diff options
Diffstat (limited to 'arch/riscv/kernel/cpufeature.c')
| -rw-r--r-- | arch/riscv/kernel/cpufeature.c | 130 |
1 files changed, 109 insertions, 21 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index d959d207a40d..1b2d42d7f589 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -7,12 +7,15 @@ */ #include <linux/bitmap.h> +#include <linux/ctype.h> #include <linux/of.h> #include <asm/processor.h> #include <asm/hwcap.h> #include <asm/smp.h> #include <asm/switch_to.h> +#define NUM_ALPHA_EXTS ('z' - 'a' + 1) + unsigned long elf_hwcap __read_mostly; /* Host ISA bitmap */ @@ -63,8 +66,8 @@ void __init riscv_fill_hwcap(void) { struct device_node *node; const char *isa; - char print_str[BITS_PER_LONG + 1]; - size_t i, j, isa_len; + char print_str[NUM_ALPHA_EXTS + 1]; + int i, j; static unsigned long isa2hwcap[256] = {0}; isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I; @@ -80,7 +83,8 @@ void __init riscv_fill_hwcap(void) for_each_of_cpu_node(node) { unsigned long this_hwcap = 0; - unsigned long this_isa = 0; + DECLARE_BITMAP(this_isa, RISCV_ISA_EXT_MAX); + const char *temp; if (riscv_of_processor_hartid(node) < 0) continue; @@ -90,23 +94,106 @@ void __init riscv_fill_hwcap(void) continue; } - i = 0; - isa_len = strlen(isa); + temp = isa; #if IS_ENABLED(CONFIG_32BIT) if (!strncmp(isa, "rv32", 4)) - i += 4; + isa += 4; #elif IS_ENABLED(CONFIG_64BIT) if (!strncmp(isa, "rv64", 4)) - i += 4; + isa += 4; #endif - for (; i < isa_len; ++i) { - this_hwcap |= isa2hwcap[(unsigned char)(isa[i])]; - /* - * TODO: X, Y and Z extension parsing for Host ISA - * bitmap will be added in-future. - */ - if ('a' <= isa[i] && isa[i] < 'x') - this_isa |= (1UL << (isa[i] - 'a')); + /* The riscv,isa DT property must start with rv64 or rv32 */ + if (temp == isa) + continue; + bitmap_zero(this_isa, RISCV_ISA_EXT_MAX); + for (; *isa; ++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 'x': + case 'z': + ext_long = true; + /* Multi-letter extension must be delimited */ + for (; *isa && *isa != '_'; ++isa) + if (unlikely(!islower(*isa) + && !isdigit(*isa))) + ext_err = true; + /* Parse backwards */ + ext_end = isa; + if (unlikely(ext_err)) + break; + if (!isdigit(ext_end[-1])) + break; + /* Skip the minor version */ + while (isdigit(*--ext_end)) + ; + if (ext_end[0] != 'p' + || !isdigit(ext_end[-1])) { + /* Advance it to offset the pre-decrement */ + ++ext_end; + break; + } + /* Skip the major version */ + while (isdigit(*--ext_end)) + ; + ++ext_end; + break; + default: + if (unlikely(!islower(*ext))) { + ext_err = true; + break; + } + /* Find next extension */ + if (!isdigit(*isa)) + break; + /* Skip the minor version */ + while (isdigit(*++isa)) + ; + if (*isa != 'p') + break; + if (!isdigit(*++isa)) { + --isa; + break; + } + /* Skip the major version */ + while (isdigit(*++isa)) + ; + break; + } + if (*isa != '_') + --isa; + +#define SET_ISA_EXT_MAP(name, bit) \ + do { \ + if ((ext_end - ext == sizeof(name) - 1) && \ + !memcmp(ext, name, sizeof(name) - 1)) \ + set_bit(bit, this_isa); \ + } while (false) \ + + if (unlikely(ext_err)) + continue; + if (!ext_long) { + this_hwcap |= isa2hwcap[(unsigned char)(*ext)]; + set_bit(*ext - 'a', this_isa); + } else { + SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF); + } +#undef SET_ISA_EXT_MAP } /* @@ -119,10 +206,11 @@ void __init riscv_fill_hwcap(void) else elf_hwcap = this_hwcap; - if (riscv_isa[0]) - riscv_isa[0] &= this_isa; + if (bitmap_weight(riscv_isa, RISCV_ISA_EXT_MAX)) + bitmap_and(riscv_isa, riscv_isa, this_isa, RISCV_ISA_EXT_MAX); else - riscv_isa[0] = this_isa; + bitmap_copy(riscv_isa, this_isa, RISCV_ISA_EXT_MAX); + } /* We don't support systems with F but without D, so mask those out @@ -133,13 +221,13 @@ void __init riscv_fill_hwcap(void) } memset(print_str, 0, sizeof(print_str)); - for (i = 0, j = 0; i < BITS_PER_LONG; i++) + 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: ISA extensions %s\n", print_str); + pr_info("riscv: base ISA extensions %s\n", print_str); memset(print_str, 0, sizeof(print_str)); - for (i = 0, j = 0; i < BITS_PER_LONG; i++) + 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); |