diff options
Diffstat (limited to 'crypto/async_tx/async_xor.c')
| -rw-r--r-- | crypto/async_tx/async_xor.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c new file mode 100644 index 000000000..1a3855284 --- /dev/null +++ b/crypto/async_tx/async_xor.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * xor offload engine api + * + * Copyright © 2006, Intel Corporation. + * + * Dan Williams <dan.j.williams@intel.com> + * + * with architecture considerations by: + * Neil Brown <neilb@suse.de> + * Jeff Garzik <jeff@garzik.org> + */ +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/dma-mapping.h> +#include <linux/raid/xor.h> +#include <linux/async_tx.h> + +/* 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 dmaengine_unmap_data *unmap, + struct async_submit_ctl *submit) +{ + struct dma_device *dma = chan->device; + struct dma_async_tx_descriptor *tx = NULL; + 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 = 0; + int src_cnt = unmap->to_cnt; + int xor_src_cnt; + dma_addr_t dma_dest = unmap->addr[unmap->to_cnt]; + dma_addr_t *src_list = unmap->addr; + + while (src_cnt) { + dma_addr_t tmp; + + submit->flags = flags_orig; + xor_src_cnt = min(src_cnt, (int)dma->max_xor); + /* if we are submitting additional xors, leave the chain open + * and clear the callback parameters + */ + if (src_cnt > xor_src_cnt) { + submit->flags &= ~ASYNC_TX_ACK; + submit->flags |= ASYNC_TX_FENCE; + 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; + + /* Drivers force forward progress in case they can not provide a + * descriptor + */ + tmp = src_list[0]; + if (src_list > unmap->addr) + src_list[0] = dma_dest; + tx = dma->device_prep_dma_xor(chan, dma_dest, src_list, + xor_src_cnt, unmap->len, + dma_flags); + + if (unlikely(!tx)) + async_tx_quiesce(&submit->depend_tx); + + /* spin wait for the preceding transactions to complete */ + while (unlikely(!tx)) { + dma_async_issue_pending(chan); + tx = dma->device_prep_dma_xor(chan, dma_dest, + src_list, + xor_src_cnt, unmap->len, + dma_flags); + } + src_list[0] = tmp; + + dma_set_unmap(tx, unmap); + async_tx_submit(chan, tx, submit); + submit->depend_tx = tx; + + if (src_cnt > xor_src_cnt) { + /* drop completed sources */ + src_cnt -= xor_src_cnt; + /* use the intermediate result a source */ + src_cnt++; + src_list += xor_src_cnt - 1; + } else + break; + } + + return tx; +} + +static void +do_sync_xor_offs(struct page *dest, unsigned int offset, + struct page **src_list, unsigned int *src_offs, + int src_cnt, size_t len, struct async_submit_ctl *submit) +{ + int i; + int xor_src_cnt = 0; + int src_off = 0; + void *dest_buf; + void **srcs; + + if (submit->scribble) + srcs = submit->scribble; + else + srcs = (void **) src_list; + + /* convert to buffer pointers */ + for (i = 0; i < src_cnt; i++) + if (src_list[i]) + srcs[xor_src_cnt++] = page_address(src_list[i]) + + (src_offs ? src_offs[i] : offset); + src_cnt = xor_src_cnt; + /* set destination address */ + dest_buf = page_address(dest) + offset; + + if (submit->flags & ASYNC_TX_XOR_ZERO_DST) + 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]); + + /* drop completed sources */ + src_cnt -= xor_src_cnt; + src_off += xor_src_cnt; + } + + async_tx_sync_epilog(submit); +} + +static inline bool +dma_xor_aligned_offsets(struct dma_device *device, unsigned int offset, + unsigned int *src_offs, int src_cnt, int len) +{ + int i; + + if (!is_dma_xor_aligned(device, offset, 0, len)) + return false; + + if (!src_offs) + return true; + + for (i = 0; i < src_cnt; i++) { + if (!is_dma_xor_aligned(device, src_offs[i], 0, len)) + return false; + } + return true; +} + +/** + * async_xor_offs - attempt to xor a set of blocks with a dma engine. + * @dest: destination page + * @offset: dst offset to start transaction + * @src_list: array of source pages + * @src_offs: array of source pages offset, NULL means common src/dst offset + * @src_cnt: number of source pages + * @len: length in bytes + * @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 engines is that they only + * use the destination buffer as a source when it is explicitly 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_offs(struct page *dest, unsigned int offset, + struct page **src_list, unsigned int *src_offs, + int src_cnt, size_t len, struct async_submit_ctl *submit) +{ + 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 dmaengine_unmap_data *unmap = NULL; + + BUG_ON(src_cnt <= 1); + + if (device) + unmap = dmaengine_get_unmap_data(device->dev, src_cnt+1, GFP_NOWAIT); + + if (unmap && dma_xor_aligned_offsets(device, offset, + src_offs, src_cnt, len)) { + struct dma_async_tx_descriptor *tx; + int i, j; + + /* run the xor asynchronously */ + pr_debug("%s (async): len: %zu\n", __func__, len); + + unmap->len = len; + for (i = 0, j = 0; i < src_cnt; i++) { + if (!src_list[i]) + continue; + unmap->to_cnt++; + unmap->addr[j++] = dma_map_page(device->dev, src_list[i], + src_offs ? src_offs[i] : offset, + len, DMA_TO_DEVICE); + } + + /* map it bidirectional as it may be re-used as a source */ + unmap->addr[j] = dma_map_page(device->dev, dest, offset, len, + DMA_BIDIRECTIONAL); + unmap->bidi_cnt = 1; + + tx = do_async_xor(chan, unmap, submit); + dmaengine_unmap_put(unmap); + return tx; + } else { + dmaengine_unmap_put(unmap); + /* 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__); + + /* in the sync case the dest is an implied source + * (assumes the dest is the first source) + */ + if (submit->flags & ASYNC_TX_XOR_DROP_DST) { + src_cnt--; + src_list++; + if (src_offs) + src_offs++; + } + + /* wait for any prerequisite operations */ + async_tx_quiesce(&submit->depend_tx); + + do_sync_xor_offs(dest, offset, src_list, src_offs, + src_cnt, len, submit); + + return NULL; + } +} +EXPORT_SYMBOL_GPL(async_xor_offs); + +/** + * async_xor - attempt to xor a set of blocks with a dma engine. + * @dest: destination page + * @src_list: array of source pages + * @offset: common src/dst offset to start transaction + * @src_cnt: number of source pages + * @len: length in bytes + * @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 engines is that they only + * use the destination buffer as a source when it is explicitly 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, struct async_submit_ctl *submit) +{ + return async_xor_offs(dest, offset, src_list, NULL, + src_cnt, len, submit); +} +EXPORT_SYMBOL_GPL(async_xor); + +static int page_is_zero(struct page *p, unsigned int offset, size_t len) +{ + return !memchr_inv(page_address(p) + offset, 0, len); +} + +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_val_offs - attempt a xor parity check with a dma engine. + * @dest: destination page used if the xor is performed synchronously + * @offset: des offset in pages to start transaction + * @src_list: array of source pages + * @src_offs: array of source pages offset, NULL means common src/det offset + * @src_cnt: number of source pages + * @len: length in bytes + * @result: 0 if sum == 0 else non-zero + * @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_val_offs(struct page *dest, unsigned int offset, + struct page **src_list, unsigned int *src_offs, + int src_cnt, size_t len, enum sum_check_flags *result, + struct async_submit_ctl *submit) +{ + 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; + struct dmaengine_unmap_data *unmap = NULL; + + BUG_ON(src_cnt <= 1); + + if (device) + unmap = dmaengine_get_unmap_data(device->dev, src_cnt, GFP_NOWAIT); + + if (unmap && src_cnt <= device->max_xor && + dma_xor_aligned_offsets(device, offset, src_offs, src_cnt, 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++) { + unmap->addr[i] = dma_map_page(device->dev, src_list[i], + src_offs ? src_offs[i] : offset, + len, DMA_TO_DEVICE); + unmap->to_cnt++; + } + unmap->len = len; + + tx = device->device_prep_dma_xor_val(chan, unmap->addr, src_cnt, + len, result, + dma_prep_flags); + if (unlikely(!tx)) { + async_tx_quiesce(&submit->depend_tx); + + while (!tx) { + dma_async_issue_pending(chan); + tx = device->device_prep_dma_xor_val(chan, + unmap->addr, src_cnt, len, result, + dma_prep_flags); + } + } + dma_set_unmap(tx, unmap); + async_tx_submit(chan, tx, submit); + } else { + 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__); + + submit->flags |= ASYNC_TX_XOR_DROP_DST; + submit->flags &= ~ASYNC_TX_ACK; + + tx = async_xor_offs(dest, offset, src_list, src_offs, + src_cnt, len, submit); + + async_tx_quiesce(&tx); + + *result = !page_is_zero(dest, offset, len) << SUM_CHECK_P; + + async_tx_sync_epilog(submit); + submit->flags = flags_orig; + } + dmaengine_unmap_put(unmap); + + return tx; +} +EXPORT_SYMBOL_GPL(async_xor_val_offs); + +/** + * 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 + * @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 + * @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_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) +{ + return async_xor_val_offs(dest, offset, src_list, NULL, src_cnt, + len, result, submit); +} +EXPORT_SYMBOL_GPL(async_xor_val); + +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api"); +MODULE_LICENSE("GPL"); |