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| author | James Hogan <jhogan@kernel.org> | 2017-11-22 11:30:30 +0000 |
|---|---|---|
| committer | James Hogan <jhogan@kernel.org> | 2018-01-22 20:51:55 +0000 |
| commit | 8e4789d288e0155db1929b5672252429e52b36a8 (patch) | |
| tree | 9854c6979a31354be2f95d58ac2edf00826ada55 /arch | |
| parent | ed21e00777c558dfd3ad2bc0a8f88bf4e204be75 (diff) | |
| download | linux-8e4789d288e0155db1929b5672252429e52b36a8.tar.bz2 | |
MIPS: XPA: Use XPA instructions in assembly
Utilise XPA instructions MFHC0 & MTHC0 in inline assembly instead of
directly encoding them with the _ASM_INSN* macros, and transparently
implement these instructions as assembler macros if the toolchain
doesn't support them natively, using the recently introduced assembler
macro helpers.
The old direct encodings were restricted to using the register $at, so
this allows the extra register moves to go away (saving a grand total of
24 bytes).
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17775/
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/Makefile | 6 | ||||
| -rw-r--r-- | arch/mips/include/asm/mipsregs.h | 26 |
2 files changed, 22 insertions, 10 deletions
diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 0f20f84de53b..d1ca839c3981 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -216,6 +216,12 @@ cflags-$(toolchain-msa) += -DTOOLCHAIN_SUPPORTS_MSA endif toolchain-virt := $(call cc-option-yn,$(mips-cflags) -mvirt) cflags-$(toolchain-virt) += -DTOOLCHAIN_SUPPORTS_VIRT +# For -mmicromips, use -Wa,-fatal-warnings to catch unsupported -mxpa which +# only warns +xpa-cflags-y := $(mips-cflags) +xpa-cflags-$(micromips-ase) += -mmicromips -Wa$(comma)-fatal-warnings +toolchain-xpa := $(call cc-option-yn,$(xpa-cflags-y) -mxpa) +cflags-$(toolchain-xpa) += -DTOOLCHAIN_SUPPORTS_XPA # # Firmware support diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 509879f6a1e3..f336846fb415 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1504,18 +1504,27 @@ do { \ local_irq_restore(__flags); \ } while (0) +#ifndef TOOLCHAIN_SUPPORTS_XPA +_ASM_MACRO_2R_1S(mfhc0, rt, rs, sel, + _ASM_INSN_IF_MIPS(0x40400000 | __rt << 16 | __rs << 11 | \\sel) + _ASM_INSN32_IF_MM(0x000000f4 | __rt << 21 | __rs << 16 | \\sel << 11)); +_ASM_MACRO_2R_1S(mthc0, rt, rd, sel, + _ASM_INSN_IF_MIPS(0x40c00000 | __rt << 16 | __rd << 11 | \\sel) + _ASM_INSN32_IF_MM(0x000002f4 | __rt << 21 | __rd << 16 | \\sel << 11)); +#define _ASM_SET_XPA "" +#else /* !TOOLCHAIN_SUPPORTS_XPA */ +#define _ASM_SET_XPA ".set\txpa\n\t" +#endif + #define __readx_32bit_c0_register(source) \ ({ \ unsigned int __res; \ \ __asm__ __volatile__( \ " .set push \n" \ - " .set noat \n" \ " .set mips32r2 \n" \ - " # mfhc0 $1, %1 \n" \ - _ASM_INSN_IF_MIPS(0x40410000 | ((%1 & 0x1f) << 11)) \ - _ASM_INSN32_IF_MM(0x002000f4 | ((%1 & 0x1f) << 16)) \ - " move %0, $1 \n" \ + _ASM_SET_XPA \ + " mfhc0 %0, $%1 \n" \ " .set pop \n" \ : "=r" (__res) \ : "i" (source)); \ @@ -1526,12 +1535,9 @@ do { \ do { \ __asm__ __volatile__( \ " .set push \n" \ - " .set noat \n" \ " .set mips32r2 \n" \ - " move $1, %0 \n" \ - " # mthc0 $1, %1 \n" \ - _ASM_INSN_IF_MIPS(0x40c10000 | ((%1 & 0x1f) << 11)) \ - _ASM_INSN32_IF_MM(0x002002f4 | ((%1 & 0x1f) << 16)) \ + _ASM_SET_XPA \ + " mthc0 %0, $%1 \n" \ " .set pop \n" \ : \ : "r" (value), "i" (register)); \ |