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>

3 files changed, 0 insertions, 94 deletions

diff --git a/arch/tile/lib/exports.c b/arch/tile/lib/exports.c
index 82733c8..16326f2 100644
--- a/arch/tile/lib/exports.c
+++ b/arch/tile/lib/exports.c
@@ -18,8 +18,6 @@
 
 /* arch/tile/lib/usercopy.S */
 #include <linux/uaccess.h>
-EXPORT_SYMBOL(strnlen_user_asm);
-EXPORT_SYMBOL(strncpy_from_user_asm);
 EXPORT_SYMBOL(clear_user_asm);
 EXPORT_SYMBOL(flush_user_asm);
 EXPORT_SYMBOL(finv_user_asm);
diff --git a/arch/tile/lib/usercopy_32.S b/arch/tile/lib/usercopy_32.S
index 1bc1622..db93ad5 100644
--- a/arch/tile/lib/usercopy_32.S
+++ b/arch/tile/lib/usercopy_32.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)
-	{ bz r1, 2f; addi r3, r0, -1 }  /* bias down to include NUL */
-1:      { lb_u r4, r0; addi r1, r1, -1 }
-	bz r4, 2f
-	{ bnzt 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 4
-	.word 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)
-	{ bz r2, 2f; move r3, r0 }
-1:	{ lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
-	{ sb r0, r4; addi r0, r0, 1 }
-	bz r4, 2f
-	bnzt 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 4
-	.word 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.
diff --git a/arch/tile/lib/usercopy_64.S b/arch/tile/lib/usercopy_64.S
index b3b31a3..9322dc5 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.