2 * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
4 * Modifications for ppc64:
5 * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
7 * Copyright 2008 Michael Ellerman, IBM Corporation.
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.
15 #include <linux/types.h>
16 #include <linux/jump_label.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/init.h>
20 #include <asm/cputable.h>
21 #include <asm/code-patching.h>
23 #include <asm/sections.h>
24 #include <asm/setup.h>
25 #include <asm/firmware.h>
36 static unsigned int *calc_addr(struct fixup_entry
*fcur
, long offset
)
39 * We store the offset to the code as a negative offset from
40 * the start of the alt_entry, to support the VDSO. This
41 * routine converts that back into an actual address.
43 return (unsigned int *)((unsigned long)fcur
+ offset
);
46 static int patch_alt_instruction(unsigned int *src
, unsigned int *dest
,
47 unsigned int *alt_start
, unsigned int *alt_end
)
53 if (instr_is_relative_branch(*src
)) {
54 unsigned int *target
= (unsigned int *)branch_target(src
);
56 /* Branch within the section doesn't need translating */
57 if (target
< alt_start
|| target
>= alt_end
) {
58 instr
= translate_branch(dest
, src
);
64 patch_instruction(dest
, instr
);
69 static int patch_feature_section(unsigned long value
, struct fixup_entry
*fcur
)
71 unsigned int *start
, *end
, *alt_start
, *alt_end
, *src
, *dest
;
73 start
= calc_addr(fcur
, fcur
->start_off
);
74 end
= calc_addr(fcur
, fcur
->end_off
);
75 alt_start
= calc_addr(fcur
, fcur
->alt_start_off
);
76 alt_end
= calc_addr(fcur
, fcur
->alt_end_off
);
78 if ((alt_end
- alt_start
) > (end
- start
))
81 if ((value
& fcur
->mask
) == fcur
->value
)
87 for (; src
< alt_end
; src
++, dest
++) {
88 if (patch_alt_instruction(src
, dest
, alt_start
, alt_end
))
92 for (; dest
< end
; dest
++)
93 patch_instruction(dest
, PPC_INST_NOP
);
98 void do_feature_fixups(unsigned long value
, void *fixup_start
, void *fixup_end
)
100 struct fixup_entry
*fcur
, *fend
;
105 for (; fcur
< fend
; fcur
++) {
106 if (patch_feature_section(value
, fcur
)) {
108 printk("Unable to patch feature section at %p - %p" \
110 calc_addr(fcur
, fcur
->start_off
),
111 calc_addr(fcur
, fcur
->end_off
),
112 calc_addr(fcur
, fcur
->alt_start_off
),
113 calc_addr(fcur
, fcur
->alt_end_off
));
118 void do_lwsync_fixups(unsigned long value
, void *fixup_start
, void *fixup_end
)
123 if (!(value
& CPU_FTR_LWSYNC
))
129 for (; start
< end
; start
++) {
130 dest
= (void *)start
+ *start
;
131 patch_instruction(dest
, PPC_INST_LWSYNC
);
135 static void do_final_fixups(void)
137 #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
139 unsigned long length
;
141 if (PHYSICAL_START
== 0)
144 src
= (int *)(KERNELBASE
+ PHYSICAL_START
);
145 dest
= (int *)KERNELBASE
;
146 length
= (__end_interrupts
- _stext
) / sizeof(int);
149 patch_instruction(dest
, *src
);
156 static unsigned long __initdata saved_cpu_features
;
157 static unsigned int __initdata saved_mmu_features
;
159 static unsigned long __initdata saved_firmware_features
;
162 void __init
apply_feature_fixups(void)
164 struct cpu_spec
*spec
= *PTRRELOC(&cur_cpu_spec
);
166 *PTRRELOC(&saved_cpu_features
) = spec
->cpu_features
;
167 *PTRRELOC(&saved_mmu_features
) = spec
->mmu_features
;
170 * Apply the CPU-specific and firmware specific fixups to kernel text
171 * (nop out sections not relevant to this CPU or this firmware).
173 do_feature_fixups(spec
->cpu_features
,
174 PTRRELOC(&__start___ftr_fixup
),
175 PTRRELOC(&__stop___ftr_fixup
));
177 do_feature_fixups(spec
->mmu_features
,
178 PTRRELOC(&__start___mmu_ftr_fixup
),
179 PTRRELOC(&__stop___mmu_ftr_fixup
));
181 do_lwsync_fixups(spec
->cpu_features
,
182 PTRRELOC(&__start___lwsync_fixup
),
183 PTRRELOC(&__stop___lwsync_fixup
));
186 saved_firmware_features
= powerpc_firmware_features
;
187 do_feature_fixups(powerpc_firmware_features
,
188 &__start___fw_ftr_fixup
, &__stop___fw_ftr_fixup
);
193 * Initialise jump label. This causes all the cpu/mmu_has_feature()
194 * checks to take on their correct polarity based on the current set of
198 cpu_feature_keys_init();
199 mmu_feature_keys_init();
202 static int __init
check_features(void)
204 WARN(saved_cpu_features
!= cur_cpu_spec
->cpu_features
,
205 "CPU features changed after feature patching!\n");
206 WARN(saved_mmu_features
!= cur_cpu_spec
->mmu_features
,
207 "MMU features changed after feature patching!\n");
209 WARN(saved_firmware_features
!= powerpc_firmware_features
,
210 "Firmware features changed after feature patching!\n");
215 late_initcall(check_features
);
217 #ifdef CONFIG_FTR_FIXUP_SELFTEST
220 if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
222 /* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
223 static struct fixup_entry fixup
;
225 static long calc_offset(struct fixup_entry
*entry
, unsigned int *p
)
227 return (unsigned long)p
- (unsigned long)entry
;
230 static void test_basic_patching(void)
232 extern unsigned int ftr_fixup_test1
;
233 extern unsigned int end_ftr_fixup_test1
;
234 extern unsigned int ftr_fixup_test1_orig
;
235 extern unsigned int ftr_fixup_test1_expected
;
236 int size
= &end_ftr_fixup_test1
- &ftr_fixup_test1
;
238 fixup
.value
= fixup
.mask
= 8;
239 fixup
.start_off
= calc_offset(&fixup
, &ftr_fixup_test1
+ 1);
240 fixup
.end_off
= calc_offset(&fixup
, &ftr_fixup_test1
+ 2);
241 fixup
.alt_start_off
= fixup
.alt_end_off
= 0;
244 check(memcmp(&ftr_fixup_test1
, &ftr_fixup_test1_orig
, size
) == 0);
246 /* Check we don't patch if the value matches */
247 patch_feature_section(8, &fixup
);
248 check(memcmp(&ftr_fixup_test1
, &ftr_fixup_test1_orig
, size
) == 0);
250 /* Check we do patch if the value doesn't match */
251 patch_feature_section(0, &fixup
);
252 check(memcmp(&ftr_fixup_test1
, &ftr_fixup_test1_expected
, size
) == 0);
254 /* Check we do patch if the mask doesn't match */
255 memcpy(&ftr_fixup_test1
, &ftr_fixup_test1_orig
, size
);
256 check(memcmp(&ftr_fixup_test1
, &ftr_fixup_test1_orig
, size
) == 0);
257 patch_feature_section(~8, &fixup
);
258 check(memcmp(&ftr_fixup_test1
, &ftr_fixup_test1_expected
, size
) == 0);
261 static void test_alternative_patching(void)
263 extern unsigned int ftr_fixup_test2
;
264 extern unsigned int end_ftr_fixup_test2
;
265 extern unsigned int ftr_fixup_test2_orig
;
266 extern unsigned int ftr_fixup_test2_alt
;
267 extern unsigned int ftr_fixup_test2_expected
;
268 int size
= &end_ftr_fixup_test2
- &ftr_fixup_test2
;
270 fixup
.value
= fixup
.mask
= 0xF;
271 fixup
.start_off
= calc_offset(&fixup
, &ftr_fixup_test2
+ 1);
272 fixup
.end_off
= calc_offset(&fixup
, &ftr_fixup_test2
+ 2);
273 fixup
.alt_start_off
= calc_offset(&fixup
, &ftr_fixup_test2_alt
);
274 fixup
.alt_end_off
= calc_offset(&fixup
, &ftr_fixup_test2_alt
+ 1);
277 check(memcmp(&ftr_fixup_test2
, &ftr_fixup_test2_orig
, size
) == 0);
279 /* Check we don't patch if the value matches */
280 patch_feature_section(0xF, &fixup
);
281 check(memcmp(&ftr_fixup_test2
, &ftr_fixup_test2_orig
, size
) == 0);
283 /* Check we do patch if the value doesn't match */
284 patch_feature_section(0, &fixup
);
285 check(memcmp(&ftr_fixup_test2
, &ftr_fixup_test2_expected
, size
) == 0);
287 /* Check we do patch if the mask doesn't match */
288 memcpy(&ftr_fixup_test2
, &ftr_fixup_test2_orig
, size
);
289 check(memcmp(&ftr_fixup_test2
, &ftr_fixup_test2_orig
, size
) == 0);
290 patch_feature_section(~0xF, &fixup
);
291 check(memcmp(&ftr_fixup_test2
, &ftr_fixup_test2_expected
, size
) == 0);
294 static void test_alternative_case_too_big(void)
296 extern unsigned int ftr_fixup_test3
;
297 extern unsigned int end_ftr_fixup_test3
;
298 extern unsigned int ftr_fixup_test3_orig
;
299 extern unsigned int ftr_fixup_test3_alt
;
300 int size
= &end_ftr_fixup_test3
- &ftr_fixup_test3
;
302 fixup
.value
= fixup
.mask
= 0xC;
303 fixup
.start_off
= calc_offset(&fixup
, &ftr_fixup_test3
+ 1);
304 fixup
.end_off
= calc_offset(&fixup
, &ftr_fixup_test3
+ 2);
305 fixup
.alt_start_off
= calc_offset(&fixup
, &ftr_fixup_test3_alt
);
306 fixup
.alt_end_off
= calc_offset(&fixup
, &ftr_fixup_test3_alt
+ 2);
309 check(memcmp(&ftr_fixup_test3
, &ftr_fixup_test3_orig
, size
) == 0);
311 /* Expect nothing to be patched, and the error returned to us */
312 check(patch_feature_section(0xF, &fixup
) == 1);
313 check(memcmp(&ftr_fixup_test3
, &ftr_fixup_test3_orig
, size
) == 0);
314 check(patch_feature_section(0, &fixup
) == 1);
315 check(memcmp(&ftr_fixup_test3
, &ftr_fixup_test3_orig
, size
) == 0);
316 check(patch_feature_section(~0xF, &fixup
) == 1);
317 check(memcmp(&ftr_fixup_test3
, &ftr_fixup_test3_orig
, size
) == 0);
320 static void test_alternative_case_too_small(void)
322 extern unsigned int ftr_fixup_test4
;
323 extern unsigned int end_ftr_fixup_test4
;
324 extern unsigned int ftr_fixup_test4_orig
;
325 extern unsigned int ftr_fixup_test4_alt
;
326 extern unsigned int ftr_fixup_test4_expected
;
327 int size
= &end_ftr_fixup_test4
- &ftr_fixup_test4
;
330 /* Check a high-bit flag */
331 flag
= 1UL << ((sizeof(unsigned long) - 1) * 8);
332 fixup
.value
= fixup
.mask
= flag
;
333 fixup
.start_off
= calc_offset(&fixup
, &ftr_fixup_test4
+ 1);
334 fixup
.end_off
= calc_offset(&fixup
, &ftr_fixup_test4
+ 5);
335 fixup
.alt_start_off
= calc_offset(&fixup
, &ftr_fixup_test4_alt
);
336 fixup
.alt_end_off
= calc_offset(&fixup
, &ftr_fixup_test4_alt
+ 2);
339 check(memcmp(&ftr_fixup_test4
, &ftr_fixup_test4_orig
, size
) == 0);
341 /* Check we don't patch if the value matches */
342 patch_feature_section(flag
, &fixup
);
343 check(memcmp(&ftr_fixup_test4
, &ftr_fixup_test4_orig
, size
) == 0);
345 /* Check we do patch if the value doesn't match */
346 patch_feature_section(0, &fixup
);
347 check(memcmp(&ftr_fixup_test4
, &ftr_fixup_test4_expected
, size
) == 0);
349 /* Check we do patch if the mask doesn't match */
350 memcpy(&ftr_fixup_test4
, &ftr_fixup_test4_orig
, size
);
351 check(memcmp(&ftr_fixup_test4
, &ftr_fixup_test4_orig
, size
) == 0);
352 patch_feature_section(~flag
, &fixup
);
353 check(memcmp(&ftr_fixup_test4
, &ftr_fixup_test4_expected
, size
) == 0);
356 static void test_alternative_case_with_branch(void)
358 extern unsigned int ftr_fixup_test5
;
359 extern unsigned int end_ftr_fixup_test5
;
360 extern unsigned int ftr_fixup_test5_expected
;
361 int size
= &end_ftr_fixup_test5
- &ftr_fixup_test5
;
363 check(memcmp(&ftr_fixup_test5
, &ftr_fixup_test5_expected
, size
) == 0);
366 static void test_alternative_case_with_external_branch(void)
368 extern unsigned int ftr_fixup_test6
;
369 extern unsigned int end_ftr_fixup_test6
;
370 extern unsigned int ftr_fixup_test6_expected
;
371 int size
= &end_ftr_fixup_test6
- &ftr_fixup_test6
;
373 check(memcmp(&ftr_fixup_test6
, &ftr_fixup_test6_expected
, size
) == 0);
376 static void test_cpu_macros(void)
378 extern u8 ftr_fixup_test_FTR_macros
;
379 extern u8 ftr_fixup_test_FTR_macros_expected
;
380 unsigned long size
= &ftr_fixup_test_FTR_macros_expected
-
381 &ftr_fixup_test_FTR_macros
;
383 /* The fixups have already been done for us during boot */
384 check(memcmp(&ftr_fixup_test_FTR_macros
,
385 &ftr_fixup_test_FTR_macros_expected
, size
) == 0);
388 static void test_fw_macros(void)
391 extern u8 ftr_fixup_test_FW_FTR_macros
;
392 extern u8 ftr_fixup_test_FW_FTR_macros_expected
;
393 unsigned long size
= &ftr_fixup_test_FW_FTR_macros_expected
-
394 &ftr_fixup_test_FW_FTR_macros
;
396 /* The fixups have already been done for us during boot */
397 check(memcmp(&ftr_fixup_test_FW_FTR_macros
,
398 &ftr_fixup_test_FW_FTR_macros_expected
, size
) == 0);
402 static void test_lwsync_macros(void)
404 extern u8 lwsync_fixup_test
;
405 extern u8 end_lwsync_fixup_test
;
406 extern u8 lwsync_fixup_test_expected_LWSYNC
;
407 extern u8 lwsync_fixup_test_expected_SYNC
;
408 unsigned long size
= &end_lwsync_fixup_test
-
411 /* The fixups have already been done for us during boot */
412 if (cur_cpu_spec
->cpu_features
& CPU_FTR_LWSYNC
) {
413 check(memcmp(&lwsync_fixup_test
,
414 &lwsync_fixup_test_expected_LWSYNC
, size
) == 0);
416 check(memcmp(&lwsync_fixup_test
,
417 &lwsync_fixup_test_expected_SYNC
, size
) == 0);
421 static int __init
test_feature_fixups(void)
423 printk(KERN_DEBUG
"Running feature fixup self-tests ...\n");
425 test_basic_patching();
426 test_alternative_patching();
427 test_alternative_case_too_big();
428 test_alternative_case_too_small();
429 test_alternative_case_with_branch();
430 test_alternative_case_with_external_branch();
433 test_lwsync_macros();
437 late_initcall(test_feature_fixups
);
439 #endif /* CONFIG_FTR_FIXUP_SELFTEST */