]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - crypto/async_tx/async_xor.c
async_tx: ensure the xor destination buffer remains dma-mapped
[linux-2.6-omap-h63xx.git] / crypto / async_tx / async_xor.c
index 3a0dddca5a1097e473d103a15797547da66e7bf1..1fcf45ac81ecefd22ad23fe53aa333ffe2b6efa8 100644 (file)
  *     when CONFIG_DMA_ENGINE=n
  */
 static __always_inline struct dma_async_tx_descriptor *
-do_async_xor(struct dma_device *device,
-       struct dma_chan *chan, struct page *dest, struct page **src_list,
-       unsigned int offset, unsigned int src_cnt, size_t len,
-       enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
-       dma_async_tx_callback cb_fn, void *cb_param)
+do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
+            unsigned int offset, int src_cnt, size_t len,
+            enum async_tx_flags flags,
+            struct dma_async_tx_descriptor *depend_tx,
+            dma_async_tx_callback cb_fn, void *cb_param)
 {
-       dma_addr_t dma_dest;
+       struct dma_device *dma = chan->device;
        dma_addr_t *dma_src = (dma_addr_t *) src_list;
-       struct dma_async_tx_descriptor *tx;
+       struct dma_async_tx_descriptor *tx = NULL;
+       int src_off = 0;
        int i;
-       unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
-
-       pr_debug("%s: len: %zu\n", __func__, len);
-
-       dma_dest = dma_map_page(device->dev, dest, offset, len,
-                               DMA_FROM_DEVICE);
+       dma_async_tx_callback _cb_fn;
+       void *_cb_param;
+       enum async_tx_flags async_flags;
+       enum dma_ctrl_flags dma_flags;
+       int xor_src_cnt;
+       dma_addr_t dma_dest;
 
+       dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_FROM_DEVICE);
        for (i = 0; i < src_cnt; i++)
-               dma_src[i] = dma_map_page(device->dev, src_list[i], offset,
+               dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,
                                          len, DMA_TO_DEVICE);
 
-       /* Since we have clobbered the src_list we are committed
-        * to doing this asynchronously.  Drivers force forward progress
-        * in case they can not provide a descriptor
-        */
-       tx = device->device_prep_dma_xor(chan, dma_dest, dma_src, src_cnt, len,
-                                        dma_prep_flags);
-       if (!tx) {
-               if (depend_tx)
+       while (src_cnt) {
+               async_flags = flags;
+               dma_flags = 0;
+               xor_src_cnt = min(src_cnt, dma->max_xor);
+               /* if we are submitting additional xors, leave the chain open,
+                * clear the callback parameters, and leave the destination
+                * buffer mapped
+                */
+               if (src_cnt > xor_src_cnt) {
+                       async_flags &= ~ASYNC_TX_ACK;
+                       dma_flags = DMA_COMPL_SKIP_DEST_UNMAP;
+                       _cb_fn = NULL;
+                       _cb_param = NULL;
+               } else {
+                       _cb_fn = cb_fn;
+                       _cb_param = cb_param;
+               }
+               if (_cb_fn)
+                       dma_flags |= DMA_PREP_INTERRUPT;
+
+               /* Since we have clobbered the src_list we are committed
+                * to doing this asynchronously.  Drivers force forward progress
+                * in case they can not provide a descriptor
+                */
+               tx = dma->device_prep_dma_xor(chan, dma_dest, &dma_src[src_off],
+                                             xor_src_cnt, len, dma_flags);
+
+               if (unlikely(!tx && depend_tx))
                        dma_wait_for_async_tx(depend_tx);
 
-               while (!tx)
-                       tx = device->device_prep_dma_xor(chan, dma_dest,
-                                                        dma_src, src_cnt, len,
-                                                        dma_prep_flags);
-       }
+               /* spin wait for the preceeding transactions to complete */
+               while (unlikely(!tx))
+                       tx = dma->device_prep_dma_xor(chan, dma_dest,
+                                                     &dma_src[src_off],
+                                                     xor_src_cnt, len,
+                                                     dma_flags);
+
+               async_tx_submit(chan, tx, async_flags, depend_tx, _cb_fn,
+                               _cb_param);
+
+               depend_tx = tx;
+               flags |= ASYNC_TX_DEP_ACK;
+
+               if (src_cnt > xor_src_cnt) {
+                       /* drop completed sources */
+                       src_cnt -= xor_src_cnt;
+                       src_off += xor_src_cnt;
 
-       async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+                       /* use the intermediate result a source */
+                       dma_src[--src_off] = dma_dest;
+                       src_cnt++;
+               } else
+                       break;
+       }
 
        return tx;
 }
 
 static void
 do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
-       unsigned int src_cnt, size_t len, enum async_tx_flags flags,
-       struct dma_async_tx_descriptor *depend_tx,
-       dma_async_tx_callback cb_fn, void *cb_param)
+           int src_cnt, size_t len, enum async_tx_flags flags,
+           struct dma_async_tx_descriptor *depend_tx,
+           dma_async_tx_callback cb_fn, void *cb_param)
 {
-       void *_dest;
        int i;
-
-       pr_debug("%s: len: %zu\n", __func__, len);
+       int xor_src_cnt;
+       int src_off = 0;
+       void *dest_buf;
+       void **srcs = (void **) src_list;
 
        /* reuse the 'src_list' array to convert to buffer pointers */
        for (i = 0; i < src_cnt; i++)
-               src_list[i] = (struct page *)
-                       (page_address(src_list[i]) + offset);
+               srcs[i] = page_address(src_list[i]) + offset;
 
        /* set destination address */
-       _dest = page_address(dest) + offset;
+       dest_buf = page_address(dest) + offset;
 
        if (flags & ASYNC_TX_XOR_ZERO_DST)
-               memset(_dest, 0, len);
+               memset(dest_buf, 0, len);
+
+       while (src_cnt > 0) {
+               /* process up to 'MAX_XOR_BLOCKS' sources */
+               xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
+               xor_blocks(xor_src_cnt, len, dest_buf, &srcs[src_off]);
 
-       xor_blocks(src_cnt, len, _dest,
-               (void **) src_list);
+               /* drop completed sources */
+               src_cnt -= xor_src_cnt;
+               src_off += xor_src_cnt;
+       }
 
        async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
 }
@@ -132,106 +178,42 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
        struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_XOR,
                                                      &dest, 1, src_list,
                                                      src_cnt, len);
-       struct dma_device *device = chan ? chan->device : NULL;
-       struct dma_async_tx_descriptor *tx = NULL;
-       dma_async_tx_callback _cb_fn;
-       void *_cb_param;
-       unsigned long local_flags;
-       int xor_src_cnt;
-       int i = 0, src_off = 0;
-
        BUG_ON(src_cnt <= 1);
 
-       while (src_cnt) {
-               local_flags = flags;
-               if (device) { /* run the xor asynchronously */
-                       xor_src_cnt = min(src_cnt, device->max_xor);
-                       /* if we are submitting additional xors
-                        * only set the callback on the last transaction
-                        */
-                       if (src_cnt > xor_src_cnt) {
-                               local_flags &= ~ASYNC_TX_ACK;
-                               _cb_fn = NULL;
-                               _cb_param = NULL;
-                       } else {
-                               _cb_fn = cb_fn;
-                               _cb_param = cb_param;
-                       }
-
-                       tx = do_async_xor(device, chan, dest,
-                                         &src_list[src_off], offset,
-                                         xor_src_cnt, len, local_flags,
-                                         depend_tx, _cb_fn, _cb_param);
-               } else { /* run the xor synchronously */
-                       /* in the sync case the dest is an implied source
-                        * (assumes the dest is at the src_off index)
-                        */
-                       if (flags & ASYNC_TX_XOR_DROP_DST) {
-                               src_cnt--;
-                               src_off++;
-                       }
-
-                       /* process up to 'MAX_XOR_BLOCKS' sources */
-                       xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
+       if (chan) {
+               /* run the xor asynchronously */
+               pr_debug("%s (async): len: %zu\n", __func__, len);
 
-                       /* if we are submitting additional xors
-                        * only set the callback on the last transaction
-                        */
-                       if (src_cnt > xor_src_cnt) {
-                               local_flags &= ~ASYNC_TX_ACK;
-                               _cb_fn = NULL;
-                               _cb_param = NULL;
-                       } else {
-                               _cb_fn = cb_fn;
-                               _cb_param = cb_param;
-                       }
-
-                       /* wait for any prerequisite operations */
-                       if (depend_tx) {
-                               /* if ack is already set then we cannot be sure
-                                * we are referring to the correct operation
-                                */
-                               BUG_ON(async_tx_test_ack(depend_tx));
-                               if (dma_wait_for_async_tx(depend_tx) ==
-                                       DMA_ERROR)
-                                       panic("%s: DMA_ERROR waiting for "
-                                               "depend_tx\n",
-                                               __func__);
-                       }
-
-                       do_sync_xor(dest, &src_list[src_off], offset,
-                               xor_src_cnt, len, local_flags, depend_tx,
-                               _cb_fn, _cb_param);
-               }
+               return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
+                                   flags, depend_tx, cb_fn, cb_param);
+       } else {
+               /* run the xor synchronously */
+               pr_debug("%s (sync): len: %zu\n", __func__, len);
 
-               /* the previous tx is hidden from the client,
-                * so ack it
+               /* in the sync case the dest is an implied source
+                * (assumes the dest is the first source)
                 */
-               if (i && depend_tx)
-                       async_tx_ack(depend_tx);
-
-               depend_tx = tx;
+               if (flags & ASYNC_TX_XOR_DROP_DST) {
+                       src_cnt--;
+                       src_list++;
+               }
 
-               if (src_cnt > xor_src_cnt) {
-                       /* drop completed sources */
-                       src_cnt -= xor_src_cnt;
-                       src_off += xor_src_cnt;
+               /* wait for any prerequisite operations */
+               if (depend_tx) {
+                       /* if ack is already set then we cannot be sure
+                        * we are referring to the correct operation
+                        */
+                       BUG_ON(async_tx_test_ack(depend_tx));
+                       if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR)
+                               panic("%s: DMA_ERROR waiting for depend_tx\n",
+                                       __func__);
+               }
 
-                       /* unconditionally preserve the destination */
-                       flags &= ~ASYNC_TX_XOR_ZERO_DST;
+               do_sync_xor(dest, src_list, offset, src_cnt, len,
+                           flags, depend_tx, cb_fn, cb_param);
 
-                       /* use the intermediate result a source, but remember
-                        * it's dropped, because it's implied, in the sync case
-                        */
-                       src_list[--src_off] = dest;
-                       src_cnt++;
-                       flags |= ASYNC_TX_XOR_DROP_DST;
-               } else
-                       src_cnt = 0;
-               i++;
+               return NULL;
        }
-
-       return tx;
 }
 EXPORT_SYMBOL_GPL(async_xor);