2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2003, 04, 07 Ralf Baechle <ralf@linux-mips.org>
7 * Copyright (C) MIPS Technologies, Inc.
8 * written by Ralf Baechle <ralf@linux-mips.org>
10 #ifndef _ASM_HAZARDS_H
11 #define _ASM_HAZARDS_H
13 #include <linux/stringify.h>
14 #include <asm/compiler.h>
25 #if (defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
26 defined(CONFIG_CPU_MIPSR6)) && \
27 !defined(CONFIG_CPU_CAVIUM_OCTEON) && !defined(CONFIG_CPU_LOONGSON64)
30 * MIPSR2 defines ehb for hazard avoidance
33 #define __mtc0_tlbw_hazard \
36 #define __mtc0_tlbr_hazard \
39 #define __tlbw_use_hazard \
42 #define __tlb_read_hazard \
45 #define __tlb_probe_hazard \
48 #define __irq_enable_hazard \
51 #define __irq_disable_hazard \
54 #define __back_to_back_c0_hazard \
58 * gcc has a tradition of misscompiling the previous construct using the
59 * address of a label as argument to inline assembler. Gas otoh has the
60 * annoying difference between la and dla which are only usable for 32-bit
61 * rsp. 64-bit code, so can't be used without conditional compilation.
62 * The alternative is switching the assembler to 64-bit code which happens
63 * to work right even for 32-bit code...
65 #define instruction_hazard() \
69 __asm__ __volatile__( \
71 " .set "MIPS_ISA_LEVEL" \n" \
79 #elif (defined(CONFIG_CPU_MIPSR1) && !defined(CONFIG_MIPS_ALCHEMY)) || \
80 defined(CONFIG_CPU_BMIPS)
83 * These are slightly complicated by the fact that we guarantee R1 kernels to
84 * run fine on R2 processors.
87 #define __mtc0_tlbw_hazard \
92 #define __mtc0_tlbr_hazard \
97 #define __tlbw_use_hazard \
103 #define __tlb_read_hazard \
109 #define __tlb_probe_hazard \
115 #define __irq_enable_hazard \
121 #define __irq_disable_hazard \
127 #define __back_to_back_c0_hazard \
134 * gcc has a tradition of misscompiling the previous construct using the
135 * address of a label as argument to inline assembler. Gas otoh has the
136 * annoying difference between la and dla which are only usable for 32-bit
137 * rsp. 64-bit code, so can't be used without conditional compilation.
138 * The alternative is switching the assembler to 64-bit code which happens
139 * to work right even for 32-bit code...
141 #define __instruction_hazard() \
145 __asm__ __volatile__( \
147 " .set mips64r2 \n" \
155 #define instruction_hazard() \
157 if (cpu_has_mips_r2_r6) \
158 __instruction_hazard(); \
161 #elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \
162 defined(CONFIG_CPU_LOONGSON2EF) || defined(CONFIG_CPU_LOONGSON64) || \
163 defined(CONFIG_CPU_R10000) || defined(CONFIG_CPU_R5500)
166 * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
169 #define __mtc0_tlbw_hazard
171 #define __mtc0_tlbr_hazard
173 #define __tlbw_use_hazard
175 #define __tlb_read_hazard
177 #define __tlb_probe_hazard
179 #define __irq_enable_hazard
181 #define __irq_disable_hazard
183 #define __back_to_back_c0_hazard
185 #define instruction_hazard() do { } while (0)
187 #elif defined(CONFIG_CPU_SB1)
190 * Mostly like R4000 for historic reasons
192 #define __mtc0_tlbw_hazard
194 #define __mtc0_tlbr_hazard
196 #define __tlbw_use_hazard
198 #define __tlb_read_hazard
200 #define __tlb_probe_hazard
202 #define __irq_enable_hazard
204 #define __irq_disable_hazard \
209 #define __back_to_back_c0_hazard
211 #define instruction_hazard() do { } while (0)
216 * Finally the catchall case for all other processors including R4000, R4400,
217 * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
219 * The taken branch will result in a two cycle penalty for the two killed
220 * instructions on R4000 / R4400. Other processors only have a single cycle
221 * hazard so this is nice trick to have an optimal code for a range of
224 #define __mtc0_tlbw_hazard \
228 #define __mtc0_tlbr_hazard \
232 #define __tlbw_use_hazard \
237 #define __tlb_read_hazard \
242 #define __tlb_probe_hazard \
247 #define __irq_enable_hazard \
252 #define __irq_disable_hazard \
257 #define __back_to_back_c0_hazard \
262 #define instruction_hazard() do { } while (0)
269 #if defined(CONFIG_CPU_SB1)
271 #define __enable_fpu_hazard \
280 #define __disable_fpu_hazard
282 #elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
283 defined(CONFIG_CPU_MIPSR6)
285 #define __enable_fpu_hazard \
288 #define __disable_fpu_hazard \
293 #define __enable_fpu_hazard \
299 #define __disable_fpu_hazard \
306 #define _ssnop ___ssnop
308 #define mtc0_tlbw_hazard __mtc0_tlbw_hazard
309 #define mtc0_tlbr_hazard __mtc0_tlbr_hazard
310 #define tlbw_use_hazard __tlbw_use_hazard
311 #define tlb_read_hazard __tlb_read_hazard
312 #define tlb_probe_hazard __tlb_probe_hazard
313 #define irq_enable_hazard __irq_enable_hazard
314 #define irq_disable_hazard __irq_disable_hazard
315 #define back_to_back_c0_hazard __back_to_back_c0_hazard
316 #define enable_fpu_hazard __enable_fpu_hazard
317 #define disable_fpu_hazard __disable_fpu_hazard
323 __asm__ __volatile__( \
324 __stringify(___ssnop) \
330 __asm__ __volatile__( \
331 __stringify(___ehb) \
336 #define mtc0_tlbw_hazard() \
338 __asm__ __volatile__( \
339 __stringify(__mtc0_tlbw_hazard) \
344 #define mtc0_tlbr_hazard() \
346 __asm__ __volatile__( \
347 __stringify(__mtc0_tlbr_hazard) \
352 #define tlbw_use_hazard() \
354 __asm__ __volatile__( \
355 __stringify(__tlbw_use_hazard) \
360 #define tlb_read_hazard() \
362 __asm__ __volatile__( \
363 __stringify(__tlb_read_hazard) \
368 #define tlb_probe_hazard() \
370 __asm__ __volatile__( \
371 __stringify(__tlb_probe_hazard) \
376 #define irq_enable_hazard() \
378 __asm__ __volatile__( \
379 __stringify(__irq_enable_hazard) \
384 #define irq_disable_hazard() \
386 __asm__ __volatile__( \
387 __stringify(__irq_disable_hazard) \
392 #define back_to_back_c0_hazard() \
394 __asm__ __volatile__( \
395 __stringify(__back_to_back_c0_hazard) \
400 #define enable_fpu_hazard() \
402 __asm__ __volatile__( \
403 __stringify(__enable_fpu_hazard) \
408 #define disable_fpu_hazard() \
410 __asm__ __volatile__( \
411 __stringify(__disable_fpu_hazard) \
416 * MIPS R2 instruction hazard barrier. Needs to be called as a subroutine.
418 extern void mips_ihb(void);
420 #endif /* __ASSEMBLY__ */
422 #endif /* _ASM_HAZARDS_H */