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 <asm/cputable.h>
18 #include <asm/code-patching.h>
19 #include <asm/page.h>
20 #include <asm/sections.h>
21 #include <asm/setup.h>
22 #include <asm/security_features.h>
23 #include <asm/firmware.h>
24 
25 struct fixup_entry {
26 	unsigned long	mask;
27 	unsigned long	value;
28 	long		start_off;
29 	long		end_off;
30 	long		alt_start_off;
31 	long		alt_end_off;
32 };
33 
34 static unsigned int *calc_addr(struct fixup_entry *fcur, long offset)
35 {
36 	/*
37 	 * We store the offset to the code as a negative offset from
38 	 * the start of the alt_entry, to support the VDSO. This
39 	 * routine converts that back into an actual address.
40 	 */
41 	return (unsigned int *)((unsigned long)fcur + offset);
42 }
43 
44 static int patch_alt_instruction(unsigned int *src, unsigned int *dest,
45 				 unsigned int *alt_start, unsigned int *alt_end)
46 {
47 	unsigned int instr;
48 
49 	instr = *src;
50 
51 	if (instr_is_relative_branch(*src)) {
52 		unsigned int *target = (unsigned int *)branch_target(src);
53 
54 		/* Branch within the section doesn't need translating */
55 		if (target < alt_start || target > alt_end) {
56 			instr = translate_branch(dest, src);
57 			if (!instr)
58 				return 1;
59 		}
60 	}
61 
62 	raw_patch_instruction(dest, instr);
63 
64 	return 0;
65 }
66 
67 static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
68 {
69 	unsigned int *start, *end, *alt_start, *alt_end, *src, *dest;
70 
71 	start = calc_addr(fcur, fcur->start_off);
72 	end = calc_addr(fcur, fcur->end_off);
73 	alt_start = calc_addr(fcur, fcur->alt_start_off);
74 	alt_end = calc_addr(fcur, fcur->alt_end_off);
75 
76 	if ((alt_end - alt_start) > (end - start))
77 		return 1;
78 
79 	if ((value & fcur->mask) == fcur->value)
80 		return 0;
81 
82 	src = alt_start;
83 	dest = start;
84 
85 	for (; src < alt_end; src++, dest++) {
86 		if (patch_alt_instruction(src, dest, alt_start, alt_end))
87 			return 1;
88 	}
89 
90 	for (; dest < end; dest++)
91 		raw_patch_instruction(dest, PPC_INST_NOP);
92 
93 	return 0;
94 }
95 
96 void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
97 {
98 	struct fixup_entry *fcur, *fend;
99 
100 	fcur = fixup_start;
101 	fend = fixup_end;
102 
103 	for (; fcur < fend; fcur++) {
104 		if (patch_feature_section(value, fcur)) {
105 			WARN_ON(1);
106 			printk("Unable to patch feature section at %p - %p" \
107 				" with %p - %p\n",
108 				calc_addr(fcur, fcur->start_off),
109 				calc_addr(fcur, fcur->end_off),
110 				calc_addr(fcur, fcur->alt_start_off),
111 				calc_addr(fcur, fcur->alt_end_off));
112 		}
113 	}
114 }
115 
116 #ifdef CONFIG_PPC_BOOK3S_64
117 static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
118 {
119 	unsigned int instrs[3], *dest;
120 	long *start, *end;
121 	int i;
122 
123 	start = PTRRELOC(&__start___stf_entry_barrier_fixup),
124 	end = PTRRELOC(&__stop___stf_entry_barrier_fixup);
125 
126 	instrs[0] = 0x60000000; /* nop */
127 	instrs[1] = 0x60000000; /* nop */
128 	instrs[2] = 0x60000000; /* nop */
129 
130 	i = 0;
131 	if (types & STF_BARRIER_FALLBACK) {
132 		instrs[i++] = 0x7d4802a6; /* mflr r10		*/
133 		instrs[i++] = 0x60000000; /* branch patched below */
134 		instrs[i++] = 0x7d4803a6; /* mtlr r10		*/
135 	} else if (types & STF_BARRIER_EIEIO) {
136 		instrs[i++] = 0x7e0006ac; /* eieio + bit 6 hint */
137 	} else if (types & STF_BARRIER_SYNC_ORI) {
138 		instrs[i++] = 0x7c0004ac; /* hwsync		*/
139 		instrs[i++] = 0xe94d0000; /* ld r10,0(r13)	*/
140 		instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
141 	}
142 
143 	for (i = 0; start < end; start++, i++) {
144 		dest = (void *)start + *start;
145 
146 		pr_devel("patching dest %lx\n", (unsigned long)dest);
147 
148 		patch_instruction(dest, instrs[0]);
149 
150 		if (types & STF_BARRIER_FALLBACK)
151 			patch_branch(dest + 1, (unsigned long)&stf_barrier_fallback,
152 				     BRANCH_SET_LINK);
153 		else
154 			patch_instruction(dest + 1, instrs[1]);
155 
156 		patch_instruction(dest + 2, instrs[2]);
157 	}
158 
159 	printk(KERN_DEBUG "stf-barrier: patched %d entry locations (%s barrier)\n", i,
160 		(types == STF_BARRIER_NONE)                  ? "no" :
161 		(types == STF_BARRIER_FALLBACK)              ? "fallback" :
162 		(types == STF_BARRIER_EIEIO)                 ? "eieio" :
163 		(types == (STF_BARRIER_SYNC_ORI))            ? "hwsync"
164 		                                           : "unknown");
165 }
166 
167 static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
168 {
169 	unsigned int instrs[6], *dest;
170 	long *start, *end;
171 	int i;
172 
173 	start = PTRRELOC(&__start___stf_exit_barrier_fixup),
174 	end = PTRRELOC(&__stop___stf_exit_barrier_fixup);
175 
176 	instrs[0] = 0x60000000; /* nop */
177 	instrs[1] = 0x60000000; /* nop */
178 	instrs[2] = 0x60000000; /* nop */
179 	instrs[3] = 0x60000000; /* nop */
180 	instrs[4] = 0x60000000; /* nop */
181 	instrs[5] = 0x60000000; /* nop */
182 
183 	i = 0;
184 	if (types & STF_BARRIER_FALLBACK || types & STF_BARRIER_SYNC_ORI) {
185 		if (cpu_has_feature(CPU_FTR_HVMODE)) {
186 			instrs[i++] = 0x7db14ba6; /* mtspr 0x131, r13 (HSPRG1) */
187 			instrs[i++] = 0x7db04aa6; /* mfspr r13, 0x130 (HSPRG0) */
188 		} else {
189 			instrs[i++] = 0x7db243a6; /* mtsprg 2,r13	*/
190 			instrs[i++] = 0x7db142a6; /* mfsprg r13,1    */
191 	        }
192 		instrs[i++] = 0x7c0004ac; /* hwsync		*/
193 		instrs[i++] = 0xe9ad0000; /* ld r13,0(r13)	*/
194 		instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
195 		if (cpu_has_feature(CPU_FTR_HVMODE)) {
196 			instrs[i++] = 0x7db14aa6; /* mfspr r13, 0x131 (HSPRG1) */
197 		} else {
198 			instrs[i++] = 0x7db242a6; /* mfsprg r13,2 */
199 		}
200 	} else if (types & STF_BARRIER_EIEIO) {
201 		instrs[i++] = 0x7e0006ac; /* eieio + bit 6 hint */
202 	}
203 
204 	for (i = 0; start < end; start++, i++) {
205 		dest = (void *)start + *start;
206 
207 		pr_devel("patching dest %lx\n", (unsigned long)dest);
208 
209 		patch_instruction(dest, instrs[0]);
210 		patch_instruction(dest + 1, instrs[1]);
211 		patch_instruction(dest + 2, instrs[2]);
212 		patch_instruction(dest + 3, instrs[3]);
213 		patch_instruction(dest + 4, instrs[4]);
214 		patch_instruction(dest + 5, instrs[5]);
215 	}
216 	printk(KERN_DEBUG "stf-barrier: patched %d exit locations (%s barrier)\n", i,
217 		(types == STF_BARRIER_NONE)                  ? "no" :
218 		(types == STF_BARRIER_FALLBACK)              ? "fallback" :
219 		(types == STF_BARRIER_EIEIO)                 ? "eieio" :
220 		(types == (STF_BARRIER_SYNC_ORI))            ? "hwsync"
221 		                                           : "unknown");
222 }
223 
224 
225 void do_stf_barrier_fixups(enum stf_barrier_type types)
226 {
227 	do_stf_entry_barrier_fixups(types);
228 	do_stf_exit_barrier_fixups(types);
229 }
230 
231 void do_rfi_flush_fixups(enum l1d_flush_type types)
232 {
233 	unsigned int instrs[3], *dest;
234 	long *start, *end;
235 	int i;
236 
237 	start = PTRRELOC(&__start___rfi_flush_fixup),
238 	end = PTRRELOC(&__stop___rfi_flush_fixup);
239 
240 	instrs[0] = 0x60000000; /* nop */
241 	instrs[1] = 0x60000000; /* nop */
242 	instrs[2] = 0x60000000; /* nop */
243 
244 	if (types & L1D_FLUSH_FALLBACK)
245 		/* b .+16 to fallback flush */
246 		instrs[0] = 0x48000010;
247 
248 	i = 0;
249 	if (types & L1D_FLUSH_ORI) {
250 		instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
251 		instrs[i++] = 0x63de0000; /* ori 30,30,0 L1d flush*/
252 	}
253 
254 	if (types & L1D_FLUSH_MTTRIG)
255 		instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */
256 
257 	for (i = 0; start < end; start++, i++) {
258 		dest = (void *)start + *start;
259 
260 		pr_devel("patching dest %lx\n", (unsigned long)dest);
261 
262 		patch_instruction(dest, instrs[0]);
263 		patch_instruction(dest + 1, instrs[1]);
264 		patch_instruction(dest + 2, instrs[2]);
265 	}
266 
267 	printk(KERN_DEBUG "rfi-flush: patched %d locations (%s flush)\n", i,
268 		(types == L1D_FLUSH_NONE)       ? "no" :
269 		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
270 		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
271 							? "ori+mttrig type"
272 							: "ori type" :
273 		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
274 						: "unknown");
275 }
276 
277 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
278 {
279 	unsigned int instr, *dest;
280 	long *start, *end;
281 	int i;
282 
283 	start = fixup_start;
284 	end = fixup_end;
285 
286 	instr = 0x60000000; /* nop */
287 
288 	if (enable) {
289 		pr_info("barrier-nospec: using ORI speculation barrier\n");
290 		instr = 0x63ff0000; /* ori 31,31,0 speculation barrier */
291 	}
292 
293 	for (i = 0; start < end; start++, i++) {
294 		dest = (void *)start + *start;
295 
296 		pr_devel("patching dest %lx\n", (unsigned long)dest);
297 		patch_instruction(dest, instr);
298 	}
299 
300 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
301 }
302 
303 #endif /* CONFIG_PPC_BOOK3S_64 */
304 
305 #ifdef CONFIG_PPC_BARRIER_NOSPEC
306 void do_barrier_nospec_fixups(bool enable)
307 {
308 	void *start, *end;
309 
310 	start = PTRRELOC(&__start___barrier_nospec_fixup),
311 	end = PTRRELOC(&__stop___barrier_nospec_fixup);
312 
313 	do_barrier_nospec_fixups_range(enable, start, end);
314 }
315 #endif /* CONFIG_PPC_BARRIER_NOSPEC */
316 
317 #ifdef CONFIG_PPC_FSL_BOOK3E
318 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
319 {
320 	unsigned int instr[2], *dest;
321 	long *start, *end;
322 	int i;
323 
324 	start = fixup_start;
325 	end = fixup_end;
326 
327 	instr[0] = PPC_INST_NOP;
328 	instr[1] = PPC_INST_NOP;
329 
330 	if (enable) {
331 		pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
332 		instr[0] = PPC_INST_ISYNC;
333 		instr[1] = PPC_INST_SYNC;
334 	}
335 
336 	for (i = 0; start < end; start++, i++) {
337 		dest = (void *)start + *start;
338 
339 		pr_devel("patching dest %lx\n", (unsigned long)dest);
340 		patch_instruction(dest, instr[0]);
341 		patch_instruction(dest + 1, instr[1]);
342 	}
343 
344 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
345 }
346 
347 static void patch_btb_flush_section(long *curr)
348 {
349 	unsigned int *start, *end;
350 
351 	start = (void *)curr + *curr;
352 	end = (void *)curr + *(curr + 1);
353 	for (; start < end; start++) {
354 		pr_devel("patching dest %lx\n", (unsigned long)start);
355 		patch_instruction(start, PPC_INST_NOP);
356 	}
357 }
358 
359 void do_btb_flush_fixups(void)
360 {
361 	long *start, *end;
362 
363 	start = PTRRELOC(&__start__btb_flush_fixup);
364 	end = PTRRELOC(&__stop__btb_flush_fixup);
365 
366 	for (; start < end; start += 2)
367 		patch_btb_flush_section(start);
368 }
369 #endif /* CONFIG_PPC_FSL_BOOK3E */
370 
371 void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
372 {
373 	long *start, *end;
374 	unsigned int *dest;
375 
376 	if (!(value & CPU_FTR_LWSYNC))
377 		return ;
378 
379 	start = fixup_start;
380 	end = fixup_end;
381 
382 	for (; start < end; start++) {
383 		dest = (void *)start + *start;
384 		raw_patch_instruction(dest, PPC_INST_LWSYNC);
385 	}
386 }
387 
388 static void do_final_fixups(void)
389 {
390 #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
391 	int *src, *dest;
392 	unsigned long length;
393 
394 	if (PHYSICAL_START == 0)
395 		return;
396 
397 	src = (int *)(KERNELBASE + PHYSICAL_START);
398 	dest = (int *)KERNELBASE;
399 	length = (__end_interrupts - _stext) / sizeof(int);
400 
401 	while (length--) {
402 		raw_patch_instruction(dest, *src);
403 		src++;
404 		dest++;
405 	}
406 #endif
407 }
408 
409 static unsigned long __initdata saved_cpu_features;
410 static unsigned int __initdata saved_mmu_features;
411 #ifdef CONFIG_PPC64
412 static unsigned long __initdata saved_firmware_features;
413 #endif
414 
415 void __init apply_feature_fixups(void)
416 {
417 	struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
418 
419 	*PTRRELOC(&saved_cpu_features) = spec->cpu_features;
420 	*PTRRELOC(&saved_mmu_features) = spec->mmu_features;
421 
422 	/*
423 	 * Apply the CPU-specific and firmware specific fixups to kernel text
424 	 * (nop out sections not relevant to this CPU or this firmware).
425 	 */
426 	do_feature_fixups(spec->cpu_features,
427 			  PTRRELOC(&__start___ftr_fixup),
428 			  PTRRELOC(&__stop___ftr_fixup));
429 
430 	do_feature_fixups(spec->mmu_features,
431 			  PTRRELOC(&__start___mmu_ftr_fixup),
432 			  PTRRELOC(&__stop___mmu_ftr_fixup));
433 
434 	do_lwsync_fixups(spec->cpu_features,
435 			 PTRRELOC(&__start___lwsync_fixup),
436 			 PTRRELOC(&__stop___lwsync_fixup));
437 
438 #ifdef CONFIG_PPC64
439 	saved_firmware_features = powerpc_firmware_features;
440 	do_feature_fixups(powerpc_firmware_features,
441 			  &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
442 #endif
443 	do_final_fixups();
444 }
445 
446 void __init setup_feature_keys(void)
447 {
448 	/*
449 	 * Initialise jump label. This causes all the cpu/mmu_has_feature()
450 	 * checks to take on their correct polarity based on the current set of
451 	 * CPU/MMU features.
452 	 */
453 	jump_label_init();
454 	cpu_feature_keys_init();
455 	mmu_feature_keys_init();
456 }
457 
458 static int __init check_features(void)
459 {
460 	WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
461 	     "CPU features changed after feature patching!\n");
462 	WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
463 	     "MMU features changed after feature patching!\n");
464 #ifdef CONFIG_PPC64
465 	WARN(saved_firmware_features != powerpc_firmware_features,
466 	     "Firmware features changed after feature patching!\n");
467 #endif
468 
469 	return 0;
470 }
471 late_initcall(check_features);
472 
473 #ifdef CONFIG_FTR_FIXUP_SELFTEST
474 
475 #define check(x)	\
476 	if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
477 
478 /* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
479 static struct fixup_entry fixup;
480 
481 static long calc_offset(struct fixup_entry *entry, unsigned int *p)
482 {
483 	return (unsigned long)p - (unsigned long)entry;
484 }
485 
486 static void test_basic_patching(void)
487 {
488 	extern unsigned int ftr_fixup_test1[];
489 	extern unsigned int end_ftr_fixup_test1[];
490 	extern unsigned int ftr_fixup_test1_orig[];
491 	extern unsigned int ftr_fixup_test1_expected[];
492 	int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
493 
494 	fixup.value = fixup.mask = 8;
495 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
496 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
497 	fixup.alt_start_off = fixup.alt_end_off = 0;
498 
499 	/* Sanity check */
500 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
501 
502 	/* Check we don't patch if the value matches */
503 	patch_feature_section(8, &fixup);
504 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
505 
506 	/* Check we do patch if the value doesn't match */
507 	patch_feature_section(0, &fixup);
508 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
509 
510 	/* Check we do patch if the mask doesn't match */
511 	memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
512 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
513 	patch_feature_section(~8, &fixup);
514 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
515 }
516 
517 static void test_alternative_patching(void)
518 {
519 	extern unsigned int ftr_fixup_test2[];
520 	extern unsigned int end_ftr_fixup_test2[];
521 	extern unsigned int ftr_fixup_test2_orig[];
522 	extern unsigned int ftr_fixup_test2_alt[];
523 	extern unsigned int ftr_fixup_test2_expected[];
524 	int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
525 
526 	fixup.value = fixup.mask = 0xF;
527 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
528 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
529 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
530 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
531 
532 	/* Sanity check */
533 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
534 
535 	/* Check we don't patch if the value matches */
536 	patch_feature_section(0xF, &fixup);
537 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
538 
539 	/* Check we do patch if the value doesn't match */
540 	patch_feature_section(0, &fixup);
541 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
542 
543 	/* Check we do patch if the mask doesn't match */
544 	memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
545 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
546 	patch_feature_section(~0xF, &fixup);
547 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
548 }
549 
550 static void test_alternative_case_too_big(void)
551 {
552 	extern unsigned int ftr_fixup_test3[];
553 	extern unsigned int end_ftr_fixup_test3[];
554 	extern unsigned int ftr_fixup_test3_orig[];
555 	extern unsigned int ftr_fixup_test3_alt[];
556 	int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
557 
558 	fixup.value = fixup.mask = 0xC;
559 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
560 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
561 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
562 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
563 
564 	/* Sanity check */
565 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
566 
567 	/* Expect nothing to be patched, and the error returned to us */
568 	check(patch_feature_section(0xF, &fixup) == 1);
569 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
570 	check(patch_feature_section(0, &fixup) == 1);
571 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
572 	check(patch_feature_section(~0xF, &fixup) == 1);
573 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
574 }
575 
576 static void test_alternative_case_too_small(void)
577 {
578 	extern unsigned int ftr_fixup_test4[];
579 	extern unsigned int end_ftr_fixup_test4[];
580 	extern unsigned int ftr_fixup_test4_orig[];
581 	extern unsigned int ftr_fixup_test4_alt[];
582 	extern unsigned int ftr_fixup_test4_expected[];
583 	int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4);
584 	unsigned long flag;
585 
586 	/* Check a high-bit flag */
587 	flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
588 	fixup.value = fixup.mask = flag;
589 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
590 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
591 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
592 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
593 
594 	/* Sanity check */
595 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
596 
597 	/* Check we don't patch if the value matches */
598 	patch_feature_section(flag, &fixup);
599 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
600 
601 	/* Check we do patch if the value doesn't match */
602 	patch_feature_section(0, &fixup);
603 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
604 
605 	/* Check we do patch if the mask doesn't match */
606 	memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
607 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
608 	patch_feature_section(~flag, &fixup);
609 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
610 }
611 
612 static void test_alternative_case_with_branch(void)
613 {
614 	extern unsigned int ftr_fixup_test5[];
615 	extern unsigned int end_ftr_fixup_test5[];
616 	extern unsigned int ftr_fixup_test5_expected[];
617 	int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
618 
619 	check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
620 }
621 
622 static void test_alternative_case_with_external_branch(void)
623 {
624 	extern unsigned int ftr_fixup_test6[];
625 	extern unsigned int end_ftr_fixup_test6[];
626 	extern unsigned int ftr_fixup_test6_expected[];
627 	int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
628 
629 	check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
630 }
631 
632 static void test_alternative_case_with_branch_to_end(void)
633 {
634 	extern unsigned int ftr_fixup_test7[];
635 	extern unsigned int end_ftr_fixup_test7[];
636 	extern unsigned int ftr_fixup_test7_expected[];
637 	int size = 4 * (end_ftr_fixup_test7 - ftr_fixup_test7);
638 
639 	check(memcmp(ftr_fixup_test7, ftr_fixup_test7_expected, size) == 0);
640 }
641 
642 static void test_cpu_macros(void)
643 {
644 	extern u8 ftr_fixup_test_FTR_macros[];
645 	extern u8 ftr_fixup_test_FTR_macros_expected[];
646 	unsigned long size = ftr_fixup_test_FTR_macros_expected -
647 			     ftr_fixup_test_FTR_macros;
648 
649 	/* The fixups have already been done for us during boot */
650 	check(memcmp(ftr_fixup_test_FTR_macros,
651 		     ftr_fixup_test_FTR_macros_expected, size) == 0);
652 }
653 
654 static void test_fw_macros(void)
655 {
656 #ifdef CONFIG_PPC64
657 	extern u8 ftr_fixup_test_FW_FTR_macros[];
658 	extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
659 	unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
660 			     ftr_fixup_test_FW_FTR_macros;
661 
662 	/* The fixups have already been done for us during boot */
663 	check(memcmp(ftr_fixup_test_FW_FTR_macros,
664 		     ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
665 #endif
666 }
667 
668 static void test_lwsync_macros(void)
669 {
670 	extern u8 lwsync_fixup_test[];
671 	extern u8 end_lwsync_fixup_test[];
672 	extern u8 lwsync_fixup_test_expected_LWSYNC[];
673 	extern u8 lwsync_fixup_test_expected_SYNC[];
674 	unsigned long size = end_lwsync_fixup_test -
675 			     lwsync_fixup_test;
676 
677 	/* The fixups have already been done for us during boot */
678 	if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
679 		check(memcmp(lwsync_fixup_test,
680 			     lwsync_fixup_test_expected_LWSYNC, size) == 0);
681 	} else {
682 		check(memcmp(lwsync_fixup_test,
683 			     lwsync_fixup_test_expected_SYNC, size) == 0);
684 	}
685 }
686 
687 static int __init test_feature_fixups(void)
688 {
689 	printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
690 
691 	test_basic_patching();
692 	test_alternative_patching();
693 	test_alternative_case_too_big();
694 	test_alternative_case_too_small();
695 	test_alternative_case_with_branch();
696 	test_alternative_case_with_external_branch();
697 	test_alternative_case_with_branch_to_end();
698 	test_cpu_macros();
699 	test_fw_macros();
700 	test_lwsync_macros();
701 
702 	return 0;
703 }
704 late_initcall(test_feature_fixups);
705 
706 #endif /* CONFIG_FTR_FIXUP_SELFTEST */
707