mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
463 lines
13 KiB
463 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Copyright(c) 2007 Yuri Tikhonov <[email protected]> |
|
* Copyright(c) 2009 Intel Corporation |
|
*/ |
|
#include <linux/kernel.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/module.h> |
|
#include <linux/dma-mapping.h> |
|
#include <linux/raid/pq.h> |
|
#include <linux/async_tx.h> |
|
#include <linux/gfp.h> |
|
|
|
/** |
|
* 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]) |
|
|
|
#define MAX_DISKS 255 |
|
|
|
/** |
|
* 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; |
|
|
|
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; |
|
} |
|
if (submit->flags & ASYNC_TX_FENCE) |
|
dma_flags |= DMA_PREP_FENCE; |
|
|
|
/* 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 *offsets, 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]) + offsets[i]; |
|
|
|
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); |
|
} |
|
|
|
static inline bool |
|
is_dma_pq_aligned_offs(struct dma_device *dev, unsigned int *offs, |
|
int src_cnt, size_t len) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < src_cnt; i++) { |
|
if (!is_dma_pq_aligned(dev, offs[i], 0, len)) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
/** |
|
* async_gen_syndrome - asynchronously calculate a raid6 syndrome |
|
* @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 |
|
* @offsets: offset array 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 *offsets, 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 > MAX_DISKS || !(P(blocks, disks) || Q(blocks, disks))); |
|
|
|
if (device) |
|
unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOWAIT); |
|
|
|
/* 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_offs(device, offsets, disks, len)) { |
|
struct dma_async_tx_descriptor *tx; |
|
enum dma_ctrl_flags dma_flags = 0; |
|
unsigned char coefs[MAX_DISKS]; |
|
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], |
|
offsets[i], 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), |
|
P(offsets, disks), |
|
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), |
|
Q(offsets, disks), |
|
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; |
|
P(offsets, disks) = 0; |
|
} |
|
if (!Q(blocks, disks)) { |
|
Q(blocks, disks) = pq_scribble_page; |
|
Q(offsets, disks) = 0; |
|
} |
|
do_sync_gen_syndrome(blocks, offsets, 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 |
|
* @s_off: spare buffer page offset |
|
* @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 *offsets, int disks, |
|
size_t len, enum sum_check_flags *pqres, struct page *spare, |
|
unsigned int s_off, 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[MAX_DISKS]; |
|
enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0; |
|
struct dmaengine_unmap_data *unmap = NULL; |
|
|
|
BUG_ON(disks < 4 || disks > MAX_DISKS); |
|
|
|
if (device) |
|
unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOWAIT); |
|
|
|
if (unmap && disks <= dma_maxpq(device, 0) && |
|
is_dma_pq_aligned_offs(device, offsets, disks, 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], |
|
offsets[i], 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), |
|
P(offsets, disks), 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), |
|
Q(offsets, disks), 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); |
|
} else { |
|
struct page *p_src = P(blocks, disks); |
|
unsigned int p_off = P(offsets, disks); |
|
struct page *q_src = Q(blocks, disks); |
|
unsigned int q_off = Q(offsets, 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_offs(spare, s_off, |
|
blocks, offsets, disks-2, len, submit); |
|
async_tx_quiesce(&tx); |
|
p = page_address(p_src) + p_off; |
|
s = page_address(spare) + s_off; |
|
*pqres |= !!memcmp(p, s, len) << SUM_CHECK_P; |
|
} |
|
|
|
if (q_src) { |
|
P(blocks, disks) = NULL; |
|
Q(blocks, disks) = spare; |
|
Q(offsets, disks) = s_off; |
|
init_async_submit(submit, 0, NULL, NULL, NULL, scribble); |
|
tx = async_gen_syndrome(blocks, offsets, disks, |
|
len, submit); |
|
async_tx_quiesce(&tx); |
|
q = page_address(q_src) + q_off; |
|
s = page_address(spare) + s_off; |
|
*pqres |= !!memcmp(q, s, len) << SUM_CHECK_Q; |
|
} |
|
|
|
/* restore P, Q and submit */ |
|
P(blocks, disks) = p_src; |
|
P(offsets, disks) = p_off; |
|
Q(blocks, disks) = q_src; |
|
Q(offsets, disks) = q_off; |
|
|
|
submit->cb_fn = cb_fn_orig; |
|
submit->cb_param = cb_param_orig; |
|
submit->flags = flags_orig; |
|
async_tx_sync_epilog(submit); |
|
tx = NULL; |
|
} |
|
dmaengine_unmap_put(unmap); |
|
|
|
return tx; |
|
} |
|
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) |
|
{ |
|
__free_page(pq_scribble_page); |
|
} |
|
|
|
module_init(async_pq_init); |
|
module_exit(async_pq_exit); |
|
|
|
MODULE_DESCRIPTION("asynchronous raid6 syndrome generation/validation"); |
|
MODULE_LICENSE("GPL");
|
|
|