mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
5bf6c07a18
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>
90 lines
2.7 KiB
ArmAsm
90 lines
2.7 KiB
ArmAsm
/*
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* Copyright 2011 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/linkage.h>
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#include <asm/errno.h>
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#include <asm/cache.h>
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#include <arch/chip.h>
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/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
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/*
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* clear_user_asm takes the user target address in r0 and the
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* number of bytes to zero in r1.
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* It returns the number of uncopiable bytes (hopefully zero) in r0.
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* Note that we don't use a separate .fixup section here since we fall
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* through into the "fixup" code as the last straight-line bundle anyway.
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*/
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STD_ENTRY(clear_user_asm)
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{ beqz r1, 2f; or r2, r0, r1 }
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andi r2, r2, 7
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beqzt r2, .Lclear_aligned_user_asm
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1: { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
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bnezt r1, 1b
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2: { move r0, r1; jrp lr }
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.pushsection __ex_table,"a"
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.align 8
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.quad 1b, 2b
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.popsection
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.Lclear_aligned_user_asm:
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1: { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 }
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bnezt r1, 1b
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2: { move r0, r1; jrp lr }
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STD_ENDPROC(clear_user_asm)
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.pushsection __ex_table,"a"
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.align 8
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.quad 1b, 2b
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.popsection
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/*
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* flush_user_asm takes the user target address in r0 and the
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* number of bytes to flush in r1.
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* It returns the number of unflushable bytes (hopefully zero) in r0.
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*/
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STD_ENTRY(flush_user_asm)
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beqz r1, 2f
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{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
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{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
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{ and r0, r0, r2; and r1, r1, r2 }
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{ sub r1, r1, r0 }
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1: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
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{ addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b }
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2: { move r0, r1; jrp lr }
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STD_ENDPROC(flush_user_asm)
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.pushsection __ex_table,"a"
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.align 8
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.quad 1b, 2b
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.popsection
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/*
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* finv_user_asm takes the user target address in r0 and the
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* number of bytes to flush-invalidate in r1.
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* It returns the number of not finv'able bytes (hopefully zero) in r0.
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*/
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STD_ENTRY(finv_user_asm)
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beqz r1, 2f
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{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
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{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
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{ and r0, r0, r2; and r1, r1, r2 }
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{ sub r1, r1, r0 }
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1: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
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{ addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b }
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2: { move r0, r1; jrp lr }
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STD_ENDPROC(finv_user_asm)
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.pushsection __ex_table,"a"
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.align 8
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.quad 1b, 2b
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.popsection
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