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 
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 
47 static int patch_alt_instruction(u32 *src, u32 *dest, u32 *alt_start, u32 *alt_end)
48 {
49 	int err;
50 	ppc_inst_t 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 
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 
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
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 
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 static DEFINE_MUTEX(exit_flush_lock);
232 
233 static int __do_stf_barrier_fixups(void *data)
234 {
235 	enum stf_barrier_type *types = data;
236 
237 	do_stf_entry_barrier_fixups(*types);
238 	do_stf_exit_barrier_fixups(*types);
239 
240 	return 0;
241 }
242 
243 void do_stf_barrier_fixups(enum stf_barrier_type types)
244 {
245 	/*
246 	 * The call to the fallback entry flush, and the fallback/sync-ori exit
247 	 * flush can not be safely patched in/out while other CPUs are
248 	 * executing them. So call __do_stf_barrier_fixups() on one CPU while
249 	 * all other CPUs spin in the stop machine core with interrupts hard
250 	 * disabled.
251 	 *
252 	 * The branch to mark interrupt exits non-reentrant is enabled first,
253 	 * then stop_machine runs which will ensure all CPUs are out of the
254 	 * low level interrupt exit code before patching. After the patching,
255 	 * if allowed, then flip the branch to allow fast exits.
256 	 */
257 
258 	// Prevent static key update races with do_rfi_flush_fixups()
259 	mutex_lock(&exit_flush_lock);
260 	static_branch_enable(&interrupt_exit_not_reentrant);
261 
262 	stop_machine(__do_stf_barrier_fixups, &types, NULL);
263 
264 	if ((types & STF_BARRIER_FALLBACK) || (types & STF_BARRIER_SYNC_ORI))
265 		stf_exit_reentrant = false;
266 	else
267 		stf_exit_reentrant = true;
268 
269 	if (stf_exit_reentrant && rfi_exit_reentrant)
270 		static_branch_disable(&interrupt_exit_not_reentrant);
271 
272 	mutex_unlock(&exit_flush_lock);
273 }
274 
275 void do_uaccess_flush_fixups(enum l1d_flush_type types)
276 {
277 	unsigned int instrs[4], *dest;
278 	long *start, *end;
279 	int i;
280 
281 	start = PTRRELOC(&__start___uaccess_flush_fixup);
282 	end = PTRRELOC(&__stop___uaccess_flush_fixup);
283 
284 	instrs[0] = PPC_RAW_NOP();
285 	instrs[1] = PPC_RAW_NOP();
286 	instrs[2] = PPC_RAW_NOP();
287 	instrs[3] = PPC_RAW_BLR();
288 
289 	i = 0;
290 	if (types == L1D_FLUSH_FALLBACK) {
291 		instrs[3] = PPC_RAW_NOP();
292 		/* fallthrough to fallback flush */
293 	}
294 
295 	if (types & L1D_FLUSH_ORI) {
296 		instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
297 		instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
298 	}
299 
300 	if (types & L1D_FLUSH_MTTRIG)
301 		instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
302 
303 	for (i = 0; start < end; start++, i++) {
304 		dest = (void *)start + *start;
305 
306 		pr_devel("patching dest %lx\n", (unsigned long)dest);
307 
308 		patch_instruction(dest, ppc_inst(instrs[0]));
309 
310 		patch_instruction(dest + 1, ppc_inst(instrs[1]));
311 		patch_instruction(dest + 2, ppc_inst(instrs[2]));
312 		patch_instruction(dest + 3, ppc_inst(instrs[3]));
313 	}
314 
315 	printk(KERN_DEBUG "uaccess-flush: patched %d locations (%s flush)\n", i,
316 		(types == L1D_FLUSH_NONE)       ? "no" :
317 		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
318 		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
319 							? "ori+mttrig type"
320 							: "ori type" :
321 		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
322 						: "unknown");
323 }
324 
325 static int __do_entry_flush_fixups(void *data)
326 {
327 	enum l1d_flush_type types = *(enum l1d_flush_type *)data;
328 	unsigned int instrs[3], *dest;
329 	long *start, *end;
330 	int i;
331 
332 	instrs[0] = PPC_RAW_NOP();
333 	instrs[1] = PPC_RAW_NOP();
334 	instrs[2] = PPC_RAW_NOP();
335 
336 	i = 0;
337 	if (types == L1D_FLUSH_FALLBACK) {
338 		instrs[i++] = PPC_RAW_MFLR(_R10);
339 		instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
340 		instrs[i++] = PPC_RAW_MTLR(_R10);
341 	}
342 
343 	if (types & L1D_FLUSH_ORI) {
344 		instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
345 		instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
346 	}
347 
348 	if (types & L1D_FLUSH_MTTRIG)
349 		instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
350 
351 	/*
352 	 * If we're patching in or out the fallback flush we need to be careful about the
353 	 * order in which we patch instructions. That's because it's possible we could
354 	 * take a page fault after patching one instruction, so the sequence of
355 	 * instructions must be safe even in a half patched state.
356 	 *
357 	 * To make that work, when patching in the fallback flush we patch in this order:
358 	 *  - the mflr		(dest)
359 	 *  - the mtlr		(dest + 2)
360 	 *  - the branch	(dest + 1)
361 	 *
362 	 * That ensures the sequence is safe to execute at any point. In contrast if we
363 	 * patch the mtlr last, it's possible we could return from the branch and not
364 	 * restore LR, leading to a crash later.
365 	 *
366 	 * When patching out the fallback flush (either with nops or another flush type),
367 	 * we patch in this order:
368 	 *  - the branch	(dest + 1)
369 	 *  - the mtlr		(dest + 2)
370 	 *  - the mflr		(dest)
371 	 *
372 	 * Note we are protected by stop_machine() from other CPUs executing the code in a
373 	 * semi-patched state.
374 	 */
375 
376 	start = PTRRELOC(&__start___entry_flush_fixup);
377 	end = PTRRELOC(&__stop___entry_flush_fixup);
378 	for (i = 0; start < end; start++, i++) {
379 		dest = (void *)start + *start;
380 
381 		pr_devel("patching dest %lx\n", (unsigned long)dest);
382 
383 		if (types == L1D_FLUSH_FALLBACK) {
384 			patch_instruction(dest, ppc_inst(instrs[0]));
385 			patch_instruction(dest + 2, ppc_inst(instrs[2]));
386 			patch_branch(dest + 1,
387 				     (unsigned long)&entry_flush_fallback, BRANCH_SET_LINK);
388 		} else {
389 			patch_instruction(dest + 1, ppc_inst(instrs[1]));
390 			patch_instruction(dest + 2, ppc_inst(instrs[2]));
391 			patch_instruction(dest, ppc_inst(instrs[0]));
392 		}
393 	}
394 
395 	start = PTRRELOC(&__start___scv_entry_flush_fixup);
396 	end = PTRRELOC(&__stop___scv_entry_flush_fixup);
397 	for (; start < end; start++, i++) {
398 		dest = (void *)start + *start;
399 
400 		pr_devel("patching dest %lx\n", (unsigned long)dest);
401 
402 		if (types == L1D_FLUSH_FALLBACK) {
403 			patch_instruction(dest, ppc_inst(instrs[0]));
404 			patch_instruction(dest + 2, ppc_inst(instrs[2]));
405 			patch_branch(dest + 1,
406 				     (unsigned long)&scv_entry_flush_fallback, BRANCH_SET_LINK);
407 		} else {
408 			patch_instruction(dest + 1, ppc_inst(instrs[1]));
409 			patch_instruction(dest + 2, ppc_inst(instrs[2]));
410 			patch_instruction(dest, ppc_inst(instrs[0]));
411 		}
412 	}
413 
414 
415 	printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
416 		(types == L1D_FLUSH_NONE)       ? "no" :
417 		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
418 		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
419 							? "ori+mttrig type"
420 							: "ori type" :
421 		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
422 						: "unknown");
423 
424 	return 0;
425 }
426 
427 void do_entry_flush_fixups(enum l1d_flush_type types)
428 {
429 	/*
430 	 * The call to the fallback flush can not be safely patched in/out while
431 	 * other CPUs are executing it. So call __do_entry_flush_fixups() on one
432 	 * CPU while all other CPUs spin in the stop machine core with interrupts
433 	 * hard disabled.
434 	 */
435 	stop_machine(__do_entry_flush_fixups, &types, NULL);
436 }
437 
438 static int __do_rfi_flush_fixups(void *data)
439 {
440 	enum l1d_flush_type types = *(enum l1d_flush_type *)data;
441 	unsigned int instrs[3], *dest;
442 	long *start, *end;
443 	int i;
444 
445 	start = PTRRELOC(&__start___rfi_flush_fixup);
446 	end = PTRRELOC(&__stop___rfi_flush_fixup);
447 
448 	instrs[0] = PPC_RAW_NOP();
449 	instrs[1] = PPC_RAW_NOP();
450 	instrs[2] = PPC_RAW_NOP();
451 
452 	if (types & L1D_FLUSH_FALLBACK)
453 		/* b .+16 to fallback flush */
454 		instrs[0] = PPC_INST_BRANCH | 16;
455 
456 	i = 0;
457 	if (types & L1D_FLUSH_ORI) {
458 		instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
459 		instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
460 	}
461 
462 	if (types & L1D_FLUSH_MTTRIG)
463 		instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
464 
465 	for (i = 0; start < end; start++, i++) {
466 		dest = (void *)start + *start;
467 
468 		pr_devel("patching dest %lx\n", (unsigned long)dest);
469 
470 		patch_instruction(dest, ppc_inst(instrs[0]));
471 		patch_instruction(dest + 1, ppc_inst(instrs[1]));
472 		patch_instruction(dest + 2, ppc_inst(instrs[2]));
473 	}
474 
475 	printk(KERN_DEBUG "rfi-flush: patched %d locations (%s flush)\n", i,
476 		(types == L1D_FLUSH_NONE)       ? "no" :
477 		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
478 		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
479 							? "ori+mttrig type"
480 							: "ori type" :
481 		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
482 						: "unknown");
483 
484 	return 0;
485 }
486 
487 void do_rfi_flush_fixups(enum l1d_flush_type types)
488 {
489 	/*
490 	 * stop_machine gets all CPUs out of the interrupt exit handler same
491 	 * as do_stf_barrier_fixups. do_rfi_flush_fixups patching can run
492 	 * without stop_machine, so this could be achieved with a broadcast
493 	 * IPI instead, but this matches the stf sequence.
494 	 */
495 
496 	// Prevent static key update races with do_stf_barrier_fixups()
497 	mutex_lock(&exit_flush_lock);
498 	static_branch_enable(&interrupt_exit_not_reentrant);
499 
500 	stop_machine(__do_rfi_flush_fixups, &types, NULL);
501 
502 	if (types & L1D_FLUSH_FALLBACK)
503 		rfi_exit_reentrant = false;
504 	else
505 		rfi_exit_reentrant = true;
506 
507 	if (stf_exit_reentrant && rfi_exit_reentrant)
508 		static_branch_disable(&interrupt_exit_not_reentrant);
509 
510 	mutex_unlock(&exit_flush_lock);
511 }
512 
513 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
514 {
515 	unsigned int instr, *dest;
516 	long *start, *end;
517 	int i;
518 
519 	start = fixup_start;
520 	end = fixup_end;
521 
522 	instr = PPC_RAW_NOP();
523 
524 	if (enable) {
525 		pr_info("barrier-nospec: using ORI speculation barrier\n");
526 		instr = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
527 	}
528 
529 	for (i = 0; start < end; start++, i++) {
530 		dest = (void *)start + *start;
531 
532 		pr_devel("patching dest %lx\n", (unsigned long)dest);
533 		patch_instruction(dest, ppc_inst(instr));
534 	}
535 
536 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
537 }
538 
539 #endif /* CONFIG_PPC_BOOK3S_64 */
540 
541 #ifdef CONFIG_PPC_BARRIER_NOSPEC
542 void do_barrier_nospec_fixups(bool enable)
543 {
544 	void *start, *end;
545 
546 	start = PTRRELOC(&__start___barrier_nospec_fixup);
547 	end = PTRRELOC(&__stop___barrier_nospec_fixup);
548 
549 	do_barrier_nospec_fixups_range(enable, start, end);
550 }
551 #endif /* CONFIG_PPC_BARRIER_NOSPEC */
552 
553 #ifdef CONFIG_PPC_FSL_BOOK3E
554 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
555 {
556 	unsigned int instr[2], *dest;
557 	long *start, *end;
558 	int i;
559 
560 	start = fixup_start;
561 	end = fixup_end;
562 
563 	instr[0] = PPC_RAW_NOP();
564 	instr[1] = PPC_RAW_NOP();
565 
566 	if (enable) {
567 		pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
568 		instr[0] = PPC_RAW_ISYNC();
569 		instr[1] = PPC_RAW_SYNC();
570 	}
571 
572 	for (i = 0; start < end; start++, i++) {
573 		dest = (void *)start + *start;
574 
575 		pr_devel("patching dest %lx\n", (unsigned long)dest);
576 		patch_instruction(dest, ppc_inst(instr[0]));
577 		patch_instruction(dest + 1, ppc_inst(instr[1]));
578 	}
579 
580 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
581 }
582 
583 static void __init patch_btb_flush_section(long *curr)
584 {
585 	unsigned int *start, *end;
586 
587 	start = (void *)curr + *curr;
588 	end = (void *)curr + *(curr + 1);
589 	for (; start < end; start++) {
590 		pr_devel("patching dest %lx\n", (unsigned long)start);
591 		patch_instruction(start, ppc_inst(PPC_RAW_NOP()));
592 	}
593 }
594 
595 void __init do_btb_flush_fixups(void)
596 {
597 	long *start, *end;
598 
599 	start = PTRRELOC(&__start__btb_flush_fixup);
600 	end = PTRRELOC(&__stop__btb_flush_fixup);
601 
602 	for (; start < end; start += 2)
603 		patch_btb_flush_section(start);
604 }
605 #endif /* CONFIG_PPC_FSL_BOOK3E */
606 
607 void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
608 {
609 	long *start, *end;
610 	u32 *dest;
611 
612 	if (!(value & CPU_FTR_LWSYNC))
613 		return ;
614 
615 	start = fixup_start;
616 	end = fixup_end;
617 
618 	for (; start < end; start++) {
619 		dest = (void *)start + *start;
620 		raw_patch_instruction(dest, ppc_inst(PPC_INST_LWSYNC));
621 	}
622 }
623 
624 static void __init do_final_fixups(void)
625 {
626 #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
627 	ppc_inst_t inst;
628 	u32 *src, *dest, *end;
629 
630 	if (PHYSICAL_START == 0)
631 		return;
632 
633 	src = (u32 *)(KERNELBASE + PHYSICAL_START);
634 	dest = (u32 *)KERNELBASE;
635 	end = (void *)src + (__end_interrupts - _stext);
636 
637 	while (src < end) {
638 		inst = ppc_inst_read(src);
639 		raw_patch_instruction(dest, inst);
640 		src = ppc_inst_next(src, src);
641 		dest = ppc_inst_next(dest, dest);
642 	}
643 #endif
644 }
645 
646 static unsigned long __initdata saved_cpu_features;
647 static unsigned int __initdata saved_mmu_features;
648 #ifdef CONFIG_PPC64
649 static unsigned long __initdata saved_firmware_features;
650 #endif
651 
652 void __init apply_feature_fixups(void)
653 {
654 	struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
655 
656 	*PTRRELOC(&saved_cpu_features) = spec->cpu_features;
657 	*PTRRELOC(&saved_mmu_features) = spec->mmu_features;
658 
659 	/*
660 	 * Apply the CPU-specific and firmware specific fixups to kernel text
661 	 * (nop out sections not relevant to this CPU or this firmware).
662 	 */
663 	do_feature_fixups(spec->cpu_features,
664 			  PTRRELOC(&__start___ftr_fixup),
665 			  PTRRELOC(&__stop___ftr_fixup));
666 
667 	do_feature_fixups(spec->mmu_features,
668 			  PTRRELOC(&__start___mmu_ftr_fixup),
669 			  PTRRELOC(&__stop___mmu_ftr_fixup));
670 
671 	do_lwsync_fixups(spec->cpu_features,
672 			 PTRRELOC(&__start___lwsync_fixup),
673 			 PTRRELOC(&__stop___lwsync_fixup));
674 
675 #ifdef CONFIG_PPC64
676 	saved_firmware_features = powerpc_firmware_features;
677 	do_feature_fixups(powerpc_firmware_features,
678 			  &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
679 #endif
680 	do_final_fixups();
681 }
682 
683 void __init setup_feature_keys(void)
684 {
685 	/*
686 	 * Initialise jump label. This causes all the cpu/mmu_has_feature()
687 	 * checks to take on their correct polarity based on the current set of
688 	 * CPU/MMU features.
689 	 */
690 	jump_label_init();
691 	cpu_feature_keys_init();
692 	mmu_feature_keys_init();
693 }
694 
695 static int __init check_features(void)
696 {
697 	WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
698 	     "CPU features changed after feature patching!\n");
699 	WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
700 	     "MMU features changed after feature patching!\n");
701 #ifdef CONFIG_PPC64
702 	WARN(saved_firmware_features != powerpc_firmware_features,
703 	     "Firmware features changed after feature patching!\n");
704 #endif
705 
706 	return 0;
707 }
708 late_initcall(check_features);
709 
710 #ifdef CONFIG_FTR_FIXUP_SELFTEST
711 
712 #define check(x)	\
713 	if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
714 
715 /* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
716 static struct fixup_entry fixup;
717 
718 static long __init calc_offset(struct fixup_entry *entry, unsigned int *p)
719 {
720 	return (unsigned long)p - (unsigned long)entry;
721 }
722 
723 static void __init test_basic_patching(void)
724 {
725 	extern unsigned int ftr_fixup_test1[];
726 	extern unsigned int end_ftr_fixup_test1[];
727 	extern unsigned int ftr_fixup_test1_orig[];
728 	extern unsigned int ftr_fixup_test1_expected[];
729 	int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
730 
731 	fixup.value = fixup.mask = 8;
732 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
733 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
734 	fixup.alt_start_off = fixup.alt_end_off = 0;
735 
736 	/* Sanity check */
737 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
738 
739 	/* Check we don't patch if the value matches */
740 	patch_feature_section(8, &fixup);
741 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
742 
743 	/* Check we do patch if the value doesn't match */
744 	patch_feature_section(0, &fixup);
745 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
746 
747 	/* Check we do patch if the mask doesn't match */
748 	memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
749 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
750 	patch_feature_section(~8, &fixup);
751 	check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
752 }
753 
754 static void __init test_alternative_patching(void)
755 {
756 	extern unsigned int ftr_fixup_test2[];
757 	extern unsigned int end_ftr_fixup_test2[];
758 	extern unsigned int ftr_fixup_test2_orig[];
759 	extern unsigned int ftr_fixup_test2_alt[];
760 	extern unsigned int ftr_fixup_test2_expected[];
761 	int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
762 
763 	fixup.value = fixup.mask = 0xF;
764 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
765 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
766 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
767 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
768 
769 	/* Sanity check */
770 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
771 
772 	/* Check we don't patch if the value matches */
773 	patch_feature_section(0xF, &fixup);
774 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
775 
776 	/* Check we do patch if the value doesn't match */
777 	patch_feature_section(0, &fixup);
778 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
779 
780 	/* Check we do patch if the mask doesn't match */
781 	memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
782 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
783 	patch_feature_section(~0xF, &fixup);
784 	check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
785 }
786 
787 static void __init test_alternative_case_too_big(void)
788 {
789 	extern unsigned int ftr_fixup_test3[];
790 	extern unsigned int end_ftr_fixup_test3[];
791 	extern unsigned int ftr_fixup_test3_orig[];
792 	extern unsigned int ftr_fixup_test3_alt[];
793 	int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
794 
795 	fixup.value = fixup.mask = 0xC;
796 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
797 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
798 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
799 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
800 
801 	/* Sanity check */
802 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
803 
804 	/* Expect nothing to be patched, and the error returned to us */
805 	check(patch_feature_section(0xF, &fixup) == 1);
806 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
807 	check(patch_feature_section(0, &fixup) == 1);
808 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
809 	check(patch_feature_section(~0xF, &fixup) == 1);
810 	check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
811 }
812 
813 static void __init test_alternative_case_too_small(void)
814 {
815 	extern unsigned int ftr_fixup_test4[];
816 	extern unsigned int end_ftr_fixup_test4[];
817 	extern unsigned int ftr_fixup_test4_orig[];
818 	extern unsigned int ftr_fixup_test4_alt[];
819 	extern unsigned int ftr_fixup_test4_expected[];
820 	int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4);
821 	unsigned long flag;
822 
823 	/* Check a high-bit flag */
824 	flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
825 	fixup.value = fixup.mask = flag;
826 	fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
827 	fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
828 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
829 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
830 
831 	/* Sanity check */
832 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
833 
834 	/* Check we don't patch if the value matches */
835 	patch_feature_section(flag, &fixup);
836 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
837 
838 	/* Check we do patch if the value doesn't match */
839 	patch_feature_section(0, &fixup);
840 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
841 
842 	/* Check we do patch if the mask doesn't match */
843 	memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
844 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
845 	patch_feature_section(~flag, &fixup);
846 	check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
847 }
848 
849 static void test_alternative_case_with_branch(void)
850 {
851 	extern unsigned int ftr_fixup_test5[];
852 	extern unsigned int end_ftr_fixup_test5[];
853 	extern unsigned int ftr_fixup_test5_expected[];
854 	int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
855 
856 	check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
857 }
858 
859 static void __init test_alternative_case_with_external_branch(void)
860 {
861 	extern unsigned int ftr_fixup_test6[];
862 	extern unsigned int end_ftr_fixup_test6[];
863 	extern unsigned int ftr_fixup_test6_expected[];
864 	int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
865 
866 	check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
867 }
868 
869 static void __init test_alternative_case_with_branch_to_end(void)
870 {
871 	extern unsigned int ftr_fixup_test7[];
872 	extern unsigned int end_ftr_fixup_test7[];
873 	extern unsigned int ftr_fixup_test7_expected[];
874 	int size = 4 * (end_ftr_fixup_test7 - ftr_fixup_test7);
875 
876 	check(memcmp(ftr_fixup_test7, ftr_fixup_test7_expected, size) == 0);
877 }
878 
879 static void __init test_cpu_macros(void)
880 {
881 	extern u8 ftr_fixup_test_FTR_macros[];
882 	extern u8 ftr_fixup_test_FTR_macros_expected[];
883 	unsigned long size = ftr_fixup_test_FTR_macros_expected -
884 			     ftr_fixup_test_FTR_macros;
885 
886 	/* The fixups have already been done for us during boot */
887 	check(memcmp(ftr_fixup_test_FTR_macros,
888 		     ftr_fixup_test_FTR_macros_expected, size) == 0);
889 }
890 
891 static void __init test_fw_macros(void)
892 {
893 #ifdef CONFIG_PPC64
894 	extern u8 ftr_fixup_test_FW_FTR_macros[];
895 	extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
896 	unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
897 			     ftr_fixup_test_FW_FTR_macros;
898 
899 	/* The fixups have already been done for us during boot */
900 	check(memcmp(ftr_fixup_test_FW_FTR_macros,
901 		     ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
902 #endif
903 }
904 
905 static void __init test_lwsync_macros(void)
906 {
907 	extern u8 lwsync_fixup_test[];
908 	extern u8 end_lwsync_fixup_test[];
909 	extern u8 lwsync_fixup_test_expected_LWSYNC[];
910 	extern u8 lwsync_fixup_test_expected_SYNC[];
911 	unsigned long size = end_lwsync_fixup_test -
912 			     lwsync_fixup_test;
913 
914 	/* The fixups have already been done for us during boot */
915 	if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
916 		check(memcmp(lwsync_fixup_test,
917 			     lwsync_fixup_test_expected_LWSYNC, size) == 0);
918 	} else {
919 		check(memcmp(lwsync_fixup_test,
920 			     lwsync_fixup_test_expected_SYNC, size) == 0);
921 	}
922 }
923 
924 #ifdef CONFIG_PPC64
925 static void __init test_prefix_patching(void)
926 {
927 	extern unsigned int ftr_fixup_prefix1[];
928 	extern unsigned int end_ftr_fixup_prefix1[];
929 	extern unsigned int ftr_fixup_prefix1_orig[];
930 	extern unsigned int ftr_fixup_prefix1_expected[];
931 	int size = sizeof(unsigned int) * (end_ftr_fixup_prefix1 - ftr_fixup_prefix1);
932 
933 	fixup.value = fixup.mask = 8;
934 	fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix1 + 1);
935 	fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix1 + 3);
936 	fixup.alt_start_off = fixup.alt_end_off = 0;
937 
938 	/* Sanity check */
939 	check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) == 0);
940 
941 	patch_feature_section(0, &fixup);
942 	check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_expected, size) == 0);
943 	check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) != 0);
944 }
945 
946 static void __init test_prefix_alt_patching(void)
947 {
948 	extern unsigned int ftr_fixup_prefix2[];
949 	extern unsigned int end_ftr_fixup_prefix2[];
950 	extern unsigned int ftr_fixup_prefix2_orig[];
951 	extern unsigned int ftr_fixup_prefix2_expected[];
952 	extern unsigned int ftr_fixup_prefix2_alt[];
953 	int size = sizeof(unsigned int) * (end_ftr_fixup_prefix2 - ftr_fixup_prefix2);
954 
955 	fixup.value = fixup.mask = 8;
956 	fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix2 + 1);
957 	fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix2 + 3);
958 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix2_alt);
959 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix2_alt + 2);
960 	/* Sanity check */
961 	check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) == 0);
962 
963 	patch_feature_section(0, &fixup);
964 	check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_expected, size) == 0);
965 	check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) != 0);
966 }
967 
968 static void __init test_prefix_word_alt_patching(void)
969 {
970 	extern unsigned int ftr_fixup_prefix3[];
971 	extern unsigned int end_ftr_fixup_prefix3[];
972 	extern unsigned int ftr_fixup_prefix3_orig[];
973 	extern unsigned int ftr_fixup_prefix3_expected[];
974 	extern unsigned int ftr_fixup_prefix3_alt[];
975 	int size = sizeof(unsigned int) * (end_ftr_fixup_prefix3 - ftr_fixup_prefix3);
976 
977 	fixup.value = fixup.mask = 8;
978 	fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix3 + 1);
979 	fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix3 + 4);
980 	fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix3_alt);
981 	fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix3_alt + 3);
982 	/* Sanity check */
983 	check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) == 0);
984 
985 	patch_feature_section(0, &fixup);
986 	check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_expected, size) == 0);
987 	patch_feature_section(0, &fixup);
988 	check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) != 0);
989 }
990 #else
991 static inline void test_prefix_patching(void) {}
992 static inline void test_prefix_alt_patching(void) {}
993 static inline void test_prefix_word_alt_patching(void) {}
994 #endif /* CONFIG_PPC64 */
995 
996 static int __init test_feature_fixups(void)
997 {
998 	printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
999 
1000 	test_basic_patching();
1001 	test_alternative_patching();
1002 	test_alternative_case_too_big();
1003 	test_alternative_case_too_small();
1004 	test_alternative_case_with_branch();
1005 	test_alternative_case_with_external_branch();
1006 	test_alternative_case_with_branch_to_end();
1007 	test_cpu_macros();
1008 	test_fw_macros();
1009 	test_lwsync_macros();
1010 	test_prefix_patching();
1011 	test_prefix_alt_patching();
1012 	test_prefix_word_alt_patching();
1013 
1014 	return 0;
1015 }
1016 late_initcall(test_feature_fixups);
1017 
1018 #endif /* CONFIG_FTR_FIXUP_SELFTEST */
1019