From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/riscv/kernel/cpufeature.c | 732 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 732 insertions(+) create mode 100644 arch/riscv/kernel/cpufeature.c (limited to 'arch/riscv/kernel/cpufeature.c') diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c new file mode 100644 index 0000000000..e12cd22755 --- /dev/null +++ b/arch/riscv/kernel/cpufeature.c @@ -0,0 +1,732 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copied from arch/arm64/kernel/cpufeature.c + * + * Copyright (C) 2015 ARM Ltd. + * Copyright (C) 2017 SiFive + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "copy-unaligned.h" + +#define NUM_ALPHA_EXTS ('z' - 'a' + 1) + +#define MISALIGNED_ACCESS_JIFFIES_LG2 1 +#define MISALIGNED_BUFFER_SIZE 0x4000 +#define MISALIGNED_COPY_SIZE ((MISALIGNED_BUFFER_SIZE / 2) - 0x80) + +unsigned long elf_hwcap __read_mostly; + +/* Host ISA bitmap */ +static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly; + +/* Per-cpu ISA extensions. */ +struct riscv_isainfo hart_isa[NR_CPUS]; + +/* Performance information */ +DEFINE_PER_CPU(long, misaligned_access_speed); + +/** + * riscv_isa_extension_base() - Get base extension word + * + * @isa_bitmap: ISA bitmap to use + * Return: base extension word as unsigned long value + * + * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used. + */ +unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap) +{ + if (!isa_bitmap) + return riscv_isa[0]; + return isa_bitmap[0]; +} +EXPORT_SYMBOL_GPL(riscv_isa_extension_base); + +/** + * __riscv_isa_extension_available() - Check whether given extension + * is available or not + * + * @isa_bitmap: ISA bitmap to use + * @bit: bit position of the desired extension + * Return: true or false + * + * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used. + */ +bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit) +{ + const unsigned long *bmap = (isa_bitmap) ? isa_bitmap : riscv_isa; + + if (bit >= RISCV_ISA_EXT_MAX) + return false; + + return test_bit(bit, bmap) ? true : false; +} +EXPORT_SYMBOL_GPL(__riscv_isa_extension_available); + +static bool riscv_isa_extension_check(int id) +{ + switch (id) { + case RISCV_ISA_EXT_ZICBOM: + if (!riscv_cbom_block_size) { + pr_err("Zicbom detected in ISA string, disabling as no cbom-block-size found\n"); + return false; + } else if (!is_power_of_2(riscv_cbom_block_size)) { + pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n"); + return false; + } + return true; + case RISCV_ISA_EXT_ZICBOZ: + if (!riscv_cboz_block_size) { + pr_err("Zicboz detected in ISA string, but no cboz-block-size found\n"); + return false; + } else if (!is_power_of_2(riscv_cboz_block_size)) { + pr_err("cboz-block-size present, but is not a power-of-2\n"); + return false; + } + return true; + } + + return true; +} + +#define __RISCV_ISA_EXT_DATA(_name, _id) { \ + .name = #_name, \ + .property = #_name, \ + .id = _id, \ +} + +/* + * The canonical order of ISA extension names in the ISA string is defined in + * chapter 27 of the unprivileged specification. + * + * Ordinarily, for in-kernel data structures, this order is unimportant but + * isa_ext_arr defines the order of the ISA string in /proc/cpuinfo. + * + * The specification uses vague wording, such as should, when it comes to + * ordering, so for our purposes the following rules apply: + * + * 1. All multi-letter extensions must be separated from other extensions by an + * underscore. + * + * 2. Additional standard extensions (starting with 'Z') must be sorted after + * single-letter extensions and before any higher-privileged extensions. + * + * 3. The first letter following the 'Z' conventionally indicates the most + * closely related alphabetical extension category, IMAFDQLCBKJTPVH. + * If multiple 'Z' extensions are named, they must be ordered first by + * category, then alphabetically within a category. + * + * 3. Standard supervisor-level extensions (starting with 'S') must be listed + * after standard unprivileged extensions. If multiple supervisor-level + * extensions are listed, they must be ordered alphabetically. + * + * 4. Standard machine-level extensions (starting with 'Zxm') must be listed + * after any lower-privileged, standard extensions. If multiple + * machine-level extensions are listed, they must be ordered + * alphabetically. + * + * 5. Non-standard extensions (starting with 'X') must be listed after all + * standard extensions. If multiple non-standard extensions are listed, they + * must be ordered alphabetically. + * + * An example string following the order is: + * rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux + * + * New entries to this struct should follow the ordering rules described above. + */ +const struct riscv_isa_ext_data riscv_isa_ext[] = { + __RISCV_ISA_EXT_DATA(i, RISCV_ISA_EXT_i), + __RISCV_ISA_EXT_DATA(m, RISCV_ISA_EXT_m), + __RISCV_ISA_EXT_DATA(a, RISCV_ISA_EXT_a), + __RISCV_ISA_EXT_DATA(f, RISCV_ISA_EXT_f), + __RISCV_ISA_EXT_DATA(d, RISCV_ISA_EXT_d), + __RISCV_ISA_EXT_DATA(q, RISCV_ISA_EXT_q), + __RISCV_ISA_EXT_DATA(c, RISCV_ISA_EXT_c), + __RISCV_ISA_EXT_DATA(b, RISCV_ISA_EXT_b), + __RISCV_ISA_EXT_DATA(k, RISCV_ISA_EXT_k), + __RISCV_ISA_EXT_DATA(j, RISCV_ISA_EXT_j), + __RISCV_ISA_EXT_DATA(p, RISCV_ISA_EXT_p), + __RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v), + __RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h), + __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM), + __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ), + __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR), + __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR), + __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI), + __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE), + __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM), + __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), + __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), + __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS), + __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), + __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), + __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), + __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), + __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL), + __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT), + __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT), +}; + +const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext); + +static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct riscv_isainfo *isainfo, + unsigned long *isa2hwcap, const char *isa) +{ + /* + * For all possible cpus, we have already validated in + * the boot process that they at least contain "rv" and + * whichever of "32"/"64" this kernel supports, and so this + * section can be skipped. + */ + isa += 4; + + while (*isa) { + const char *ext = isa++; + const char *ext_end = isa; + bool ext_long = false, ext_err = false; + + switch (*ext) { + case 's': + /* + * Workaround for invalid single-letter 's' & 'u'(QEMU). + * No need to set the bit in riscv_isa as 's' & 'u' are + * not valid ISA extensions. It works until multi-letter + * extension starting with "Su" appears. + */ + if (ext[-1] != '_' && ext[1] == 'u') { + ++isa; + ext_err = true; + break; + } + fallthrough; + case 'S': + case 'x': + case 'X': + case 'z': + case 'Z': + /* + * Before attempting to parse the extension itself, we find its end. + * As multi-letter extensions must be split from other multi-letter + * extensions with an "_", the end of a multi-letter extension will + * either be the null character or the "_" at the start of the next + * multi-letter extension. + * + * Next, as the extensions version is currently ignored, we + * eliminate that portion. This is done by parsing backwards from + * the end of the extension, removing any numbers. This may be a + * major or minor number however, so the process is repeated if a + * minor number was found. + * + * ext_end is intended to represent the first character *after* the + * name portion of an extension, but will be decremented to the last + * character itself while eliminating the extensions version number. + * A simple re-increment solves this problem. + */ + ext_long = true; + for (; *isa && *isa != '_'; ++isa) + if (unlikely(!isalnum(*isa))) + ext_err = true; + + ext_end = isa; + if (unlikely(ext_err)) + break; + + if (!isdigit(ext_end[-1])) + break; + + while (isdigit(*--ext_end)) + ; + + if (tolower(ext_end[0]) != 'p' || !isdigit(ext_end[-1])) { + ++ext_end; + break; + } + + while (isdigit(*--ext_end)) + ; + + ++ext_end; + break; + default: + /* + * Things are a little easier for single-letter extensions, as they + * are parsed forwards. + * + * After checking that our starting position is valid, we need to + * ensure that, when isa was incremented at the start of the loop, + * that it arrived at the start of the next extension. + * + * If we are already on a non-digit, there is nothing to do. Either + * we have a multi-letter extension's _, or the start of an + * extension. + * + * Otherwise we have found the current extension's major version + * number. Parse past it, and a subsequent p/minor version number + * if present. The `p` extension must not appear immediately after + * a number, so there is no fear of missing it. + * + */ + if (unlikely(!isalpha(*ext))) { + ext_err = true; + break; + } + + if (!isdigit(*isa)) + break; + + while (isdigit(*++isa)) + ; + + if (tolower(*isa) != 'p') + break; + + if (!isdigit(*++isa)) { + --isa; + break; + } + + while (isdigit(*++isa)) + ; + + break; + } + + /* + * The parser expects that at the start of an iteration isa points to the + * first character of the next extension. As we stop parsing an extension + * on meeting a non-alphanumeric character, an extra increment is needed + * where the succeeding extension is a multi-letter prefixed with an "_". + */ + if (*isa == '_') + ++isa; + +#define SET_ISA_EXT_MAP(name, bit) \ + do { \ + if ((ext_end - ext == strlen(name)) && \ + !strncasecmp(ext, name, strlen(name)) && \ + riscv_isa_extension_check(bit)) \ + set_bit(bit, isainfo->isa); \ + } while (false) \ + + if (unlikely(ext_err)) + continue; + if (!ext_long) { + int nr = tolower(*ext) - 'a'; + + if (riscv_isa_extension_check(nr)) { + *this_hwcap |= isa2hwcap[nr]; + set_bit(nr, isainfo->isa); + } + } else { + for (int i = 0; i < riscv_isa_ext_count; i++) + SET_ISA_EXT_MAP(riscv_isa_ext[i].name, + riscv_isa_ext[i].id); + } +#undef SET_ISA_EXT_MAP + } +} + +static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) +{ + struct device_node *node; + const char *isa; + int rc; + struct acpi_table_header *rhct; + acpi_status status; + unsigned int cpu; + + if (!acpi_disabled) { + status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct); + if (ACPI_FAILURE(status)) + return; + } + + for_each_possible_cpu(cpu) { + struct riscv_isainfo *isainfo = &hart_isa[cpu]; + unsigned long this_hwcap = 0; + + if (acpi_disabled) { + node = of_cpu_device_node_get(cpu); + if (!node) { + pr_warn("Unable to find cpu node\n"); + continue; + } + + rc = of_property_read_string(node, "riscv,isa", &isa); + of_node_put(node); + if (rc) { + pr_warn("Unable to find \"riscv,isa\" devicetree entry\n"); + continue; + } + } else { + rc = acpi_get_riscv_isa(rhct, cpu, &isa); + if (rc < 0) { + pr_warn("Unable to get ISA for the hart - %d\n", cpu); + continue; + } + } + + riscv_parse_isa_string(&this_hwcap, isainfo, isa2hwcap, isa); + + /* + * These ones were as they were part of the base ISA when the + * port & dt-bindings were upstreamed, and so can be set + * unconditionally where `i` is in riscv,isa on DT systems. + */ + if (acpi_disabled) { + set_bit(RISCV_ISA_EXT_ZICSR, isainfo->isa); + set_bit(RISCV_ISA_EXT_ZIFENCEI, isainfo->isa); + set_bit(RISCV_ISA_EXT_ZICNTR, isainfo->isa); + set_bit(RISCV_ISA_EXT_ZIHPM, isainfo->isa); + } + + /* + * All "okay" hart should have same isa. Set HWCAP based on + * common capabilities of every "okay" hart, in case they don't + * have. + */ + if (elf_hwcap) + elf_hwcap &= this_hwcap; + else + elf_hwcap = this_hwcap; + + if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) + bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); + else + bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); + } + + if (!acpi_disabled && rhct) + acpi_put_table((struct acpi_table_header *)rhct); +} + +static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) { + unsigned long this_hwcap = 0; + struct device_node *cpu_node; + struct riscv_isainfo *isainfo = &hart_isa[cpu]; + + cpu_node = of_cpu_device_node_get(cpu); + if (!cpu_node) { + pr_warn("Unable to find cpu node\n"); + continue; + } + + if (!of_property_present(cpu_node, "riscv,isa-extensions")) { + of_node_put(cpu_node); + continue; + } + + for (int i = 0; i < riscv_isa_ext_count; i++) { + if (of_property_match_string(cpu_node, "riscv,isa-extensions", + riscv_isa_ext[i].property) < 0) + continue; + + if (!riscv_isa_extension_check(riscv_isa_ext[i].id)) + continue; + + /* Only single letter extensions get set in hwcap */ + if (strnlen(riscv_isa_ext[i].name, 2) == 1) + this_hwcap |= isa2hwcap[riscv_isa_ext[i].id]; + + set_bit(riscv_isa_ext[i].id, isainfo->isa); + } + + of_node_put(cpu_node); + + /* + * All "okay" harts should have same isa. Set HWCAP based on + * common capabilities of every "okay" hart, in case they don't. + */ + if (elf_hwcap) + elf_hwcap &= this_hwcap; + else + elf_hwcap = this_hwcap; + + if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) + bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); + else + bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); + } + + if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) + return -ENOENT; + + return 0; +} + +#ifdef CONFIG_RISCV_ISA_FALLBACK +bool __initdata riscv_isa_fallback = true; +#else +bool __initdata riscv_isa_fallback; +static int __init riscv_isa_fallback_setup(char *__unused) +{ + riscv_isa_fallback = true; + return 1; +} +early_param("riscv_isa_fallback", riscv_isa_fallback_setup); +#endif + +void __init riscv_fill_hwcap(void) +{ + char print_str[NUM_ALPHA_EXTS + 1]; + unsigned long isa2hwcap[26] = {0}; + int i, j; + + isa2hwcap['i' - 'a'] = COMPAT_HWCAP_ISA_I; + isa2hwcap['m' - 'a'] = COMPAT_HWCAP_ISA_M; + isa2hwcap['a' - 'a'] = COMPAT_HWCAP_ISA_A; + isa2hwcap['f' - 'a'] = COMPAT_HWCAP_ISA_F; + isa2hwcap['d' - 'a'] = COMPAT_HWCAP_ISA_D; + isa2hwcap['c' - 'a'] = COMPAT_HWCAP_ISA_C; + isa2hwcap['v' - 'a'] = COMPAT_HWCAP_ISA_V; + + if (!acpi_disabled) { + riscv_fill_hwcap_from_isa_string(isa2hwcap); + } else { + int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); + + if (ret && riscv_isa_fallback) { + pr_info("Falling back to deprecated \"riscv,isa\"\n"); + riscv_fill_hwcap_from_isa_string(isa2hwcap); + } + } + + /* + * We don't support systems with F but without D, so mask those out + * here. + */ + if ((elf_hwcap & COMPAT_HWCAP_ISA_F) && !(elf_hwcap & COMPAT_HWCAP_ISA_D)) { + pr_info("This kernel does not support systems with F but not D\n"); + elf_hwcap &= ~COMPAT_HWCAP_ISA_F; + } + + if (elf_hwcap & COMPAT_HWCAP_ISA_V) { + riscv_v_setup_vsize(); + /* + * ISA string in device tree might have 'v' flag, but + * CONFIG_RISCV_ISA_V is disabled in kernel. + * Clear V flag in elf_hwcap if CONFIG_RISCV_ISA_V is disabled. + */ + if (!IS_ENABLED(CONFIG_RISCV_ISA_V)) + elf_hwcap &= ~COMPAT_HWCAP_ISA_V; + } + + memset(print_str, 0, sizeof(print_str)); + for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++) + if (riscv_isa[0] & BIT_MASK(i)) + print_str[j++] = (char)('a' + i); + pr_info("riscv: base ISA extensions %s\n", print_str); + + memset(print_str, 0, sizeof(print_str)); + for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++) + if (elf_hwcap & BIT_MASK(i)) + print_str[j++] = (char)('a' + i); + pr_info("riscv: ELF capabilities %s\n", print_str); +} + +unsigned long riscv_get_elf_hwcap(void) +{ + unsigned long hwcap; + + hwcap = (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)); + + if (!riscv_v_vstate_ctrl_user_allowed()) + hwcap &= ~COMPAT_HWCAP_ISA_V; + + return hwcap; +} + +void check_unaligned_access(int cpu) +{ + u64 start_cycles, end_cycles; + u64 word_cycles; + u64 byte_cycles; + int ratio; + unsigned long start_jiffies, now; + struct page *page; + void *dst; + void *src; + long speed = RISCV_HWPROBE_MISALIGNED_SLOW; + + /* We are already set since the last check */ + if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN) + return; + + page = alloc_pages(GFP_NOWAIT, get_order(MISALIGNED_BUFFER_SIZE)); + if (!page) { + pr_warn("Can't alloc pages to measure memcpy performance"); + return; + } + + /* Make an unaligned destination buffer. */ + dst = (void *)((unsigned long)page_address(page) | 0x1); + /* Unalign src as well, but differently (off by 1 + 2 = 3). */ + src = dst + (MISALIGNED_BUFFER_SIZE / 2); + src += 2; + word_cycles = -1ULL; + /* Do a warmup. */ + __riscv_copy_words_unaligned(dst, src, MISALIGNED_COPY_SIZE); + preempt_disable(); + start_jiffies = jiffies; + while ((now = jiffies) == start_jiffies) + cpu_relax(); + + /* + * For a fixed amount of time, repeatedly try the function, and take + * the best time in cycles as the measurement. + */ + while (time_before(jiffies, now + (1 << MISALIGNED_ACCESS_JIFFIES_LG2))) { + start_cycles = get_cycles64(); + /* Ensure the CSR read can't reorder WRT to the copy. */ + mb(); + __riscv_copy_words_unaligned(dst, src, MISALIGNED_COPY_SIZE); + /* Ensure the copy ends before the end time is snapped. */ + mb(); + end_cycles = get_cycles64(); + if ((end_cycles - start_cycles) < word_cycles) + word_cycles = end_cycles - start_cycles; + } + + byte_cycles = -1ULL; + __riscv_copy_bytes_unaligned(dst, src, MISALIGNED_COPY_SIZE); + start_jiffies = jiffies; + while ((now = jiffies) == start_jiffies) + cpu_relax(); + + while (time_before(jiffies, now + (1 << MISALIGNED_ACCESS_JIFFIES_LG2))) { + start_cycles = get_cycles64(); + mb(); + __riscv_copy_bytes_unaligned(dst, src, MISALIGNED_COPY_SIZE); + mb(); + end_cycles = get_cycles64(); + if ((end_cycles - start_cycles) < byte_cycles) + byte_cycles = end_cycles - start_cycles; + } + + preempt_enable(); + + /* Don't divide by zero. */ + if (!word_cycles || !byte_cycles) { + pr_warn("cpu%d: rdtime lacks granularity needed to measure unaligned access speed\n", + cpu); + + goto out; + } + + if (word_cycles < byte_cycles) + speed = RISCV_HWPROBE_MISALIGNED_FAST; + + ratio = div_u64((byte_cycles * 100), word_cycles); + pr_info("cpu%d: Ratio of byte access time to unaligned word access is %d.%02d, unaligned accesses are %s\n", + cpu, + ratio / 100, + ratio % 100, + (speed == RISCV_HWPROBE_MISALIGNED_FAST) ? "fast" : "slow"); + + per_cpu(misaligned_access_speed, cpu) = speed; + +out: + __free_pages(page, get_order(MISALIGNED_BUFFER_SIZE)); +} + +static int check_unaligned_access_boot_cpu(void) +{ + check_unaligned_access(0); + return 0; +} + +arch_initcall(check_unaligned_access_boot_cpu); + +#ifdef CONFIG_RISCV_ALTERNATIVE +/* + * Alternative patch sites consider 48 bits when determining when to patch + * the old instruction sequence with the new. These bits are broken into a + * 16-bit vendor ID and a 32-bit patch ID. A non-zero vendor ID means the + * patch site is for an erratum, identified by the 32-bit patch ID. When + * the vendor ID is zero, the patch site is for a cpufeature. cpufeatures + * further break down patch ID into two 16-bit numbers. The lower 16 bits + * are the cpufeature ID and the upper 16 bits are used for a value specific + * to the cpufeature and patch site. If the upper 16 bits are zero, then it + * implies no specific value is specified. cpufeatures that want to control + * patching on a per-site basis will provide non-zero values and implement + * checks here. The checks return true when patching should be done, and + * false otherwise. + */ +static bool riscv_cpufeature_patch_check(u16 id, u16 value) +{ + if (!value) + return true; + + switch (id) { + case RISCV_ISA_EXT_ZICBOZ: + /* + * Zicboz alternative applications provide the maximum + * supported block size order, or zero when it doesn't + * matter. If the current block size exceeds the maximum, + * then the alternative cannot be applied. + */ + return riscv_cboz_block_size <= (1U << value); + } + + return false; +} + +void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, + struct alt_entry *end, + unsigned int stage) +{ + struct alt_entry *alt; + void *oldptr, *altptr; + u16 id, value; + + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + return; + + for (alt = begin; alt < end; alt++) { + if (alt->vendor_id != 0) + continue; + + id = PATCH_ID_CPUFEATURE_ID(alt->patch_id); + + if (id >= RISCV_ISA_EXT_MAX) { + WARN(1, "This extension id:%d is not in ISA extension list", id); + continue; + } + + if (!__riscv_isa_extension_available(NULL, id)) + continue; + + value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id); + if (!riscv_cpufeature_patch_check(id, value)) + continue; + + oldptr = ALT_OLD_PTR(alt); + altptr = ALT_ALT_PTR(alt); + + mutex_lock(&text_mutex); + patch_text_nosync(oldptr, altptr, alt->alt_len); + riscv_alternative_fix_offsets(oldptr, alt->alt_len, oldptr - altptr); + mutex_unlock(&text_mutex); + } +} +#endif -- cgit v1.2.3