#include <linux/raid/xor.h>
#include <linux/async_tx.h>
-/* do_async_xor - dma map the pages and perform the xor with an engine.
- * This routine is marked __always_inline so it can be compiled away
- * 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 - dma map the pages and perform the xor with an engine */
+static __async_inline struct dma_async_tx_descriptor *
+do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
+ unsigned int offset, int src_cnt, size_t len, dma_addr_t *dma_src,
+ struct async_submit_ctl *submit)
{
- dma_addr_t dma_dest;
- dma_addr_t *dma_src = (dma_addr_t *) src_list;
- struct dma_async_tx_descriptor *tx;
+ struct dma_device *dma = chan->device;
+ struct dma_async_tx_descriptor *tx = NULL;
+ int src_off = 0;
int i;
- unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+ dma_async_tx_callback cb_fn_orig = submit->cb_fn;
+ void *cb_param_orig = submit->cb_param;
+ enum async_tx_flags flags_orig = submit->flags;
+ enum dma_ctrl_flags dma_flags;
+ int xor_src_cnt = 0;
+ dma_addr_t dma_dest;
- pr_debug("%s: len: %zu\n", __func__, len);
+ /* map the dest bidrectional in case it is re-used as a source */
+ dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
+ for (i = 0; i < src_cnt; i++) {
+ /* only map the dest once */
+ if (!src_list[i])
+ continue;
+ if (unlikely(src_list[i] == dest)) {
+ dma_src[xor_src_cnt++] = dma_dest;
+ continue;
+ }
+ dma_src[xor_src_cnt++] = dma_map_page(dma->dev, src_list[i], offset,
+ len, DMA_TO_DEVICE);
+ }
+ src_cnt = xor_src_cnt;
+
+ while (src_cnt) {
+ submit->flags = flags_orig;
+ dma_flags = 0;
+ xor_src_cnt = min(src_cnt, (int)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) {
+ submit->flags &= ~ASYNC_TX_ACK;
+ submit->flags |= ASYNC_TX_FENCE;
+ dma_flags = DMA_COMPL_SKIP_DEST_UNMAP;
+ submit->cb_fn = NULL;
+ submit->cb_param = NULL;
+ } else {
+ submit->cb_fn = cb_fn_orig;
+ submit->cb_param = cb_param_orig;
+ }
+ if (submit->cb_fn)
+ dma_flags |= DMA_PREP_INTERRUPT;
+ if (submit->flags & ASYNC_TX_FENCE)
+ dma_flags |= DMA_PREP_FENCE;
+ /* 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))
+ async_tx_quiesce(&submit->depend_tx);
+
+ /* spin wait for the preceeding transactions to complete */
+ while (unlikely(!tx)) {
+ dma_async_issue_pending(chan);
+ tx = dma->device_prep_dma_xor(chan, dma_dest,
+ &dma_src[src_off],
+ xor_src_cnt, len,
+ dma_flags);
+ }
- dma_dest = dma_map_page(device->dev, dest, offset, len,
- DMA_FROM_DEVICE);
+ async_tx_submit(chan, tx, submit);
+ submit->depend_tx = tx;
- for (i = 0; i < src_cnt; i++)
- dma_src[i] = dma_map_page(device->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)
- 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);
- }
+ 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, struct async_submit_ctl *submit)
{
- void *_dest;
int i;
+ int xor_src_cnt = 0;
+ int src_off = 0;
+ void *dest_buf;
+ void **srcs;
- pr_debug("%s: len: %zu\n", __func__, len);
+ if (submit->scribble)
+ srcs = submit->scribble;
+ else
+ srcs = (void **) src_list;
- /* reuse the 'src_list' array to convert to buffer pointers */
+ /* convert to buffer pointers */
for (i = 0; i < src_cnt; i++)
- src_list[i] = (struct page *)
- (page_address(src_list[i]) + offset);
-
+ if (src_list[i])
+ srcs[xor_src_cnt++] = page_address(src_list[i]) + offset;
+ src_cnt = xor_src_cnt;
/* 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);
+ if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
+ memset(dest_buf, 0, len);
- xor_blocks(src_cnt, len, _dest,
- (void **) src_list);
+ 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]);
- async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
+ /* drop completed sources */
+ src_cnt -= xor_src_cnt;
+ src_off += xor_src_cnt;
+ }
+
+ async_tx_sync_epilog(submit);
}
/**
* async_xor - attempt to xor a set of blocks with a dma engine.
- * xor_blocks always uses the dest as a source so the ASYNC_TX_XOR_ZERO_DST
- * flag must be set to not include dest data in the calculation. The
- * assumption with dma eninges is that they only use the destination
- * buffer as a source when it is explicity specified in the source list.
* @dest: destination page
- * @src_list: array of source pages (if the dest is also a source it must be
- * at index zero). The contents of this array may be overwritten.
- * @offset: offset in pages to start transaction
+ * @src_list: array of source pages
+ * @offset: common src/dst offset to start transaction
* @src_cnt: number of source pages
* @len: length in bytes
- * @flags: ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DEST,
- * ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
- * @depend_tx: xor depends on the result of this transaction.
- * @cb_fn: function to call when the xor completes
- * @cb_param: parameter to pass to the callback routine
+ * @submit: submission / completion modifiers
+ *
+ * honored flags: ASYNC_TX_ACK, ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DST
+ *
+ * xor_blocks always uses the dest as a source so the
+ * ASYNC_TX_XOR_ZERO_DST flag must be set to not include dest data in
+ * the calculation. The assumption with dma eninges is that they only
+ * use the destination buffer as a source when it is explicity specified
+ * in the source list.
+ *
+ * src_list note: if the dest is also a source it must be at index zero.
+ * The contents of this array will be overwritten if a scribble region
+ * is not specified.
*/
struct dma_async_tx_descriptor *
async_xor(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)
+ int src_cnt, size_t len, struct async_submit_ctl *submit)
{
- struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_XOR,
+ struct dma_chan *chan = async_tx_find_channel(submit, 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;
+ dma_addr_t *dma_src = NULL;
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++;
- }
+ if (submit->scribble)
+ dma_src = submit->scribble;
+ else if (sizeof(dma_addr_t) <= sizeof(struct page *))
+ dma_src = (dma_addr_t *) src_list;
- /* process up to 'MAX_XOR_BLOCKS' sources */
- xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
-
- /* 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;
- }
+ 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);
- /* 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(depend_tx->ack);
- 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,
+ dma_src, submit);
+ } else {
+ /* run the xor synchronously */
+ pr_debug("%s (sync): len: %zu\n", __func__, len);
+ WARN_ONCE(chan, "%s: no space for dma address conversion\n",
+ __func__);
- /* 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 (submit->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 */
+ async_tx_quiesce(&submit->depend_tx);
- /* unconditionally preserve the destination */
- flags &= ~ASYNC_TX_XOR_ZERO_DST;
+ do_sync_xor(dest, src_list, offset, src_cnt, len, submit);
- /* 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);
memcmp(a, a + 4, len - 4) == 0);
}
+static inline struct dma_chan *
+xor_val_chan(struct async_submit_ctl *submit, struct page *dest,
+ struct page **src_list, int src_cnt, size_t len)
+{
+ #ifdef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
+ return NULL;
+ #endif
+ return async_tx_find_channel(submit, DMA_XOR_VAL, &dest, 1, src_list,
+ src_cnt, len);
+}
+
/**
- * async_xor_zero_sum - attempt a xor parity check with a dma engine.
+ * async_xor_val - attempt a xor parity check with a dma engine.
* @dest: destination page used if the xor is performed synchronously
- * @src_list: array of source pages. The dest page must be listed as a source
- * at index zero. The contents of this array may be overwritten.
+ * @src_list: array of source pages
* @offset: offset in pages to start transaction
* @src_cnt: number of source pages
* @len: length in bytes
* @result: 0 if sum == 0 else non-zero
- * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
- * @depend_tx: xor depends on the result of this transaction.
- * @cb_fn: function to call when the xor completes
- * @cb_param: parameter to pass to the callback routine
+ * @submit: submission / completion modifiers
+ *
+ * honored flags: ASYNC_TX_ACK
+ *
+ * src_list note: if the dest is also a source it must be at index zero.
+ * The contents of this array will be overwritten if a scribble region
+ * is not specified.
*/
struct dma_async_tx_descriptor *
-async_xor_zero_sum(struct page *dest, struct page **src_list,
- unsigned int offset, int src_cnt, size_t len,
- u32 *result, enum async_tx_flags flags,
- struct dma_async_tx_descriptor *depend_tx,
- dma_async_tx_callback cb_fn, void *cb_param)
+async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
+ int src_cnt, size_t len, enum sum_check_flags *result,
+ struct async_submit_ctl *submit)
{
- struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_ZERO_SUM,
- &dest, 1, src_list,
- src_cnt, len);
+ struct dma_chan *chan = xor_val_chan(submit, dest, src_list, src_cnt, len);
struct dma_device *device = chan ? chan->device : NULL;
struct dma_async_tx_descriptor *tx = NULL;
+ dma_addr_t *dma_src = NULL;
BUG_ON(src_cnt <= 1);
- if (device) {
- dma_addr_t *dma_src = (dma_addr_t *) src_list;
- unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+ if (submit->scribble)
+ dma_src = submit->scribble;
+ 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 &&
+ is_dma_xor_aligned(device, offset, 0, len)) {
+ unsigned long dma_prep_flags = 0;
int i;
pr_debug("%s: (async) len: %zu\n", __func__, len);
+ if (submit->cb_fn)
+ dma_prep_flags |= DMA_PREP_INTERRUPT;
+ if (submit->flags & ASYNC_TX_FENCE)
+ dma_prep_flags |= DMA_PREP_FENCE;
for (i = 0; i < src_cnt; i++)
dma_src[i] = dma_map_page(device->dev, src_list[i],
offset, len, DMA_TO_DEVICE);
- tx = device->device_prep_dma_zero_sum(chan, dma_src, src_cnt,
- len, result,
- dma_prep_flags);
- if (!tx) {
- if (depend_tx)
- dma_wait_for_async_tx(depend_tx);
+ tx = device->device_prep_dma_xor_val(chan, dma_src, src_cnt,
+ len, result,
+ dma_prep_flags);
+ if (unlikely(!tx)) {
+ async_tx_quiesce(&submit->depend_tx);
- while (!tx)
- tx = device->device_prep_dma_zero_sum(chan,
+ while (!tx) {
+ dma_async_issue_pending(chan);
+ tx = device->device_prep_dma_xor_val(chan,
dma_src, src_cnt, len, result,
dma_prep_flags);
+ }
}
- async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+ async_tx_submit(chan, tx, submit);
} else {
- unsigned long xor_flags = flags;
+ enum async_tx_flags flags_orig = submit->flags;
pr_debug("%s: (sync) len: %zu\n", __func__, len);
+ WARN_ONCE(device && src_cnt <= device->max_xor,
+ "%s: no space for dma address conversion\n",
+ __func__);
- xor_flags |= ASYNC_TX_XOR_DROP_DST;
- xor_flags &= ~ASYNC_TX_ACK;
-
- tx = async_xor(dest, src_list, offset, src_cnt, len, xor_flags,
- depend_tx, NULL, NULL);
+ submit->flags |= ASYNC_TX_XOR_DROP_DST;
+ submit->flags &= ~ASYNC_TX_ACK;
- if (tx) {
- if (dma_wait_for_async_tx(tx) == DMA_ERROR)
- panic("%s: DMA_ERROR waiting for tx\n",
- __func__);
- async_tx_ack(tx);
- }
+ tx = async_xor(dest, src_list, offset, src_cnt, len, submit);
- *result = page_is_zero(dest, offset, len) ? 0 : 1;
+ async_tx_quiesce(&tx);
- tx = NULL;
+ *result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;
- async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
+ async_tx_sync_epilog(submit);
+ submit->flags = flags_orig;
}
return tx;
}
-EXPORT_SYMBOL_GPL(async_xor_zero_sum);
-
-static int __init async_xor_init(void)
-{
- #ifdef CONFIG_DMA_ENGINE
- /* To conserve stack space the input src_list (array of page pointers)
- * is reused to hold the array of dma addresses passed to the driver.
- * This conversion is only possible when dma_addr_t is less than the
- * the size of a pointer. HIGHMEM64G is known to violate this
- * assumption.
- */
- BUILD_BUG_ON(sizeof(dma_addr_t) > sizeof(struct page *));
- #endif
-
- return 0;
-}
-
-static void __exit async_xor_exit(void)
-{
- do { } while (0);
-}
-
-module_init(async_xor_init);
-module_exit(async_xor_exit);
+EXPORT_SYMBOL_GPL(async_xor_val);
MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
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