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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-07-13 18:16:01 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2017-08-09 18:52:07 +0100
commit6ec4e2514decd6fb4782a9364fa71d6244d05af4 (patch)
treee555e55f6e136bc749a01cf600620ee3f7c7671b /lib/raid6/recov_neon.c
parent35129dde88afad07f54b332d4f9eda2d254b80f2 (diff)
md/raid6: implement recovery using ARM NEON intrinsics
Provide a NEON accelerated implementation of the recovery algorithm, which supersedes the default byte-by-byte one. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'lib/raid6/recov_neon.c')
-rw-r--r--lib/raid6/recov_neon.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/lib/raid6/recov_neon.c b/lib/raid6/recov_neon.c
new file mode 100644
index 000000000000..eeb5c4065b92
--- /dev/null
+++ b/lib/raid6/recov_neon.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2012 Intel Corporation
+ * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/raid/pq.h>
+
+#ifdef __KERNEL__
+#include <asm/neon.h>
+#else
+#define kernel_neon_begin()
+#define kernel_neon_end()
+#define cpu_has_neon() (1)
+#endif
+
+static int raid6_has_neon(void)
+{
+ return cpu_has_neon();
+}
+
+void __raid6_2data_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dp,
+ uint8_t *dq, const uint8_t *pbmul,
+ const uint8_t *qmul);
+
+void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq,
+ const uint8_t *qmul);
+
+static void raid6_2data_recov_neon(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) */
+
+ 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_vgfmul[raid6_gfexi[failb-faila]];
+ qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^
+ raid6_gfexp[failb]]];
+
+ kernel_neon_begin();
+ __raid6_2data_recov_neon(bytes, p, q, dp, dq, pbmul, qmul);
+ kernel_neon_end();
+}
+
+static void raid6_datap_recov_neon(int disks, size_t bytes, int faila,
+ void **ptrs)
+{
+ u8 *p, *q, *dq;
+ const u8 *qmul; /* Q multiplier table */
+
+ 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_vgfmul[raid6_gfinv[raid6_gfexp[faila]]];
+
+ kernel_neon_begin();
+ __raid6_datap_recov_neon(bytes, p, q, dq, qmul);
+ kernel_neon_end();
+}
+
+const struct raid6_recov_calls raid6_recov_neon = {
+ .data2 = raid6_2data_recov_neon,
+ .datap = raid6_datap_recov_neon,
+ .valid = raid6_has_neon,
+ .name = "neon",
+ .priority = 10,
+};