lib/raid6: Add AVX512 optimized gen_syndrome functions

Optimize RAID6 gen_syndrom functions to take advantage of
the 512-bit ZMM integer instructions introduced in AVX512.

AVX512 optimized gen_syndrom functions, which is simply based
on avx2.c written by Yuanhan Liu and sse2.c written by hpa.

The patch was tested and benchmarked before submission on
a hardware that has AVX512 flags to support such instructions

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jim Kukunas <james.t.kukunas@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>

4 files changed, 314 insertions, 1 deletions

diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile
index 3b10a48fa040..8948268d47b4 100644
--- a/lib/raid6/Makefile
+++ b/lib/raid6/Makefile
@@ -3,7 +3,7 @@ obj-$(CONFIG_RAID6_PQ)	+= raid6_pq.o
 raid6_pq-y	+= algos.o recov.o tables.o int1.o int2.o int4.o \
 		   int8.o int16.o int32.o
 
-raid6_pq-$(CONFIG_X86) += recov_ssse3.o recov_avx2.o mmx.o sse1.o sse2.o avx2.o
+raid6_pq-$(CONFIG_X86) += recov_ssse3.o recov_avx2.o mmx.o sse1.o sse2.o avx2.o avx512.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
diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c
index 975c6e0434bd..f5f090c52dd9 100644
--- a/lib/raid6/algos.c
+++ b/lib/raid6/algos.c
@@ -49,6 +49,10 @@ const struct raid6_calls * const raid6_algos[] = {
 	&raid6_avx2x1,
 	&raid6_avx2x2,
 #endif
+#ifdef CONFIG_AS_AVX512
+	&raid6_avx512x1,
+	&raid6_avx512x2,
+#endif
 #endif
 #if defined(__x86_64__) && !defined(__arch_um__)
 	&raid6_sse2x1,
@@ -59,6 +63,11 @@ const struct raid6_calls * const raid6_algos[] = {
 	&raid6_avx2x2,
 	&raid6_avx2x4,
 #endif
+#ifdef CONFIG_AS_AVX512
+	&raid6_avx512x1,
+	&raid6_avx512x2,
+	&raid6_avx512x4,
+#endif
 #endif
 #ifdef CONFIG_ALTIVEC
 	&raid6_altivec1,
diff --git a/lib/raid6/avx512.c b/lib/raid6/avx512.c
new file mode 100644
index 000000000000..b1188a6e51a6
--- /dev/null
+++ b/lib/raid6/avx512.c
@@ -0,0 +1,294 @@
+/* -*- linux-c -*- --------------------------------------------------------
+ *
+ *   Copyright (C) 2016 Intel Corporation
+ *
+ *   Author: Gayatri Kammela <gayatri.kammela@intel.com>
+ *   Author: Megha Dey <megha.dey@linux.intel.com>
+ *
+ *   Based on avx2.c: Copyright 2012 Yuanhan Liu All Rights Reserved
+ *   Based on sse2.c: Copyright 2002 H. Peter Anvin - All Rights Reserved
+ *
+ *   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, Inc., 53 Temple Place Ste 330,
+ *   Boston MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * -----------------------------------------------------------------------
+ */
+
+/*
+ * AVX512 implementation of RAID-6 syndrome functions
+ *
+ */
+
+#ifdef CONFIG_AS_AVX512
+
+#include <linux/raid/pq.h>
+#include "x86.h"
+
+static const struct raid6_avx512_constants {
+	u64 x1d[8];
+} raid6_avx512_constants __aligned(512) = {
+	{ 0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL,
+	  0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL,
+	  0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL,
+	  0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL,},
+};
+
+static int raid6_have_avx512(void)
+{
+	return boot_cpu_has(X86_FEATURE_AVX2) &&
+		boot_cpu_has(X86_FEATURE_AVX) &&
+		boot_cpu_has(X86_FEATURE_AVX512F) &&
+		boot_cpu_has(X86_FEATURE_AVX512BW) &&
+		boot_cpu_has(X86_FEATURE_AVX512VL) &&
+		boot_cpu_has(X86_FEATURE_AVX512DQ);
+}
+
+static void raid6_avx5121_gen_syndrome(int disks, size_t bytes, void **ptrs)
+{
+	u8 **dptr = (u8 **)ptrs;
+	u8 *p, *q;
+	int d, z, z0;
+
+	z0 = disks - 3;         /* Highest data disk */
+	p = dptr[z0+1];         /* XOR parity */
+	q = dptr[z0+2];         /* RS syndrome */
+
+	kernel_fpu_begin();
+
+	asm volatile("vmovdqa64 %0,%%zmm0\n\t"
+		     "vpxorq %%zmm1,%%zmm1,%%zmm1" /* Zero temp */
+		     :
+		     : "m" (raid6_avx512_constants.x1d[0]));
+
+	for (d = 0; d < bytes; d += 64) {
+		asm volatile("prefetchnta %0\n\t"
+			     "vmovdqa64 %0,%%zmm2\n\t"     /* P[0] */
+			     "prefetchnta %1\n\t"
+			     "vmovdqa64 %%zmm2,%%zmm4\n\t" /* Q[0] */
+			     "vmovdqa64 %1,%%zmm6"
+			     :
+			     : "m" (dptr[z0][d]), "m" (dptr[z0-1][d]));
+		for (z = z0-2; z >= 0; z--) {
+			asm volatile("prefetchnta %0\n\t"
+				     "vpcmpgtb %%zmm4,%%zmm1,%%k1\n\t"
+				     "vpmovm2b %%k1,%%zmm5\n\t"
+				     "vpaddb %%zmm4,%%zmm4,%%zmm4\n\t"
+				     "vpandq %%zmm0,%%zmm5,%%zmm5\n\t"
+				     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+				     "vpxorq %%zmm6,%%zmm2,%%zmm2\n\t"
+				     "vpxorq %%zmm6,%%zmm4,%%zmm4\n\t"
+				     "vmovdqa64 %0,%%zmm6"
+				     :
+				     : "m" (dptr[z][d]));
+		}
+		asm volatile("vpcmpgtb %%zmm4,%%zmm1,%%k1\n\t"
+			     "vpmovm2b %%k1,%%zmm5\n\t"
+			     "vpaddb %%zmm4,%%zmm4,%%zmm4\n\t"
+			     "vpandq %%zmm0,%%zmm5,%%zmm5\n\t"
+			     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+			     "vpxorq %%zmm6,%%zmm2,%%zmm2\n\t"
+			     "vpxorq %%zmm6,%%zmm4,%%zmm4\n\t"
+			     "vmovntdq %%zmm2,%0\n\t"
+			     "vpxorq %%zmm2,%%zmm2,%%zmm2\n\t"
+			     "vmovntdq %%zmm4,%1\n\t"
+			     "vpxorq %%zmm4,%%zmm4,%%zmm4"
+			     :
+			     : "m" (p[d]), "m" (q[d]));
+	}
+
+	asm volatile("sfence" : : : "memory");
+	kernel_fpu_end();
+}
+
+const struct raid6_calls raid6_avx512x1 = {
+	raid6_avx5121_gen_syndrome,
+	NULL,                   /* XOR not yet implemented */
+	raid6_have_avx512,
+	"avx512x1",
+	1                       /* Has cache hints */
+};
+
+/*
+ * Unrolled-by-2 AVX512 implementation
+ */
+static void raid6_avx5122_gen_syndrome(int disks, size_t bytes, void **ptrs)
+{
+	u8 **dptr = (u8 **)ptrs;
+	u8 *p, *q;
+	int d, z, z0;
+
+	z0 = disks - 3;         /* Highest data disk */
+	p = dptr[z0+1];         /* XOR parity */
+	q = dptr[z0+2];         /* RS syndrome */
+
+	kernel_fpu_begin();
+
+	asm volatile("vmovdqa64 %0,%%zmm0\n\t"
+		     "vpxorq %%zmm1,%%zmm1,%%zmm1" /* Zero temp */
+		     :
+		     : "m" (raid6_avx512_constants.x1d[0]));
+
+	/* We uniformly assume a single prefetch covers at least 64 bytes */
+	for (d = 0; d < bytes; d += 128) {
+		asm volatile("prefetchnta %0\n\t"
+			     "prefetchnta %1\n\t"
+			     "vmovdqa64 %0,%%zmm2\n\t"      /* P[0] */
+			     "vmovdqa64 %1,%%zmm3\n\t"      /* P[1] */
+			     "vmovdqa64 %%zmm2,%%zmm4\n\t"  /* Q[0] */
+			     "vmovdqa64 %%zmm3,%%zmm6"      /* Q[1] */
+			     :
+			     : "m" (dptr[z0][d]), "m" (dptr[z0][d+64]));
+		for (z = z0-1; z >= 0; z--) {
+			asm volatile("prefetchnta %0\n\t"
+				     "prefetchnta %1\n\t"
+				     "vpcmpgtb %%zmm4,%%zmm1,%%k1\n\t"
+				     "vpcmpgtb %%zmm6,%%zmm1,%%k2\n\t"
+				     "vpmovm2b %%k1,%%zmm5\n\t"
+				     "vpmovm2b %%k2,%%zmm7\n\t"
+				     "vpaddb %%zmm4,%%zmm4,%%zmm4\n\t"
+				     "vpaddb %%zmm6,%%zmm6,%%zmm6\n\t"
+				     "vpandq %%zmm0,%%zmm5,%%zmm5\n\t"
+				     "vpandq %%zmm0,%%zmm7,%%zmm7\n\t"
+				     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+				     "vpxorq %%zmm7,%%zmm6,%%zmm6\n\t"
+				     "vmovdqa64 %0,%%zmm5\n\t"
+				     "vmovdqa64 %1,%%zmm7\n\t"
+				     "vpxorq %%zmm5,%%zmm2,%%zmm2\n\t"
+				     "vpxorq %%zmm7,%%zmm3,%%zmm3\n\t"
+				     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+				     "vpxorq %%zmm7,%%zmm6,%%zmm6"
+				     :
+				     : "m" (dptr[z][d]), "m" (dptr[z][d+64]));
+		}
+		asm volatile("vmovntdq %%zmm2,%0\n\t"
+			     "vmovntdq %%zmm3,%1\n\t"
+			     "vmovntdq %%zmm4,%2\n\t"
+			     "vmovntdq %%zmm6,%3"
+			     :
+			     : "m" (p[d]), "m" (p[d+64]), "m" (q[d]),
+			       "m" (q[d+64]));
+	}
+
+	asm volatile("sfence" : : : "memory");
+	kernel_fpu_end();
+}
+
+const struct raid6_calls raid6_avx512x2 = {
+	raid6_avx5122_gen_syndrome,
+	NULL,                   /* XOR not yet implemented */
+	raid6_have_avx512,
+	"avx512x2",
+	1                       /* Has cache hints */
+};
+
+#ifdef CONFIG_X86_64
+
+/*
+ * Unrolled-by-4 AVX2 implementation
+ */
+static void raid6_avx5124_gen_syndrome(int disks, size_t bytes, void **ptrs)
+{
+	u8 **dptr = (u8 **)ptrs;
+	u8 *p, *q;
+	int d, z, z0;
+
+	z0 = disks - 3;         /* Highest data disk */
+	p = dptr[z0+1];         /* XOR parity */
+	q = dptr[z0+2];         /* RS syndrome */
+
+	kernel_fpu_begin();
+
+	asm volatile("vmovdqa64 %0,%%zmm0\n\t"
+		     "vpxorq %%zmm1,%%zmm1,%%zmm1\n\t"       /* Zero temp */
+		     "vpxorq %%zmm2,%%zmm2,%%zmm2\n\t"       /* P[0] */
+		     "vpxorq %%zmm3,%%zmm3,%%zmm3\n\t"       /* P[1] */
+		     "vpxorq %%zmm4,%%zmm4,%%zmm4\n\t"       /* Q[0] */
+		     "vpxorq %%zmm6,%%zmm6,%%zmm6\n\t"       /* Q[1] */
+		     "vpxorq %%zmm10,%%zmm10,%%zmm10\n\t"    /* P[2] */
+		     "vpxorq %%zmm11,%%zmm11,%%zmm11\n\t"    /* P[3] */
+		     "vpxorq %%zmm12,%%zmm12,%%zmm12\n\t"    /* Q[2] */
+		     "vpxorq %%zmm14,%%zmm14,%%zmm14"        /* Q[3] */
+		     :
+		     : "m" (raid6_avx512_constants.x1d[0]));
+
+	for (d = 0; d < bytes; d += 256) {
+		for (z = z0; z >= 0; z--) {
+		asm volatile("prefetchnta %0\n\t"
+			     "prefetchnta %1\n\t"
+			     "prefetchnta %2\n\t"
+			     "prefetchnta %3\n\t"
+			     "vpcmpgtb %%zmm4,%%zmm1,%%k1\n\t"
+			     "vpcmpgtb %%zmm6,%%zmm1,%%k2\n\t"
+			     "vpcmpgtb %%zmm12,%%zmm1,%%k3\n\t"
+			     "vpcmpgtb %%zmm14,%%zmm1,%%k4\n\t"
+			     "vpmovm2b %%k1,%%zmm5\n\t"
+			     "vpmovm2b %%k2,%%zmm7\n\t"
+			     "vpmovm2b %%k3,%%zmm13\n\t"
+			     "vpmovm2b %%k4,%%zmm15\n\t"
+			     "vpaddb %%zmm4,%%zmm4,%%zmm4\n\t"
+			     "vpaddb %%zmm6,%%zmm6,%%zmm6\n\t"
+			     "vpaddb %%zmm12,%%zmm12,%%zmm12\n\t"
+			     "vpaddb %%zmm14,%%zmm14,%%zmm14\n\t"
+			     "vpandq %%zmm0,%%zmm5,%%zmm5\n\t"
+			     "vpandq %%zmm0,%%zmm7,%%zmm7\n\t"
+			     "vpandq %%zmm0,%%zmm13,%%zmm13\n\t"
+			     "vpandq %%zmm0,%%zmm15,%%zmm15\n\t"
+			     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+			     "vpxorq %%zmm7,%%zmm6,%%zmm6\n\t"
+			     "vpxorq %%zmm13,%%zmm12,%%zmm12\n\t"
+			     "vpxorq %%zmm15,%%zmm14,%%zmm14\n\t"
+			     "vmovdqa64 %0,%%zmm5\n\t"
+			     "vmovdqa64 %1,%%zmm7\n\t"
+			     "vmovdqa64 %2,%%zmm13\n\t"
+			     "vmovdqa64 %3,%%zmm15\n\t"
+			     "vpxorq %%zmm5,%%zmm2,%%zmm2\n\t"
+			     "vpxorq %%zmm7,%%zmm3,%%zmm3\n\t"
+			     "vpxorq %%zmm13,%%zmm10,%%zmm10\n\t"
+			     "vpxorq %%zmm15,%%zmm11,%%zmm11\n"
+			     "vpxorq %%zmm5,%%zmm4,%%zmm4\n\t"
+			     "vpxorq %%zmm7,%%zmm6,%%zmm6\n\t"
+			     "vpxorq %%zmm13,%%zmm12,%%zmm12\n\t"
+			     "vpxorq %%zmm15,%%zmm14,%%zmm14"
+			     :
+			     : "m" (dptr[z][d]), "m" (dptr[z][d+64]),
+			       "m" (dptr[z][d+128]), "m" (dptr[z][d+192]));
+		}
+		asm volatile("vmovntdq %%zmm2,%0\n\t"
+			     "vpxorq %%zmm2,%%zmm2,%%zmm2\n\t"
+			     "vmovntdq %%zmm3,%1\n\t"
+			     "vpxorq %%zmm3,%%zmm3,%%zmm3\n\t"
+			     "vmovntdq %%zmm10,%2\n\t"
+			     "vpxorq %%zmm10,%%zmm10,%%zmm10\n\t"
+			     "vmovntdq %%zmm11,%3\n\t"
+			     "vpxorq %%zmm11,%%zmm11,%%zmm11\n\t"
+			     "vmovntdq %%zmm4,%4\n\t"
+			     "vpxorq %%zmm4,%%zmm4,%%zmm4\n\t"
+			     "vmovntdq %%zmm6,%5\n\t"
+			     "vpxorq %%zmm6,%%zmm6,%%zmm6\n\t"
+			     "vmovntdq %%zmm12,%6\n\t"
+			     "vpxorq %%zmm12,%%zmm12,%%zmm12\n\t"
+			     "vmovntdq %%zmm14,%7\n\t"
+			     "vpxorq %%zmm14,%%zmm14,%%zmm14"
+			     :
+			     : "m" (p[d]), "m" (p[d+64]), "m" (p[d+128]),
+			       "m" (p[d+192]), "m" (q[d]), "m" (q[d+64]),
+			       "m" (q[d+128]), "m" (q[d+192]));
+	}
+
+	asm volatile("sfence" : : : "memory");
+	kernel_fpu_end();
+}
+
+const struct raid6_calls raid6_avx512x4 = {
+	raid6_avx5124_gen_syndrome,
+	NULL,                   /* XOR not yet implemented */
+	raid6_have_avx512,
+	"avx512x4",
+	1                       /* Has cache hints */
+};
+#endif
+
+#endif /* CONFIG_AS_AVX512 */
diff --git a/lib/raid6/x86.h b/lib/raid6/x86.h
index 8fe9d9662abb..834d268a4b05 100644
--- a/lib/raid6/x86.h
+++ b/lib/raid6/x86.h
@@ -46,6 +46,16 @@ static inline void kernel_fpu_end(void)
 #define X86_FEATURE_SSSE3	(4*32+ 9) /* Supplemental SSE-3 */
 #define X86_FEATURE_AVX	(4*32+28) /* Advanced Vector Extensions */
 #define X86_FEATURE_AVX2        (9*32+ 5) /* AVX2 instructions */
+#define X86_FEATURE_AVX512F     (9*32+16) /* AVX-512 Foundation */
+#define X86_FEATURE_AVX512DQ    (9*32+17) /* AVX-512 DQ (Double/Quad granular)
+					   * Instructions
+					   */
+#define X86_FEATURE_AVX512BW    (9*32+30) /* AVX-512 BW (Byte/Word granular)
+					   * Instructions
+					   */
+#define X86_FEATURE_AVX512VL    (9*32+31) /* AVX-512 VL (128/256 Vector Length)
+					   * Extensions
+					   */
 #define X86_FEATURE_MMXEXT	(1*32+22) /* AMD MMX extensions */
 
 /* Should work well enough on modern CPUs for testing */