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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#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 */
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 defined(CONFIG_CPU_BMIPS)
92
93/*
94 * These are slightly complicated by the fact that we guarantee R1 kernels to
95 * run fine on R2 processors.
96 */
97ASMMACRO(mtc0_tlbw_hazard,
98 _ssnop; _ssnop; _ehb
99 )
100ASMMACRO(tlbw_use_hazard,
101 _ssnop; _ssnop; _ssnop; _ehb
102 )
103ASMMACRO(tlb_probe_hazard,
104 _ssnop; _ssnop; _ssnop; _ehb
105 )
106ASMMACRO(irq_enable_hazard,
107 _ssnop; _ssnop; _ssnop; _ehb
108 )
109ASMMACRO(irq_disable_hazard,
110 _ssnop; _ssnop; _ssnop; _ehb
111 )
112ASMMACRO(back_to_back_c0_hazard,
113 _ssnop; _ssnop; _ssnop; _ehb
114 )
115/*
116 * gcc has a tradition of misscompiling the previous construct using the
117 * address of a label as argument to inline assembler. Gas otoh has the
118 * annoying difference between la and dla which are only usable for 32-bit
119 * rsp. 64-bit code, so can't be used without conditional compilation.
120 * The alterantive is switching the assembler to 64-bit code which happens
121 * to work right even for 32-bit code ...
122 */
123#define __instruction_hazard() \
124do { \
125 unsigned long tmp; \
126 \
127 __asm__ __volatile__( \
128 " .set mips64r2 \n" \
129 " dla %0, 1f \n" \
130 " jr.hb %0 \n" \
131 " .set mips0 \n" \
132 "1: \n" \
133 : "=r" (tmp)); \
134} while (0)
135
136#define instruction_hazard() \
137do { \
138 if (cpu_has_mips_r2) \
139 __instruction_hazard(); \
140} while (0)
141
142#elif defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_CPU_CAVIUM_OCTEON) || \
143 defined(CONFIG_CPU_LOONGSON2) || defined(CONFIG_CPU_R10000) || \
144 defined(CONFIG_CPU_R5500)
145
146/*
147 * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
148 */
149
150ASMMACRO(mtc0_tlbw_hazard,
151 )
152ASMMACRO(tlbw_use_hazard,
153 )
154ASMMACRO(tlb_probe_hazard,
155 )
156ASMMACRO(irq_enable_hazard,
157 )
158ASMMACRO(irq_disable_hazard,
159 )
160ASMMACRO(back_to_back_c0_hazard,
161 )
162#define instruction_hazard() do { } while (0)
163
164#elif defined(CONFIG_CPU_RM9000)
165
166/*
167 * RM9000 hazards. When the JTLB is updated by tlbwi or tlbwr, a subsequent
168 * use of the JTLB for instructions should not occur for 4 cpu cycles and use
169 * for data translations should not occur for 3 cpu cycles.
170 */
171
172ASMMACRO(mtc0_tlbw_hazard,
173 _ssnop; _ssnop; _ssnop; _ssnop
174 )
175ASMMACRO(tlbw_use_hazard,
176 _ssnop; _ssnop; _ssnop; _ssnop
177 )
178ASMMACRO(tlb_probe_hazard,
179 _ssnop; _ssnop; _ssnop; _ssnop
180 )
181ASMMACRO(irq_enable_hazard,
182 )
183ASMMACRO(irq_disable_hazard,
184 )
185ASMMACRO(back_to_back_c0_hazard,
186 )
187#define instruction_hazard() do { } while (0)
188
189#elif defined(CONFIG_CPU_SB1)
190
191/*
192 * Mostly like R4000 for historic reasons
193 */
194ASMMACRO(mtc0_tlbw_hazard,
195 )
196ASMMACRO(tlbw_use_hazard,
197 )
198ASMMACRO(tlb_probe_hazard,
199 )
200ASMMACRO(irq_enable_hazard,
201 )
202ASMMACRO(irq_disable_hazard,
203 _ssnop; _ssnop; _ssnop
204 )
205ASMMACRO(back_to_back_c0_hazard,
206 )
207#define instruction_hazard() do { } while (0)
208
209#else
210
211/*
212 * Finally the catchall case for all other processors including R4000, R4400,
213 * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
214 *
215 * The taken branch will result in a two cycle penalty for the two killed
216 * instructions on R4000 / R4400. Other processors only have a single cycle
217 * hazard so this is nice trick to have an optimal code for a range of
218 * processors.
219 */
220ASMMACRO(mtc0_tlbw_hazard,
221 nop; nop
222 )
223ASMMACRO(tlbw_use_hazard,
224 nop; nop; nop
225 )
226ASMMACRO(tlb_probe_hazard,
227 nop; nop; nop
228 )
229ASMMACRO(irq_enable_hazard,
230 _ssnop; _ssnop; _ssnop;
231 )
232ASMMACRO(irq_disable_hazard,
233 nop; nop; nop
234 )
235ASMMACRO(back_to_back_c0_hazard,
236 _ssnop; _ssnop; _ssnop;
237 )
238#define instruction_hazard() do { } while (0)
239
240#endif
241
242
243/* FPU hazards */
244
245#if defined(CONFIG_CPU_SB1)
246ASMMACRO(enable_fpu_hazard,
247 .set push;
248 .set mips64;
249 .set noreorder;
250 _ssnop;
251 bnezl $0, .+4;
252 _ssnop;
253 .set pop
254)
255ASMMACRO(disable_fpu_hazard,
256)
257
258#elif defined(CONFIG_CPU_MIPSR2)
259ASMMACRO(enable_fpu_hazard,
260 _ehb
261)
262ASMMACRO(disable_fpu_hazard,
263 _ehb
264)
265#else
266ASMMACRO(enable_fpu_hazard,
267 nop; nop; nop; nop
268)
269ASMMACRO(disable_fpu_hazard,
270 _ehb
271)
272#endif
273
274#endif /* _ASM_HAZARDS_H */