I/OAT: Add completion callback for async_tx interface use

The async_tx interface includes a completion callback.  This adds support
for using that callback, including using interrupts on completion.

[akpm@linux-foundation.org: various fixes]
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index 15906027c8de..7e4a785c2dff 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -212,6 +212,18 @@ static dma_cookie_t ioat_tx_submit(struct dma_async_tx_descriptor *tx)
         } while (len && (new = ioat_dma_get_next_descriptor(ioat_chan)));
 
         hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
+        if (new->async_tx.callback) {
+                hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
+                if (first != new) {
+                        /* move callback into to last desc */
+                        new->async_tx.callback = first->async_tx.callback;
+                        new->async_tx.callback_param
+                                        = first->async_tx.callback_param;
+                        first->async_tx.callback = NULL;
+                        first->async_tx.callback_param = NULL;
+                }
+        }
+
         new->tx_cnt = desc_count;
         new->async_tx.ack = orig_ack; /* client is in control of this ack */
 
@@ -517,6 +529,11 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan)
                                         pci_unmap_addr(desc, src),
                                         pci_unmap_len(desc, len),
                                         PCI_DMA_TODEVICE);
+                        if (desc->async_tx.callback) {
+                                desc->async_tx.callback(
+                                                desc->async_tx.callback_param);
+                                desc->async_tx.callback = NULL;
+                        }
                 }
 
                 if (desc->async_tx.phys != phys_complete) {
@@ -638,6 +655,12 @@ static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
  */
 #define IOAT_TEST_SIZE 2000
 
+static void ioat_dma_test_callback(void *dma_async_param)
+{
+        printk(KERN_ERR "ioatdma: ioat_dma_test_callback(%p)\n",
+                        dma_async_param);
+}
+
 /**
  * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
  * @device: device to be tested
@@ -692,6 +715,8 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
         addr = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
                         DMA_FROM_DEVICE);
         ioat_set_dest(addr, tx, 0);
+        tx->callback = ioat_dma_test_callback;
+        tx->callback_param = (void *)0x8086;
         cookie = ioat_tx_submit(tx);
         if (cookie < 0) {
                 dev_err(&device->pdev->dev,