mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
f5b55fa1f8
The XC instruction can be used to improve the speed of the raid6 recovery. The loops now operate on blocks of 256 bytes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
117 lines
2.7 KiB
C
117 lines
2.7 KiB
C
/*
|
|
* RAID-6 data recovery in dual failure mode based on the XC instruction.
|
|
*
|
|
* Copyright IBM Corp. 2016
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/raid/pq.h>
|
|
|
|
static inline void xor_block(u8 *p1, u8 *p2)
|
|
{
|
|
typedef struct { u8 _[256]; } addrtype;
|
|
|
|
asm volatile(
|
|
" xc 0(256,%[p1]),0(%[p2])\n"
|
|
: "+m" (*(addrtype *) p1) : "m" (*(addrtype *) p2),
|
|
[p1] "a" (p1), [p2] "a" (p2) : "cc");
|
|
}
|
|
|
|
/* Recover two failed data blocks. */
|
|
static void raid6_2data_recov_s390xc(int disks, size_t bytes, int faila,
|
|
int failb, void **ptrs)
|
|
{
|
|
u8 *p, *q, *dp, *dq;
|
|
const u8 *pbmul; /* P multiplier table for B data */
|
|
const u8 *qmul; /* Q multiplier table (for both) */
|
|
int i;
|
|
|
|
p = (u8 *)ptrs[disks-2];
|
|
q = (u8 *)ptrs[disks-1];
|
|
|
|
/* Compute syndrome with zero for the missing data pages
|
|
Use the dead data pages as temporary storage for
|
|
delta p and delta q */
|
|
dp = (u8 *)ptrs[faila];
|
|
ptrs[faila] = (void *)raid6_empty_zero_page;
|
|
ptrs[disks-2] = dp;
|
|
dq = (u8 *)ptrs[failb];
|
|
ptrs[failb] = (void *)raid6_empty_zero_page;
|
|
ptrs[disks-1] = dq;
|
|
|
|
raid6_call.gen_syndrome(disks, bytes, ptrs);
|
|
|
|
/* Restore pointer table */
|
|
ptrs[faila] = dp;
|
|
ptrs[failb] = dq;
|
|
ptrs[disks-2] = p;
|
|
ptrs[disks-1] = q;
|
|
|
|
/* Now, pick the proper data tables */
|
|
pbmul = raid6_gfmul[raid6_gfexi[failb-faila]];
|
|
qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]];
|
|
|
|
/* Now do it... */
|
|
while (bytes) {
|
|
xor_block(dp, p);
|
|
xor_block(dq, q);
|
|
for (i = 0; i < 256; i++)
|
|
dq[i] = pbmul[dp[i]] ^ qmul[dq[i]];
|
|
xor_block(dp, dq);
|
|
p += 256;
|
|
q += 256;
|
|
dp += 256;
|
|
dq += 256;
|
|
bytes -= 256;
|
|
}
|
|
}
|
|
|
|
/* Recover failure of one data block plus the P block */
|
|
static void raid6_datap_recov_s390xc(int disks, size_t bytes, int faila,
|
|
void **ptrs)
|
|
{
|
|
u8 *p, *q, *dq;
|
|
const u8 *qmul; /* Q multiplier table */
|
|
int i;
|
|
|
|
p = (u8 *)ptrs[disks-2];
|
|
q = (u8 *)ptrs[disks-1];
|
|
|
|
/* Compute syndrome with zero for the missing data page
|
|
Use the dead data page as temporary storage for delta q */
|
|
dq = (u8 *)ptrs[faila];
|
|
ptrs[faila] = (void *)raid6_empty_zero_page;
|
|
ptrs[disks-1] = dq;
|
|
|
|
raid6_call.gen_syndrome(disks, bytes, ptrs);
|
|
|
|
/* Restore pointer table */
|
|
ptrs[faila] = dq;
|
|
ptrs[disks-1] = q;
|
|
|
|
/* Now, pick the proper data tables */
|
|
qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]]];
|
|
|
|
/* Now do it... */
|
|
while (bytes) {
|
|
xor_block(dq, q);
|
|
for (i = 0; i < 256; i++)
|
|
dq[i] = qmul[dq[i]];
|
|
xor_block(p, dq);
|
|
p += 256;
|
|
q += 256;
|
|
dq += 256;
|
|
bytes -= 256;
|
|
}
|
|
}
|
|
|
|
|
|
const struct raid6_recov_calls raid6_recov_s390xc = {
|
|
.data2 = raid6_2data_recov_s390xc,
|
|
.datap = raid6_datap_recov_s390xc,
|
|
.valid = NULL,
|
|
.name = "s390xc",
|
|
.priority = 1,
|
|
};
|