diff options
| author | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-10 17:39:59 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-14 03:36:11 +0300 |
| commit | 61a6fccc0bd2e8030b2672a52ef3f6706b2b2ee4 (patch) | |
| tree | 7f10ae1216e9e65ec4a5770a168adbe0e725f479 /arch/loongarch/lib/unaligned.S | |
| parent | dbcd7f5fafea64dbe588c4ec18bc309fde5d1e1c (diff) | |
| download | linux-61a6fccc0bd2e8030b2672a52ef3f6706b2b2ee4.tar.xz | |
LoongArch: Add unaligned access support
Loongson-2 series (Loongson-2K500, Loongson-2K1000) don't support
unaligned access in hardware, while Loongson-3 series (Loongson-3A5000,
Loongson-3C5000) are configurable whether support unaligned access in
hardware. This patch add unaligned access emulation for those LoongArch
processors without hardware support.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/lib/unaligned.S')
| -rw-r--r-- | arch/loongarch/lib/unaligned.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/loongarch/lib/unaligned.S b/arch/loongarch/lib/unaligned.S new file mode 100644 index 000000000000..9177fd638f07 --- /dev/null +++ b/arch/loongarch/lib/unaligned.S @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ + +#include <linux/linkage.h> + +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/asm-extable.h> +#include <asm/errno.h> +#include <asm/export.h> +#include <asm/regdef.h> + +.L_fixup_handle_unaligned: + li.w a0, -EFAULT + jr ra + +/* + * unsigned long unaligned_read(void *addr, void *value, unsigned long n, bool sign) + * + * a0: addr + * a1: value + * a2: n + * a3: sign + */ +SYM_FUNC_START(unaligned_read) + beqz a2, 5f + + li.w t2, 0 + addi.d t0, a2, -1 + slli.d t1, t0, 3 + add.d a0, a0, t0 + + beqz a3, 2f +1: ld.b t3, a0, 0 + b 3f + +2: ld.bu t3, a0, 0 +3: sll.d t3, t3, t1 + or t2, t2, t3 + addi.d t1, t1, -8 + addi.d a0, a0, -1 + addi.d a2, a2, -1 + bgtz a2, 2b +4: st.d t2, a1, 0 + + move a0, a2 + jr ra + +5: li.w a0, -EFAULT + jr ra + + _asm_extable 1b, .L_fixup_handle_unaligned + _asm_extable 2b, .L_fixup_handle_unaligned + _asm_extable 4b, .L_fixup_handle_unaligned +SYM_FUNC_END(unaligned_read) + +/* + * unsigned long unaligned_write(void *addr, unsigned long value, unsigned long n) + * + * a0: addr + * a1: value + * a2: n + */ +SYM_FUNC_START(unaligned_write) + beqz a2, 3f + + li.w t0, 0 +1: srl.d t1, a1, t0 +2: st.b t1, a0, 0 + addi.d t0, t0, 8 + addi.d a2, a2, -1 + addi.d a0, a0, 1 + bgtz a2, 1b + + move a0, a2 + jr ra + +3: li.w a0, -EFAULT + jr ra + + _asm_extable 2b, .L_fixup_handle_unaligned +SYM_FUNC_END(unaligned_write) |