powerpc: Add VMX optimised xor for RAID5
Add a VMX optimised xor, used primarily for RAID5. On a POWER7 blade
this is a decent win:
32regs : 17932.800 MB/sec
altivec : 19724.800 MB/sec
The bigger gain is when the same test is run in SMT4 mode, as it
would if there was a lot of work going on:
8regs : 8377.600 MB/sec
altivec : 15801.600 MB/sec
I tested this against an array created without the patch, and also
verified it worked as expected on a little endian kernel.
[ Fix !CONFIG_ALTIVEC build -- BenH ]
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/lib/xor_vmx.c b/arch/powerpc/lib/xor_vmx.c
new file mode 100644
index 0000000..e905f7c
--- /dev/null
+++ b/arch/powerpc/lib/xor_vmx.c
@@ -0,0 +1,177 @@
+/*
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2012
+ *
+ * Author: Anton Blanchard <anton@au.ibm.com>
+ */
+#include <altivec.h>
+
+#include <linux/preempt.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <asm/switch_to.h>
+
+typedef vector signed char unative_t;
+
+#define DEFINE(V) \
+ unative_t *V = (unative_t *)V##_in; \
+ unative_t V##_0, V##_1, V##_2, V##_3
+
+#define LOAD(V) \
+ do { \
+ V##_0 = V[0]; \
+ V##_1 = V[1]; \
+ V##_2 = V[2]; \
+ V##_3 = V[3]; \
+ } while (0)
+
+#define STORE(V) \
+ do { \
+ V[0] = V##_0; \
+ V[1] = V##_1; \
+ V[2] = V##_2; \
+ V[3] = V##_3; \
+ } while (0)
+
+#define XOR(V1, V2) \
+ do { \
+ V1##_0 = vec_xor(V1##_0, V2##_0); \
+ V1##_1 = vec_xor(V1##_1, V2##_1); \
+ V1##_2 = vec_xor(V1##_2, V2##_2); \
+ V1##_3 = vec_xor(V1##_3, V2##_3); \
+ } while (0)
+
+void xor_altivec_2(unsigned long bytes, unsigned long *v1_in,
+ unsigned long *v2_in)
+{
+ DEFINE(v1);
+ DEFINE(v2);
+ unsigned long lines = bytes / (sizeof(unative_t)) / 4;
+
+ preempt_disable();
+ enable_kernel_altivec();
+
+ do {
+ LOAD(v1);
+ LOAD(v2);
+ XOR(v1, v2);
+ STORE(v1);
+
+ v1 += 4;
+ v2 += 4;
+ } while (--lines > 0);
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(xor_altivec_2);
+
+void xor_altivec_3(unsigned long bytes, unsigned long *v1_in,
+ unsigned long *v2_in, unsigned long *v3_in)
+{
+ DEFINE(v1);
+ DEFINE(v2);
+ DEFINE(v3);
+ unsigned long lines = bytes / (sizeof(unative_t)) / 4;
+
+ preempt_disable();
+ enable_kernel_altivec();
+
+ do {
+ LOAD(v1);
+ LOAD(v2);
+ LOAD(v3);
+ XOR(v1, v2);
+ XOR(v1, v3);
+ STORE(v1);
+
+ v1 += 4;
+ v2 += 4;
+ v3 += 4;
+ } while (--lines > 0);
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(xor_altivec_3);
+
+void xor_altivec_4(unsigned long bytes, unsigned long *v1_in,
+ unsigned long *v2_in, unsigned long *v3_in,
+ unsigned long *v4_in)
+{
+ DEFINE(v1);
+ DEFINE(v2);
+ DEFINE(v3);
+ DEFINE(v4);
+ unsigned long lines = bytes / (sizeof(unative_t)) / 4;
+
+ preempt_disable();
+ enable_kernel_altivec();
+
+ do {
+ LOAD(v1);
+ LOAD(v2);
+ LOAD(v3);
+ LOAD(v4);
+ XOR(v1, v2);
+ XOR(v3, v4);
+ XOR(v1, v3);
+ STORE(v1);
+
+ v1 += 4;
+ v2 += 4;
+ v3 += 4;
+ v4 += 4;
+ } while (--lines > 0);
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(xor_altivec_4);
+
+void xor_altivec_5(unsigned long bytes, unsigned long *v1_in,
+ unsigned long *v2_in, unsigned long *v3_in,
+ unsigned long *v4_in, unsigned long *v5_in)
+{
+ DEFINE(v1);
+ DEFINE(v2);
+ DEFINE(v3);
+ DEFINE(v4);
+ DEFINE(v5);
+ unsigned long lines = bytes / (sizeof(unative_t)) / 4;
+
+ preempt_disable();
+ enable_kernel_altivec();
+
+ do {
+ LOAD(v1);
+ LOAD(v2);
+ LOAD(v3);
+ LOAD(v4);
+ LOAD(v5);
+ XOR(v1, v2);
+ XOR(v3, v4);
+ XOR(v1, v5);
+ XOR(v1, v3);
+ STORE(v1);
+
+ v1 += 4;
+ v2 += 4;
+ v3 += 4;
+ v4 += 4;
+ v5 += 4;
+ } while (--lines > 0);
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(xor_altivec_5);