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Diffstat (limited to 'arch/tile/lib/usercopy_64.S')
| -rw-r--r-- | arch/tile/lib/usercopy_64.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/tile/lib/usercopy_64.S b/arch/tile/lib/usercopy_64.S new file mode 100644 index 000000000..b3b31a330 --- /dev/null +++ b/arch/tile/lib/usercopy_64.S @@ -0,0 +1,135 @@ +/* + * Copyright 2011 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/linkage.h> +#include <asm/errno.h> +#include <asm/cache.h> +#include <arch/chip.h> + +/* 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. + * Note that we don't use a separate .fixup section here since we fall + * through into the "fixup" code as the last straight-line bundle anyway. + */ +STD_ENTRY(clear_user_asm) + { beqz r1, 2f; or r2, r0, r1 } + andi r2, r2, 7 + beqzt r2, .Lclear_aligned_user_asm +1: { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 } + bnezt r1, 1b +2: { move r0, r1; jrp lr } + .pushsection __ex_table,"a" + .align 8 + .quad 1b, 2b + .popsection + +.Lclear_aligned_user_asm: +1: { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 } + bnezt r1, 1b +2: { move r0, r1; jrp lr } + STD_ENDPROC(clear_user_asm) + .pushsection __ex_table,"a" + .align 8 + .quad 1b, 2b + .popsection + +/* + * flush_user_asm takes the user target address in r0 and the + * number of bytes to flush in r1. + * It returns the number of unflushable bytes (hopefully zero) in r0. + */ +STD_ENTRY(flush_user_asm) + beqz r1, 2f + { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } + { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } + { and r0, r0, r2; and r1, r1, r2 } + { sub r1, r1, r0 } +1: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() } + { addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b } +2: { move r0, r1; jrp lr } + STD_ENDPROC(flush_user_asm) + .pushsection __ex_table,"a" + .align 8 + .quad 1b, 2b + .popsection + +/* + * finv_user_asm takes the user target address in r0 and the + * number of bytes to flush-invalidate in r1. + * It returns the number of not finv'able bytes (hopefully zero) in r0. + */ +STD_ENTRY(finv_user_asm) + beqz r1, 2f + { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } + { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } + { and r0, r0, r2; and r1, r1, r2 } + { sub r1, r1, r0 } +1: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() } + { addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b } +2: { move r0, r1; jrp lr } + STD_ENDPROC(finv_user_asm) + .pushsection __ex_table,"a" + .align 8 + .quad 1b, 2b + .popsection |