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authorAnton Blanchard <anton@samba.org>2012-05-30 20:22:09 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-07-03 14:14:46 +1000
commitb3f271e86e5a440713716bb222e1aa1227994c50 (patch)
treea215f44357cf20c9f2b342a7bdb840bb85ca4cb1 /arch/powerpc/lib
parentbce4b4bd91efab9dca693ac37c8ddf88103280d8 (diff)
powerpc: POWER7 optimised memcpy using VMX and enhanced prefetch
Implement a POWER7 optimised memcpy using VMX and enhanced prefetch instructions. This is a copy of the POWER7 optimised copy_to_user/copy_from_user loop. Detailed implementation and performance details can be found in commit a66086b8197d (powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX). I noticed memcpy issues when profiling a RAID6 workload: .memcpy .async_memcpy .async_copy_data .__raid_run_ops .handle_stripe .raid5d .md_thread I created a simplified testcase by building a RAID6 array with 4 1GB ramdisks (booting with brd.rd_size=1048576): # mdadm -CR -e 1.2 /dev/md0 --level=6 -n4 /dev/ram[0-3] I then timed how long it took to write to the entire array: # dd if=/dev/zero of=/dev/md0 bs=1M Before: 892 MB/s After: 999 MB/s A 12% improvement. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/lib')
-rw-r--r--arch/powerpc/lib/Makefile3
-rw-r--r--arch/powerpc/lib/memcpy_64.S4
-rw-r--r--arch/powerpc/lib/memcpy_power7.S650
3 files changed, 656 insertions, 1 deletions
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 873805ec3ed6..746e0c895cd7 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -17,7 +17,8 @@ obj-$(CONFIG_HAS_IOMEM) += devres.o
obj-$(CONFIG_PPC64) += copypage_64.o copyuser_64.o \
memcpy_64.o usercopy_64.o mem_64.o string.o \
checksum_wrappers_64.o hweight_64.o \
- copyuser_power7.o string_64.o copypage_power7.o
+ copyuser_power7.o string_64.o copypage_power7.o \
+ memcpy_power7.o
obj-$(CONFIG_XMON) += sstep.o ldstfp.o
obj-$(CONFIG_KPROBES) += sstep.o ldstfp.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += sstep.o ldstfp.o
diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
index 82fea3963e15..d2bbbc8d7dc0 100644
--- a/arch/powerpc/lib/memcpy_64.S
+++ b/arch/powerpc/lib/memcpy_64.S
@@ -11,7 +11,11 @@
.align 7
_GLOBAL(memcpy)
+BEGIN_FTR_SECTION
std r3,48(r1) /* save destination pointer for return value */
+FTR_SECTION_ELSE
+ b memcpy_power7
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
PPC_MTOCRF(0x01,r5)
cmpldi cr1,r5,16
neg r6,r3 # LS 3 bits = # bytes to 8-byte dest bdry
diff --git a/arch/powerpc/lib/memcpy_power7.S b/arch/powerpc/lib/memcpy_power7.S
new file mode 100644
index 000000000000..84674d897937
--- /dev/null
+++ b/arch/powerpc/lib/memcpy_power7.S
@@ -0,0 +1,650 @@
+/*
+ * 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 <asm/ppc_asm.h>
+
+#define STACKFRAMESIZE 256
+#define STK_REG(i) (112 + ((i)-14)*8)
+
+_GLOBAL(memcpy_power7)
+#ifdef CONFIG_ALTIVEC
+ cmpldi r5,16
+ cmpldi cr1,r5,4096
+
+ std r3,48(r1)
+
+ blt .Lshort_copy
+ bgt cr1,.Lvmx_copy
+#else
+ cmpldi r5,16
+
+ std r3,48(r1)
+
+ blt .Lshort_copy
+#endif
+
+.Lnonvmx_copy:
+ /* Get the source 8B aligned */
+ neg r6,r4
+ mtocrf 0x01,r6
+ clrldi r6,r6,(64-3)
+
+ bf cr7*4+3,1f
+ lbz r0,0(r4)
+ addi r4,r4,1
+ stb r0,0(r3)
+ addi r3,r3,1
+
+1: bf cr7*4+2,2f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+2: bf cr7*4+1,3f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+3: sub r5,r5,r6
+ cmpldi r5,128
+ blt 5f
+
+ mflr r0
+ stdu r1,-STACKFRAMESIZE(r1)
+ std r14,STK_REG(r14)(r1)
+ std r15,STK_REG(r15)(r1)
+ std r16,STK_REG(r16)(r1)
+ std r17,STK_REG(r17)(r1)
+ std r18,STK_REG(r18)(r1)
+ std r19,STK_REG(r19)(r1)
+ std r20,STK_REG(r20)(r1)
+ std r21,STK_REG(r21)(r1)
+ std r22,STK_REG(r22)(r1)
+ std r0,STACKFRAMESIZE+16(r1)
+
+ srdi r6,r5,7
+ mtctr r6
+
+ /* Now do cacheline (128B) sized loads and stores. */
+ .align 5
+4:
+ ld r0,0(r4)
+ ld r6,8(r4)
+ ld r7,16(r4)
+ ld r8,24(r4)
+ ld r9,32(r4)
+ ld r10,40(r4)
+ ld r11,48(r4)
+ ld r12,56(r4)
+ ld r14,64(r4)
+ ld r15,72(r4)
+ ld r16,80(r4)
+ ld r17,88(r4)
+ ld r18,96(r4)
+ ld r19,104(r4)
+ ld r20,112(r4)
+ ld r21,120(r4)
+ addi r4,r4,128
+ std r0,0(r3)
+ std r6,8(r3)
+ std r7,16(r3)
+ std r8,24(r3)
+ std r9,32(r3)
+ std r10,40(r3)
+ std r11,48(r3)
+ std r12,56(r3)
+ std r14,64(r3)
+ std r15,72(r3)
+ std r16,80(r3)
+ std r17,88(r3)
+ std r18,96(r3)
+ std r19,104(r3)
+ std r20,112(r3)
+ std r21,120(r3)
+ addi r3,r3,128
+ bdnz 4b
+
+ clrldi r5,r5,(64-7)
+
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+ ld r17,STK_REG(r17)(r1)
+ ld r18,STK_REG(r18)(r1)
+ ld r19,STK_REG(r19)(r1)
+ ld r20,STK_REG(r20)(r1)
+ ld r21,STK_REG(r21)(r1)
+ ld r22,STK_REG(r22)(r1)
+ addi r1,r1,STACKFRAMESIZE
+
+ /* Up to 127B to go */
+5: srdi r6,r5,4
+ mtocrf 0x01,r6
+
+6: bf cr7*4+1,7f
+ ld r0,0(r4)
+ ld r6,8(r4)
+ ld r7,16(r4)
+ ld r8,24(r4)
+ ld r9,32(r4)
+ ld r10,40(r4)
+ ld r11,48(r4)
+ ld r12,56(r4)
+ addi r4,r4,64
+ std r0,0(r3)
+ std r6,8(r3)
+ std r7,16(r3)
+ std r8,24(r3)
+ std r9,32(r3)
+ std r10,40(r3)
+ std r11,48(r3)
+ std r12,56(r3)
+ addi r3,r3,64
+
+ /* Up to 63B to go */
+7: bf cr7*4+2,8f
+ ld r0,0(r4)
+ ld r6,8(r4)
+ ld r7,16(r4)
+ ld r8,24(r4)
+ addi r4,r4,32
+ std r0,0(r3)
+ std r6,8(r3)
+ std r7,16(r3)
+ std r8,24(r3)
+ addi r3,r3,32
+
+ /* Up to 31B to go */
+8: bf cr7*4+3,9f
+ ld r0,0(r4)
+ ld r6,8(r4)
+ addi r4,r4,16
+ std r0,0(r3)
+ std r6,8(r3)
+ addi r3,r3,16
+
+9: clrldi r5,r5,(64-4)
+
+ /* Up to 15B to go */
+.Lshort_copy:
+ mtocrf 0x01,r5
+ bf cr7*4+0,12f
+ lwz r0,0(r4) /* Less chance of a reject with word ops */
+ lwz r6,4(r4)
+ addi r4,r4,8
+ stw r0,0(r3)
+ stw r6,4(r3)
+ addi r3,r3,8
+
+12: bf cr7*4+1,13f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+13: bf cr7*4+2,14f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+14: bf cr7*4+3,15f
+ lbz r0,0(r4)
+ stb r0,0(r3)
+
+15: ld r3,48(r1)
+ blr
+
+.Lunwind_stack_nonvmx_copy:
+ addi r1,r1,STACKFRAMESIZE
+ b .Lnonvmx_copy
+
+#ifdef CONFIG_ALTIVEC
+.Lvmx_copy:
+ mflr r0
+ std r4,56(r1)
+ std r5,64(r1)
+ std r0,16(r1)
+ stdu r1,-STACKFRAMESIZE(r1)
+ bl .enter_vmx_copy
+ cmpwi r3,0
+ ld r0,STACKFRAMESIZE+16(r1)
+ ld r3,STACKFRAMESIZE+48(r1)
+ ld r4,STACKFRAMESIZE+56(r1)
+ ld r5,STACKFRAMESIZE+64(r1)
+ mtlr r0
+
+ /*
+ * We prefetch both the source and destination using enhanced touch
+ * instructions. We use a stream ID of 0 for the load side and
+ * 1 for the store side.
+ */
+ clrrdi r6,r4,7
+ clrrdi r9,r3,7
+ ori r9,r9,1 /* stream=1 */
+
+ srdi r7,r5,7 /* length in cachelines, capped at 0x3FF */
+ cmpldi cr1,r7,0x3FF
+ ble cr1,1f
+ li r7,0x3FF
+1: lis r0,0x0E00 /* depth=7 */
+ sldi r7,r7,7
+ or r7,r7,r0
+ ori r10,r7,1 /* stream=1 */
+
+ lis r8,0x8000 /* GO=1 */
+ clrldi r8,r8,32
+
+.machine push
+.machine "power4"
+ dcbt r0,r6,0b01000
+ dcbt r0,r7,0b01010
+ dcbtst r0,r9,0b01000
+ dcbtst r0,r10,0b01010
+ eieio
+ dcbt r0,r8,0b01010 /* GO */
+.machine pop
+
+ beq .Lunwind_stack_nonvmx_copy
+
+ /*
+ * If source and destination are not relatively aligned we use a
+ * slower permute loop.
+ */
+ xor r6,r4,r3
+ rldicl. r6,r6,0,(64-4)
+ bne .Lvmx_unaligned_copy
+
+ /* Get the destination 16B aligned */
+ neg r6,r3
+ mtocrf 0x01,r6
+ clrldi r6,r6,(64-4)
+
+ bf cr7*4+3,1f
+ lbz r0,0(r4)
+ addi r4,r4,1
+ stb r0,0(r3)
+ addi r3,r3,1
+
+1: bf cr7*4+2,2f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+2: bf cr7*4+1,3f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+3: bf cr7*4+0,4f
+ ld r0,0(r4)
+ addi r4,r4,8
+ std r0,0(r3)
+ addi r3,r3,8
+
+4: sub r5,r5,r6
+
+ /* Get the desination 128B aligned */
+ neg r6,r3
+ srdi r7,r6,4
+ mtocrf 0x01,r7
+ clrldi r6,r6,(64-7)
+
+ li r9,16
+ li r10,32
+ li r11,48
+
+ bf cr7*4+3,5f
+ lvx vr1,r0,r4
+ addi r4,r4,16
+ stvx vr1,r0,r3
+ addi r3,r3,16
+
+5: bf cr7*4+2,6f
+ lvx vr1,r0,r4
+ lvx vr0,r4,r9
+ addi r4,r4,32
+ stvx vr1,r0,r3
+ stvx vr0,r3,r9
+ addi r3,r3,32
+
+6: bf cr7*4+1,7f
+ lvx vr3,r0,r4
+ lvx vr2,r4,r9
+ lvx vr1,r4,r10
+ lvx vr0,r4,r11
+ addi r4,r4,64
+ stvx vr3,r0,r3
+ stvx vr2,r3,r9
+ stvx vr1,r3,r10
+ stvx vr0,r3,r11
+ addi r3,r3,64
+
+7: sub r5,r5,r6
+ srdi r6,r5,7
+
+ std r14,STK_REG(r14)(r1)
+ std r15,STK_REG(r15)(r1)
+ std r16,STK_REG(r16)(r1)
+
+ li r12,64
+ li r14,80
+ li r15,96
+ li r16,112
+
+ mtctr r6
+
+ /*
+ * Now do cacheline sized loads and stores. By this stage the
+ * cacheline stores are also cacheline aligned.
+ */
+ .align 5
+8:
+ lvx vr7,r0,r4
+ lvx vr6,r4,r9
+ lvx vr5,r4,r10
+ lvx vr4,r4,r11
+ lvx vr3,r4,r12
+ lvx vr2,r4,r14
+ lvx vr1,r4,r15
+ lvx vr0,r4,r16
+ addi r4,r4,128
+ stvx vr7,r0,r3
+ stvx vr6,r3,r9
+ stvx vr5,r3,r10
+ stvx vr4,r3,r11
+ stvx vr3,r3,r12
+ stvx vr2,r3,r14
+ stvx vr1,r3,r15
+ stvx vr0,r3,r16
+ addi r3,r3,128
+ bdnz 8b
+
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+
+ /* Up to 127B to go */
+ clrldi r5,r5,(64-7)
+ srdi r6,r5,4
+ mtocrf 0x01,r6
+
+ bf cr7*4+1,9f
+ lvx vr3,r0,r4
+ lvx vr2,r4,r9
+ lvx vr1,r4,r10
+ lvx vr0,r4,r11
+ addi r4,r4,64
+ stvx vr3,r0,r3
+ stvx vr2,r3,r9
+ stvx vr1,r3,r10
+ stvx vr0,r3,r11
+ addi r3,r3,64
+
+9: bf cr7*4+2,10f
+ lvx vr1,r0,r4
+ lvx vr0,r4,r9
+ addi r4,r4,32
+ stvx vr1,r0,r3
+ stvx vr0,r3,r9
+ addi r3,r3,32
+
+10: bf cr7*4+3,11f
+ lvx vr1,r0,r4
+ addi r4,r4,16
+ stvx vr1,r0,r3
+ addi r3,r3,16
+
+ /* Up to 15B to go */
+11: clrldi r5,r5,(64-4)
+ mtocrf 0x01,r5
+ bf cr7*4+0,12f
+ ld r0,0(r4)
+ addi r4,r4,8
+ std r0,0(r3)
+ addi r3,r3,8
+
+12: bf cr7*4+1,13f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+13: bf cr7*4+2,14f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+14: bf cr7*4+3,15f
+ lbz r0,0(r4)
+ stb r0,0(r3)
+
+15: addi r1,r1,STACKFRAMESIZE
+ ld r3,48(r1)
+ b .exit_vmx_copy /* tail call optimise */
+
+.Lvmx_unaligned_copy:
+ /* Get the destination 16B aligned */
+ neg r6,r3
+ mtocrf 0x01,r6
+ clrldi r6,r6,(64-4)
+
+ bf cr7*4+3,1f
+ lbz r0,0(r4)
+ addi r4,r4,1
+ stb r0,0(r3)
+ addi r3,r3,1
+
+1: bf cr7*4+2,2f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+2: bf cr7*4+1,3f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+3: bf cr7*4+0,4f
+ lwz r0,0(r4) /* Less chance of a reject with word ops */
+ lwz r7,4(r4)
+ addi r4,r4,8
+ stw r0,0(r3)
+ stw r7,4(r3)
+ addi r3,r3,8
+
+4: sub r5,r5,r6
+
+ /* Get the desination 128B aligned */
+ neg r6,r3
+ srdi r7,r6,4
+ mtocrf 0x01,r7
+ clrldi r6,r6,(64-7)
+
+ li r9,16
+ li r10,32
+ li r11,48
+
+ lvsl vr16,0,r4 /* Setup permute control vector */
+ lvx vr0,0,r4
+ addi r4,r4,16
+
+ bf cr7*4+3,5f
+ lvx vr1,r0,r4
+ vperm vr8,vr0,vr1,vr16
+ addi r4,r4,16
+ stvx vr8,r0,r3
+ addi r3,r3,16
+ vor vr0,vr1,vr1
+
+5: bf cr7*4+2,6f
+ lvx vr1,r0,r4
+ vperm vr8,vr0,vr1,vr16
+ lvx vr0,r4,r9
+ vperm vr9,vr1,vr0,vr16
+ addi r4,r4,32
+ stvx vr8,r0,r3
+ stvx vr9,r3,r9
+ addi r3,r3,32
+
+6: bf cr7*4+1,7f
+ lvx vr3,r0,r4
+ vperm vr8,vr0,vr3,vr16
+ lvx vr2,r4,r9
+ vperm vr9,vr3,vr2,vr16
+ lvx vr1,r4,r10
+ vperm vr10,vr2,vr1,vr16
+ lvx vr0,r4,r11
+ vperm vr11,vr1,vr0,vr16
+ addi r4,r4,64
+ stvx vr8,r0,r3
+ stvx vr9,r3,r9
+ stvx vr10,r3,r10
+ stvx vr11,r3,r11
+ addi r3,r3,64
+
+7: sub r5,r5,r6
+ srdi r6,r5,7
+
+ std r14,STK_REG(r14)(r1)
+ std r15,STK_REG(r15)(r1)
+ std r16,STK_REG(r16)(r1)
+
+ li r12,64
+ li r14,80
+ li r15,96
+ li r16,112
+
+ mtctr r6
+
+ /*
+ * Now do cacheline sized loads and stores. By this stage the
+ * cacheline stores are also cacheline aligned.
+ */
+ .align 5
+8:
+ lvx vr7,r0,r4
+ vperm vr8,vr0,vr7,vr16
+ lvx vr6,r4,r9
+ vperm vr9,vr7,vr6,vr16
+ lvx vr5,r4,r10
+ vperm vr10,vr6,vr5,vr16
+ lvx vr4,r4,r11
+ vperm vr11,vr5,vr4,vr16
+ lvx vr3,r4,r12
+ vperm vr12,vr4,vr3,vr16
+ lvx vr2,r4,r14
+ vperm vr13,vr3,vr2,vr16
+ lvx vr1,r4,r15
+ vperm vr14,vr2,vr1,vr16
+ lvx vr0,r4,r16
+ vperm vr15,vr1,vr0,vr16
+ addi r4,r4,128
+ stvx vr8,r0,r3
+ stvx vr9,r3,r9
+ stvx vr10,r3,r10
+ stvx vr11,r3,r11
+ stvx vr12,r3,r12
+ stvx vr13,r3,r14
+ stvx vr14,r3,r15
+ stvx vr15,r3,r16
+ addi r3,r3,128
+ bdnz 8b
+
+ ld r14,STK_REG(r14)(r1)
+ ld r15,STK_REG(r15)(r1)
+ ld r16,STK_REG(r16)(r1)
+
+ /* Up to 127B to go */
+ clrldi r5,r5,(64-7)
+ srdi r6,r5,4
+ mtocrf 0x01,r6
+
+ bf cr7*4+1,9f
+ lvx vr3,r0,r4
+ vperm vr8,vr0,vr3,vr16
+ lvx vr2,r4,r9
+ vperm vr9,vr3,vr2,vr16
+ lvx vr1,r4,r10
+ vperm vr10,vr2,vr1,vr16
+ lvx vr0,r4,r11
+ vperm vr11,vr1,vr0,vr16
+ addi r4,r4,64
+ stvx vr8,r0,r3
+ stvx vr9,r3,r9
+ stvx vr10,r3,r10
+ stvx vr11,r3,r11
+ addi r3,r3,64
+
+9: bf cr7*4+2,10f
+ lvx vr1,r0,r4
+ vperm vr8,vr0,vr1,vr16
+ lvx vr0,r4,r9
+ vperm vr9,vr1,vr0,vr16
+ addi r4,r4,32
+ stvx vr8,r0,r3
+ stvx vr9,r3,r9
+ addi r3,r3,32
+
+10: bf cr7*4+3,11f
+ lvx vr1,r0,r4
+ vperm vr8,vr0,vr1,vr16
+ addi r4,r4,16
+ stvx vr8,r0,r3
+ addi r3,r3,16
+
+ /* Up to 15B to go */
+11: clrldi r5,r5,(64-4)
+ addi r4,r4,-16 /* Unwind the +16 load offset */
+ mtocrf 0x01,r5
+ bf cr7*4+0,12f
+ lwz r0,0(r4) /* Less chance of a reject with word ops */
+ lwz r6,4(r4)
+ addi r4,r4,8
+ stw r0,0(r3)
+ stw r6,4(r3)
+ addi r3,r3,8
+
+12: bf cr7*4+1,13f
+ lwz r0,0(r4)
+ addi r4,r4,4
+ stw r0,0(r3)
+ addi r3,r3,4
+
+13: bf cr7*4+2,14f
+ lhz r0,0(r4)
+ addi r4,r4,2
+ sth r0,0(r3)
+ addi r3,r3,2
+
+14: bf cr7*4+3,15f
+ lbz r0,0(r4)
+ stb r0,0(r3)
+
+15: addi r1,r1,STACKFRAMESIZE
+ ld r3,48(r1)
+ b .exit_vmx_copy /* tail call optimise */
+#endif /* CONFiG_ALTIVEC */