct pt_device *pt)
    +{
    + struct dma_device *dma_dev = &pt->dma_dev;
    +
    + dma_async_device_unregister(dma_dev);
    +
    + kmem_cache_destroy(pt->dma_desc_cache);
    + kmem_cache_destroy(pt->dma_cmd_cache);
    +}
    diff --git a/drivers/dma/ptdma/ptdma.h b/drivers/dma/ptdma/ptdma.h
    index 4e89517..e8bb4e7 100644
    --- a/drivers/dma/ptdma/ptdma.h
    +++ b/drivers/dma/ptdma/ptdma.h
    @@ -25,6 +25,7 @@
    #include <linux/list.h>
    #include <linux/wait.h>
    #include <linux/dmapool.h>
    +#include <linux/dmaengine.h>

    #define MAX_PT_NAME_LEN 16
    #define MAX_DMAPOOL_NAME_LEN 32
    @@ -227,6 +228,39 @@ struct pt_cmd {
    void *data;
    };

    +struct pt_dma_cmd {
    + struct list_head entry;
    + struct pt_cmd pt_cmd;
    +};
    +
    +struct pt_dma_desc {
    + struct list_head entry;
    +
    + struct pt_device *pt;
    +
    + struct list_head pending;
    + struct list_head active;
    +
    + enum dma_status status;
    + struct dma_async_tx_descriptor tx_desc;
    + size_t len;
    +};
    +
    +struct pt_dma_chan {
    + struct pt_device *pt;
    +
    + spinlock_t lock;
    + struct list_head created;
    + struct list_head pending;
    + struct list_head active;
    + struct list_head complete;
    +
    + struct tasklet_struct cleanup_tasklet;
    +
    + enum dma_status status;
    + struct dma_chan dma_chan;
    +};
    +
    struct pt_cmd_queue {
    struct pt_device *pt;

    @@ -310,6 +344,12 @@ struct pt_device {
    */
    struct pt_cmd_queue cmd_q;

    + /* Support for the DMA Engine capabilities */
    + struct dma_device dma_dev;
    + struct pt_dma_chan *pt_dma_chan;
    + struct kmem_cache *dma_cmd_cache;
    + struct kmem_cache *dma_desc_cache;
    +
    wait_queue_head_t lsb_queue;
    unsigned int lsb_count;
    u32 lsb_start;
    @@ -460,6 +500,9 @@ int pt_cmd_queue_thread(void *data);

    int pt_run_cmd(struct pt_cmd_queue *cmd_q, struct pt_cmd *cmd);

    +int pt_dmaengine_register(struct pt_device *pt);
    +void pt_dmaengine_unregister(struct pt_device *pt);
    +
    int pt_core_init(struct pt_device *pt);
    void pt_core_destroy(struct pt_device *pt);

    --
    2.7.4
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      Last update: 2019-09-24 09:33    [W:4.426 / U:0.016 seconds]
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