linux/lib/raid6/recov_s390xc.c
Linus Torvalds e991acf1bc Significant patch series in this pull request:
- The 2 patch series "squashfs: Remove page->mapping references" from
   Matthew Wilcox gets us closer to being able to remove page->mapping.
 
 - The 5 patch series "relayfs: misc changes" from Jason Xing does some
   maintenance and minor feature addition work in relayfs.
 
 - The 5 patch series "kdump: crashkernel reservation from CMA" from Jiri
   Bohac switches us from static preallocation of the kdump crashkernel's
   working memory over to dynamic allocation.  So the difficulty of
   a-priori estimation of the second kernel's needs is removed and the
   first kernel obtains extra memory.
 
 - The 5 patch series "generalize panic_print's dump function to be used
   by other kernel parts" from Feng Tang implements some consolidation and
   rationalizatio of the various ways in which a faiing kernel splats
   information at the operator.
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Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...
2025-08-03 16:23:09 -07:00

116 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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/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] = raid6_get_zero_page();
ptrs[disks-2] = dp;
dq = (u8 *)ptrs[failb];
ptrs[failb] = raid6_get_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] = raid6_get_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,
};