Jan Beulich
2012-Jun-29 14:29 UTC
[PATCH] linux-2.6.18/x86: make xor block handling uniform
Irrespective of the elimination of raw CR0 reads and writes, any of the
methods requiring access to the floating point/XMM state still perform
worse than the integer register based ones (at least as long as the
virtual CR0.TS is set upon entry). Thus un-define XOR_SELECT_TEMPLATE
in both 32- and 64-bit.
On 64-bit additionally make the integer register based routines
available for selection in the first place, and remove the duplicate
code in the Xen specific header in favor of a small adjustment to the
native one (using read_cr0()/clts()/write_cr0() instead of open coded
accesses in the inline assembly).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- /dev/null
+++ b/include/asm-i386/mach-xen/asm/xor.h
@@ -0,0 +1,3 @@
+#include_next <asm/xor.h>
+
+#undef XOR_SELECT_TEMPLATE
--- a/include/asm-x86_64/mach-xen/asm/xor.h
+++ b/include/asm-x86_64/mach-xen/asm/xor.h
@@ -1,328 +1,17 @@
-/*
- * x86-64 changes / gcc fixes from Andi Kleen.
- * Copyright 2002 Andi Kleen, SuSE Labs.
- *
- * This hasn''t been optimized for the hammer yet, but there are likely
- * no advantages to be gotten from x86-64 here anyways.
- */
+#include_next <asm/xor.h>
-typedef struct { unsigned long a,b; } __attribute__((aligned(16))) xmm_store_t;
+#undef XOR_SELECT_TEMPLATE
-/* Doesn''t use gcc to save the XMM registers, because there is no easy
way to
- tell it to do a clts before the register saving. */
-#define XMMS_SAVE do { \
- preempt_disable(); \
- if (!(current_thread_info()->status & TS_USEDFPU)) \
- clts(); \
- __asm__ __volatile__ ( \
- "movups %%xmm0,(%1) ;\n\t" \
- "movups %%xmm1,0x10(%1) ;\n\t" \
- "movups %%xmm2,0x20(%1) ;\n\t" \
- "movups %%xmm3,0x30(%1) ;\n\t" \
- : "=&r" (cr0) \
- : "r" (xmm_save) \
- : "memory"); \
-} while(0)
-
-#define XMMS_RESTORE do { \
- asm volatile ( \
- "sfence ;\n\t" \
- "movups (%1),%%xmm0 ;\n\t" \
- "movups 0x10(%1),%%xmm1 ;\n\t" \
- "movups 0x20(%1),%%xmm2 ;\n\t" \
- "movups 0x30(%1),%%xmm3 ;\n\t" \
- : \
- : "r" (cr0), "r" (xmm_save) \
- : "memory"); \
- if (!(current_thread_info()->status & TS_USEDFPU)) \
- stts(); \
- preempt_enable(); \
-} while(0)
-
-#define OFFS(x) "16*("#x")"
-#define PF_OFFS(x) "256+16*("#x")"
-#define PF0(x) " prefetchnta "PF_OFFS(x)"(%[p1]) ;\n"
-#define LD(x,y) " movaps "OFFS(x)"(%[p1]),
%%xmm"#y" ;\n"
-#define ST(x,y) " movaps %%xmm"#y",
"OFFS(x)"(%[p1]) ;\n"
-#define PF1(x) " prefetchnta "PF_OFFS(x)"(%[p2]) ;\n"
-#define PF2(x) " prefetchnta "PF_OFFS(x)"(%[p3]) ;\n"
-#define PF3(x) " prefetchnta "PF_OFFS(x)"(%[p4]) ;\n"
-#define PF4(x) " prefetchnta "PF_OFFS(x)"(%[p5]) ;\n"
-#define PF5(x) " prefetchnta "PF_OFFS(x)"(%[p6]) ;\n"
-#define XO1(x,y) " xorps "OFFS(x)"(%[p2]),
%%xmm"#y" ;\n"
-#define XO2(x,y) " xorps "OFFS(x)"(%[p3]),
%%xmm"#y" ;\n"
-#define XO3(x,y) " xorps "OFFS(x)"(%[p4]),
%%xmm"#y" ;\n"
-#define XO4(x,y) " xorps "OFFS(x)"(%[p5]),
%%xmm"#y" ;\n"
-#define XO5(x,y) " xorps "OFFS(x)"(%[p6]),
%%xmm"#y" ;\n"
-
-
-static void
-xor_sse_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
-{
- unsigned int lines = bytes >> 8;
- unsigned long cr0;
- xmm_store_t xmm_save[4];
-
- XMMS_SAVE;
-
- asm volatile (
-#undef BLOCK
-#define BLOCK(i) \
- LD(i,0) \
- LD(i+1,1) \
- PF1(i) \
- PF1(i+2) \
- LD(i+2,2) \
- LD(i+3,3) \
- PF0(i+4) \
- PF0(i+6) \
- XO1(i,0) \
- XO1(i+1,1) \
- XO1(i+2,2) \
- XO1(i+3,3) \
- ST(i,0) \
- ST(i+1,1) \
- ST(i+2,2) \
- ST(i+3,3) \
-
-
- PF0(0)
- PF0(2)
-
- " .align 32 ;\n"
- " 1: ;\n"
-
- BLOCK(0)
- BLOCK(4)
- BLOCK(8)
- BLOCK(12)
-
- " addq %[inc], %[p1] ;\n"
- " addq %[inc], %[p2] ;\n"
- " decl %[cnt] ; jnz 1b"
- : [p1] "+r" (p1), [p2] "+r" (p2), [cnt] "+r"
(lines)
- : [inc] "r" (256UL)
- : "memory");
-
- XMMS_RESTORE;
-}
-
-static void
-xor_sse_3(unsigned long bytes, unsigned long *p1, unsigned long *p2,
- unsigned long *p3)
-{
- unsigned int lines = bytes >> 8;
- xmm_store_t xmm_save[4];
- unsigned long cr0;
-
- XMMS_SAVE;
-
- __asm__ __volatile__ (
-#undef BLOCK
-#define BLOCK(i) \
- PF1(i) \
- PF1(i+2) \
- LD(i,0) \
- LD(i+1,1) \
- LD(i+2,2) \
- LD(i+3,3) \
- PF2(i) \
- PF2(i+2) \
- PF0(i+4) \
- PF0(i+6) \
- XO1(i,0) \
- XO1(i+1,1) \
- XO1(i+2,2) \
- XO1(i+3,3) \
- XO2(i,0) \
- XO2(i+1,1) \
- XO2(i+2,2) \
- XO2(i+3,3) \
- ST(i,0) \
- ST(i+1,1) \
- ST(i+2,2) \
- ST(i+3,3) \
-
-
- PF0(0)
- PF0(2)
-
- " .align 32 ;\n"
- " 1: ;\n"
-
- BLOCK(0)
- BLOCK(4)
- BLOCK(8)
- BLOCK(12)
-
- " addq %[inc], %[p1] ;\n"
- " addq %[inc], %[p2] ;\n"
- " addq %[inc], %[p3] ;\n"
- " decl %[cnt] ; jnz 1b"
- : [cnt] "+r" (lines),
- [p1] "+r" (p1), [p2] "+r" (p2), [p3] "+r" (p3)
- : [inc] "r" (256UL)
- : "memory");
- XMMS_RESTORE;
-}
-
-static void
-xor_sse_4(unsigned long bytes, unsigned long *p1, unsigned long *p2,
- unsigned long *p3, unsigned long *p4)
-{
- unsigned int lines = bytes >> 8;
- xmm_store_t xmm_save[4];
- unsigned long cr0;
-
- XMMS_SAVE;
-
- __asm__ __volatile__ (
-#undef BLOCK
-#define BLOCK(i) \
- PF1(i) \
- PF1(i+2) \
- LD(i,0) \
- LD(i+1,1) \
- LD(i+2,2) \
- LD(i+3,3) \
- PF2(i) \
- PF2(i+2) \
- XO1(i,0) \
- XO1(i+1,1) \
- XO1(i+2,2) \
- XO1(i+3,3) \
- PF3(i) \
- PF3(i+2) \
- PF0(i+4) \
- PF0(i+6) \
- XO2(i,0) \
- XO2(i+1,1) \
- XO2(i+2,2) \
- XO2(i+3,3) \
- XO3(i,0) \
- XO3(i+1,1) \
- XO3(i+2,2) \
- XO3(i+3,3) \
- ST(i,0) \
- ST(i+1,1) \
- ST(i+2,2) \
- ST(i+3,3) \
-
-
- PF0(0)
- PF0(2)
-
- " .align 32 ;\n"
- " 1: ;\n"
-
- BLOCK(0)
- BLOCK(4)
- BLOCK(8)
- BLOCK(12)
-
- " addq %[inc], %[p1] ;\n"
- " addq %[inc], %[p2] ;\n"
- " addq %[inc], %[p3] ;\n"
- " addq %[inc], %[p4] ;\n"
- " decl %[cnt] ; jnz 1b"
- : [cnt] "+c" (lines),
- [p1] "+r" (p1), [p2] "+r" (p2), [p3] "+r"
(p3), [p4] "+r" (p4)
- : [inc] "r" (256UL)
- : "memory" );
-
- XMMS_RESTORE;
-}
-
-static void
-xor_sse_5(unsigned long bytes, unsigned long *p1, unsigned long *p2,
- unsigned long *p3, unsigned long *p4, unsigned long *p5)
-{
- unsigned int lines = bytes >> 8;
- xmm_store_t xmm_save[4];
- unsigned long cr0;
-
- XMMS_SAVE;
-
- __asm__ __volatile__ (
-#undef BLOCK
-#define BLOCK(i) \
- PF1(i) \
- PF1(i+2) \
- LD(i,0) \
- LD(i+1,1) \
- LD(i+2,2) \
- LD(i+3,3) \
- PF2(i) \
- PF2(i+2) \
- XO1(i,0) \
- XO1(i+1,1) \
- XO1(i+2,2) \
- XO1(i+3,3) \
- PF3(i) \
- PF3(i+2) \
- XO2(i,0) \
- XO2(i+1,1) \
- XO2(i+2,2) \
- XO2(i+3,3) \
- PF4(i) \
- PF4(i+2) \
- PF0(i+4) \
- PF0(i+6) \
- XO3(i,0) \
- XO3(i+1,1) \
- XO3(i+2,2) \
- XO3(i+3,3) \
- XO4(i,0) \
- XO4(i+1,1) \
- XO4(i+2,2) \
- XO4(i+3,3) \
- ST(i,0) \
- ST(i+1,1) \
- ST(i+2,2) \
- ST(i+3,3) \
-
-
- PF0(0)
- PF0(2)
-
- " .align 32 ;\n"
- " 1: ;\n"
-
- BLOCK(0)
- BLOCK(4)
- BLOCK(8)
- BLOCK(12)
-
- " addq %[inc], %[p1] ;\n"
- " addq %[inc], %[p2] ;\n"
- " addq %[inc], %[p3] ;\n"
- " addq %[inc], %[p4] ;\n"
- " addq %[inc], %[p5] ;\n"
- " decl %[cnt] ; jnz 1b"
- : [cnt] "+c" (lines),
- [p1] "+r" (p1), [p2] "+r" (p2), [p3] "+r"
(p3), [p4] "+r" (p4),
- [p5] "+r" (p5)
- : [inc] "r" (256UL)
- : "memory");
-
- XMMS_RESTORE;
-}
-
-static struct xor_block_template xor_block_sse = {
- .name = "generic_sse",
- .do_2 = xor_sse_2,
- .do_3 = xor_sse_3,
- .do_4 = xor_sse_4,
- .do_5 = xor_sse_5,
-};
+/* Also try the generic routines. */
+#undef XOR_TRY_TEMPLATES
+#include <asm-generic/xor.h>
#undef XOR_TRY_TEMPLATES
-#define XOR_TRY_TEMPLATES \
- do { \
+#define XOR_TRY_TEMPLATES \
+ do { \
+ xor_speed(&xor_block_8regs); \
+ xor_speed(&xor_block_8regs_p); \
+ xor_speed(&xor_block_32regs); \
+ xor_speed(&xor_block_32regs_p); \
xor_speed(&xor_block_sse); \
} while (0)
-
-/* We force the use of the SSE xor block because it can write around L2.
- We may also be able to load into the L1 only depending on how the cpu
- deals with a load to a line that is being prefetched. */
-#define XOR_SELECT_TEMPLATE(FASTEST) (&xor_block_sse)
--- a/include/asm-x86_64/xor.h
+++ b/include/asm-x86_64/xor.h
@@ -39,14 +39,14 @@ typedef struct { unsigned long a,b; } __
tell it to do a clts before the register saving. */
#define XMMS_SAVE do { \
preempt_disable(); \
+ cr0 = read_cr0(); \
+ clts(); \
asm volatile ( \
- "movq %%cr0,%0 ;\n\t" \
- "clts ;\n\t" \
"movups %%xmm0,(%1) ;\n\t" \
"movups %%xmm1,0x10(%1) ;\n\t" \
"movups %%xmm2,0x20(%1) ;\n\t" \
"movups %%xmm3,0x30(%1) ;\n\t" \
- : "=&r" (cr0) \
+ : "+r" (cr0) \
: "r" (xmm_save) \
: "memory"); \
} while(0)
@@ -58,10 +58,10 @@ typedef struct { unsigned long a,b; } __
"movups 0x10(%1),%%xmm1 ;\n\t" \
"movups 0x20(%1),%%xmm2 ;\n\t" \
"movups 0x30(%1),%%xmm3 ;\n\t" \
- "movq %0,%%cr0 ;\n\t" \
: \
: "r" (cr0), "r" (xmm_save) \
: "memory"); \
+ write_cr0(cr0); \
preempt_enable(); \
} while(0)
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel