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1/*
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
4 * for more details.
5 *
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>
9 */
10#ifndef _ASM_HAZARDS_H
11#define _ASM_HAZARDS_H
12
13#ifdef __ASSEMBLY__
14#define ASMMACRO(name, code...) .macro name; code; .endm
15#else
16
17#include <asm/cpu-features.h>
18
19#define ASMMACRO(name, code...) \
20__asm__(".macro " #name "; " #code "; .endm"); \
21 \
22static inline void name(void) \
23{ \
24 __asm__ __volatile__ (#name); \
25}
26
27/*
28 * MIPS R2 instruction hazard barrier. Needs to be called as a subroutine.
29 */
30extern void mips_ihb(void);
31
32#endif
33
34ASMMACRO(_ssnop,
35 sll $0, $0, 1
36 )
37
38ASMMACRO(_ehb,
39 sll $0, $0, 3
40 )
41
42/*
43 * TLB hazards
44 */
45#if defined(CONFIG_CPU_MIPSR2) && !defined(CONFIG_CPU_CAVIUM_OCTEON)
46
47/*
48 * MIPSR2 defines ehb for hazard avoidance
49 */
50
51ASMMACRO(mtc0_tlbw_hazard,
52 _ehb
53 )
54ASMMACRO(tlbw_use_hazard,
55 _ehb
56 )
57ASMMACRO(tlb_probe_hazard,
58 _ehb
59 )
60ASMMACRO(irq_enable_hazard,
61 _ehb
62 )
63ASMMACRO(irq_disable_hazard,
64 _ehb
65 )
66ASMMACRO(back_to_back_c0_hazard,
67 _ehb
68 )
69/*
70 * gcc has a tradition of misscompiling the previous construct using the
71 * address of a label as argument to inline assembler. Gas otoh has the
72 * annoying difference between la and dla which are only usable for 32-bit
73 * rsp. 64-bit code, so can't be used without conditional compilation.
74 * The alterantive is switching the assembler to 64-bit code which happens
75 * to work right even for 32-bit code ...
76 */
77#define instruction_hazard() \
78do { \
79 unsigned long tmp; \
80 \
81 __asm__ __volatile__( \
82 " .set mips64r2 \n" \
83 " dla %0, 1f \n" \
84 " jr.hb %0 \n" \
85 " .set mips0 \n" \
86 "1: \n" \
87 : "=r" (tmp)); \
88} while (0)
89
90#elif defined(CONFIG_CPU_MIPSR1) && !defined(CONFIG_MIPS_ALCHEMY)
91
92/*
93 * These are slightly complicated by the fact that we guarantee R1 kernels to
94 * run fine on R2 processors.
95 */
96ASMMACRO(mtc0_tlbw_hazard,
97 _ssnop; _ssnop; _ehb
98 )
99ASMMACRO(tlbw_use_hazard,
100 _ssnop; _ssnop; _ssnop; _ehb
101 )
102ASMMACRO(tlb_probe_hazard,
103 _ssnop; _ssnop; _ssnop; _ehb
104 )
105ASMMACRO(irq_enable_hazard,
106 _ssnop; _ssnop; _ssnop; _ehb
107 )
108ASMMACRO(irq_disable_hazard,
109 _ssnop; _ssnop; _ssnop; _ehb
110 )
111ASMMACRO(back_to_back_c0_hazard,
112 _ssnop; _ssnop; _ssnop; _ehb
113 )
114/*
115 * gcc has a tradition of misscompiling the previous construct using the
116 * address of a label as argument to inline assembler. Gas otoh has the
117 * annoying difference between la and dla which are only usable for 32-bit
118 * rsp. 64-bit code, so can't be used without conditional compilation.
119 * The alterantive is switching the assembler to 64-bit code which happens
120 * to work right even for 32-bit code ...
121 */
122#define __instruction_hazard() \
123do { \
124 unsigned long tmp; \
125 \
126 __asm__ __volatile__( \
127 " .set mips64r2 \n" \
128 " dla %0, 1f \n" \
129 " jr.hb %0 \n" \
130 " .set mips0 \n" \
131 "1: \n" \
132 : "=r" (tmp)); \
133} while (0)
134
135#define instruction_hazard() \
136do { \
137 if (cpu_has_mips_r2) \
138 __instruction_hazard(); \
139} while (0)
140
141#elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \
142 defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_R10000) || \
143 defined(CONFIG_CPU_R5500)
144
145/*
146 * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
147 */
148
149ASMMACRO(mtc0_tlbw_hazard,
150 )
151ASMMACRO(tlbw_use_hazard,
152 )
153ASMMACRO(tlb_probe_hazard,
154 )
155ASMMACRO(irq_enable_hazard,
156 )
157ASMMACRO(irq_disable_hazard,
158 )
159ASMMACRO(back_to_back_c0_hazard,
160 )
161#define instruction_hazard() do { } while (0)
162
163#elif defined(CONFIG_CPU_RM9000)
164
165/*
166 * RM9000 hazards. When the JTLB is updated by tlbwi or tlbwr, a subsequent
167 * use of the JTLB for instructions should not occur for 4 cpu cycles and use
168 * for data translations should not occur for 3 cpu cycles.
169 */
170
171ASMMACRO(mtc0_tlbw_hazard,
172 _ssnop; _ssnop; _ssnop; _ssnop
173 )
174ASMMACRO(tlbw_use_hazard,
175 _ssnop; _ssnop; _ssnop; _ssnop
176 )
177ASMMACRO(tlb_probe_hazard,
178 _ssnop; _ssnop; _ssnop; _ssnop
179 )
180ASMMACRO(irq_enable_hazard,
181 )
182ASMMACRO(irq_disable_hazard,
183 )
184ASMMACRO(back_to_back_c0_hazard,
185 )
186#define instruction_hazard() do { } while (0)
187
188#elif defined(CONFIG_CPU_SB1)
189
190/*
191 * Mostly like R4000 for historic reasons
192 */
193ASMMACRO(mtc0_tlbw_hazard,
194 )
195ASMMACRO(tlbw_use_hazard,
196 )
197ASMMACRO(tlb_probe_hazard,
198 )
199ASMMACRO(irq_enable_hazard,
200 )
201ASMMACRO(irq_disable_hazard,
202 _ssnop; _ssnop; _ssnop
203 )
204ASMMACRO(back_to_back_c0_hazard,
205 )
206#define instruction_hazard() do { } while (0)
207
208#else
209
210/*
211 * Finally the catchall case for all other processors including R4000, R4400,
212 * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
213 *
214 * The taken branch will result in a two cycle penalty for the two killed
215 * instructions on R4000 / R4400. Other processors only have a single cycle
216 * hazard so this is nice trick to have an optimal code for a range of
217 * processors.
218 */
219ASMMACRO(mtc0_tlbw_hazard,
220 nop; nop
221 )
222ASMMACRO(tlbw_use_hazard,
223 nop; nop; nop
224 )
225ASMMACRO(tlb_probe_hazard,
226 nop; nop; nop
227 )
228ASMMACRO(irq_enable_hazard,
229 _ssnop; _ssnop; _ssnop;
230 )
231ASMMACRO(irq_disable_hazard,
232 nop; nop; nop
233 )
234ASMMACRO(back_to_back_c0_hazard,
235 _ssnop; _ssnop; _ssnop;
236 )
237#define instruction_hazard() do { } while (0)
238
239#endif
240
241
242/* FPU hazards */
243
244#if defined(CONFIG_CPU_SB1)
245ASMMACRO(enable_fpu_hazard,
246 .set push;
247 .set mips64;
248 .set noreorder;
249 _ssnop;
250 bnezl $0, .+4;
251 _ssnop;
252 .set pop
253)
254ASMMACRO(disable_fpu_hazard,
255)
256
257#elif defined(CONFIG_CPU_MIPSR2)
258ASMMACRO(enable_fpu_hazard,
259 _ehb
260)
261ASMMACRO(disable_fpu_hazard,
262 _ehb
263)
264#else
265ASMMACRO(enable_fpu_hazard,
266 nop; nop; nop; nop
267)
268ASMMACRO(disable_fpu_hazard,
269 _ehb
270)
271#endif
272
273#endif /* _ASM_HAZARDS_H */
1/*
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
4 * for more details.
5 *
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>
9 */
10#ifndef _ASM_HAZARDS_H
11#define _ASM_HAZARDS_H
12
13#include <linux/stringify.h>
14#include <asm/compiler.h>
15
16#define ___ssnop \
17 sll $0, $0, 1
18
19#define ___ehb \
20 sll $0, $0, 3
21
22/*
23 * TLB hazards
24 */
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)
28
29/*
30 * MIPSR2 defines ehb for hazard avoidance
31 */
32
33#define __mtc0_tlbw_hazard \
34 ___ehb
35
36#define __mtc0_tlbr_hazard \
37 ___ehb
38
39#define __tlbw_use_hazard \
40 ___ehb
41
42#define __tlb_read_hazard \
43 ___ehb
44
45#define __tlb_probe_hazard \
46 ___ehb
47
48#define __irq_enable_hazard \
49 ___ehb
50
51#define __irq_disable_hazard \
52 ___ehb
53
54#define __back_to_back_c0_hazard \
55 ___ehb
56
57/*
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...
64 */
65#define instruction_hazard() \
66do { \
67 unsigned long tmp; \
68 \
69 __asm__ __volatile__( \
70 " .set push \n" \
71 " .set "MIPS_ISA_LEVEL" \n" \
72 " dla %0, 1f \n" \
73 " jr.hb %0 \n" \
74 " .set pop \n" \
75 "1: \n" \
76 : "=r" (tmp)); \
77} while (0)
78
79#elif (defined(CONFIG_CPU_MIPSR1) && !defined(CONFIG_MIPS_ALCHEMY)) || \
80 defined(CONFIG_CPU_BMIPS)
81
82/*
83 * These are slightly complicated by the fact that we guarantee R1 kernels to
84 * run fine on R2 processors.
85 */
86
87#define __mtc0_tlbw_hazard \
88 ___ssnop; \
89 ___ssnop; \
90 ___ehb
91
92#define __mtc0_tlbr_hazard \
93 ___ssnop; \
94 ___ssnop; \
95 ___ehb
96
97#define __tlbw_use_hazard \
98 ___ssnop; \
99 ___ssnop; \
100 ___ssnop; \
101 ___ehb
102
103#define __tlb_read_hazard \
104 ___ssnop; \
105 ___ssnop; \
106 ___ssnop; \
107 ___ehb
108
109#define __tlb_probe_hazard \
110 ___ssnop; \
111 ___ssnop; \
112 ___ssnop; \
113 ___ehb
114
115#define __irq_enable_hazard \
116 ___ssnop; \
117 ___ssnop; \
118 ___ssnop; \
119 ___ehb
120
121#define __irq_disable_hazard \
122 ___ssnop; \
123 ___ssnop; \
124 ___ssnop; \
125 ___ehb
126
127#define __back_to_back_c0_hazard \
128 ___ssnop; \
129 ___ssnop; \
130 ___ssnop; \
131 ___ehb
132
133/*
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...
140 */
141#define __instruction_hazard() \
142do { \
143 unsigned long tmp; \
144 \
145 __asm__ __volatile__( \
146 " .set push \n" \
147 " .set mips64r2 \n" \
148 " dla %0, 1f \n" \
149 " jr.hb %0 \n" \
150 " .set pop \n" \
151 "1: \n" \
152 : "=r" (tmp)); \
153} while (0)
154
155#define instruction_hazard() \
156do { \
157 if (cpu_has_mips_r2_r6) \
158 __instruction_hazard(); \
159} while (0)
160
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)
164
165/*
166 * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
167 */
168
169#define __mtc0_tlbw_hazard
170
171#define __mtc0_tlbr_hazard
172
173#define __tlbw_use_hazard
174
175#define __tlb_read_hazard
176
177#define __tlb_probe_hazard
178
179#define __irq_enable_hazard
180
181#define __irq_disable_hazard
182
183#define __back_to_back_c0_hazard
184
185#define instruction_hazard() do { } while (0)
186
187#elif defined(CONFIG_CPU_SB1)
188
189/*
190 * Mostly like R4000 for historic reasons
191 */
192#define __mtc0_tlbw_hazard
193
194#define __mtc0_tlbr_hazard
195
196#define __tlbw_use_hazard
197
198#define __tlb_read_hazard
199
200#define __tlb_probe_hazard
201
202#define __irq_enable_hazard
203
204#define __irq_disable_hazard \
205 ___ssnop; \
206 ___ssnop; \
207 ___ssnop
208
209#define __back_to_back_c0_hazard
210
211#define instruction_hazard() do { } while (0)
212
213#else
214
215/*
216 * Finally the catchall case for all other processors including R4000, R4400,
217 * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
218 *
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
222 * processors.
223 */
224#define __mtc0_tlbw_hazard \
225 nop; \
226 nop
227
228#define __mtc0_tlbr_hazard \
229 nop; \
230 nop
231
232#define __tlbw_use_hazard \
233 nop; \
234 nop; \
235 nop
236
237#define __tlb_read_hazard \
238 nop; \
239 nop; \
240 nop
241
242#define __tlb_probe_hazard \
243 nop; \
244 nop; \
245 nop
246
247#define __irq_enable_hazard \
248 ___ssnop; \
249 ___ssnop; \
250 ___ssnop
251
252#define __irq_disable_hazard \
253 nop; \
254 nop; \
255 nop
256
257#define __back_to_back_c0_hazard \
258 ___ssnop; \
259 ___ssnop; \
260 ___ssnop
261
262#define instruction_hazard() do { } while (0)
263
264#endif
265
266
267/* FPU hazards */
268
269#if defined(CONFIG_CPU_SB1)
270
271#define __enable_fpu_hazard \
272 .set push; \
273 .set mips64; \
274 .set noreorder; \
275 ___ssnop; \
276 bnezl $0, .+4; \
277 ___ssnop; \
278 .set pop
279
280#define __disable_fpu_hazard
281
282#elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
283 defined(CONFIG_CPU_MIPSR6)
284
285#define __enable_fpu_hazard \
286 ___ehb
287
288#define __disable_fpu_hazard \
289 ___ehb
290
291#else
292
293#define __enable_fpu_hazard \
294 nop; \
295 nop; \
296 nop; \
297 nop
298
299#define __disable_fpu_hazard \
300 ___ehb
301
302#endif
303
304#ifdef __ASSEMBLY__
305
306#define _ssnop ___ssnop
307#define _ehb ___ehb
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
318
319#else
320
321#define _ssnop() \
322do { \
323 __asm__ __volatile__( \
324 __stringify(___ssnop) \
325 ); \
326} while (0)
327
328#define _ehb() \
329do { \
330 __asm__ __volatile__( \
331 __stringify(___ehb) \
332 ); \
333} while (0)
334
335
336#define mtc0_tlbw_hazard() \
337do { \
338 __asm__ __volatile__( \
339 __stringify(__mtc0_tlbw_hazard) \
340 ); \
341} while (0)
342
343
344#define mtc0_tlbr_hazard() \
345do { \
346 __asm__ __volatile__( \
347 __stringify(__mtc0_tlbr_hazard) \
348 ); \
349} while (0)
350
351
352#define tlbw_use_hazard() \
353do { \
354 __asm__ __volatile__( \
355 __stringify(__tlbw_use_hazard) \
356 ); \
357} while (0)
358
359
360#define tlb_read_hazard() \
361do { \
362 __asm__ __volatile__( \
363 __stringify(__tlb_read_hazard) \
364 ); \
365} while (0)
366
367
368#define tlb_probe_hazard() \
369do { \
370 __asm__ __volatile__( \
371 __stringify(__tlb_probe_hazard) \
372 ); \
373} while (0)
374
375
376#define irq_enable_hazard() \
377do { \
378 __asm__ __volatile__( \
379 __stringify(__irq_enable_hazard) \
380 ); \
381} while (0)
382
383
384#define irq_disable_hazard() \
385do { \
386 __asm__ __volatile__( \
387 __stringify(__irq_disable_hazard) \
388 ); \
389} while (0)
390
391
392#define back_to_back_c0_hazard() \
393do { \
394 __asm__ __volatile__( \
395 __stringify(__back_to_back_c0_hazard) \
396 ); \
397} while (0)
398
399
400#define enable_fpu_hazard() \
401do { \
402 __asm__ __volatile__( \
403 __stringify(__enable_fpu_hazard) \
404 ); \
405} while (0)
406
407
408#define disable_fpu_hazard() \
409do { \
410 __asm__ __volatile__( \
411 __stringify(__disable_fpu_hazard) \
412 ); \
413} while (0)
414
415/*
416 * MIPS R2 instruction hazard barrier. Needs to be called as a subroutine.
417 */
418extern void mips_ihb(void);
419
420#endif /* __ASSEMBLY__ */
421
422#endif /* _ASM_HAZARDS_H */