1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copied from arch/arm64/kernel/cpufeature.c
5 * Copyright (C) 2015 ARM Ltd.
6 * Copyright (C) 2017 SiFive
9 #include <linux/acpi.h>
10 #include <linux/bitmap.h>
11 #include <linux/ctype.h>
12 #include <linux/log2.h>
13 #include <linux/memory.h>
14 #include <linux/module.h>
17 #include <asm/alternative.h>
18 #include <asm/cacheflush.h>
19 #include <asm/cpufeature.h>
20 #include <asm/hwcap.h>
21 #include <asm/hwprobe.h>
22 #include <asm/patch.h>
23 #include <asm/processor.h>
24 #include <asm/vector.h>
26 #include "copy-unaligned.h"
28 #define NUM_ALPHA_EXTS ('z' - 'a' + 1)
30 #define MISALIGNED_ACCESS_JIFFIES_LG2 1
31 #define MISALIGNED_BUFFER_SIZE 0x4000
32 #define MISALIGNED_COPY_SIZE ((MISALIGNED_BUFFER_SIZE / 2) - 0x80)
34 unsigned long elf_hwcap __read_mostly
;
37 static DECLARE_BITMAP(riscv_isa
, RISCV_ISA_EXT_MAX
) __read_mostly
;
39 /* Per-cpu ISA extensions. */
40 struct riscv_isainfo hart_isa
[NR_CPUS
];
42 /* Performance information */
43 DEFINE_PER_CPU(long, misaligned_access_speed
);
46 * riscv_isa_extension_base() - Get base extension word
48 * @isa_bitmap: ISA bitmap to use
49 * Return: base extension word as unsigned long value
51 * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
53 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap
)
59 EXPORT_SYMBOL_GPL(riscv_isa_extension_base
);
62 * __riscv_isa_extension_available() - Check whether given extension
65 * @isa_bitmap: ISA bitmap to use
66 * @bit: bit position of the desired extension
67 * Return: true or false
69 * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
71 bool __riscv_isa_extension_available(const unsigned long *isa_bitmap
, int bit
)
73 const unsigned long *bmap
= (isa_bitmap
) ? isa_bitmap
: riscv_isa
;
75 if (bit
>= RISCV_ISA_EXT_MAX
)
78 return test_bit(bit
, bmap
) ? true : false;
80 EXPORT_SYMBOL_GPL(__riscv_isa_extension_available
);
82 static bool riscv_isa_extension_check(int id
)
85 case RISCV_ISA_EXT_ZICBOM
:
86 if (!riscv_cbom_block_size
) {
87 pr_err("Zicbom detected in ISA string, disabling as no cbom-block-size found\n");
89 } else if (!is_power_of_2(riscv_cbom_block_size
)) {
90 pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n");
94 case RISCV_ISA_EXT_ZICBOZ
:
95 if (!riscv_cboz_block_size
) {
96 pr_err("Zicboz detected in ISA string, but no cboz-block-size found\n");
98 } else if (!is_power_of_2(riscv_cboz_block_size
)) {
99 pr_err("cboz-block-size present, but is not a power-of-2\n");
108 #define __RISCV_ISA_EXT_DATA(_name, _id) { \
110 .property = #_name, \
115 * The canonical order of ISA extension names in the ISA string is defined in
116 * chapter 27 of the unprivileged specification.
118 * Ordinarily, for in-kernel data structures, this order is unimportant but
119 * isa_ext_arr defines the order of the ISA string in /proc/cpuinfo.
121 * The specification uses vague wording, such as should, when it comes to
122 * ordering, so for our purposes the following rules apply:
124 * 1. All multi-letter extensions must be separated from other extensions by an
127 * 2. Additional standard extensions (starting with 'Z') must be sorted after
128 * single-letter extensions and before any higher-privileged extensions.
130 * 3. The first letter following the 'Z' conventionally indicates the most
131 * closely related alphabetical extension category, IMAFDQLCBKJTPVH.
132 * If multiple 'Z' extensions are named, they must be ordered first by
133 * category, then alphabetically within a category.
135 * 3. Standard supervisor-level extensions (starting with 'S') must be listed
136 * after standard unprivileged extensions. If multiple supervisor-level
137 * extensions are listed, they must be ordered alphabetically.
139 * 4. Standard machine-level extensions (starting with 'Zxm') must be listed
140 * after any lower-privileged, standard extensions. If multiple
141 * machine-level extensions are listed, they must be ordered
144 * 5. Non-standard extensions (starting with 'X') must be listed after all
145 * standard extensions. If multiple non-standard extensions are listed, they
146 * must be ordered alphabetically.
148 * An example string following the order is:
149 * rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux
151 * New entries to this struct should follow the ordering rules described above.
153 const struct riscv_isa_ext_data riscv_isa_ext
[] = {
154 __RISCV_ISA_EXT_DATA(i
, RISCV_ISA_EXT_i
),
155 __RISCV_ISA_EXT_DATA(m
, RISCV_ISA_EXT_m
),
156 __RISCV_ISA_EXT_DATA(a
, RISCV_ISA_EXT_a
),
157 __RISCV_ISA_EXT_DATA(f
, RISCV_ISA_EXT_f
),
158 __RISCV_ISA_EXT_DATA(d
, RISCV_ISA_EXT_d
),
159 __RISCV_ISA_EXT_DATA(q
, RISCV_ISA_EXT_q
),
160 __RISCV_ISA_EXT_DATA(c
, RISCV_ISA_EXT_c
),
161 __RISCV_ISA_EXT_DATA(b
, RISCV_ISA_EXT_b
),
162 __RISCV_ISA_EXT_DATA(k
, RISCV_ISA_EXT_k
),
163 __RISCV_ISA_EXT_DATA(j
, RISCV_ISA_EXT_j
),
164 __RISCV_ISA_EXT_DATA(p
, RISCV_ISA_EXT_p
),
165 __RISCV_ISA_EXT_DATA(v
, RISCV_ISA_EXT_v
),
166 __RISCV_ISA_EXT_DATA(h
, RISCV_ISA_EXT_h
),
167 __RISCV_ISA_EXT_DATA(zicbom
, RISCV_ISA_EXT_ZICBOM
),
168 __RISCV_ISA_EXT_DATA(zicboz
, RISCV_ISA_EXT_ZICBOZ
),
169 __RISCV_ISA_EXT_DATA(zicntr
, RISCV_ISA_EXT_ZICNTR
),
170 __RISCV_ISA_EXT_DATA(zicsr
, RISCV_ISA_EXT_ZICSR
),
171 __RISCV_ISA_EXT_DATA(zifencei
, RISCV_ISA_EXT_ZIFENCEI
),
172 __RISCV_ISA_EXT_DATA(zihintpause
, RISCV_ISA_EXT_ZIHINTPAUSE
),
173 __RISCV_ISA_EXT_DATA(zihpm
, RISCV_ISA_EXT_ZIHPM
),
174 __RISCV_ISA_EXT_DATA(zba
, RISCV_ISA_EXT_ZBA
),
175 __RISCV_ISA_EXT_DATA(zbb
, RISCV_ISA_EXT_ZBB
),
176 __RISCV_ISA_EXT_DATA(zbs
, RISCV_ISA_EXT_ZBS
),
177 __RISCV_ISA_EXT_DATA(smaia
, RISCV_ISA_EXT_SMAIA
),
178 __RISCV_ISA_EXT_DATA(ssaia
, RISCV_ISA_EXT_SSAIA
),
179 __RISCV_ISA_EXT_DATA(sscofpmf
, RISCV_ISA_EXT_SSCOFPMF
),
180 __RISCV_ISA_EXT_DATA(sstc
, RISCV_ISA_EXT_SSTC
),
181 __RISCV_ISA_EXT_DATA(svinval
, RISCV_ISA_EXT_SVINVAL
),
182 __RISCV_ISA_EXT_DATA(svnapot
, RISCV_ISA_EXT_SVNAPOT
),
183 __RISCV_ISA_EXT_DATA(svpbmt
, RISCV_ISA_EXT_SVPBMT
),
186 const size_t riscv_isa_ext_count
= ARRAY_SIZE(riscv_isa_ext
);
188 static void __init
riscv_parse_isa_string(unsigned long *this_hwcap
, struct riscv_isainfo
*isainfo
,
189 unsigned long *isa2hwcap
, const char *isa
)
192 * For all possible cpus, we have already validated in
193 * the boot process that they at least contain "rv" and
194 * whichever of "32"/"64" this kernel supports, and so this
195 * section can be skipped.
200 const char *ext
= isa
++;
201 const char *ext_end
= isa
;
202 bool ext_long
= false, ext_err
= false;
207 * Workaround for invalid single-letter 's' & 'u'(QEMU).
208 * No need to set the bit in riscv_isa as 's' & 'u' are
209 * not valid ISA extensions. It works until multi-letter
210 * extension starting with "Su" appears.
212 if (ext
[-1] != '_' && ext
[1] == 'u') {
224 * Before attempting to parse the extension itself, we find its end.
225 * As multi-letter extensions must be split from other multi-letter
226 * extensions with an "_", the end of a multi-letter extension will
227 * either be the null character or the "_" at the start of the next
228 * multi-letter extension.
230 * Next, as the extensions version is currently ignored, we
231 * eliminate that portion. This is done by parsing backwards from
232 * the end of the extension, removing any numbers. This may be a
233 * major or minor number however, so the process is repeated if a
234 * minor number was found.
236 * ext_end is intended to represent the first character *after* the
237 * name portion of an extension, but will be decremented to the last
238 * character itself while eliminating the extensions version number.
239 * A simple re-increment solves this problem.
242 for (; *isa
&& *isa
!= '_'; ++isa
)
243 if (unlikely(!isalnum(*isa
)))
247 if (unlikely(ext_err
))
250 if (!isdigit(ext_end
[-1]))
253 while (isdigit(*--ext_end
))
256 if (tolower(ext_end
[0]) != 'p' || !isdigit(ext_end
[-1])) {
261 while (isdigit(*--ext_end
))
268 * Things are a little easier for single-letter extensions, as they
269 * are parsed forwards.
271 * After checking that our starting position is valid, we need to
272 * ensure that, when isa was incremented at the start of the loop,
273 * that it arrived at the start of the next extension.
275 * If we are already on a non-digit, there is nothing to do. Either
276 * we have a multi-letter extension's _, or the start of an
279 * Otherwise we have found the current extension's major version
280 * number. Parse past it, and a subsequent p/minor version number
281 * if present. The `p` extension must not appear immediately after
282 * a number, so there is no fear of missing it.
285 if (unlikely(!isalpha(*ext
))) {
293 while (isdigit(*++isa
))
296 if (tolower(*isa
) != 'p')
299 if (!isdigit(*++isa
)) {
304 while (isdigit(*++isa
))
311 * The parser expects that at the start of an iteration isa points to the
312 * first character of the next extension. As we stop parsing an extension
313 * on meeting a non-alphanumeric character, an extra increment is needed
314 * where the succeeding extension is a multi-letter prefixed with an "_".
319 #define SET_ISA_EXT_MAP(name, bit) \
321 if ((ext_end - ext == strlen(name)) && \
322 !strncasecmp(ext, name, strlen(name)) && \
323 riscv_isa_extension_check(bit)) \
324 set_bit(bit, isainfo->isa); \
327 if (unlikely(ext_err))
330 int nr
= tolower(*ext
) - 'a';
332 if (riscv_isa_extension_check(nr
)) {
333 *this_hwcap
|= isa2hwcap
[nr
];
334 set_bit(nr
, isainfo
->isa
);
337 for (int i
= 0; i
< riscv_isa_ext_count
; i
++)
338 SET_ISA_EXT_MAP(riscv_isa_ext
[i
].name
,
339 riscv_isa_ext
[i
].id
);
341 #undef SET_ISA_EXT_MAP
345 static void __init
riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap
)
347 struct device_node
*node
;
350 struct acpi_table_header
*rhct
;
354 if (!acpi_disabled
) {
355 status
= acpi_get_table(ACPI_SIG_RHCT
, 0, &rhct
);
356 if (ACPI_FAILURE(status
))
360 for_each_possible_cpu(cpu
) {
361 struct riscv_isainfo
*isainfo
= &hart_isa
[cpu
];
362 unsigned long this_hwcap
= 0;
365 node
= of_cpu_device_node_get(cpu
);
367 pr_warn("Unable to find cpu node\n");
371 rc
= of_property_read_string(node
, "riscv,isa", &isa
);
374 pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
378 rc
= acpi_get_riscv_isa(rhct
, cpu
, &isa
);
380 pr_warn("Unable to get ISA for the hart - %d\n", cpu
);
385 riscv_parse_isa_string(&this_hwcap
, isainfo
, isa2hwcap
, isa
);
388 * These ones were as they were part of the base ISA when the
389 * port & dt-bindings were upstreamed, and so can be set
390 * unconditionally where `i` is in riscv,isa on DT systems.
393 set_bit(RISCV_ISA_EXT_ZICSR
, isainfo
->isa
);
394 set_bit(RISCV_ISA_EXT_ZIFENCEI
, isainfo
->isa
);
395 set_bit(RISCV_ISA_EXT_ZICNTR
, isainfo
->isa
);
396 set_bit(RISCV_ISA_EXT_ZIHPM
, isainfo
->isa
);
400 * All "okay" hart should have same isa. Set HWCAP based on
401 * common capabilities of every "okay" hart, in case they don't
405 elf_hwcap
&= this_hwcap
;
407 elf_hwcap
= this_hwcap
;
409 if (bitmap_empty(riscv_isa
, RISCV_ISA_EXT_MAX
))
410 bitmap_copy(riscv_isa
, isainfo
->isa
, RISCV_ISA_EXT_MAX
);
412 bitmap_and(riscv_isa
, riscv_isa
, isainfo
->isa
, RISCV_ISA_EXT_MAX
);
415 if (!acpi_disabled
&& rhct
)
416 acpi_put_table((struct acpi_table_header
*)rhct
);
419 static int __init
riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap
)
423 for_each_possible_cpu(cpu
) {
424 unsigned long this_hwcap
= 0;
425 struct device_node
*cpu_node
;
426 struct riscv_isainfo
*isainfo
= &hart_isa
[cpu
];
428 cpu_node
= of_cpu_device_node_get(cpu
);
430 pr_warn("Unable to find cpu node\n");
434 if (!of_property_present(cpu_node
, "riscv,isa-extensions")) {
435 of_node_put(cpu_node
);
439 for (int i
= 0; i
< riscv_isa_ext_count
; i
++) {
440 if (of_property_match_string(cpu_node
, "riscv,isa-extensions",
441 riscv_isa_ext
[i
].property
) < 0)
444 if (!riscv_isa_extension_check(riscv_isa_ext
[i
].id
))
447 /* Only single letter extensions get set in hwcap */
448 if (strnlen(riscv_isa_ext
[i
].name
, 2) == 1)
449 this_hwcap
|= isa2hwcap
[riscv_isa_ext
[i
].id
];
451 set_bit(riscv_isa_ext
[i
].id
, isainfo
->isa
);
454 of_node_put(cpu_node
);
457 * All "okay" harts should have same isa. Set HWCAP based on
458 * common capabilities of every "okay" hart, in case they don't.
461 elf_hwcap
&= this_hwcap
;
463 elf_hwcap
= this_hwcap
;
465 if (bitmap_empty(riscv_isa
, RISCV_ISA_EXT_MAX
))
466 bitmap_copy(riscv_isa
, isainfo
->isa
, RISCV_ISA_EXT_MAX
);
468 bitmap_and(riscv_isa
, riscv_isa
, isainfo
->isa
, RISCV_ISA_EXT_MAX
);
471 if (bitmap_empty(riscv_isa
, RISCV_ISA_EXT_MAX
))
477 #ifdef CONFIG_RISCV_ISA_FALLBACK
478 bool __initdata riscv_isa_fallback
= true;
480 bool __initdata riscv_isa_fallback
;
481 static int __init
riscv_isa_fallback_setup(char *__unused
)
483 riscv_isa_fallback
= true;
486 early_param("riscv_isa_fallback", riscv_isa_fallback_setup
);
489 void __init
riscv_fill_hwcap(void)
491 char print_str
[NUM_ALPHA_EXTS
+ 1];
492 unsigned long isa2hwcap
[26] = {0};
495 isa2hwcap
['i' - 'a'] = COMPAT_HWCAP_ISA_I
;
496 isa2hwcap
['m' - 'a'] = COMPAT_HWCAP_ISA_M
;
497 isa2hwcap
['a' - 'a'] = COMPAT_HWCAP_ISA_A
;
498 isa2hwcap
['f' - 'a'] = COMPAT_HWCAP_ISA_F
;
499 isa2hwcap
['d' - 'a'] = COMPAT_HWCAP_ISA_D
;
500 isa2hwcap
['c' - 'a'] = COMPAT_HWCAP_ISA_C
;
501 isa2hwcap
['v' - 'a'] = COMPAT_HWCAP_ISA_V
;
503 if (!acpi_disabled
) {
504 riscv_fill_hwcap_from_isa_string(isa2hwcap
);
506 int ret
= riscv_fill_hwcap_from_ext_list(isa2hwcap
);
508 if (ret
&& riscv_isa_fallback
) {
509 pr_info("Falling back to deprecated \"riscv,isa\"\n");
510 riscv_fill_hwcap_from_isa_string(isa2hwcap
);
515 * We don't support systems with F but without D, so mask those out
518 if ((elf_hwcap
& COMPAT_HWCAP_ISA_F
) && !(elf_hwcap
& COMPAT_HWCAP_ISA_D
)) {
519 pr_info("This kernel does not support systems with F but not D\n");
520 elf_hwcap
&= ~COMPAT_HWCAP_ISA_F
;
523 if (elf_hwcap
& COMPAT_HWCAP_ISA_V
) {
524 riscv_v_setup_vsize();
526 * ISA string in device tree might have 'v' flag, but
527 * CONFIG_RISCV_ISA_V is disabled in kernel.
528 * Clear V flag in elf_hwcap if CONFIG_RISCV_ISA_V is disabled.
530 if (!IS_ENABLED(CONFIG_RISCV_ISA_V
))
531 elf_hwcap
&= ~COMPAT_HWCAP_ISA_V
;
534 memset(print_str
, 0, sizeof(print_str
));
535 for (i
= 0, j
= 0; i
< NUM_ALPHA_EXTS
; i
++)
536 if (riscv_isa
[0] & BIT_MASK(i
))
537 print_str
[j
++] = (char)('a' + i
);
538 pr_info("riscv: base ISA extensions %s\n", print_str
);
540 memset(print_str
, 0, sizeof(print_str
));
541 for (i
= 0, j
= 0; i
< NUM_ALPHA_EXTS
; i
++)
542 if (elf_hwcap
& BIT_MASK(i
))
543 print_str
[j
++] = (char)('a' + i
);
544 pr_info("riscv: ELF capabilities %s\n", print_str
);
547 unsigned long riscv_get_elf_hwcap(void)
551 hwcap
= (elf_hwcap
& ((1UL << RISCV_ISA_EXT_BASE
) - 1));
553 if (!riscv_v_vstate_ctrl_user_allowed())
554 hwcap
&= ~COMPAT_HWCAP_ISA_V
;
559 void check_unaligned_access(int cpu
)
561 u64 start_cycles
, end_cycles
;
565 unsigned long start_jiffies
, now
;
569 long speed
= RISCV_HWPROBE_MISALIGNED_SLOW
;
571 page
= alloc_pages(GFP_NOWAIT
, get_order(MISALIGNED_BUFFER_SIZE
));
573 pr_warn("Can't alloc pages to measure memcpy performance");
577 /* Make an unaligned destination buffer. */
578 dst
= (void *)((unsigned long)page_address(page
) | 0x1);
579 /* Unalign src as well, but differently (off by 1 + 2 = 3). */
580 src
= dst
+ (MISALIGNED_BUFFER_SIZE
/ 2);
584 __riscv_copy_words_unaligned(dst
, src
, MISALIGNED_COPY_SIZE
);
586 start_jiffies
= jiffies
;
587 while ((now
= jiffies
) == start_jiffies
)
591 * For a fixed amount of time, repeatedly try the function, and take
592 * the best time in cycles as the measurement.
594 while (time_before(jiffies
, now
+ (1 << MISALIGNED_ACCESS_JIFFIES_LG2
))) {
595 start_cycles
= get_cycles64();
596 /* Ensure the CSR read can't reorder WRT to the copy. */
598 __riscv_copy_words_unaligned(dst
, src
, MISALIGNED_COPY_SIZE
);
599 /* Ensure the copy ends before the end time is snapped. */
601 end_cycles
= get_cycles64();
602 if ((end_cycles
- start_cycles
) < word_cycles
)
603 word_cycles
= end_cycles
- start_cycles
;
607 __riscv_copy_bytes_unaligned(dst
, src
, MISALIGNED_COPY_SIZE
);
608 start_jiffies
= jiffies
;
609 while ((now
= jiffies
) == start_jiffies
)
612 while (time_before(jiffies
, now
+ (1 << MISALIGNED_ACCESS_JIFFIES_LG2
))) {
613 start_cycles
= get_cycles64();
615 __riscv_copy_bytes_unaligned(dst
, src
, MISALIGNED_COPY_SIZE
);
617 end_cycles
= get_cycles64();
618 if ((end_cycles
- start_cycles
) < byte_cycles
)
619 byte_cycles
= end_cycles
- start_cycles
;
624 /* Don't divide by zero. */
625 if (!word_cycles
|| !byte_cycles
) {
626 pr_warn("cpu%d: rdtime lacks granularity needed to measure unaligned access speed\n",
632 if (word_cycles
< byte_cycles
)
633 speed
= RISCV_HWPROBE_MISALIGNED_FAST
;
635 ratio
= div_u64((byte_cycles
* 100), word_cycles
);
636 pr_info("cpu%d: Ratio of byte access time to unaligned word access is %d.%02d, unaligned accesses are %s\n",
640 (speed
== RISCV_HWPROBE_MISALIGNED_FAST
) ? "fast" : "slow");
642 per_cpu(misaligned_access_speed
, cpu
) = speed
;
645 __free_pages(page
, get_order(MISALIGNED_BUFFER_SIZE
));
648 static int check_unaligned_access_boot_cpu(void)
650 check_unaligned_access(0);
654 arch_initcall(check_unaligned_access_boot_cpu
);
656 #ifdef CONFIG_RISCV_ALTERNATIVE
658 * Alternative patch sites consider 48 bits when determining when to patch
659 * the old instruction sequence with the new. These bits are broken into a
660 * 16-bit vendor ID and a 32-bit patch ID. A non-zero vendor ID means the
661 * patch site is for an erratum, identified by the 32-bit patch ID. When
662 * the vendor ID is zero, the patch site is for a cpufeature. cpufeatures
663 * further break down patch ID into two 16-bit numbers. The lower 16 bits
664 * are the cpufeature ID and the upper 16 bits are used for a value specific
665 * to the cpufeature and patch site. If the upper 16 bits are zero, then it
666 * implies no specific value is specified. cpufeatures that want to control
667 * patching on a per-site basis will provide non-zero values and implement
668 * checks here. The checks return true when patching should be done, and
671 static bool riscv_cpufeature_patch_check(u16 id
, u16 value
)
677 case RISCV_ISA_EXT_ZICBOZ
:
679 * Zicboz alternative applications provide the maximum
680 * supported block size order, or zero when it doesn't
681 * matter. If the current block size exceeds the maximum,
682 * then the alternative cannot be applied.
684 return riscv_cboz_block_size
<= (1U << value
);
690 void __init_or_module
riscv_cpufeature_patch_func(struct alt_entry
*begin
,
691 struct alt_entry
*end
,
694 struct alt_entry
*alt
;
695 void *oldptr
, *altptr
;
698 if (stage
== RISCV_ALTERNATIVES_EARLY_BOOT
)
701 for (alt
= begin
; alt
< end
; alt
++) {
702 if (alt
->vendor_id
!= 0)
705 id
= PATCH_ID_CPUFEATURE_ID(alt
->patch_id
);
707 if (id
>= RISCV_ISA_EXT_MAX
) {
708 WARN(1, "This extension id:%d is not in ISA extension list", id
);
712 if (!__riscv_isa_extension_available(NULL
, id
))
715 value
= PATCH_ID_CPUFEATURE_VALUE(alt
->patch_id
);
716 if (!riscv_cpufeature_patch_check(id
, value
))
719 oldptr
= ALT_OLD_PTR(alt
);
720 altptr
= ALT_ALT_PTR(alt
);
722 mutex_lock(&text_mutex
);
723 patch_text_nosync(oldptr
, altptr
, alt
->alt_len
);
724 riscv_alternative_fix_offsets(oldptr
, alt
->alt_len
, oldptr
- altptr
);
725 mutex_unlock(&text_mutex
);