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| author | Michal Simek <monstr@monstr.eu> | 2011-06-10 12:49:08 +0400 |
|---|---|---|
| committer | Michal Simek <monstr@monstr.eu> | 2011-10-14 14:24:26 +0400 |
| commit | ebe211254bfa6295f4ab0b33c7c881bdfabbab60 (patch) | |
| tree | 08345bf06ede9d07585342f1264a12a47f2a0c50 /arch/microblaze/lib/uaccess_old.S | |
| parent | 782d491fc210fac03976d01071145728339b6887 (diff) | |
| download | linux-ebe211254bfa6295f4ab0b33c7c881bdfabbab60.tar.xz | |
microblaze: Add loop unrolling for PAGE in copy_tofrom_user
Increase performance by loop unrolling.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/lib/uaccess_old.S')
| -rw-r--r-- | arch/microblaze/lib/uaccess_old.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/microblaze/lib/uaccess_old.S b/arch/microblaze/lib/uaccess_old.S index d09f2dce648d..142492ec270f 100644 --- a/arch/microblaze/lib/uaccess_old.S +++ b/arch/microblaze/lib/uaccess_old.S @@ -10,6 +10,7 @@ #include <linux/errno.h> #include <linux/linkage.h> +#include <asm/page.h> /* * int __strncpy_user(char *to, char *from, int len); @@ -102,6 +103,49 @@ __strnlen_user: .section __ex_table,"a" .word 1b,4b +/* Loop unrolling for __copy_tofrom_user */ +#define COPY(offset) \ +1: lwi r4 , r6, 0x0000 + offset; \ +2: lwi r19, r6, 0x0004 + offset; \ +3: lwi r20, r6, 0x0008 + offset; \ +4: lwi r21, r6, 0x000C + offset; \ +5: lwi r22, r6, 0x0010 + offset; \ +6: lwi r23, r6, 0x0014 + offset; \ +7: lwi r24, r6, 0x0018 + offset; \ +8: lwi r25, r6, 0x001C + offset; \ +9: swi r4 , r5, 0x0000 + offset; \ +10: swi r19, r5, 0x0004 + offset; \ +11: swi r20, r5, 0x0008 + offset; \ +12: swi r21, r5, 0x000C + offset; \ +13: swi r22, r5, 0x0010 + offset; \ +14: swi r23, r5, 0x0014 + offset; \ +15: swi r24, r5, 0x0018 + offset; \ +16: swi r25, r5, 0x001C + offset; \ + .section __ex_table,"a"; \ + .word 1b, 0f; \ + .word 2b, 0f; \ + .word 3b, 0f; \ + .word 4b, 0f; \ + .word 5b, 0f; \ + .word 6b, 0f; \ + .word 7b, 0f; \ + .word 8b, 0f; \ + .word 9b, 0f; \ + .word 10b, 0f; \ + .word 11b, 0f; \ + .word 12b, 0f; \ + .word 13b, 0f; \ + .word 14b, 0f; \ + .word 15b, 0f; \ + .word 16b, 0f; \ + .text + +#define COPY_80(offset) \ + COPY(0x00 + offset);\ + COPY(0x20 + offset);\ + COPY(0x40 + offset);\ + COPY(0x60 + offset); + /* * int __copy_tofrom_user(char *to, char *from, int len) * Return: @@ -126,6 +170,10 @@ __copy_tofrom_user: bneid r3, bu1 /* if r3 is not zero then byte copying */ or r3, r0, r0 + rsubi r3, r7, PAGE_SIZE /* detect PAGE_SIZE */ + beqid r3, page; + or r3, r0, r0 + w1: lw r4, r6, r3 /* at least one 4 byte copy */ w2: sw r4, r5, r3 addik r7, r7, -4 @@ -140,6 +188,42 @@ w2: sw r4, r5, r3 .word w2, 0f; .text +.align 4 /* Alignment is important to keep icache happy */ +page: /* Create room on stack and save registers for storign values */ + addik r1, r1, -32 + swi r19, r1, 4 + swi r20, r1, 8 + swi r21, r1, 12 + swi r22, r1, 16 + swi r23, r1, 20 + swi r24, r1, 24 + swi r25, r1, 28 +loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */ + /* Loop unrolling to get performance boost */ + COPY_80(0x000); + COPY_80(0x080); + COPY_80(0x100); + COPY_80(0x180); + /* copy loop */ + addik r6, r6, 0x200 + addik r7, r7, -0x200 + bneid r7, loop + addik r5, r5, 0x200 + /* Restore register content */ + lwi r19, r1, 4 + lwi r20, r1, 8 + lwi r21, r1, 12 + lwi r22, r1, 16 + lwi r23, r1, 20 + lwi r24, r1, 24 + lwi r25, r1, 28 + addik r1, r1, 32 + /* return back */ + addik r3, r7, 0 + rtsd r15, 8 + nop + +.align 4 /* Alignment is important to keep icache happy */ bu1: lbu r4,r6,r3 bu2: sb r4,r5,r3 addik r7,r7,-1 |