[PATCH v4 2/3] dmaengine: ptdma: register PTDMA controller as a DMA resource

Sanjay R Mehta
2020-04-28T21:14:46Z

From: Sanjay R Mehta <sanju.mehta@amd.com>

This registers the ptdma queue to Linux dmaengine framework
as general-purpose DMA channels.

Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
---
drivers/dma/ptdma/Kconfig | 2 +
drivers/dma/ptdma/Makefile | 3 +-
drivers/dma/ptdma/ptdma-dev.c | 35 +++
drivers/dma/ptdma/ptdma-dmaengine.c | 597 ++++++++++++++++++++++++++++++++++++
drivers/dma/ptdma/ptdma.h | 38 +++
5 files changed, 674 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 f93f9c2..694ed27 100644
--- a/drivers/dma/ptdma/Kconfig
+++ b/drivers/dma/ptdma/Kconfig
@@ -2,6 +2,8 @@
config AMD_PTDMA
tristate "AMD PassThru DMA Engine"
depends on X86_64 && PCI
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
help
Enable support for the AMD PTDMA controller. This controller
provides DMA capabilities & performs high bandwidth memory to
diff --git a/drivers/dma/ptdma/Makefile b/drivers/dma/ptdma/Makefile
index 320fa82..6fcb4ad 100644
--- a/drivers/dma/ptdma/Makefile
+++ b/drivers/dma/ptdma/Makefile
@@ -5,6 +5,7 @@

obj-$(CONFIG_AMD_PTDMA) += ptdma.o

-ptdma-objs := ptdma-dev.o
+ptdma-objs := 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 0a69fd4..14b4339 100644
--- a/drivers/dma/ptdma/ptdma-dev.c
+++ b/drivers/dma/ptdma/ptdma-dev.c
@@ -234,6 +234,8 @@ static irqreturn_t pt_core_irq_handler(int irq, void *data)

pt_core_enable_queue_interrupts(pt);

+ tasklet_schedule(&pt->tasklet);
+
return IRQ_HANDLED;
}

@@ -252,6 +254,26 @@ static void pt_init_cmdq_regs(struct pt_cmd_queue *cmd_q)
cmd_q->reg_interrupt_status = io_regs + CMD_Q_INTERRUPT_STATUS_BASE;
}

+static void pt_do_cmd_complete(unsigned long data)
+{
+ struct pt_tasklet_data *tdata = (struct pt_tasklet_data *)data;
+ struct pt_cmd *cmd = tdata->cmd;
+ struct pt_cmd_queue *cmd_q = &cmd->pt->cmd_q;
+ u32 tail;
+
+ tail = lower_32_bits(cmd_q->qdma_tail + cmd_q->qidx * Q_DESC_SIZE);
+ if (cmd_q->cmd_error) {
+ /*
+ * Log the error and flush the queue by
+ * moving the head pointer
+ */
+ pt_log_error(cmd_q->pt, cmd_q->cmd_error);
+ iowrite32(tail, cmd_q->reg_head_lo);
+ }
+
+ cmd->pt_cmd_callback(cmd->data, cmd->ret);
+}
+
int pt_core_init(struct pt_device *pt)
{
struct device *dev = pt->dev;
@@ -353,8 +375,18 @@ int pt_core_init(struct pt_device *pt)

dev_dbg(dev, "PTDMA device %s registration successful...\n", pt->name);

+ /* Register the DMA engine support */
+ ret = pt_dmaengine_register(pt);
+ if (ret)
+ goto e_dmaengine;
+
+ tasklet_init(&pt->tasklet, pt_do_cmd_complete, (ulong)&pt->tdata);
+
return 0;

+e_dmaengine:
+ free_irq(pt->pt_irq, pt);
+
e_dma_alloc:
dma_free_coherent(dev, cmd_q->qsize, cmd_q->qbase, cmd_q->qbase_dma);

@@ -370,6 +402,9 @@ 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..2b0d739
--- /dev/null
+++ b/drivers/dma/ptdma/ptdma-dmaengine.c
@@ -0,0 +1,597 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Passthrough DMA device driver
+ * -- Based on the CCP driver
+ *
+ * Copyright (C) 2016,2020 Advanced Micro Devices, Inc.
+ *
+ * Author: Sanjay R Mehta <sanju.mehta@amd.com>
+ * Author: Gary R Hook <gary.hook@amd.com>
+ */
+
+#include "ptdma.h"
+#include "../dmaengine.h"
+#include "../virt-dma.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_chan_resources(struct dma_chan *dma_chan)
+{
+ struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
+ vc.chan);
+
+ dev_dbg(chan->pt->dev, "%s - chan=%p\n", __func__, chan);
+
+ vchan_free_chan_resources(&chan->vc);
+}
+
+static void pt_do_cleanup(struct virt_dma_desc *vd)
+
+{
+ struct pt_dma_desc *desc = container_of(vd, struct pt_dma_desc, vd);
+ struct pt_device *pt = desc->pt;
+ struct pt_dma_chan *chan;
+
+ chan = container_of(desc->vd.tx.chan, struct pt_dma_chan,
+ vc.chan);
+
+ pt_free_cmd_resources(pt, &desc->active);
+ pt_free_cmd_resources(pt, &desc->pending);
+ kmem_cache_free(pt->dma_desc_cache, desc);
+}
+
+static int pt_issue_next_cmd(struct pt_dma_desc *desc)
+{
+ struct pt_passthru_engine *pt_engine;
+ struct pt_dma_cmd *cmd;
+ struct pt_device *pt;
+ struct pt_cmd *pt_cmd;
+ struct pt_cmd_queue *cmd_q;
+
+ 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->vd.tx.cookie, cmd);
+
+ pt_cmd = &cmd->pt_cmd;
+ pt = pt_cmd->pt;
+ cmd_q = &pt->cmd_q;
+ pt_engine = &pt_cmd->passthru;
+
+ if (!pt_engine->final)
+ return -EINVAL;
+
+ if (!pt_engine->src_dma || !pt_engine->dst_dma)
+ return -EINVAL;
+
+ pt->tdata.cmd = pt_cmd;
+
+ /* Execute the command */
+ pt_cmd->ret = pt_core_perform_passthru(cmd_q, pt_engine);
+
+ return 0;
+}
+
+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->vd.tx.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)
+{
+ /* Get the next DMA descriptor on the active list */
+ struct virt_dma_desc *vd = vchan_next_desc(&chan->vc);
+
+ return vd ? container_of(vd, struct pt_dma_desc, vd) : NULL;
+}
+
+static struct pt_dma_desc *__pt_next_dma_desc(struct pt_dma_chan *chan)
+{
+ /* Get the next DMA descriptor on the active list */
+ struct virt_dma_desc *vd = vchan_next_desc(&chan->vc);
+
+ if (list_empty(&chan->vc.desc_submitted))
+ return NULL;
+
+ vd = list_empty(&chan->vc.desc_issued) ?
+ list_first_entry(&chan->vc.desc_submitted,
+ struct virt_dma_desc, node) : NULL;
+
+ vchan_issue_pending(&chan->vc);
+
+ return vd ? container_of(vd, struct pt_dma_desc, vd) : NULL;
+}
+
+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;
+ struct virt_dma_desc *vd;
+ 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->vd.tx;
+ vd = &desc->vd;
+ } else {
+ tx_desc = NULL;
+ }
+
+ spin_lock_irqsave(&chan->vc.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->vd.tx.cookie, desc->status);
+
+ dma_cookie_complete(tx_desc);
+ dma_descriptor_unmap(tx_desc);
+ list_del(&desc->vd.node);
+ }
+
+ desc = pt_next_dma_desc(chan);
+
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ if (tx_desc) {
+ dmaengine_desc_get_callback_invoke(tx_desc, NULL);
+ dma_run_dependencies(tx_desc);
+ vchan_vdesc_fini(vd);
+ }
+ } while (desc);
+
+ return NULL;
+}
+
+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->vd.tx.chan, struct pt_dma_chan,
+ vc.chan);
+
+ dev_dbg(chan->pt->dev, "%s - tx %d callback, err=%d\n",
+ __func__, desc->vd.tx.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;
+ }
+}
+
+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;
+
+ vchan_tx_prep(&chan->vc, &desc->vd, flags);
+
+ 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,
+ vc.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;
+ 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->engine = PT_ENGINE_PASSTHRU;
+ 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->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;
+
+ 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,
+ vc.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->vd.tx;
+}
+
+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,
+ vc.chan);
+ struct pt_dma_desc *desc;
+
+ desc = pt_alloc_dma_desc(chan, flags);
+ if (!desc)
+ return NULL;
+
+ return &desc->vd.tx;
+}
+
+static void pt_issue_pending(struct dma_chan *dma_chan)
+{
+ struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
+ vc.chan);
+ struct pt_dma_desc *desc;
+ unsigned long flags;
+
+ dev_dbg(chan->pt->dev, "%s\n", __func__);
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+
+ desc = __pt_next_dma_desc(chan);
+
+ spin_unlock_irqrestore(&chan->vc.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,
+ vc.chan);
+ struct pt_dma_desc *desc;
+ enum dma_status ret;
+ unsigned long flags;
+ struct virt_dma_desc *vd;
+
+ ret = dma_cookie_status(dma_chan, cookie, state);
+ if (ret == DMA_COMPLETE)
+ return ret;
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ vd = vchan_find_desc(&chan->vc, cookie);
+ desc = vd ? container_of(vd, struct pt_dma_desc, vd) : NULL;
+ ret = desc->status;
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ 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,
+ vc.chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ if (chan->status == DMA_IN_PROGRESS) {
+ chan->status = DMA_PAUSED;
+ pt_stop_queue(&chan->pt->cmd_q);
+ }
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ return 0;
+}
+
+static int pt_resume(struct dma_chan *dma_chan)
+{
+ struct pt_dma_chan *chan = container_of(dma_chan, struct pt_dma_chan,
+ vc.chan);
+ struct pt_dma_desc *desc = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ if (chan->status == DMA_PAUSED) {
+ /* Indicate the channel is running again */
+ chan->status = DMA_IN_PROGRESS;
+ pt_start_queue(&chan->pt->cmd_q);
+ desc = __pt_next_dma_desc(chan);
+ }
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ /* 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,
+ vc.chan);
+
+ dev_dbg(chan->pt->dev, "%s\n", __func__);
+
+ vchan_free_chan_resources(&chan->vc);
+
+ 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;
+ chan->pt = pt;
+ dma_chan = &chan->vc.chan;
+
+ 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;
+
+ chan->vc.desc_free = pt_do_cleanup;
+ vchan_init(&chan->vc, dma_dev);
+
+ 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 5b21162..a807f4c 100644
--- a/drivers/dma/ptdma/ptdma.h
+++ b/drivers/dma/ptdma/ptdma.h
@@ -20,6 +20,9 @@
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/dmapool.h>
+#include <linux/dmaengine.h>
+
+#include "../virt-dma.h"

#define MAX_PT_NAME_LEN 16
#define MAX_DMAPOOL_NAME_LEN 32
@@ -178,6 +181,32 @@ struct pt_cmd {
void *data;
};

+struct pt_dma_cmd {
+ struct list_head entry;
+ struct pt_cmd pt_cmd;
+};
+
+struct pt_dma_desc {
+ struct virt_dma_desc vd;
+
+ struct pt_device *pt;
+
+ struct list_head pending;
+ struct list_head active;
+
+ enum dma_status status;
+
+ size_t len;
+};
+
+struct pt_dma_chan {
+ struct virt_dma_chan vc;
+
+ struct pt_device *pt;
+
+ enum dma_status status;
+};
+
struct pt_cmd_queue {
struct pt_device *pt;

@@ -246,6 +275,12 @@ 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;

struct tasklet_struct tasklet;
@@ -312,6 +347,9 @@ struct pt_dev_vdata {
const unsigned int version;
};

+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