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linux/arch/riscv/lib/memset.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 Based on 1 normalized pattern(s): 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 see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29 07:18:00 -07:00
/* SPDX-License-Identifier: GPL-2.0-only */
RISC-V: Generic library routines and assembly This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:03:19 -07:00
/*
* Copyright (C) 2013 Regents of the University of California
*/
#include <linux/linkage.h>
#include <asm/asm.h>
/* void *memset(void *, int, size_t) */
riscv: Add KASAN support This patch ports the feature Kernel Address SANitizer (KASAN). Note: The start address of shadow memory is at the beginning of kernel space, which is 2^64 - (2^39 / 2) in SV39. The size of the kernel space is 2^38 bytes so the size of shadow memory should be 2^38 / 8. Thus, the shadow memory would not overlap with the fixmap area. There are currently two limitations in this port, 1. RV64 only: KASAN need large address space for extra shadow memory region. 2. KASAN can't debug the modules since the modules are allocated in VMALLOC area. We mapped the shadow memory, which corresponding to VMALLOC area, to the kasan_early_shadow_page because we don't have enough physical space for all the shadow memory corresponding to VMALLOC area. Signed-off-by: Nick Hu <nickhu@andestech.com> Reported-by: Greentime Hu <green.hu@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-06 10:38:32 -08:00
ENTRY(__memset)
WEAK(memset)
RISC-V: Generic library routines and assembly This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:03:19 -07:00
move t0, a0 /* Preserve return value */
/* Defer to byte-oriented fill for small sizes */
sltiu a3, a2, 16
bnez a3, 4f
/*
* Round to nearest XLEN-aligned address
* greater than or equal to start address
*/
addi a3, t0, SZREG-1
andi a3, a3, ~(SZREG-1)
beq a3, t0, 2f /* Skip if already aligned */
/* Handle initial misalignment */
sub a4, a3, t0
1:
sb a1, 0(t0)
addi t0, t0, 1
bltu t0, a3, 1b
sub a2, a2, a4 /* Update count */
2: /* Duff's device with 32 XLEN stores per iteration */
/* Broadcast value into all bytes */
andi a1, a1, 0xff
slli a3, a1, 8
or a1, a3, a1
slli a3, a1, 16
or a1, a3, a1
#ifdef CONFIG_64BIT
slli a3, a1, 32
or a1, a3, a1
#endif
/* Calculate end address */
andi a4, a2, ~(SZREG-1)
add a3, t0, a4
andi a4, a4, 31*SZREG /* Calculate remainder */
beqz a4, 3f /* Shortcut if no remainder */
neg a4, a4
addi a4, a4, 32*SZREG /* Calculate initial offset */
/* Adjust start address with offset */
sub t0, t0, a4
/* Jump into loop body */
/* Assumes 32-bit instruction lengths */
la a5, 3f
#ifdef CONFIG_64BIT
srli a4, a4, 1
#endif
add a5, a5, a4
jr a5
3:
REG_S a1, 0(t0)
REG_S a1, SZREG(t0)
REG_S a1, 2*SZREG(t0)
REG_S a1, 3*SZREG(t0)
REG_S a1, 4*SZREG(t0)
REG_S a1, 5*SZREG(t0)
REG_S a1, 6*SZREG(t0)
REG_S a1, 7*SZREG(t0)
REG_S a1, 8*SZREG(t0)
REG_S a1, 9*SZREG(t0)
REG_S a1, 10*SZREG(t0)
REG_S a1, 11*SZREG(t0)
REG_S a1, 12*SZREG(t0)
REG_S a1, 13*SZREG(t0)
REG_S a1, 14*SZREG(t0)
REG_S a1, 15*SZREG(t0)
REG_S a1, 16*SZREG(t0)
REG_S a1, 17*SZREG(t0)
REG_S a1, 18*SZREG(t0)
REG_S a1, 19*SZREG(t0)
REG_S a1, 20*SZREG(t0)
REG_S a1, 21*SZREG(t0)
REG_S a1, 22*SZREG(t0)
REG_S a1, 23*SZREG(t0)
REG_S a1, 24*SZREG(t0)
REG_S a1, 25*SZREG(t0)
REG_S a1, 26*SZREG(t0)
REG_S a1, 27*SZREG(t0)
REG_S a1, 28*SZREG(t0)
REG_S a1, 29*SZREG(t0)
REG_S a1, 30*SZREG(t0)
REG_S a1, 31*SZREG(t0)
addi t0, t0, 32*SZREG
bltu t0, a3, 3b
andi a2, a2, SZREG-1 /* Update count */
4:
/* Handle trailing misalignment */
beqz a2, 6f
add a3, t0, a2
5:
sb a1, 0(t0)
addi t0, t0, 1
bltu t0, a3, 5b
6:
ret
riscv: Add KASAN support This patch ports the feature Kernel Address SANitizer (KASAN). Note: The start address of shadow memory is at the beginning of kernel space, which is 2^64 - (2^39 / 2) in SV39. The size of the kernel space is 2^38 bytes so the size of shadow memory should be 2^38 / 8. Thus, the shadow memory would not overlap with the fixmap area. There are currently two limitations in this port, 1. RV64 only: KASAN need large address space for extra shadow memory region. 2. KASAN can't debug the modules since the modules are allocated in VMALLOC area. We mapped the shadow memory, which corresponding to VMALLOC area, to the kasan_early_shadow_page because we don't have enough physical space for all the shadow memory corresponding to VMALLOC area. Signed-off-by: Nick Hu <nickhu@andestech.com> Reported-by: Greentime Hu <green.hu@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-06 10:38:32 -08:00
END(__memset)
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