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() \
66 do { \
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() \
142 do { \
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() \
156 do { \
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() \
322 do { \
323 __asm__ __volatile__( \
324 __stringify(___ssnop) \
325 ); \
326 } while (0)
327
328 #define _ehb() \
329 do { \
330 __asm__ __volatile__( \
331 __stringify(___ehb) \
332 ); \
333 } while (0)
334
335
336 #define mtc0_tlbw_hazard() \
337 do { \
338 __asm__ __volatile__( \
339 __stringify(__mtc0_tlbw_hazard) \
340 ); \
341 } while (0)
342
343
344 #define mtc0_tlbr_hazard() \
345 do { \
346 __asm__ __volatile__( \
347 __stringify(__mtc0_tlbr_hazard) \
348 ); \
349 } while (0)
350
351
352 #define tlbw_use_hazard() \
353 do { \
354 __asm__ __volatile__( \
355 __stringify(__tlbw_use_hazard) \
356 ); \
357 } while (0)
358
359
360 #define tlb_read_hazard() \
361 do { \
362 __asm__ __volatile__( \
363 __stringify(__tlb_read_hazard) \
364 ); \
365 } while (0)
366
367
368 #define tlb_probe_hazard() \
369 do { \
370 __asm__ __volatile__( \
371 __stringify(__tlb_probe_hazard) \
372 ); \
373 } while (0)
374
375
376 #define irq_enable_hazard() \
377 do { \
378 __asm__ __volatile__( \
379 __stringify(__irq_enable_hazard) \
380 ); \
381 } while (0)
382
383
384 #define irq_disable_hazard() \
385 do { \
386 __asm__ __volatile__( \
387 __stringify(__irq_disable_hazard) \
388 ); \
389 } while (0)
390
391
392 #define back_to_back_c0_hazard() \
393 do { \
394 __asm__ __volatile__( \
395 __stringify(__back_to_back_c0_hazard) \
396 ); \
397 } while (0)
398
399
400 #define enable_fpu_hazard() \
401 do { \
402 __asm__ __volatile__( \
403 __stringify(__enable_fpu_hazard) \
404 ); \
405 } while (0)
406
407
408 #define disable_fpu_hazard() \
409 do { \
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 */
418 extern void mips_ihb(void);
419
420 #endif /* __ASSEMBLY__ */
421
422 #endif /* _ASM_HAZARDS_H */
423
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.