diff options
Diffstat (limited to 'kernel/arch/x86/lib/copy_user_64.S')
| -rw-r--r-- | kernel/arch/x86/lib/copy_user_64.S | 187 |
1 files changed, 150 insertions, 37 deletions
diff --git a/kernel/arch/x86/lib/copy_user_64.S b/kernel/arch/x86/lib/copy_user_64.S index fa997dfae..27f89c79a 100644 --- a/kernel/arch/x86/lib/copy_user_64.S +++ b/kernel/arch/x86/lib/copy_user_64.S @@ -7,7 +7,6 @@ */ #include <linux/linkage.h> -#include <asm/dwarf2.h> #include <asm/current.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> @@ -16,33 +15,8 @@ #include <asm/asm.h> #include <asm/smap.h> - .macro ALIGN_DESTINATION - /* check for bad alignment of destination */ - movl %edi,%ecx - andl $7,%ecx - jz 102f /* already aligned */ - subl $8,%ecx - negl %ecx - subl %ecx,%edx -100: movb (%rsi),%al -101: movb %al,(%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz 100b -102: - .section .fixup,"ax" -103: addl %ecx,%edx /* ecx is zerorest also */ - jmp copy_user_handle_tail - .previous - - _ASM_EXTABLE(100b,103b) - _ASM_EXTABLE(101b,103b) - .endm - /* Standard copy_to_user with segment limit checking */ ENTRY(_copy_to_user) - CFI_STARTPROC GET_THREAD_INFO(%rax) movq %rdi,%rcx addq %rdx,%rcx @@ -54,12 +28,10 @@ ENTRY(_copy_to_user) X86_FEATURE_REP_GOOD, \ "jmp copy_user_enhanced_fast_string", \ X86_FEATURE_ERMS - CFI_ENDPROC ENDPROC(_copy_to_user) /* Standard copy_from_user with segment limit checking */ ENTRY(_copy_from_user) - CFI_STARTPROC GET_THREAD_INFO(%rax) movq %rsi,%rcx addq %rdx,%rcx @@ -71,14 +43,12 @@ ENTRY(_copy_from_user) X86_FEATURE_REP_GOOD, \ "jmp copy_user_enhanced_fast_string", \ X86_FEATURE_ERMS - CFI_ENDPROC ENDPROC(_copy_from_user) .section .fixup,"ax" /* must zero dest */ ENTRY(bad_from_user) bad_from_user: - CFI_STARTPROC movl %edx,%ecx xorl %eax,%eax rep @@ -86,7 +56,6 @@ bad_from_user: bad_to_user: movl %edx,%eax ret - CFI_ENDPROC ENDPROC(bad_from_user) .previous @@ -104,7 +73,6 @@ ENDPROC(bad_from_user) * eax uncopied bytes or 0 if successful. */ ENTRY(copy_user_generic_unrolled) - CFI_STARTPROC ASM_STAC cmpl $8,%edx jb 20f /* less then 8 bytes, go to byte copy loop */ @@ -186,7 +154,6 @@ ENTRY(copy_user_generic_unrolled) _ASM_EXTABLE(19b,40b) _ASM_EXTABLE(21b,50b) _ASM_EXTABLE(22b,50b) - CFI_ENDPROC ENDPROC(copy_user_generic_unrolled) /* Some CPUs run faster using the string copy instructions. @@ -208,7 +175,6 @@ ENDPROC(copy_user_generic_unrolled) * eax uncopied bytes or 0 if successful. */ ENTRY(copy_user_generic_string) - CFI_STARTPROC ASM_STAC cmpl $8,%edx jb 2f /* less than 8 bytes, go to byte copy loop */ @@ -233,7 +199,6 @@ ENTRY(copy_user_generic_string) _ASM_EXTABLE(1b,11b) _ASM_EXTABLE(3b,12b) - CFI_ENDPROC ENDPROC(copy_user_generic_string) /* @@ -249,7 +214,6 @@ ENDPROC(copy_user_generic_string) * eax uncopied bytes or 0 if successful. */ ENTRY(copy_user_enhanced_fast_string) - CFI_STARTPROC ASM_STAC movl %edx,%ecx 1: rep @@ -264,5 +228,154 @@ ENTRY(copy_user_enhanced_fast_string) .previous _ASM_EXTABLE(1b,12b) - CFI_ENDPROC ENDPROC(copy_user_enhanced_fast_string) + +/* + * copy_user_nocache - Uncached memory copy with exception handling + * This will force destination out of cache for more performance. + * + * Note: Cached memory copy is used when destination or size is not + * naturally aligned. That is: + * - Require 8-byte alignment when size is 8 bytes or larger. + * - Require 4-byte alignment when size is 4 bytes. + */ +ENTRY(__copy_user_nocache) + ASM_STAC + + /* If size is less than 8 bytes, go to 4-byte copy */ + cmpl $8,%edx + jb .L_4b_nocache_copy_entry + + /* If destination is not 8-byte aligned, "cache" copy to align it */ + ALIGN_DESTINATION + + /* Set 4x8-byte copy count and remainder */ + movl %edx,%ecx + andl $63,%edx + shrl $6,%ecx + jz .L_8b_nocache_copy_entry /* jump if count is 0 */ + + /* Perform 4x8-byte nocache loop-copy */ +.L_4x8b_nocache_copy_loop: +1: movq (%rsi),%r8 +2: movq 1*8(%rsi),%r9 +3: movq 2*8(%rsi),%r10 +4: movq 3*8(%rsi),%r11 +5: movnti %r8,(%rdi) +6: movnti %r9,1*8(%rdi) +7: movnti %r10,2*8(%rdi) +8: movnti %r11,3*8(%rdi) +9: movq 4*8(%rsi),%r8 +10: movq 5*8(%rsi),%r9 +11: movq 6*8(%rsi),%r10 +12: movq 7*8(%rsi),%r11 +13: movnti %r8,4*8(%rdi) +14: movnti %r9,5*8(%rdi) +15: movnti %r10,6*8(%rdi) +16: movnti %r11,7*8(%rdi) + leaq 64(%rsi),%rsi + leaq 64(%rdi),%rdi + decl %ecx + jnz .L_4x8b_nocache_copy_loop + + /* Set 8-byte copy count and remainder */ +.L_8b_nocache_copy_entry: + movl %edx,%ecx + andl $7,%edx + shrl $3,%ecx + jz .L_4b_nocache_copy_entry /* jump if count is 0 */ + + /* Perform 8-byte nocache loop-copy */ +.L_8b_nocache_copy_loop: +20: movq (%rsi),%r8 +21: movnti %r8,(%rdi) + leaq 8(%rsi),%rsi + leaq 8(%rdi),%rdi + decl %ecx + jnz .L_8b_nocache_copy_loop + + /* If no byte left, we're done */ +.L_4b_nocache_copy_entry: + andl %edx,%edx + jz .L_finish_copy + + /* If destination is not 4-byte aligned, go to byte copy: */ + movl %edi,%ecx + andl $3,%ecx + jnz .L_1b_cache_copy_entry + + /* Set 4-byte copy count (1 or 0) and remainder */ + movl %edx,%ecx + andl $3,%edx + shrl $2,%ecx + jz .L_1b_cache_copy_entry /* jump if count is 0 */ + + /* Perform 4-byte nocache copy: */ +30: movl (%rsi),%r8d +31: movnti %r8d,(%rdi) + leaq 4(%rsi),%rsi + leaq 4(%rdi),%rdi + + /* If no bytes left, we're done: */ + andl %edx,%edx + jz .L_finish_copy + + /* Perform byte "cache" loop-copy for the remainder */ +.L_1b_cache_copy_entry: + movl %edx,%ecx +.L_1b_cache_copy_loop: +40: movb (%rsi),%al +41: movb %al,(%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz .L_1b_cache_copy_loop + + /* Finished copying; fence the prior stores */ +.L_finish_copy: + xorl %eax,%eax + ASM_CLAC + sfence + ret + + .section .fixup,"ax" +.L_fixup_4x8b_copy: + shll $6,%ecx + addl %ecx,%edx + jmp .L_fixup_handle_tail +.L_fixup_8b_copy: + lea (%rdx,%rcx,8),%rdx + jmp .L_fixup_handle_tail +.L_fixup_4b_copy: + lea (%rdx,%rcx,4),%rdx + jmp .L_fixup_handle_tail +.L_fixup_1b_copy: + movl %ecx,%edx +.L_fixup_handle_tail: + sfence + jmp copy_user_handle_tail + .previous + + _ASM_EXTABLE(1b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(2b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(3b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(4b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(5b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(6b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(7b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(8b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(9b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(10b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(11b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(12b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(13b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(14b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(15b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(16b,.L_fixup_4x8b_copy) + _ASM_EXTABLE(20b,.L_fixup_8b_copy) + _ASM_EXTABLE(21b,.L_fixup_8b_copy) + _ASM_EXTABLE(30b,.L_fixup_4b_copy) + _ASM_EXTABLE(31b,.L_fixup_4b_copy) + _ASM_EXTABLE(40b,.L_fixup_1b_copy) + _ASM_EXTABLE(41b,.L_fixup_1b_copy) +ENDPROC(__copy_user_nocache) |