1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
4 *
5 * Modifications for ppc64:
6 * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
7 *
8 * Copyright 2008 Michael Ellerman, IBM Corporation.
9 */
10
11 #include <linux/types.h>
12 #include <linux/jump_label.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/init.h>
16 #include <linux/sched/mm.h>
17 #include <linux/stop_machine.h>
18 #include <asm/cputable.h>
19 #include <asm/code-patching.h>
20 #include <asm/interrupt.h>
21 #include <asm/page.h>
22 #include <asm/sections.h>
23 #include <asm/setup.h>
24 #include <asm/security_features.h>
25 #include <asm/firmware.h>
26 #include <asm/inst.h>
27
28 struct fixup_entry {
29 unsigned long mask;
30 unsigned long value;
31 long start_off;
32 long end_off;
33 long alt_start_off;
34 long alt_end_off;
35 };
36
calc_addr(struct fixup_entry * fcur,long offset)37 static u32 *calc_addr(struct fixup_entry *fcur, long offset)
38 {
39 /*
40 * We store the offset to the code as a negative offset from
41 * the start of the alt_entry, to support the VDSO. This
42 * routine converts that back into an actual address.
43 */
44 return (u32 *)((unsigned long)fcur + offset);
45 }
46
patch_alt_instruction(u32 * src,u32 * dest,u32 * alt_start,u32 * alt_end)47 static int patch_alt_instruction(u32 *src, u32 *dest, u32 *alt_start, u32 *alt_end)
48 {
49 int err;
50 struct ppc_inst instr;
51
52 instr = ppc_inst_read(src);
53
54 if (instr_is_relative_branch(ppc_inst_read(src))) {
55 u32 *target = (u32 *)branch_target(src);
56
57 /* Branch within the section doesn't need translating */
58 if (target < alt_start || target > alt_end) {
59 err = translate_branch(&instr, dest, src);
60 if (err)
61 return 1;
62 }
63 }
64
65 raw_patch_instruction(dest, instr);
66
67 return 0;
68 }
69
patch_feature_section(unsigned long value,struct fixup_entry * fcur)70 static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
71 {
72 u32 *start, *end, *alt_start, *alt_end, *src, *dest;
73
74 start = calc_addr(fcur, fcur->start_off);
75 end = calc_addr(fcur, fcur->end_off);
76 alt_start = calc_addr(fcur, fcur->alt_start_off);
77 alt_end = calc_addr(fcur, fcur->alt_end_off);
78
79 if ((alt_end - alt_start) > (end - start))
80 return 1;
81
82 if ((value & fcur->mask) == fcur->value)
83 return 0;
84
85 src = alt_start;
86 dest = start;
87
88 for (; src < alt_end; src = ppc_inst_next(src, src),
89 dest = ppc_inst_next(dest, dest)) {
90 if (patch_alt_instruction(src, dest, alt_start, alt_end))
91 return 1;
92 }
93
94 for (; dest < end; dest++)
95 raw_patch_instruction(dest, ppc_inst(PPC_RAW_NOP()));
96
97 return 0;
98 }
99
do_feature_fixups(unsigned long value,void * fixup_start,void * fixup_end)100 void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
101 {
102 struct fixup_entry *fcur, *fend;
103
104 fcur = fixup_start;
105 fend = fixup_end;
106
107 for (; fcur < fend; fcur++) {
108 if (patch_feature_section(value, fcur)) {
109 WARN_ON(1);
110 printk("Unable to patch feature section at %p - %p" \
111 " with %p - %p\n",
112 calc_addr(fcur, fcur->start_off),
113 calc_addr(fcur, fcur->end_off),
114 calc_addr(fcur, fcur->alt_start_off),
115 calc_addr(fcur, fcur->alt_end_off));
116 }
117 }
118 }
119
120 #ifdef CONFIG_PPC_BOOK3S_64
do_stf_entry_barrier_fixups(enum stf_barrier_type types)121 static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
122 {
123 unsigned int instrs[3], *dest;
124 long *start, *end;
125 int i;
126
127 start = PTRRELOC(&__start___stf_entry_barrier_fixup);
128 end = PTRRELOC(&__stop___stf_entry_barrier_fixup);
129
130 instrs[0] = PPC_RAW_NOP();
131 instrs[1] = PPC_RAW_NOP();
132 instrs[2] = PPC_RAW_NOP();
133
134 i = 0;
135 if (types & STF_BARRIER_FALLBACK) {
136 instrs[i++] = PPC_RAW_MFLR(_R10);
137 instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
138 instrs[i++] = PPC_RAW_MTLR(_R10);
139 } else if (types & STF_BARRIER_EIEIO) {
140 instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
141 } else if (types & STF_BARRIER_SYNC_ORI) {
142 instrs[i++] = PPC_RAW_SYNC();
143 instrs[i++] = PPC_RAW_LD(_R10, _R13, 0);
144 instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
145 }
146
147 for (i = 0; start < end; start++, i++) {
148 dest = (void *)start + *start;
149
150 pr_devel("patching dest %lx\n", (unsigned long)dest);
151
152 // See comment in do_entry_flush_fixups() RE order of patching
153 if (types & STF_BARRIER_FALLBACK) {
154 patch_instruction(dest, ppc_inst(instrs[0]));
155 patch_instruction(dest + 2, ppc_inst(instrs[2]));
156 patch_branch(dest + 1,
157 (unsigned long)&stf_barrier_fallback, BRANCH_SET_LINK);
158 } else {
159 patch_instruction(dest + 1, ppc_inst(instrs[1]));
160 patch_instruction(dest + 2, ppc_inst(instrs[2]));
161 patch_instruction(dest, ppc_inst(instrs[0]));
162 }
163 }
164
165 printk(KERN_DEBUG "stf-barrier: patched %d entry locations (%s barrier)\n", i,
166 (types == STF_BARRIER_NONE) ? "no" :
167 (types == STF_BARRIER_FALLBACK) ? "fallback" :
168 (types == STF_BARRIER_EIEIO) ? "eieio" :
169 (types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
170 : "unknown");
171 }
172
do_stf_exit_barrier_fixups(enum stf_barrier_type types)173 static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
174 {
175 unsigned int instrs[6], *dest;
176 long *start, *end;
177 int i;
178
179 start = PTRRELOC(&__start___stf_exit_barrier_fixup);
180 end = PTRRELOC(&__stop___stf_exit_barrier_fixup);
181
182 instrs[0] = PPC_RAW_NOP();
183 instrs[1] = PPC_RAW_NOP();
184 instrs[2] = PPC_RAW_NOP();
185 instrs[3] = PPC_RAW_NOP();
186 instrs[4] = PPC_RAW_NOP();
187 instrs[5] = PPC_RAW_NOP();
188
189 i = 0;
190 if (types & STF_BARRIER_FALLBACK || types & STF_BARRIER_SYNC_ORI) {
191 if (cpu_has_feature(CPU_FTR_HVMODE)) {
192 instrs[i++] = PPC_RAW_MTSPR(SPRN_HSPRG1, _R13);
193 instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG0);
194 } else {
195 instrs[i++] = PPC_RAW_MTSPR(SPRN_SPRG2, _R13);
196 instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG1);
197 }
198 instrs[i++] = PPC_RAW_SYNC();
199 instrs[i++] = PPC_RAW_LD(_R13, _R13, 0);
200 instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
201 if (cpu_has_feature(CPU_FTR_HVMODE))
202 instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG1);
203 else
204 instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG2);
205 } else if (types & STF_BARRIER_EIEIO) {
206 instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
207 }
208
209 for (i = 0; start < end; start++, i++) {
210 dest = (void *)start + *start;
211
212 pr_devel("patching dest %lx\n", (unsigned long)dest);
213
214 patch_instruction(dest, ppc_inst(instrs[0]));
215 patch_instruction(dest + 1, ppc_inst(instrs[1]));
216 patch_instruction(dest + 2, ppc_inst(instrs[2]));
217 patch_instruction(dest + 3, ppc_inst(instrs[3]));
218 patch_instruction(dest + 4, ppc_inst(instrs[4]));
219 patch_instruction(dest + 5, ppc_inst(instrs[5]));
220 }
221 printk(KERN_DEBUG "stf-barrier: patched %d exit locations (%s barrier)\n", i,
222 (types == STF_BARRIER_NONE) ? "no" :
223 (types == STF_BARRIER_FALLBACK) ? "fallback" :
224 (types == STF_BARRIER_EIEIO) ? "eieio" :
225 (types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
226 : "unknown");
227 }
228
229 static bool stf_exit_reentrant = false;
230 static bool rfi_exit_reentrant = false;
231
__do_stf_barrier_fixups(void * data)232 static int __do_stf_barrier_fixups(void *data)
233 {
234 enum stf_barrier_type *types = data;
235
236 do_stf_entry_barrier_fixups(*types);
237 do_stf_exit_barrier_fixups(*types);
238
239 return 0;
240 }
241
do_stf_barrier_fixups(enum stf_barrier_type types)242 void do_stf_barrier_fixups(enum stf_barrier_type types)
243 {
244 /*
245 * The call to the fallback entry flush, and the fallback/sync-ori exit
246 * flush can not be safely patched in/out while other CPUs are
247 * executing them. So call __do_stf_barrier_fixups() on one CPU while
248 * all other CPUs spin in the stop machine core with interrupts hard
249 * disabled.
250 *
251 * The branch to mark interrupt exits non-reentrant is enabled first,
252 * then stop_machine runs which will ensure all CPUs are out of the
253 * low level interrupt exit code before patching. After the patching,
254 * if allowed, then flip the branch to allow fast exits.
255 */
256 static_branch_enable(&interrupt_exit_not_reentrant);
257
258 stop_machine(__do_stf_barrier_fixups, &types, NULL);
259
260 if ((types & STF_BARRIER_FALLBACK) || (types & STF_BARRIER_SYNC_ORI))
261 stf_exit_reentrant = false;
262 else
263 stf_exit_reentrant = true;
264
265 if (stf_exit_reentrant && rfi_exit_reentrant)
266 static_branch_disable(&interrupt_exit_not_reentrant);
267 }
268
do_uaccess_flush_fixups(enum l1d_flush_type types)269 void do_uaccess_flush_fixups(enum l1d_flush_type types)
270 {
271 unsigned int instrs[4], *dest;
272 long *start, *end;
273 int i;
274
275 start = PTRRELOC(&__start___uaccess_flush_fixup);
276 end = PTRRELOC(&__stop___uaccess_flush_fixup);
277
278 instrs[0] = PPC_RAW_NOP();
279 instrs[1] = PPC_RAW_NOP();
280 instrs[2] = PPC_RAW_NOP();
281 instrs[3] = PPC_RAW_BLR();
282
283 i = 0;
284 if (types == L1D_FLUSH_FALLBACK) {
285 instrs[3] = PPC_RAW_NOP();
286 /* fallthrough to fallback flush */
287 }
288
289 if (types & L1D_FLUSH_ORI) {
290 instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
291 instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
292 }
293
294 if (types & L1D_FLUSH_MTTRIG)
295 instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
296
297 for (i = 0; start < end; start++, i++) {
298 dest = (void *)start + *start;
299
300 pr_devel("patching dest %lx\n", (unsigned long)dest);
301
302 patch_instruction(dest, ppc_inst(instrs[0]));
303
304 patch_instruction(dest + 1, ppc_inst(instrs[1]));
305 patch_instruction(dest + 2, ppc_inst(instrs[2]));
306 patch_instruction(dest + 3, ppc_inst(instrs[3]));
307 }
308
309 printk(KERN_DEBUG "uaccess-flush: patched %d locations (%s flush)\n", i,
310 (types == L1D_FLUSH_NONE) ? "no" :
311 (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
312 (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
313 ? "ori+mttrig type"
314 : "ori type" :
315 (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
316 : "unknown");
317 }
318
__do_entry_flush_fixups(void * data)319 static int __do_entry_flush_fixups(void *data)
320 {
321 enum l1d_flush_type types = *(enum l1d_flush_type *)data;
322 unsigned int instrs[3], *dest;
323 long *start, *end;
324 int i;
325
326 instrs[0] = PPC_RAW_NOP();
327 instrs[1] = PPC_RAW_NOP();
328 instrs[2] = PPC_RAW_NOP();
329
330 i = 0;
331 if (types == L1D_FLUSH_FALLBACK) {
332 instrs[i++] = PPC_RAW_MFLR(_R10);
333 instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
334 instrs[i++] = PPC_RAW_MTLR(_R10);
335 }
336
337 if (types & L1D_FLUSH_ORI) {
338 instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
339 instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
340 }
341
342 if (types & L1D_FLUSH_MTTRIG)
343 instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
344
345 /*
346 * If we're patching in or out the fallback flush we need to be careful about the
347 * order in which we patch instructions. That's because it's possible we could
348 * take a page fault after patching one instruction, so the sequence of
349 * instructions must be safe even in a half patched state.
350 *
351 * To make that work, when patching in the fallback flush we patch in this order:
352 * - the mflr (dest)
353 * - the mtlr (dest + 2)
354 * - the branch (dest + 1)
355 *
356 * That ensures the sequence is safe to execute at any point. In contrast if we
357 * patch the mtlr last, it's possible we could return from the branch and not
358 * restore LR, leading to a crash later.
359 *
360 * When patching out the fallback flush (either with nops or another flush type),
361 * we patch in this order:
362 * - the branch (dest + 1)
363 * - the mtlr (dest + 2)
364 * - the mflr (dest)
365 *
366 * Note we are protected by stop_machine() from other CPUs executing the code in a
367 * semi-patched state.
368 */
369
370 start = PTRRELOC(&__start___entry_flush_fixup);
371 end = PTRRELOC(&__stop___entry_flush_fixup);
372 for (i = 0; start < end; start++, i++) {
373 dest = (void *)start + *start;
374
375 pr_devel("patching dest %lx\n", (unsigned long)dest);
376
377 if (types == L1D_FLUSH_FALLBACK) {
378 patch_instruction(dest, ppc_inst(instrs[0]));
379 patch_instruction(dest + 2, ppc_inst(instrs[2]));
380 patch_branch(dest + 1,
381 (unsigned long)&entry_flush_fallback, BRANCH_SET_LINK);
382 } else {
383 patch_instruction(dest + 1, ppc_inst(instrs[1]));
384 patch_instruction(dest + 2, ppc_inst(instrs[2]));
385 patch_instruction(dest, ppc_inst(instrs[0]));
386 }
387 }
388
389 start = PTRRELOC(&__start___scv_entry_flush_fixup);
390 end = PTRRELOC(&__stop___scv_entry_flush_fixup);
391 for (; start < end; start++, i++) {
392 dest = (void *)start + *start;
393
394 pr_devel("patching dest %lx\n", (unsigned long)dest);
395
396 if (types == L1D_FLUSH_FALLBACK) {
397 patch_instruction(dest, ppc_inst(instrs[0]));
398 patch_instruction(dest + 2, ppc_inst(instrs[2]));
399 patch_branch(dest + 1,
400 (unsigned long)&scv_entry_flush_fallback, BRANCH_SET_LINK);
401 } else {
402 patch_instruction(dest + 1, ppc_inst(instrs[1]));
403 patch_instruction(dest + 2, ppc_inst(instrs[2]));
404 patch_instruction(dest, ppc_inst(instrs[0]));
405 }
406 }
407
408
409 printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
410 (types == L1D_FLUSH_NONE) ? "no" :
411 (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
412 (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
413 ? "ori+mttrig type"
414 : "ori type" :
415 (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
416 : "unknown");
417
418 return 0;
419 }
420
do_entry_flush_fixups(enum l1d_flush_type types)421 void do_entry_flush_fixups(enum l1d_flush_type types)
422 {
423 /*
424 * The call to the fallback flush can not be safely patched in/out while
425 * other CPUs are executing it. So call __do_entry_flush_fixups() on one
426 * CPU while all other CPUs spin in the stop machine core with interrupts
427 * hard disabled.
428 */
429 stop_machine(__do_entry_flush_fixups, &types, NULL);
430 }
431
__do_rfi_flush_fixups(void * data)432 static int __do_rfi_flush_fixups(void *data)
433 {
434 enum l1d_flush_type types = *(enum l1d_flush_type *)data;
435 unsigned int instrs[3], *dest;
436 long *start, *end;
437 int i;
438
439 start = PTRRELOC(&__start___rfi_flush_fixup);
440 end = PTRRELOC(&__stop___rfi_flush_fixup);
441
442 instrs[0] = PPC_RAW_NOP();
443 instrs[1] = PPC_RAW_NOP();
444 instrs[2] = PPC_RAW_NOP();
445
446 if (types & L1D_FLUSH_FALLBACK)
447 /* b .+16 to fallback flush */
448 instrs[0] = PPC_INST_BRANCH | 16;
449
450 i = 0;
451 if (types & L1D_FLUSH_ORI) {
452 instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
453 instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
454 }
455
456 if (types & L1D_FLUSH_MTTRIG)
457 instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
458
459 for (i = 0; start < end; start++, i++) {
460 dest = (void *)start + *start;
461
462 pr_devel("patching dest %lx\n", (unsigned long)dest);
463
464 patch_instruction(dest, ppc_inst(instrs[0]));
465 patch_instruction(dest + 1, ppc_inst(instrs[1]));
466 patch_instruction(dest + 2, ppc_inst(instrs[2]));
467 }
468
469 printk(KERN_DEBUG "rfi-flush: patched %d locations (%s flush)\n", i,
470 (types == L1D_FLUSH_NONE) ? "no" :
471 (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
472 (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
473 ? "ori+mttrig type"
474 : "ori type" :
475 (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
476 : "unknown");
477
478 return 0;
479 }
480
do_rfi_flush_fixups(enum l1d_flush_type types)481 void do_rfi_flush_fixups(enum l1d_flush_type types)
482 {
483 /*
484 * stop_machine gets all CPUs out of the interrupt exit handler same
485 * as do_stf_barrier_fixups. do_rfi_flush_fixups patching can run
486 * without stop_machine, so this could be achieved with a broadcast
487 * IPI instead, but this matches the stf sequence.
488 */
489 static_branch_enable(&interrupt_exit_not_reentrant);
490
491 stop_machine(__do_rfi_flush_fixups, &types, NULL);
492
493 if (types & L1D_FLUSH_FALLBACK)
494 rfi_exit_reentrant = false;
495 else
496 rfi_exit_reentrant = true;
497
498 if (stf_exit_reentrant && rfi_exit_reentrant)
499 static_branch_disable(&interrupt_exit_not_reentrant);
500 }
501
do_barrier_nospec_fixups_range(bool enable,void * fixup_start,void * fixup_end)502 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
503 {
504 unsigned int instr, *dest;
505 long *start, *end;
506 int i;
507
508 start = fixup_start;
509 end = fixup_end;
510
511 instr = PPC_RAW_NOP();
512
513 if (enable) {
514 pr_info("barrier-nospec: using ORI speculation barrier\n");
515 instr = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
516 }
517
518 for (i = 0; start < end; start++, i++) {
519 dest = (void *)start + *start;
520
521 pr_devel("patching dest %lx\n", (unsigned long)dest);
522 patch_instruction(dest, ppc_inst(instr));
523 }
524
525 printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
526 }
527
528 #endif /* CONFIG_PPC_BOOK3S_64 */
529
530 #ifdef CONFIG_PPC_BARRIER_NOSPEC
do_barrier_nospec_fixups(bool enable)531 void do_barrier_nospec_fixups(bool enable)
532 {
533 void *start, *end;
534
535 start = PTRRELOC(&__start___barrier_nospec_fixup);
536 end = PTRRELOC(&__stop___barrier_nospec_fixup);
537
538 do_barrier_nospec_fixups_range(enable, start, end);
539 }
540 #endif /* CONFIG_PPC_BARRIER_NOSPEC */
541
542 #ifdef CONFIG_PPC_FSL_BOOK3E
do_barrier_nospec_fixups_range(bool enable,void * fixup_start,void * fixup_end)543 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
544 {
545 unsigned int instr[2], *dest;
546 long *start, *end;
547 int i;
548
549 start = fixup_start;
550 end = fixup_end;
551
552 instr[0] = PPC_RAW_NOP();
553 instr[1] = PPC_RAW_NOP();
554
555 if (enable) {
556 pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
557 instr[0] = PPC_RAW_ISYNC();
558 instr[1] = PPC_RAW_SYNC();
559 }
560
561 for (i = 0; start < end; start++, i++) {
562 dest = (void *)start + *start;
563
564 pr_devel("patching dest %lx\n", (unsigned long)dest);
565 patch_instruction(dest, ppc_inst(instr[0]));
566 patch_instruction(dest + 1, ppc_inst(instr[1]));
567 }
568
569 printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
570 }
571
patch_btb_flush_section(long * curr)572 static void patch_btb_flush_section(long *curr)
573 {
574 unsigned int *start, *end;
575
576 start = (void *)curr + *curr;
577 end = (void *)curr + *(curr + 1);
578 for (; start < end; start++) {
579 pr_devel("patching dest %lx\n", (unsigned long)start);
580 patch_instruction(start, ppc_inst(PPC_RAW_NOP()));
581 }
582 }
583
do_btb_flush_fixups(void)584 void do_btb_flush_fixups(void)
585 {
586 long *start, *end;
587
588 start = PTRRELOC(&__start__btb_flush_fixup);
589 end = PTRRELOC(&__stop__btb_flush_fixup);
590
591 for (; start < end; start += 2)
592 patch_btb_flush_section(start);
593 }
594 #endif /* CONFIG_PPC_FSL_BOOK3E */
595
do_lwsync_fixups(unsigned long value,void * fixup_start,void * fixup_end)596 void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
597 {
598 long *start, *end;
599 u32 *dest;
600
601 if (!(value & CPU_FTR_LWSYNC))
602 return ;
603
604 start = fixup_start;
605 end = fixup_end;
606
607 for (; start < end; start++) {
608 dest = (void *)start + *start;
609 raw_patch_instruction(dest, ppc_inst(PPC_INST_LWSYNC));
610 }
611 }
612
do_final_fixups(void)613 static void do_final_fixups(void)
614 {
615 #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
616 struct ppc_inst inst;
617 u32 *src, *dest, *end;
618
619 if (PHYSICAL_START == 0)
620 return;
621
622 src = (u32 *)(KERNELBASE + PHYSICAL_START);
623 dest = (u32 *)KERNELBASE;
624 end = (void *)src + (__end_interrupts - _stext);
625
626 while (src < end) {
627 inst = ppc_inst_read(src);
628 raw_patch_instruction(dest, inst);
629 src = ppc_inst_next(src, src);
630 dest = ppc_inst_next(dest, dest);
631 }
632 #endif
633 }
634
635 static unsigned long __initdata saved_cpu_features;
636 static unsigned int __initdata saved_mmu_features;
637 #ifdef CONFIG_PPC64
638 static unsigned long __initdata saved_firmware_features;
639 #endif
640
apply_feature_fixups(void)641 void __init apply_feature_fixups(void)
642 {
643 struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
644
645 *PTRRELOC(&saved_cpu_features) = spec->cpu_features;
646 *PTRRELOC(&saved_mmu_features) = spec->mmu_features;
647
648 /*
649 * Apply the CPU-specific and firmware specific fixups to kernel text
650 * (nop out sections not relevant to this CPU or this firmware).
651 */
652 do_feature_fixups(spec->cpu_features,
653 PTRRELOC(&__start___ftr_fixup),
654 PTRRELOC(&__stop___ftr_fixup));
655
656 do_feature_fixups(spec->mmu_features,
657 PTRRELOC(&__start___mmu_ftr_fixup),
658 PTRRELOC(&__stop___mmu_ftr_fixup));
659
660 do_lwsync_fixups(spec->cpu_features,
661 PTRRELOC(&__start___lwsync_fixup),
662 PTRRELOC(&__stop___lwsync_fixup));
663
664 #ifdef CONFIG_PPC64
665 saved_firmware_features = powerpc_firmware_features;
666 do_feature_fixups(powerpc_firmware_features,
667 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
668 #endif
669 do_final_fixups();
670 }
671
setup_feature_keys(void)672 void __init setup_feature_keys(void)
673 {
674 /*
675 * Initialise jump label. This causes all the cpu/mmu_has_feature()
676 * checks to take on their correct polarity based on the current set of
677 * CPU/MMU features.
678 */
679 jump_label_init();
680 cpu_feature_keys_init();
681 mmu_feature_keys_init();
682 }
683
check_features(void)684 static int __init check_features(void)
685 {
686 WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
687 "CPU features changed after feature patching!\n");
688 WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
689 "MMU features changed after feature patching!\n");
690 #ifdef CONFIG_PPC64
691 WARN(saved_firmware_features != powerpc_firmware_features,
692 "Firmware features changed after feature patching!\n");
693 #endif
694
695 return 0;
696 }
697 late_initcall(check_features);
698
699 #ifdef CONFIG_FTR_FIXUP_SELFTEST
700
701 #define check(x) \
702 if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
703
704 /* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
705 static struct fixup_entry fixup;
706
calc_offset(struct fixup_entry * entry,unsigned int * p)707 static long calc_offset(struct fixup_entry *entry, unsigned int *p)
708 {
709 return (unsigned long)p - (unsigned long)entry;
710 }
711
test_basic_patching(void)712 static void test_basic_patching(void)
713 {
714 extern unsigned int ftr_fixup_test1[];
715 extern unsigned int end_ftr_fixup_test1[];
716 extern unsigned int ftr_fixup_test1_orig[];
717 extern unsigned int ftr_fixup_test1_expected[];
718 int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
719
720 fixup.value = fixup.mask = 8;
721 fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
722 fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
723 fixup.alt_start_off = fixup.alt_end_off = 0;
724
725 /* Sanity check */
726 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
727
728 /* Check we don't patch if the value matches */
729 patch_feature_section(8, &fixup);
730 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
731
732 /* Check we do patch if the value doesn't match */
733 patch_feature_section(0, &fixup);
734 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
735
736 /* Check we do patch if the mask doesn't match */
737 memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
738 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
739 patch_feature_section(~8, &fixup);
740 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
741 }
742
test_alternative_patching(void)743 static void test_alternative_patching(void)
744 {
745 extern unsigned int ftr_fixup_test2[];
746 extern unsigned int end_ftr_fixup_test2[];
747 extern unsigned int ftr_fixup_test2_orig[];
748 extern unsigned int ftr_fixup_test2_alt[];
749 extern unsigned int ftr_fixup_test2_expected[];
750 int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
751
752 fixup.value = fixup.mask = 0xF;
753 fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
754 fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
755 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
756 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
757
758 /* Sanity check */
759 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
760
761 /* Check we don't patch if the value matches */
762 patch_feature_section(0xF, &fixup);
763 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
764
765 /* Check we do patch if the value doesn't match */
766 patch_feature_section(0, &fixup);
767 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
768
769 /* Check we do patch if the mask doesn't match */
770 memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
771 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
772 patch_feature_section(~0xF, &fixup);
773 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
774 }
775
test_alternative_case_too_big(void)776 static void test_alternative_case_too_big(void)
777 {
778 extern unsigned int ftr_fixup_test3[];
779 extern unsigned int end_ftr_fixup_test3[];
780 extern unsigned int ftr_fixup_test3_orig[];
781 extern unsigned int ftr_fixup_test3_alt[];
782 int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
783
784 fixup.value = fixup.mask = 0xC;
785 fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
786 fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
787 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
788 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
789
790 /* Sanity check */
791 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
792
793 /* Expect nothing to be patched, and the error returned to us */
794 check(patch_feature_section(0xF, &fixup) == 1);
795 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
796 check(patch_feature_section(0, &fixup) == 1);
797 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
798 check(patch_feature_section(~0xF, &fixup) == 1);
799 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
800 }
801
test_alternative_case_too_small(void)802 static void test_alternative_case_too_small(void)
803 {
804 extern unsigned int ftr_fixup_test4[];
805 extern unsigned int end_ftr_fixup_test4[];
806 extern unsigned int ftr_fixup_test4_orig[];
807 extern unsigned int ftr_fixup_test4_alt[];
808 extern unsigned int ftr_fixup_test4_expected[];
809 int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4);
810 unsigned long flag;
811
812 /* Check a high-bit flag */
813 flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
814 fixup.value = fixup.mask = flag;
815 fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
816 fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
817 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
818 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
819
820 /* Sanity check */
821 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
822
823 /* Check we don't patch if the value matches */
824 patch_feature_section(flag, &fixup);
825 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
826
827 /* Check we do patch if the value doesn't match */
828 patch_feature_section(0, &fixup);
829 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
830
831 /* Check we do patch if the mask doesn't match */
832 memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
833 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
834 patch_feature_section(~flag, &fixup);
835 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
836 }
837
test_alternative_case_with_branch(void)838 static void test_alternative_case_with_branch(void)
839 {
840 extern unsigned int ftr_fixup_test5[];
841 extern unsigned int end_ftr_fixup_test5[];
842 extern unsigned int ftr_fixup_test5_expected[];
843 int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
844
845 check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
846 }
847
test_alternative_case_with_external_branch(void)848 static void test_alternative_case_with_external_branch(void)
849 {
850 extern unsigned int ftr_fixup_test6[];
851 extern unsigned int end_ftr_fixup_test6[];
852 extern unsigned int ftr_fixup_test6_expected[];
853 int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
854
855 check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
856 }
857
test_alternative_case_with_branch_to_end(void)858 static void test_alternative_case_with_branch_to_end(void)
859 {
860 extern unsigned int ftr_fixup_test7[];
861 extern unsigned int end_ftr_fixup_test7[];
862 extern unsigned int ftr_fixup_test7_expected[];
863 int size = 4 * (end_ftr_fixup_test7 - ftr_fixup_test7);
864
865 check(memcmp(ftr_fixup_test7, ftr_fixup_test7_expected, size) == 0);
866 }
867
test_cpu_macros(void)868 static void test_cpu_macros(void)
869 {
870 extern u8 ftr_fixup_test_FTR_macros[];
871 extern u8 ftr_fixup_test_FTR_macros_expected[];
872 unsigned long size = ftr_fixup_test_FTR_macros_expected -
873 ftr_fixup_test_FTR_macros;
874
875 /* The fixups have already been done for us during boot */
876 check(memcmp(ftr_fixup_test_FTR_macros,
877 ftr_fixup_test_FTR_macros_expected, size) == 0);
878 }
879
test_fw_macros(void)880 static void test_fw_macros(void)
881 {
882 #ifdef CONFIG_PPC64
883 extern u8 ftr_fixup_test_FW_FTR_macros[];
884 extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
885 unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
886 ftr_fixup_test_FW_FTR_macros;
887
888 /* The fixups have already been done for us during boot */
889 check(memcmp(ftr_fixup_test_FW_FTR_macros,
890 ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
891 #endif
892 }
893
test_lwsync_macros(void)894 static void test_lwsync_macros(void)
895 {
896 extern u8 lwsync_fixup_test[];
897 extern u8 end_lwsync_fixup_test[];
898 extern u8 lwsync_fixup_test_expected_LWSYNC[];
899 extern u8 lwsync_fixup_test_expected_SYNC[];
900 unsigned long size = end_lwsync_fixup_test -
901 lwsync_fixup_test;
902
903 /* The fixups have already been done for us during boot */
904 if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
905 check(memcmp(lwsync_fixup_test,
906 lwsync_fixup_test_expected_LWSYNC, size) == 0);
907 } else {
908 check(memcmp(lwsync_fixup_test,
909 lwsync_fixup_test_expected_SYNC, size) == 0);
910 }
911 }
912
913 #ifdef CONFIG_PPC64
test_prefix_patching(void)914 static void __init test_prefix_patching(void)
915 {
916 extern unsigned int ftr_fixup_prefix1[];
917 extern unsigned int end_ftr_fixup_prefix1[];
918 extern unsigned int ftr_fixup_prefix1_orig[];
919 extern unsigned int ftr_fixup_prefix1_expected[];
920 int size = sizeof(unsigned int) * (end_ftr_fixup_prefix1 - ftr_fixup_prefix1);
921
922 fixup.value = fixup.mask = 8;
923 fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix1 + 1);
924 fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix1 + 3);
925 fixup.alt_start_off = fixup.alt_end_off = 0;
926
927 /* Sanity check */
928 check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) == 0);
929
930 patch_feature_section(0, &fixup);
931 check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_expected, size) == 0);
932 check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) != 0);
933 }
934
test_prefix_alt_patching(void)935 static void __init test_prefix_alt_patching(void)
936 {
937 extern unsigned int ftr_fixup_prefix2[];
938 extern unsigned int end_ftr_fixup_prefix2[];
939 extern unsigned int ftr_fixup_prefix2_orig[];
940 extern unsigned int ftr_fixup_prefix2_expected[];
941 extern unsigned int ftr_fixup_prefix2_alt[];
942 int size = sizeof(unsigned int) * (end_ftr_fixup_prefix2 - ftr_fixup_prefix2);
943
944 fixup.value = fixup.mask = 8;
945 fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix2 + 1);
946 fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix2 + 3);
947 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix2_alt);
948 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix2_alt + 2);
949 /* Sanity check */
950 check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) == 0);
951
952 patch_feature_section(0, &fixup);
953 check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_expected, size) == 0);
954 check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) != 0);
955 }
956
test_prefix_word_alt_patching(void)957 static void __init test_prefix_word_alt_patching(void)
958 {
959 extern unsigned int ftr_fixup_prefix3[];
960 extern unsigned int end_ftr_fixup_prefix3[];
961 extern unsigned int ftr_fixup_prefix3_orig[];
962 extern unsigned int ftr_fixup_prefix3_expected[];
963 extern unsigned int ftr_fixup_prefix3_alt[];
964 int size = sizeof(unsigned int) * (end_ftr_fixup_prefix3 - ftr_fixup_prefix3);
965
966 fixup.value = fixup.mask = 8;
967 fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix3 + 1);
968 fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix3 + 4);
969 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix3_alt);
970 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix3_alt + 3);
971 /* Sanity check */
972 check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) == 0);
973
974 patch_feature_section(0, &fixup);
975 check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_expected, size) == 0);
976 patch_feature_section(0, &fixup);
977 check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) != 0);
978 }
979 #else
test_prefix_patching(void)980 static inline void test_prefix_patching(void) {}
test_prefix_alt_patching(void)981 static inline void test_prefix_alt_patching(void) {}
test_prefix_word_alt_patching(void)982 static inline void test_prefix_word_alt_patching(void) {}
983 #endif /* CONFIG_PPC64 */
984
test_feature_fixups(void)985 static int __init test_feature_fixups(void)
986 {
987 printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
988
989 test_basic_patching();
990 test_alternative_patching();
991 test_alternative_case_too_big();
992 test_alternative_case_too_small();
993 test_alternative_case_with_branch();
994 test_alternative_case_with_external_branch();
995 test_alternative_case_with_branch_to_end();
996 test_cpu_macros();
997 test_fw_macros();
998 test_lwsync_macros();
999 test_prefix_patching();
1000 test_prefix_alt_patching();
1001 test_prefix_word_alt_patching();
1002
1003 return 0;
1004 }
1005 late_initcall(test_feature_fixups);
1006
1007 #endif /* CONFIG_FTR_FIXUP_SELFTEST */
1008
