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Michael Ellerman51c52e82008-06-24 11:32:36 +10001/*
2 * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
3 *
4 * Modifications for ppc64:
5 * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
6 *
7 * Copyright 2008 Michael Ellerman, IBM Corporation.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
Stephen Rothwell3880ecb2010-06-28 21:08:29 +000015#include <linux/types.h>
Michael Ellerman51c52e82008-06-24 11:32:36 +100016#include <linux/kernel.h>
Michael Ellerman362e7702008-06-24 11:33:03 +100017#include <linux/string.h>
18#include <linux/init.h>
Michael Ellerman51c52e82008-06-24 11:32:36 +100019#include <asm/cputable.h>
20#include <asm/code-patching.h>
Anton Blanchardd715e432011-11-14 12:54:47 +000021#include <asm/page.h>
22#include <asm/sections.h>
Michael Ellerman51c52e82008-06-24 11:32:36 +100023
24
25struct fixup_entry {
26 unsigned long mask;
27 unsigned long value;
28 long start_off;
29 long end_off;
Michael Ellermanfac23fe2008-06-24 11:32:54 +100030 long alt_start_off;
31 long alt_end_off;
Michael Ellerman51c52e82008-06-24 11:32:36 +100032};
33
Michael Ellerman9b1a7352008-06-24 11:33:02 +100034static unsigned int *calc_addr(struct fixup_entry *fcur, long offset)
Michael Ellerman51c52e82008-06-24 11:32:36 +100035{
Michael Ellerman9b1a7352008-06-24 11:33:02 +100036 /*
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
44static 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 patch_instruction(dest, instr);
63
64 return 0;
65}
66
67static 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;
Michael Ellerman51c52e82008-06-24 11:32:36 +100078
79 if ((value & fcur->mask) == fcur->value)
Michael Ellerman9b1a7352008-06-24 11:33:02 +100080 return 0;
Michael Ellerman51c52e82008-06-24 11:32:36 +100081
Michael Ellerman9b1a7352008-06-24 11:33:02 +100082 src = alt_start;
83 dest = start;
Michael Ellerman51c52e82008-06-24 11:32:36 +100084
Michael Ellerman9b1a7352008-06-24 11:33:02 +100085 for (; src < alt_end; src++, dest++) {
86 if (patch_alt_instruction(src, dest, alt_start, alt_end))
87 return 1;
Michael Ellerman51c52e82008-06-24 11:32:36 +100088 }
Michael Ellerman9b1a7352008-06-24 11:33:02 +100089
90 for (; dest < end; dest++)
Kumar Gala16c57b32009-02-10 20:10:44 +000091 patch_instruction(dest, PPC_INST_NOP);
Michael Ellerman9b1a7352008-06-24 11:33:02 +100092
93 return 0;
Michael Ellerman51c52e82008-06-24 11:32:36 +100094}
95
96void 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
Michael Ellerman9b1a7352008-06-24 11:33:02 +1000103 for (; fcur < fend; fcur++) {
104 if (patch_feature_section(value, fcur)) {
Michael Ellerman1856c022008-07-17 14:46:00 +1000105 WARN_ON(1);
Michael Ellerman9b1a7352008-06-24 11:33:02 +1000106 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 }
Michael Ellerman51c52e82008-06-24 11:32:36 +1000114}
Michael Ellerman362e7702008-06-24 11:33:03 +1000115
Kumar Gala2d1b2022008-07-02 01:16:40 +1000116void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
117{
Benjamin Herrenschmidt3d98ffb2010-02-26 18:29:17 +1100118 long *start, *end;
119 unsigned int *dest;
Kumar Gala2d1b2022008-07-02 01:16:40 +1000120
121 if (!(value & CPU_FTR_LWSYNC))
122 return ;
123
124 start = fixup_start;
125 end = fixup_end;
126
127 for (; start < end; start++) {
128 dest = (void *)start + *start;
Kumar Gala16c57b32009-02-10 20:10:44 +0000129 patch_instruction(dest, PPC_INST_LWSYNC);
Kumar Gala2d1b2022008-07-02 01:16:40 +1000130 }
131}
132
Anton Blanchardd715e432011-11-14 12:54:47 +0000133void do_final_fixups(void)
134{
135#if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
136 int *src, *dest;
137 unsigned long length;
138
139 if (PHYSICAL_START == 0)
140 return;
141
142 src = (int *)(KERNELBASE + PHYSICAL_START);
143 dest = (int *)KERNELBASE;
144 length = (__end_interrupts - _stext) / sizeof(int);
145
146 while (length--) {
147 patch_instruction(dest, *src);
148 src++;
149 dest++;
150 }
151#endif
152}
153
Michael Ellerman362e7702008-06-24 11:33:03 +1000154#ifdef CONFIG_FTR_FIXUP_SELFTEST
155
156#define check(x) \
157 if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
158
159/* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
160static struct fixup_entry fixup;
161
162static long calc_offset(struct fixup_entry *entry, unsigned int *p)
163{
164 return (unsigned long)p - (unsigned long)entry;
165}
166
Anton Blancharde51df2c2014-08-20 08:55:18 +1000167static void test_basic_patching(void)
Michael Ellerman362e7702008-06-24 11:33:03 +1000168{
169 extern unsigned int ftr_fixup_test1;
170 extern unsigned int end_ftr_fixup_test1;
171 extern unsigned int ftr_fixup_test1_orig;
172 extern unsigned int ftr_fixup_test1_expected;
173 int size = &end_ftr_fixup_test1 - &ftr_fixup_test1;
174
175 fixup.value = fixup.mask = 8;
176 fixup.start_off = calc_offset(&fixup, &ftr_fixup_test1 + 1);
177 fixup.end_off = calc_offset(&fixup, &ftr_fixup_test1 + 2);
178 fixup.alt_start_off = fixup.alt_end_off = 0;
179
180 /* Sanity check */
181 check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
182
183 /* Check we don't patch if the value matches */
184 patch_feature_section(8, &fixup);
185 check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
186
187 /* Check we do patch if the value doesn't match */
188 patch_feature_section(0, &fixup);
189 check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_expected, size) == 0);
190
191 /* Check we do patch if the mask doesn't match */
192 memcpy(&ftr_fixup_test1, &ftr_fixup_test1_orig, size);
193 check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
194 patch_feature_section(~8, &fixup);
195 check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_expected, size) == 0);
196}
197
198static void test_alternative_patching(void)
199{
200 extern unsigned int ftr_fixup_test2;
201 extern unsigned int end_ftr_fixup_test2;
202 extern unsigned int ftr_fixup_test2_orig;
203 extern unsigned int ftr_fixup_test2_alt;
204 extern unsigned int ftr_fixup_test2_expected;
205 int size = &end_ftr_fixup_test2 - &ftr_fixup_test2;
206
207 fixup.value = fixup.mask = 0xF;
208 fixup.start_off = calc_offset(&fixup, &ftr_fixup_test2 + 1);
209 fixup.end_off = calc_offset(&fixup, &ftr_fixup_test2 + 2);
210 fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test2_alt);
211 fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test2_alt + 1);
212
213 /* Sanity check */
214 check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
215
216 /* Check we don't patch if the value matches */
217 patch_feature_section(0xF, &fixup);
218 check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
219
220 /* Check we do patch if the value doesn't match */
221 patch_feature_section(0, &fixup);
222 check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_expected, size) == 0);
223
224 /* Check we do patch if the mask doesn't match */
225 memcpy(&ftr_fixup_test2, &ftr_fixup_test2_orig, size);
226 check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_orig, size) == 0);
227 patch_feature_section(~0xF, &fixup);
228 check(memcmp(&ftr_fixup_test2, &ftr_fixup_test2_expected, size) == 0);
229}
230
231static void test_alternative_case_too_big(void)
232{
233 extern unsigned int ftr_fixup_test3;
234 extern unsigned int end_ftr_fixup_test3;
235 extern unsigned int ftr_fixup_test3_orig;
236 extern unsigned int ftr_fixup_test3_alt;
237 int size = &end_ftr_fixup_test3 - &ftr_fixup_test3;
238
239 fixup.value = fixup.mask = 0xC;
240 fixup.start_off = calc_offset(&fixup, &ftr_fixup_test3 + 1);
241 fixup.end_off = calc_offset(&fixup, &ftr_fixup_test3 + 2);
242 fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test3_alt);
243 fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test3_alt + 2);
244
245 /* Sanity check */
246 check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
247
248 /* Expect nothing to be patched, and the error returned to us */
249 check(patch_feature_section(0xF, &fixup) == 1);
250 check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
251 check(patch_feature_section(0, &fixup) == 1);
252 check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
253 check(patch_feature_section(~0xF, &fixup) == 1);
254 check(memcmp(&ftr_fixup_test3, &ftr_fixup_test3_orig, size) == 0);
255}
256
257static void test_alternative_case_too_small(void)
258{
259 extern unsigned int ftr_fixup_test4;
260 extern unsigned int end_ftr_fixup_test4;
261 extern unsigned int ftr_fixup_test4_orig;
262 extern unsigned int ftr_fixup_test4_alt;
263 extern unsigned int ftr_fixup_test4_expected;
264 int size = &end_ftr_fixup_test4 - &ftr_fixup_test4;
265 unsigned long flag;
266
267 /* Check a high-bit flag */
268 flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
269 fixup.value = fixup.mask = flag;
270 fixup.start_off = calc_offset(&fixup, &ftr_fixup_test4 + 1);
271 fixup.end_off = calc_offset(&fixup, &ftr_fixup_test4 + 5);
272 fixup.alt_start_off = calc_offset(&fixup, &ftr_fixup_test4_alt);
273 fixup.alt_end_off = calc_offset(&fixup, &ftr_fixup_test4_alt + 2);
274
275 /* Sanity check */
276 check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
277
278 /* Check we don't patch if the value matches */
279 patch_feature_section(flag, &fixup);
280 check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
281
282 /* Check we do patch if the value doesn't match */
283 patch_feature_section(0, &fixup);
284 check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_expected, size) == 0);
285
286 /* Check we do patch if the mask doesn't match */
287 memcpy(&ftr_fixup_test4, &ftr_fixup_test4_orig, size);
288 check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_orig, size) == 0);
289 patch_feature_section(~flag, &fixup);
290 check(memcmp(&ftr_fixup_test4, &ftr_fixup_test4_expected, size) == 0);
291}
292
293static void test_alternative_case_with_branch(void)
294{
295 extern unsigned int ftr_fixup_test5;
296 extern unsigned int end_ftr_fixup_test5;
297 extern unsigned int ftr_fixup_test5_expected;
298 int size = &end_ftr_fixup_test5 - &ftr_fixup_test5;
299
300 check(memcmp(&ftr_fixup_test5, &ftr_fixup_test5_expected, size) == 0);
301}
302
303static void test_alternative_case_with_external_branch(void)
304{
305 extern unsigned int ftr_fixup_test6;
306 extern unsigned int end_ftr_fixup_test6;
307 extern unsigned int ftr_fixup_test6_expected;
308 int size = &end_ftr_fixup_test6 - &ftr_fixup_test6;
309
310 check(memcmp(&ftr_fixup_test6, &ftr_fixup_test6_expected, size) == 0);
311}
312
313static void test_cpu_macros(void)
314{
Stephen Rothwell3880ecb2010-06-28 21:08:29 +0000315 extern u8 ftr_fixup_test_FTR_macros;
316 extern u8 ftr_fixup_test_FTR_macros_expected;
Michael Ellerman362e7702008-06-24 11:33:03 +1000317 unsigned long size = &ftr_fixup_test_FTR_macros_expected -
318 &ftr_fixup_test_FTR_macros;
319
320 /* The fixups have already been done for us during boot */
321 check(memcmp(&ftr_fixup_test_FTR_macros,
322 &ftr_fixup_test_FTR_macros_expected, size) == 0);
323}
324
325static void test_fw_macros(void)
326{
327#ifdef CONFIG_PPC64
Stephen Rothwell3880ecb2010-06-28 21:08:29 +0000328 extern u8 ftr_fixup_test_FW_FTR_macros;
329 extern u8 ftr_fixup_test_FW_FTR_macros_expected;
Michael Ellerman362e7702008-06-24 11:33:03 +1000330 unsigned long size = &ftr_fixup_test_FW_FTR_macros_expected -
331 &ftr_fixup_test_FW_FTR_macros;
332
333 /* The fixups have already been done for us during boot */
334 check(memcmp(&ftr_fixup_test_FW_FTR_macros,
335 &ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
336#endif
337}
338
Kumar Gala2d1b2022008-07-02 01:16:40 +1000339static void test_lwsync_macros(void)
340{
Stephen Rothwell3880ecb2010-06-28 21:08:29 +0000341 extern u8 lwsync_fixup_test;
342 extern u8 end_lwsync_fixup_test;
343 extern u8 lwsync_fixup_test_expected_LWSYNC;
344 extern u8 lwsync_fixup_test_expected_SYNC;
Kumar Gala2d1b2022008-07-02 01:16:40 +1000345 unsigned long size = &end_lwsync_fixup_test -
346 &lwsync_fixup_test;
347
348 /* The fixups have already been done for us during boot */
349 if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
350 check(memcmp(&lwsync_fixup_test,
351 &lwsync_fixup_test_expected_LWSYNC, size) == 0);
352 } else {
353 check(memcmp(&lwsync_fixup_test,
354 &lwsync_fixup_test_expected_SYNC, size) == 0);
355 }
356}
357
Michael Ellerman362e7702008-06-24 11:33:03 +1000358static int __init test_feature_fixups(void)
359{
360 printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
361
362 test_basic_patching();
363 test_alternative_patching();
364 test_alternative_case_too_big();
365 test_alternative_case_too_small();
366 test_alternative_case_with_branch();
367 test_alternative_case_with_external_branch();
368 test_cpu_macros();
369 test_fw_macros();
Kumar Gala2d1b2022008-07-02 01:16:40 +1000370 test_lwsync_macros();
Michael Ellerman362e7702008-06-24 11:33:03 +1000371
372 return 0;
373}
374late_initcall(test_feature_fixups);
375
376#endif /* CONFIG_FTR_FIXUP_SELFTEST */