This patch adds memory to memory scatter-gather support to the Marvell
mv_or DMA driver.
Signed-off-by: Stefan Roese <sr@xxxxxxx>
Cc: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Cc: Marcin Wojtas <mw@xxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
---
v2:
- Change none, but now compiles clean for x86_64 since the following patch
has been applied in the mean-time:
434cec62a6d73b8c8080cd992bc97a564fdd5a5a
bus: mvebu-mbus: Provide stub function for mvebu_mbus_get_io_win_info()
drivers/dma/mv_xor.c | 183 +++++++++++++++++++++++++++++++++++++++++++++++++--
drivers/dma/mv_xor.h | 1 +
2 files changed, 180 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 23f7528..b0d09d9 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -68,6 +68,36 @@ static void mv_desc_init(struct mv_xor_desc_slot *desc,
hw_desc->byte_count = byte_count;
}
+/* Populate the descriptor */
+static void mv_xor_config_sg_ll_desc(struct mv_xor_desc_slot *desc,
+ dma_addr_t dma_src, dma_addr_t dma_dst,
+ u32 len, struct mv_xor_desc_slot *prev)
+{
+ struct mv_xor_desc *hw_desc = desc->hw_desc;
+
+ hw_desc->status = XOR_DESC_DMA_OWNED;
+ hw_desc->phy_next_desc = 0;
+ /* Configure for XOR with only one src address -> MEMCPY */
+ hw_desc->desc_command = XOR_DESC_OPERATION_XOR | (0x1 << 0);
+ hw_desc->phy_dest_addr = dma_dst;
+ hw_desc->phy_src_addr[0] = dma_src;
+ hw_desc->byte_count = len;
+
+ if (prev) {
+ struct mv_xor_desc *hw_prev = prev->hw_desc;
+
+ hw_prev->phy_next_desc = desc->async_tx.phys;
+ }
+}
+
+static void mv_xor_desc_config_eod(struct mv_xor_desc_slot *desc)
+{
+ struct mv_xor_desc *hw_desc = desc->hw_desc;
+
+ /* Enable end-of-descriptor interrupt */
+ hw_desc->desc_command |= XOR_DESC_EOD_INT_EN;
+}
+
static void mv_desc_set_mode(struct mv_xor_desc_slot *desc)
{
struct mv_xor_desc *hw_desc = desc->hw_desc;
@@ -228,8 +258,13 @@ mv_chan_clean_completed_slots(struct mv_xor_chan *mv_chan)
list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,
node) {
- if (async_tx_test_ack(&iter->async_tx))
+ if (async_tx_test_ack(&iter->async_tx)) {
list_move_tail(&iter->node, &mv_chan->free_slots);
+ if (!list_empty(&iter->sg_tx_list)) {
+ list_splice_tail_init(&iter->sg_tx_list,
+ &mv_chan->free_slots);
+ }
+ }
}
return 0;
}
@@ -244,11 +279,20 @@ mv_desc_clean_slot(struct mv_xor_desc_slot *desc,
/* the client is allowed to attach dependent operations
* until 'ack' is set
*/
- if (!async_tx_test_ack(&desc->async_tx))
+ if (!async_tx_test_ack(&desc->async_tx)) {
/* move this slot to the completed_slots */
list_move_tail(&desc->node, &mv_chan->completed_slots);
- else
+ if (!list_empty(&desc->sg_tx_list)) {
+ list_splice_tail_init(&desc->sg_tx_list,
+ &mv_chan->completed_slots);
+ }
+ } else {
list_move_tail(&desc->node, &mv_chan->free_slots);
+ if (!list_empty(&desc->sg_tx_list)) {
+ list_splice_tail_init(&desc->sg_tx_list,
+ &mv_chan->free_slots);
+ }
+ }
return 0;
}
@@ -450,6 +494,7 @@ static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
dma_async_tx_descriptor_init(&slot->async_tx, chan);
slot->async_tx.tx_submit = mv_xor_tx_submit;
INIT_LIST_HEAD(&slot->node);
+ INIT_LIST_HEAD(&slot->sg_tx_list);
dma_desc = mv_chan->dma_desc_pool;
slot->async_tx.phys = dma_desc + idx * MV_XOR_SLOT_SIZE;
slot->idx = idx++;
@@ -617,6 +662,132 @@ mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
}
+/**
+ * mv_xor_prep_dma_sg - prepare descriptors for a memory sg transaction
+ * @chan: DMA channel
+ * @dst_sg: Destination scatter list
+ * @dst_sg_len: Number of entries in destination scatter list
+ * @src_sg: Source scatter list
+ * @src_sg_len: Number of entries in source scatter list
+ * @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_sg(struct dma_chan *chan, struct scatterlist *dst_sg,
+ unsigned int dst_sg_len, struct scatterlist *src_sg,
+ unsigned int src_sg_len, unsigned long flags)
+{
+ struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+ struct mv_xor_desc_slot *new;
+ struct mv_xor_desc_slot *first = NULL;
+ struct mv_xor_desc_slot *prev = NULL;
+ size_t len, dst_avail, src_avail;
+ dma_addr_t dma_dst, dma_src;
+ int desc_cnt = 0;
+ int ret;
+
+ dev_dbg(mv_chan_to_devp(mv_chan),
+ "%s dst_sg_len: %d src_sg_len: %d flags: %ld\n",
+ __func__, dst_sg_len, src_sg_len, flags);
+
+ dst_avail = sg_dma_len(dst_sg);
+ src_avail = sg_dma_len(src_sg);
+
+ /* Run until we are out of scatterlist entries */
+ while (true) {
+ /* Allocate and populate the descriptor */
+ desc_cnt++;
+ new = mv_chan_alloc_slot(mv_chan);
+ if (!new) {
+ dev_err(mv_chan_to_devp(mv_chan),
+ "Out of descriptors (desc_cnt=%d)!\n",
+ desc_cnt);
+ goto err;
+ }
+
+ len = min_t(size_t, src_avail, dst_avail);
+ len = min_t(size_t, len, MV_XOR_MAX_BYTE_COUNT);
+ if (len == 0)
+ goto fetch;
+
+ if (len < MV_XOR_MIN_BYTE_COUNT) {
+ dev_err(mv_chan_to_devp(mv_chan),
+ "Transfer size of %zu too small!\n", len);
+ goto err;
+ }
+
+ dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) -
+ dst_avail;
+ dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) -
+ src_avail;
+
+ /* Check if a new window needs to get added for 'dst' */
+ ret = mv_xor_add_io_win(mv_chan, dma_dst);
+ if (ret)
+ goto err;
+
+ /* Check if a new window needs to get added for 'src' */
+ ret = mv_xor_add_io_win(mv_chan, dma_src);
+ if (ret)
+ goto err;
+
+ /* Populate the descriptor */
+ mv_xor_config_sg_ll_desc(new, dma_src, dma_dst, len, prev);
+ prev = new;
+ dst_avail -= len;
+ src_avail -= len;
+
+ if (!first)
+ first = new;
+ else
+ list_move_tail(&new->node, &first->sg_tx_list);
+
+fetch:
+ /* Fetch the next dst scatterlist entry */
+ if (dst_avail == 0) {
+ if (dst_sg_len == 0)
+ break;
+
+ /* Fetch the next entry: if there are no more: done */
+ dst_sg = sg_next(dst_sg);
+ if (dst_sg == NULL)
+ break;
+
+ dst_sg_len--;
+ dst_avail = sg_dma_len(dst_sg);
+ }
+
+ /* Fetch the next src scatterlist entry */
+ if (src_avail == 0) {
+ if (src_sg_len == 0)
+ break;
+
+ /* Fetch the next entry: if there are no more: done */
+ src_sg = sg_next(src_sg);
+ if (src_sg == NULL)
+ break;
+
+ src_sg_len--;
+ src_avail = sg_dma_len(src_sg);
+ }
+ }
+
+ /* Set the EOD flag in the last descriptor */
+ mv_xor_desc_config_eod(new);
+ first->async_tx.flags = flags;
+
+ return &first->async_tx;
+
+err:
+ /* Cleanup: Move all descriptors back into the free list */
+ spin_lock_bh(&mv_chan->lock);
+ mv_desc_clean_slot(first, mv_chan);
+ spin_unlock_bh(&mv_chan->lock);
+
+ return NULL;
+}
+
static void mv_xor_free_chan_resources(struct dma_chan *chan)
{
struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
@@ -1083,6 +1254,8 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt;
if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;
+ if (dma_has_cap(DMA_SG, dma_dev->cap_mask))
+ dma_dev->device_prep_dma_sg = mv_xor_prep_dma_sg;
if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
dma_dev->max_xor = 8;
dma_dev->device_prep_dma_xor = mv_xor_prep_dma_xor;
@@ -1132,10 +1305,11 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
goto err_free_irq;
}
- dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s)\n",
+ dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s%s)\n",
mv_chan->op_in_desc ? "Descriptor Mode" : "Registers Mode",
dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",
dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "cpy " : "",
+ dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "sg " : "",
dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "intr " : "");
dma_async_device_register(dma_dev);
@@ -1378,6 +1552,7 @@ static int mv_xor_probe(struct platform_device *pdev)
dma_cap_zero(cap_mask);
dma_cap_set(DMA_MEMCPY, cap_mask);
+ dma_cap_set(DMA_SG, cap_mask);
dma_cap_set(DMA_XOR, cap_mask);
dma_cap_set(DMA_INTERRUPT, cap_mask);
diff --git a/drivers/dma/mv_xor.h b/drivers/dma/mv_xor.h
index 88eeab2..cf921dd 100644
--- a/drivers/dma/mv_xor.h
+++ b/drivers/dma/mv_xor.h
@@ -148,6 +148,7 @@ struct mv_xor_chan {
*/
struct mv_xor_desc_slot {
struct list_head node;
+ struct list_head sg_tx_list;
enum dma_transaction_type type;
void *hw_desc;
u16 idx;
--
2.10.1
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