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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 00:05:52 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 00:05:52 +0300 |
commit | e46cae441824999c858d482ca1f661cf4292c02f (patch) | |
tree | 0bf4dabec0ef16f92723ff0fac0e837f59b48cdc /lib/raid6/recov_s390xc.c | |
parent | 02bafd96f3a5d8e610b19033ffec55b92459aaae (diff) | |
parent | 6cd997db911f28f2510b771691270c52b63ed2e6 (diff) | |
download | linux-e46cae441824999c858d482ca1f661cf4292c02f.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
"The new features and main improvements in this merge for v4.9
- Support for the UBSAN sanitizer
- Set HAVE_EFFICIENT_UNALIGNED_ACCESS, it improves the code in some
places
- Improvements for the in-kernel fpu code, in particular the overhead
for multiple consecutive in kernel fpu users is recuded
- Add a SIMD implementation for the RAID6 gen and xor operations
- Add RAID6 recovery based on the XC instruction
- The PCI DMA flush logic has been improved to increase the speed of
the map / unmap operations
- The time synchronization code has seen some updates
And bug fixes all over the place"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
s390/con3270: fix insufficient space padding
s390/con3270: fix use of uninitialised data
MAINTAINERS: update DASD maintainer
s390/cio: fix accidental interrupt enabling during resume
s390/dasd: add missing \n to end of dev_err messages
s390/config: Enable config options for Docker
s390/dasd: make query host access interruptible
s390/dasd: fix panic during offline processing
s390/dasd: fix hanging offline processing
s390/pci_dma: improve lazy flush for unmap
s390/pci_dma: split dma_update_trans
s390/pci_dma: improve map_sg
s390/pci_dma: simplify dma address calculation
s390/pci_dma: remove dma address range check
iommu/s390: simplify registration of I/O address translation parameters
s390: migrate exception table users off module.h and onto extable.h
s390: export header for CLP ioctl
s390/vmur: fix irq pointer dereference in int handler
s390/dasd: add missing KOBJ_CHANGE event for unformatted devices
s390: enable UBSAN
...
Diffstat (limited to 'lib/raid6/recov_s390xc.c')
-rw-r--r-- | lib/raid6/recov_s390xc.c | 116 |
1 files changed, 116 insertions, 0 deletions
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, +}; |