/* * 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 * Copyright (C) MIPS Technologies, Inc. * written by Ralf Baechle */ #ifndef _ASM_HAZARDS_H #define _ASM_HAZARDS_H #include #include #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) && !defined(CONFIG_LOONGSON3_ENHANCEMENT) /* * MIPSR2 defines ehb for hazard avoidance */ #define __mtc0_tlbw_hazard \ ___ehb #define __mtc0_tlbr_hazard \ ___ehb #define __tlbw_use_hazard \ ___ehb #define __tlb_read_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 alternative 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 __mtc0_tlbr_hazard \ ___ssnop; \ ___ssnop; \ ___ehb #define __tlbw_use_hazard \ ___ssnop; \ ___ssnop; \ ___ssnop; \ ___ehb #define __tlb_read_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 alternative 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_LOONGSON3_ENHANCEMENT) || \ 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 __mtc0_tlbr_hazard #define __tlbw_use_hazard #define __tlb_read_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 __mtc0_tlbr_hazard #define __tlbw_use_hazard #define __tlb_read_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 __mtc0_tlbr_hazard \ nop; \ nop #define __tlbw_use_hazard \ nop; \ nop; \ nop #define __tlb_read_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 mips64r2; \ .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 mtc0_tlbr_hazard __mtc0_tlbr_hazard #define tlbw_use_hazard __tlbw_use_hazard #define tlb_read_hazard __tlb_read_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 mtc0_tlbr_hazard() \ do { \ __asm__ __volatile__( \ __stringify(__mtc0_tlbr_hazard) \ ); \ } while (0) #define tlbw_use_hazard() \ do { \ __asm__ __volatile__( \ __stringify(__tlbw_use_hazard) \ ); \ } while (0) #define tlb_read_hazard() \ do { \ __asm__ __volatile__( \ __stringify(__tlb_read_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 */