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authorChris Metcalf <cmetcalf@ezchip.com>2015-04-30 21:12:42 +0200
committerChris Metcalf <cmetcalf@ezchip.com>2015-04-30 21:23:37 +0200
commit5bf6c07a1843813d0065feaaecba622d49148d7e (patch)
tree18118d48ffe123ce6f6d3eaa67dba135adafbc1a /arch/tile/lib/usercopy_64.S
parenttile: use READ_ONCE() in arch_spin_is_locked() (diff)
downloadlinux-5bf6c07a1843813d0065feaaecba622d49148d7e.tar.xz
linux-5bf6c07a1843813d0065feaaecba622d49148d7e.zip
tile: add <asm/word-at-a-time.h> and enable support functions
This change enables the generic strncpy_from_user() and strnlen_user() using word-at-a-time.h. The tile implementation is trivial since both tilepro and tilegx have SIMD operations that do byte-wise comparisons against immediate zero for each byte, and return an 0x01 byte in each position where there is a 0x00 byte. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Diffstat (limited to 'arch/tile/lib/usercopy_64.S')
-rw-r--r--arch/tile/lib/usercopy_64.S46
1 files changed, 0 insertions, 46 deletions
diff --git a/arch/tile/lib/usercopy_64.S b/arch/tile/lib/usercopy_64.S
index b3b31a3306f8..9322dc551e91 100644
--- a/arch/tile/lib/usercopy_64.S
+++ b/arch/tile/lib/usercopy_64.S
@@ -20,52 +20,6 @@
/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
/*
- * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
- * It returns the length, including the terminating NUL, or zero on exception.
- * If length is greater than the bound, returns one plus the bound.
- */
-STD_ENTRY(strnlen_user_asm)
- { beqz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
-1: { ld1u r4, r0; addi r1, r1, -1 }
- beqz r4, 2f
- { bnezt r1, 1b; addi r0, r0, 1 }
-2: { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strnlen_user_asm)
- .pushsection .fixup,"ax"
-strnlen_user_fault:
- { move r0, zero; jrp lr }
- ENDPROC(strnlen_user_fault)
- .section __ex_table,"a"
- .align 8
- .quad 1b, strnlen_user_fault
- .popsection
-
-/*
- * strncpy_from_user_asm takes the kernel target pointer in r0,
- * the userspace source pointer in r1, and the length bound (including
- * the trailing NUL) in r2. On success, it returns the string length
- * (not including the trailing NUL), or -EFAULT on failure.
- */
-STD_ENTRY(strncpy_from_user_asm)
- { beqz r2, 2f; move r3, r0 }
-1: { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
- { st1 r0, r4; addi r0, r0, 1 }
- beqz r4, 2f
- bnezt r2, 1b
- { sub r0, r0, r3; jrp lr }
-2: addi r0, r0, -1 /* don't count the trailing NUL */
- { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strncpy_from_user_asm)
- .pushsection .fixup,"ax"
-strncpy_from_user_fault:
- { movei r0, -EFAULT; jrp lr }
- ENDPROC(strncpy_from_user_fault)
- .section __ex_table,"a"
- .align 8
- .quad 1b, strncpy_from_user_fault
- .popsection
-
-/*
* clear_user_asm takes the user target address in r0 and the
* number of bytes to zero in r1.
* It returns the number of uncopiable bytes (hopefully zero) in r0.