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Diffstat (limited to 'arch/mips/include/asm/hazards.h')
| -rw-r--r-- | arch/mips/include/asm/hazards.h | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h new file mode 100644 index 0000000..2de638f --- /dev/null +++ b/arch/mips/include/asm/hazards.h @@ -0,0 +1,271 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2003, 04, 07 Ralf Baechle <ralf@linux-mips.org> + * Copyright (C) MIPS Technologies, Inc. + * written by Ralf Baechle <ralf@linux-mips.org> + */ +#ifndef _ASM_HAZARDS_H +#define _ASM_HAZARDS_H + +#ifdef __ASSEMBLY__ +#define ASMMACRO(name, code...) .macro name; code; .endm +#else + +#include <asm/cpu-features.h> + +#define ASMMACRO(name, code...) \ +__asm__(".macro " #name "; " #code "; .endm"); \ + \ +static inline void name(void) \ +{ \ + __asm__ __volatile__ (#name); \ +} + +/* + * MIPS R2 instruction hazard barrier. Needs to be called as a subroutine. + */ +extern void mips_ihb(void); + +#endif + +ASMMACRO(_ssnop, + sll $0, $0, 1 + ) + +ASMMACRO(_ehb, + sll $0, $0, 3 + ) + +/* + * TLB hazards + */ +#if defined(CONFIG_CPU_MIPSR2) + +/* + * MIPSR2 defines ehb for hazard avoidance + */ + +ASMMACRO(mtc0_tlbw_hazard, + _ehb + ) +ASMMACRO(tlbw_use_hazard, + _ehb + ) +ASMMACRO(tlb_probe_hazard, + _ehb + ) +ASMMACRO(irq_enable_hazard, + _ehb + ) +ASMMACRO(irq_disable_hazard, + _ehb + ) +ASMMACRO(back_to_back_c0_hazard, + _ehb + ) +/* + * gcc has a tradition of misscompiling the previous construct using the + * address of a label as argument to inline assembler. Gas otoh has the + * annoying difference between la and dla which are only usable for 32-bit + * rsp. 64-bit code, so can't be used without conditional compilation. + * The alterantive is switching the assembler to 64-bit code which happens + * to work right even for 32-bit code ... + */ +#define instruction_hazard() \ +do { \ + unsigned long tmp; \ + \ + __asm__ __volatile__( \ + " .set mips64r2 \n" \ + " dla %0, 1f \n" \ + " jr.hb %0 \n" \ + " .set mips0 \n" \ + "1: \n" \ + : "=r" (tmp)); \ +} while (0) + +#elif defined(CONFIG_CPU_MIPSR1) + +/* + * These are slightly complicated by the fact that we guarantee R1 kernels to + * run fine on R2 processors. + */ +ASMMACRO(mtc0_tlbw_hazard, + _ssnop; _ssnop; _ehb + ) +ASMMACRO(tlbw_use_hazard, + _ssnop; _ssnop; _ssnop; _ehb + ) +ASMMACRO(tlb_probe_hazard, + _ssnop; _ssnop; _ssnop; _ehb + ) +ASMMACRO(irq_enable_hazard, + _ssnop; _ssnop; _ssnop; _ehb + ) +ASMMACRO(irq_disable_hazard, + _ssnop; _ssnop; _ssnop; _ehb + ) +ASMMACRO(back_to_back_c0_hazard, + _ssnop; _ssnop; _ssnop; _ehb + ) +/* + * gcc has a tradition of misscompiling the previous construct using the + * address of a label as argument to inline assembler. Gas otoh has the + * annoying difference between la and dla which are only usable for 32-bit + * rsp. 64-bit code, so can't be used without conditional compilation. + * The alterantive is switching the assembler to 64-bit code which happens + * to work right even for 32-bit code ... + */ +#define __instruction_hazard() \ +do { \ + unsigned long tmp; \ + \ + __asm__ __volatile__( \ + " .set mips64r2 \n" \ + " dla %0, 1f \n" \ + " jr.hb %0 \n" \ + " .set mips0 \n" \ + "1: \n" \ + : "=r" (tmp)); \ +} while (0) + +#define instruction_hazard() \ +do { \ + if (cpu_has_mips_r2) \ + __instruction_hazard(); \ +} while (0) + +#elif defined(CONFIG_CPU_R10000) + +/* + * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer. + */ + +ASMMACRO(mtc0_tlbw_hazard, + ) +ASMMACRO(tlbw_use_hazard, + ) +ASMMACRO(tlb_probe_hazard, + ) +ASMMACRO(irq_enable_hazard, + ) +ASMMACRO(irq_disable_hazard, + ) +ASMMACRO(back_to_back_c0_hazard, + ) +#define instruction_hazard() do { } while (0) + +#elif defined(CONFIG_CPU_RM9000) + +/* + * RM9000 hazards. When the JTLB is updated by tlbwi or tlbwr, a subsequent + * use of the JTLB for instructions should not occur for 4 cpu cycles and use + * for data translations should not occur for 3 cpu cycles. + */ + +ASMMACRO(mtc0_tlbw_hazard, + _ssnop; _ssnop; _ssnop; _ssnop + ) +ASMMACRO(tlbw_use_hazard, + _ssnop; _ssnop; _ssnop; _ssnop + ) +ASMMACRO(tlb_probe_hazard, + _ssnop; _ssnop; _ssnop; _ssnop + ) +ASMMACRO(irq_enable_hazard, + ) +ASMMACRO(irq_disable_hazard, + ) +ASMMACRO(back_to_back_c0_hazard, + ) +#define instruction_hazard() do { } while (0) + +#elif defined(CONFIG_CPU_SB1) + +/* + * Mostly like R4000 for historic reasons + */ +ASMMACRO(mtc0_tlbw_hazard, + ) +ASMMACRO(tlbw_use_hazard, + ) +ASMMACRO(tlb_probe_hazard, + ) +ASMMACRO(irq_enable_hazard, + ) +ASMMACRO(irq_disable_hazard, + _ssnop; _ssnop; _ssnop + ) +ASMMACRO(back_to_back_c0_hazard, + ) +#define instruction_hazard() do { } while (0) + +#else + +/* + * Finally the catchall case for all other processors including R4000, R4400, + * R4600, R4700, R5000, RM7000, NEC VR41xx etc. + * + * The taken branch will result in a two cycle penalty for the two killed + * instructions on R4000 / R4400. Other processors only have a single cycle + * hazard so this is nice trick to have an optimal code for a range of + * processors. + */ +ASMMACRO(mtc0_tlbw_hazard, + nop; nop + ) +ASMMACRO(tlbw_use_hazard, + nop; nop; nop + ) +ASMMACRO(tlb_probe_hazard, + nop; nop; nop + ) +ASMMACRO(irq_enable_hazard, + _ssnop; _ssnop; _ssnop; + ) +ASMMACRO(irq_disable_hazard, + nop; nop; nop + ) +ASMMACRO(back_to_back_c0_hazard, + _ssnop; _ssnop; _ssnop; + ) +#define instruction_hazard() do { } while (0) + +#endif + + +/* FPU hazards */ + +#if defined(CONFIG_CPU_SB1) +ASMMACRO(enable_fpu_hazard, + .set push; + .set mips64; + .set noreorder; + _ssnop; + bnezl $0, .+4; + _ssnop; + .set pop +) +ASMMACRO(disable_fpu_hazard, +) + +#elif defined(CONFIG_CPU_MIPSR2) +ASMMACRO(enable_fpu_hazard, + _ehb +) +ASMMACRO(disable_fpu_hazard, + _ehb +) +#else +ASMMACRO(enable_fpu_hazard, + nop; nop; nop; nop +) +ASMMACRO(disable_fpu_hazard, + _ehb +) +#endif + +#endif /* _ASM_HAZARDS_H */ |