diff options
Diffstat (limited to 'arch/mips/include/asm/hazards.h')
| -rw-r--r-- | arch/mips/include/asm/hazards.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h new file mode 100644 index 000000000..4087b47ad --- /dev/null +++ b/arch/mips/include/asm/hazards.h @@ -0,0 +1,365 @@ +/* + * 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 + +#include <linux/stringify.h> +#include <asm/compiler.h> + +#define ___ssnop \ + sll $0, $0, 1 + +#define ___ehb \ + sll $0, $0, 3 + +/* + * TLB hazards + */ +#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) && !defined(CONFIG_CPU_CAVIUM_OCTEON) + +/* + * MIPSR2 defines ehb for hazard avoidance + */ + +#define __mtc0_tlbw_hazard \ + ___ehb + +#define __tlbw_use_hazard \ + ___ehb + +#define __tlb_probe_hazard \ + ___ehb + +#define __irq_enable_hazard \ + ___ehb + +#define __irq_disable_hazard \ + ___ehb + +#define __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 "MIPS_ISA_LEVEL" \n" \ + " dla %0, 1f \n" \ + " jr.hb %0 \n" \ + " .set mips0 \n" \ + "1: \n" \ + : "=r" (tmp)); \ +} while (0) + +#elif (defined(CONFIG_CPU_MIPSR1) && !defined(CONFIG_MIPS_ALCHEMY)) || \ + defined(CONFIG_CPU_BMIPS) + +/* + * These are slightly complicated by the fact that we guarantee R1 kernels to + * run fine on R2 processors. + */ + +#define __mtc0_tlbw_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ehb + +#define __tlbw_use_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop; \ + ___ehb + +#define __tlb_probe_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop; \ + ___ehb + +#define __irq_enable_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop; \ + ___ehb + +#define __irq_disable_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop; \ + ___ehb + +#define __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_r6) \ + __instruction_hazard(); \ +} while (0) + +#elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \ + defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_R10000) || \ + defined(CONFIG_CPU_R5500) || defined(CONFIG_CPU_XLR) + +/* + * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer. + */ + +#define __mtc0_tlbw_hazard + +#define __tlbw_use_hazard + +#define __tlb_probe_hazard + +#define __irq_enable_hazard + +#define __irq_disable_hazard + +#define __back_to_back_c0_hazard + +#define instruction_hazard() do { } while (0) + +#elif defined(CONFIG_CPU_SB1) + +/* + * Mostly like R4000 for historic reasons + */ +#define __mtc0_tlbw_hazard + +#define __tlbw_use_hazard + +#define __tlb_probe_hazard + +#define __irq_enable_hazard + +#define __irq_disable_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop + +#define __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. + */ +#define __mtc0_tlbw_hazard \ + nop; \ + nop + +#define __tlbw_use_hazard \ + nop; \ + nop; \ + nop + +#define __tlb_probe_hazard \ + nop; \ + nop; \ + nop + +#define __irq_enable_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop + +#define __irq_disable_hazard \ + nop; \ + nop; \ + nop + +#define __back_to_back_c0_hazard \ + ___ssnop; \ + ___ssnop; \ + ___ssnop + +#define instruction_hazard() do { } while (0) + +#endif + + +/* FPU hazards */ + +#if defined(CONFIG_CPU_SB1) + +#define __enable_fpu_hazard \ + .set push; \ + .set mips64; \ + .set noreorder; \ + ___ssnop; \ + bnezl $0, .+4; \ + ___ssnop; \ + .set pop + +#define __disable_fpu_hazard + +#elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) + +#define __enable_fpu_hazard \ + ___ehb + +#define __disable_fpu_hazard \ + ___ehb + +#else + +#define __enable_fpu_hazard \ + nop; \ + nop; \ + nop; \ + nop + +#define __disable_fpu_hazard \ + ___ehb + +#endif + +#ifdef __ASSEMBLY__ + +#define _ssnop ___ssnop +#define _ehb ___ehb +#define mtc0_tlbw_hazard __mtc0_tlbw_hazard +#define tlbw_use_hazard __tlbw_use_hazard +#define tlb_probe_hazard __tlb_probe_hazard +#define irq_enable_hazard __irq_enable_hazard +#define irq_disable_hazard __irq_disable_hazard +#define back_to_back_c0_hazard __back_to_back_c0_hazard +#define enable_fpu_hazard __enable_fpu_hazard +#define disable_fpu_hazard __disable_fpu_hazard + +#else + +#define _ssnop() \ +do { \ + __asm__ __volatile__( \ + __stringify(___ssnop) \ + ); \ +} while (0) + +#define _ehb() \ +do { \ + __asm__ __volatile__( \ + __stringify(___ehb) \ + ); \ +} while (0) + + +#define mtc0_tlbw_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__mtc0_tlbw_hazard) \ + ); \ +} while (0) + + +#define tlbw_use_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__tlbw_use_hazard) \ + ); \ +} while (0) + + +#define tlb_probe_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__tlb_probe_hazard) \ + ); \ +} while (0) + + +#define irq_enable_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__irq_enable_hazard) \ + ); \ +} while (0) + + +#define irq_disable_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__irq_disable_hazard) \ + ); \ +} while (0) + + +#define back_to_back_c0_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__back_to_back_c0_hazard) \ + ); \ +} while (0) + + +#define enable_fpu_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__enable_fpu_hazard) \ + ); \ +} while (0) + + +#define disable_fpu_hazard() \ +do { \ + __asm__ __volatile__( \ + __stringify(__disable_fpu_hazard) \ + ); \ +} while (0) + +/* + * MIPS R2 instruction hazard barrier. Needs to be called as a subroutine. + */ +extern void mips_ihb(void); + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_HAZARDS_H */ |