dmaengine, async_tx: support alignment checks

Some engines have transfer size and address alignment restrictions.  Add
a per-operation alignment property to struct dma_device that the async
routines and dmatest can use to check alignment capabilities.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

6 files changed, 67 insertions, 6 deletions

diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c
index b38cbb3fd527..0ec1fb69d4ea 100644
--- a/crypto/async_tx/async_memcpy.c
+++ b/crypto/async_tx/async_memcpy.c
@@ -50,7 +50,7 @@ async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
         struct dma_device *device = chan ? chan->device : NULL;
         struct dma_async_tx_descriptor *tx = NULL;
 
-        if (device) {
+        if (device && is_dma_copy_aligned(device, src_offset, dest_offset, len)) {
                 dma_addr_t dma_dest, dma_src;
                 unsigned long dma_prep_flags = 0;
 
diff --git a/crypto/async_tx/async_memset.c b/crypto/async_tx/async_memset.c
index a374784e3329..58e4a8752aee 100644
--- a/crypto/async_tx/async_memset.c
+++ b/crypto/async_tx/async_memset.c
@@ -47,7 +47,7 @@ async_memset(struct page *dest, int val, unsigned int offset, size_t len,
         struct dma_device *device = chan ? chan->device : NULL;
         struct dma_async_tx_descriptor *tx = NULL;
 
-        if (device) {
+        if (device && is_dma_fill_aligned(device, offset, 0, len)) {
                 dma_addr_t dma_dest;
                 unsigned long dma_prep_flags = 0;
 
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index a25e290c39fb..b88db6d1dc65 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -211,7 +211,8 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
 
         if (dma_src && device &&
             (src_cnt <= dma_maxpq(device, 0) ||
-             dma_maxpq(device, DMA_PREP_CONTINUE) > 0)) {
+             dma_maxpq(device, DMA_PREP_CONTINUE) > 0) &&
+            is_dma_pq_aligned(device, offset, 0, len)) {
                 /* run the p+q asynchronously */
                 pr_debug("%s: (async) disks: %d len: %zu\n",
                          __func__, disks, len);
@@ -274,7 +275,8 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
         else if (sizeof(dma_addr_t) <= sizeof(struct page *))
                 dma_src = (dma_addr_t *) blocks;
 
-        if (dma_src && device && disks <= dma_maxpq(device, 0)) {
+        if (dma_src && device && disks <= dma_maxpq(device, 0) &&
+            is_dma_pq_aligned(device, offset, 0, len)) {
                 struct device *dev = device->dev;
                 dma_addr_t *pq = &dma_src[disks-2];
                 int i;
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index db279872ef3d..b459a9034aac 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -193,7 +193,7 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
         else if (sizeof(dma_addr_t) <= sizeof(struct page *))
                 dma_src = (dma_addr_t *) src_list;
 
-        if (dma_src && chan) {
+        if (dma_src && chan && is_dma_xor_aligned(chan->device, offset, 0, len)) {
                 /* run the xor asynchronously */
                 pr_debug("%s (async): len: %zu\n", __func__, len);
 
@@ -265,7 +265,8 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
         else if (sizeof(dma_addr_t) <= sizeof(struct page *))
                 dma_src = (dma_addr_t *) src_list;
 
-        if (dma_src && device && src_cnt <= device->max_xor) {
+        if (dma_src && device && src_cnt <= device->max_xor &&
+            is_dma_xor_aligned(device, offset, 0, len)) {
                 unsigned long dma_prep_flags = 0;
                 int i;
 
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 58e49e41c7a3..a3722a7384b5 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -288,6 +288,7 @@ static int dmatest_func(void *data)
                 dma_addr_t dma_dsts[dst_cnt];
                 struct completion cmp;
                 unsigned long tmo = msecs_to_jiffies(3000);
+                u8 align = 0;
 
                 total_tests++;
 
@@ -295,6 +296,18 @@ static int dmatest_func(void *data)
                 src_off = dmatest_random() % (test_buf_size - len + 1);
                 dst_off = dmatest_random() % (test_buf_size - len + 1);
 
+                /* honor alignment restrictions */
+                if (thread->type == DMA_MEMCPY)
+                        align = dev->copy_align;
+                else if (thread->type == DMA_XOR)
+                        align = dev->xor_align;
+                else if (thread->type == DMA_PQ)
+                        align = dev->pq_align;
+
+                len = (len >> align) << align;
+                src_off = (src_off >> align) << align;
+                dst_off = (dst_off >> align) << align;
+
                 dmatest_init_srcs(thread->srcs, src_off, len);
                 dmatest_init_dsts(thread->dsts, dst_off, len);
 
@@ -311,6 +324,7 @@ static int dmatest_func(void *data)
                                                      DMA_BIDIRECTIONAL);
                 }
 
+
                 if (thread->type == DMA_MEMCPY)
                         tx = dev->device_prep_dma_memcpy(chan,
                                                          dma_dsts[0] + dst_off,
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index db23fd583f98..835b9c7bf1c2 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -245,6 +245,10 @@ struct dma_async_tx_descriptor {
  * @cap_mask: one or more dma_capability flags
  * @max_xor: maximum number of xor sources, 0 if no capability
  * @max_pq: maximum number of PQ sources and PQ-continue capability
+ * @copy_align: alignment shift for memcpy operations
+ * @xor_align: alignment shift for xor operations
+ * @pq_align: alignment shift for pq operations
+ * @fill_align: alignment shift for memset operations
  * @dev_id: unique device ID
  * @dev: struct device reference for dma mapping api
  * @device_alloc_chan_resources: allocate resources and return the
@@ -271,6 +275,10 @@ struct dma_device {
         dma_cap_mask_t  cap_mask;
         unsigned short max_xor;
         unsigned short max_pq;
+        u8 copy_align;
+        u8 xor_align;
+        u8 pq_align;
+        u8 fill_align;
         #define DMA_HAS_PQ_CONTINUE (1 << 15)
 
         int dev_id;
@@ -314,6 +322,42 @@ struct dma_device {
         void (*device_issue_pending)(struct dma_chan *chan);
 };
 
+static inline bool dmaengine_check_align(u8 align, size_t off1, size_t off2, size_t len)
+{
+        size_t mask;
+
+        if (!align)
+                return true;
+        mask = (1 << align) - 1;
+        if (mask & (off1 | off2 | len))
+                return false;
+        return true;
+}
+
+static inline bool is_dma_copy_aligned(struct dma_device *dev, size_t off1,
+                                       size_t off2, size_t len)
+{
+        return dmaengine_check_align(dev->copy_align, off1, off2, len);
+}
+
+static inline bool is_dma_xor_aligned(struct dma_device *dev, size_t off1,
+                                      size_t off2, size_t len)
+{
+        return dmaengine_check_align(dev->xor_align, off1, off2, len);
+}
+
+static inline bool is_dma_pq_aligned(struct dma_device *dev, size_t off1,
+                                     size_t off2, size_t len)
+{
+        return dmaengine_check_align(dev->pq_align, off1, off2, len);
+}
+
+static inline bool is_dma_fill_aligned(struct dma_device *dev, size_t off1,
+                                       size_t off2, size_t len)
+{
+        return dmaengine_check_align(dev->fill_align, off1, off2, len);
+}
+
 static inline void
 dma_set_maxpq(struct dma_device *dma, int maxpq, int has_pq_continue)
 {