From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- crypto/async_tx/async_pq.c | 454 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 454 insertions(+) create mode 100644 crypto/async_tx/async_pq.c (limited to 'crypto/async_tx/async_pq.c') diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c new file mode 100644 index 000000000..5d355e0c2 --- /dev/null +++ b/crypto/async_tx/async_pq.c @@ -0,0 +1,454 @@ +/* + * Copyright(c) 2007 Yuri Tikhonov + * Copyright(c) 2009 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The full GNU General Public License is included in this distribution in the + * file called COPYING. + */ +#include +#include +#include +#include +#include +#include +#include + +/** + * pq_scribble_page - space to hold throwaway P or Q buffer for + * synchronous gen_syndrome + */ +static struct page *pq_scribble_page; + +/* the struct page *blocks[] parameter passed to async_gen_syndrome() + * and async_syndrome_val() contains the 'P' destination address at + * blocks[disks-2] and the 'Q' destination address at blocks[disks-1] + * + * note: these are macros as they are used as lvalues + */ +#define P(b, d) (b[d-2]) +#define Q(b, d) (b[d-1]) + +/** + * do_async_gen_syndrome - asynchronously calculate P and/or Q + */ +static __async_inline struct dma_async_tx_descriptor * +do_async_gen_syndrome(struct dma_chan *chan, + const unsigned char *scfs, int disks, + struct dmaengine_unmap_data *unmap, + enum dma_ctrl_flags dma_flags, + struct async_submit_ctl *submit) +{ + struct dma_async_tx_descriptor *tx = NULL; + struct dma_device *dma = chan->device; + enum async_tx_flags flags_orig = submit->flags; + dma_async_tx_callback cb_fn_orig = submit->cb_fn; + dma_async_tx_callback cb_param_orig = submit->cb_param; + int src_cnt = disks - 2; + unsigned short pq_src_cnt; + dma_addr_t dma_dest[2]; + int src_off = 0; + + if (submit->flags & ASYNC_TX_FENCE) + dma_flags |= DMA_PREP_FENCE; + + while (src_cnt > 0) { + submit->flags = flags_orig; + pq_src_cnt = min(src_cnt, dma_maxpq(dma, dma_flags)); + /* if we are submitting additional pqs, leave the chain open, + * clear the callback parameters, and leave the destination + * buffers mapped + */ + if (src_cnt > pq_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 (cb_fn_orig) + dma_flags |= DMA_PREP_INTERRUPT; + } + + /* Drivers force forward progress in case they can not provide + * a descriptor + */ + for (;;) { + dma_dest[0] = unmap->addr[disks - 2]; + dma_dest[1] = unmap->addr[disks - 1]; + tx = dma->device_prep_dma_pq(chan, dma_dest, + &unmap->addr[src_off], + pq_src_cnt, + &scfs[src_off], unmap->len, + dma_flags); + if (likely(tx)) + break; + async_tx_quiesce(&submit->depend_tx); + dma_async_issue_pending(chan); + } + + dma_set_unmap(tx, unmap); + async_tx_submit(chan, tx, submit); + submit->depend_tx = tx; + + /* drop completed sources */ + src_cnt -= pq_src_cnt; + src_off += pq_src_cnt; + + dma_flags |= DMA_PREP_CONTINUE; + } + + return tx; +} + +/** + * do_sync_gen_syndrome - synchronously calculate a raid6 syndrome + */ +static void +do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks, + size_t len, struct async_submit_ctl *submit) +{ + void **srcs; + int i; + int start = -1, stop = disks - 3; + + if (submit->scribble) + srcs = submit->scribble; + else + srcs = (void **) blocks; + + for (i = 0; i < disks; i++) { + if (blocks[i] == NULL) { + BUG_ON(i > disks - 3); /* P or Q can't be zero */ + srcs[i] = (void*)raid6_empty_zero_page; + } else { + srcs[i] = page_address(blocks[i]) + offset; + if (i < disks - 2) { + stop = i; + if (start == -1) + start = i; + } + } + } + if (submit->flags & ASYNC_TX_PQ_XOR_DST) { + BUG_ON(!raid6_call.xor_syndrome); + if (start >= 0) + raid6_call.xor_syndrome(disks, start, stop, len, srcs); + } else + raid6_call.gen_syndrome(disks, len, srcs); + async_tx_sync_epilog(submit); +} + +/** + * async_gen_syndrome - asynchronously calculate a raid6 syndrome + * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 + * @offset: common offset into each block (src and dest) to start transaction + * @disks: number of blocks (including missing P or Q, see below) + * @len: length of operation in bytes + * @submit: submission/completion modifiers + * + * General note: This routine assumes a field of GF(2^8) with a + * primitive polynomial of 0x11d and a generator of {02}. + * + * 'disks' note: callers can optionally omit either P or Q (but not + * both) from the calculation by setting blocks[disks-2] or + * blocks[disks-1] to NULL. When P or Q is omitted 'len' must be <= + * PAGE_SIZE as a temporary buffer of this size is used in the + * synchronous path. 'disks' always accounts for both destination + * buffers. If any source buffers (blocks[i] where i < disks - 2) are + * set to NULL those buffers will be replaced with the raid6_zero_page + * in the synchronous path and omitted in the hardware-asynchronous + * path. + */ +struct dma_async_tx_descriptor * +async_gen_syndrome(struct page **blocks, unsigned int offset, int disks, + size_t len, struct async_submit_ctl *submit) +{ + int src_cnt = disks - 2; + struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, + &P(blocks, disks), 2, + blocks, src_cnt, len); + struct dma_device *device = chan ? chan->device : NULL; + struct dmaengine_unmap_data *unmap = NULL; + + BUG_ON(disks > 255 || !(P(blocks, disks) || Q(blocks, disks))); + + if (device) + unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOIO); + + /* XORing P/Q is only implemented in software */ + if (unmap && !(submit->flags & ASYNC_TX_PQ_XOR_DST) && + (src_cnt <= dma_maxpq(device, 0) || + dma_maxpq(device, DMA_PREP_CONTINUE) > 0) && + is_dma_pq_aligned(device, offset, 0, len)) { + struct dma_async_tx_descriptor *tx; + enum dma_ctrl_flags dma_flags = 0; + unsigned char coefs[src_cnt]; + int i, j; + + /* run the p+q asynchronously */ + pr_debug("%s: (async) disks: %d len: %zu\n", + __func__, disks, len); + + /* convert source addresses being careful to collapse 'empty' + * sources and update the coefficients accordingly + */ + unmap->len = len; + for (i = 0, j = 0; i < src_cnt; i++) { + if (blocks[i] == NULL) + continue; + unmap->addr[j] = dma_map_page(device->dev, blocks[i], offset, + len, DMA_TO_DEVICE); + coefs[j] = raid6_gfexp[i]; + unmap->to_cnt++; + j++; + } + + /* + * DMAs use destinations as sources, + * so use BIDIRECTIONAL mapping + */ + unmap->bidi_cnt++; + if (P(blocks, disks)) + unmap->addr[j++] = dma_map_page(device->dev, P(blocks, disks), + offset, len, DMA_BIDIRECTIONAL); + else { + unmap->addr[j++] = 0; + dma_flags |= DMA_PREP_PQ_DISABLE_P; + } + + unmap->bidi_cnt++; + if (Q(blocks, disks)) + unmap->addr[j++] = dma_map_page(device->dev, Q(blocks, disks), + offset, len, DMA_BIDIRECTIONAL); + else { + unmap->addr[j++] = 0; + dma_flags |= DMA_PREP_PQ_DISABLE_Q; + } + + tx = do_async_gen_syndrome(chan, coefs, j, unmap, dma_flags, submit); + dmaengine_unmap_put(unmap); + return tx; + } + + dmaengine_unmap_put(unmap); + + /* run the pq synchronously */ + pr_debug("%s: (sync) disks: %d len: %zu\n", __func__, disks, len); + + /* wait for any prerequisite operations */ + async_tx_quiesce(&submit->depend_tx); + + if (!P(blocks, disks)) { + P(blocks, disks) = pq_scribble_page; + BUG_ON(len + offset > PAGE_SIZE); + } + if (!Q(blocks, disks)) { + Q(blocks, disks) = pq_scribble_page; + BUG_ON(len + offset > PAGE_SIZE); + } + do_sync_gen_syndrome(blocks, offset, disks, len, submit); + + return NULL; +} +EXPORT_SYMBOL_GPL(async_gen_syndrome); + +static inline struct dma_chan * +pq_val_chan(struct async_submit_ctl *submit, struct page **blocks, int disks, size_t len) +{ + #ifdef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA + return NULL; + #endif + return async_tx_find_channel(submit, DMA_PQ_VAL, NULL, 0, blocks, + disks, len); +} + +/** + * async_syndrome_val - asynchronously validate a raid6 syndrome + * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 + * @offset: common offset into each block (src and dest) to start transaction + * @disks: number of blocks (including missing P or Q, see below) + * @len: length of operation in bytes + * @pqres: on val failure SUM_CHECK_P_RESULT and/or SUM_CHECK_Q_RESULT are set + * @spare: temporary result buffer for the synchronous case + * @submit: submission / completion modifiers + * + * The same notes from async_gen_syndrome apply to the 'blocks', + * and 'disks' parameters of this routine. The synchronous path + * requires a temporary result buffer and submit->scribble to be + * specified. + */ +struct dma_async_tx_descriptor * +async_syndrome_val(struct page **blocks, unsigned int offset, int disks, + size_t len, enum sum_check_flags *pqres, struct page *spare, + struct async_submit_ctl *submit) +{ + struct dma_chan *chan = pq_val_chan(submit, blocks, disks, len); + struct dma_device *device = chan ? chan->device : NULL; + struct dma_async_tx_descriptor *tx; + unsigned char coefs[disks-2]; + enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0; + struct dmaengine_unmap_data *unmap = NULL; + + BUG_ON(disks < 4); + + if (device) + unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOIO); + + if (unmap && disks <= dma_maxpq(device, 0) && + is_dma_pq_aligned(device, offset, 0, len)) { + struct device *dev = device->dev; + dma_addr_t pq[2]; + int i, j = 0, src_cnt = 0; + + pr_debug("%s: (async) disks: %d len: %zu\n", + __func__, disks, len); + + unmap->len = len; + for (i = 0; i < disks-2; i++) + if (likely(blocks[i])) { + unmap->addr[j] = dma_map_page(dev, blocks[i], + offset, len, + DMA_TO_DEVICE); + coefs[j] = raid6_gfexp[i]; + unmap->to_cnt++; + src_cnt++; + j++; + } + + if (!P(blocks, disks)) { + pq[0] = 0; + dma_flags |= DMA_PREP_PQ_DISABLE_P; + } else { + pq[0] = dma_map_page(dev, P(blocks, disks), + offset, len, + DMA_TO_DEVICE); + unmap->addr[j++] = pq[0]; + unmap->to_cnt++; + } + if (!Q(blocks, disks)) { + pq[1] = 0; + dma_flags |= DMA_PREP_PQ_DISABLE_Q; + } else { + pq[1] = dma_map_page(dev, Q(blocks, disks), + offset, len, + DMA_TO_DEVICE); + unmap->addr[j++] = pq[1]; + unmap->to_cnt++; + } + + if (submit->flags & ASYNC_TX_FENCE) + dma_flags |= DMA_PREP_FENCE; + for (;;) { + tx = device->device_prep_dma_pq_val(chan, pq, + unmap->addr, + src_cnt, + coefs, + len, pqres, + dma_flags); + if (likely(tx)) + break; + async_tx_quiesce(&submit->depend_tx); + dma_async_issue_pending(chan); + } + + dma_set_unmap(tx, unmap); + async_tx_submit(chan, tx, submit); + + return tx; + } else { + struct page *p_src = P(blocks, disks); + struct page *q_src = Q(blocks, disks); + enum async_tx_flags flags_orig = submit->flags; + dma_async_tx_callback cb_fn_orig = submit->cb_fn; + void *scribble = submit->scribble; + void *cb_param_orig = submit->cb_param; + void *p, *q, *s; + + pr_debug("%s: (sync) disks: %d len: %zu\n", + __func__, disks, len); + + /* caller must provide a temporary result buffer and + * allow the input parameters to be preserved + */ + BUG_ON(!spare || !scribble); + + /* wait for any prerequisite operations */ + async_tx_quiesce(&submit->depend_tx); + + /* recompute p and/or q into the temporary buffer and then + * check to see the result matches the current value + */ + tx = NULL; + *pqres = 0; + if (p_src) { + init_async_submit(submit, ASYNC_TX_XOR_ZERO_DST, NULL, + NULL, NULL, scribble); + tx = async_xor(spare, blocks, offset, disks-2, len, submit); + async_tx_quiesce(&tx); + p = page_address(p_src) + offset; + s = page_address(spare) + offset; + *pqres |= !!memcmp(p, s, len) << SUM_CHECK_P; + } + + if (q_src) { + P(blocks, disks) = NULL; + Q(blocks, disks) = spare; + init_async_submit(submit, 0, NULL, NULL, NULL, scribble); + tx = async_gen_syndrome(blocks, offset, disks, len, submit); + async_tx_quiesce(&tx); + q = page_address(q_src) + offset; + s = page_address(spare) + offset; + *pqres |= !!memcmp(q, s, len) << SUM_CHECK_Q; + } + + /* restore P, Q and submit */ + P(blocks, disks) = p_src; + Q(blocks, disks) = q_src; + + submit->cb_fn = cb_fn_orig; + submit->cb_param = cb_param_orig; + submit->flags = flags_orig; + async_tx_sync_epilog(submit); + + return NULL; + } +} +EXPORT_SYMBOL_GPL(async_syndrome_val); + +static int __init async_pq_init(void) +{ + pq_scribble_page = alloc_page(GFP_KERNEL); + + if (pq_scribble_page) + return 0; + + pr_err("%s: failed to allocate required spare page\n", __func__); + + return -ENOMEM; +} + +static void __exit async_pq_exit(void) +{ + put_page(pq_scribble_page); +} + +module_init(async_pq_init); +module_exit(async_pq_exit); + +MODULE_DESCRIPTION("asynchronous raid6 syndrome generation/validation"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3