diff options
Diffstat (limited to 'lib/raid6')
| -rw-r--r-- | lib/raid6/Makefile | 2 | ||||
| -rw-r--r-- | lib/raid6/algos.c | 3 | ||||
| -rw-r--r-- | lib/raid6/recov_s390xc.c | 116 |
3 files changed, 120 insertions, 1 deletions
diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile index 667b9607f8c0..29f503ebfd60 100644 --- a/lib/raid6/Makefile +++ b/lib/raid6/Makefile @@ -7,7 +7,7 @@ raid6_pq-$(CONFIG_X86) += recov_ssse3.o recov_avx2.o mmx.o sse1.o sse2.o avx2.o raid6_pq-$(CONFIG_ALTIVEC) += altivec1.o altivec2.o altivec4.o altivec8.o raid6_pq-$(CONFIG_KERNEL_MODE_NEON) += neon.o neon1.o neon2.o neon4.o neon8.o raid6_pq-$(CONFIG_TILEGX) += tilegx8.o -raid6_pq-$(CONFIG_S390) += s390vx8.o +raid6_pq-$(CONFIG_S390) += s390vx8.o recov_s390xc.o hostprogs-y += mktables diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index e1923b602bbc..592ff49df47d 100644 --- a/lib/raid6/algos.c +++ b/lib/raid6/algos.c @@ -98,6 +98,9 @@ const struct raid6_recov_calls *const raid6_recov_algos[] = { #ifdef CONFIG_AS_SSSE3 &raid6_recov_ssse3, #endif +#ifdef CONFIG_S390 + &raid6_recov_s390xc, +#endif &raid6_recov_intx1, NULL }; diff --git a/lib/raid6/recov_s390xc.c b/lib/raid6/recov_s390xc.c new file mode 100644 index 000000000000..b042dac826cc --- /dev/null +++ b/lib/raid6/recov_s390xc.c @@ -0,0 +1,116 @@ +/* + * 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, +}; |