diff options
Diffstat (limited to 'arch/riscv/kernel/cpufeature.c')
| -rw-r--r-- | arch/riscv/kernel/cpufeature.c | 83 |
1 files changed, 80 insertions, 3 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index a5ad00043104..ac202f44a670 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -6,6 +6,7 @@ * Copyright (C) 2017 SiFive */ +#include <linux/bitmap.h> #include <linux/of.h> #include <asm/processor.h> #include <asm/hwcap.h> @@ -13,15 +14,57 @@ #include <asm/switch_to.h> unsigned long elf_hwcap __read_mostly; + +/* Host ISA bitmap */ +static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly; + #ifdef CONFIG_FPU bool has_fpu __read_mostly; #endif +/** + * 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); + void riscv_fill_hwcap(void) { struct device_node *node; const char *isa; - size_t i; + char print_str[BITS_PER_LONG + 1]; + size_t i, j, isa_len; static unsigned long isa2hwcap[256] = {0}; isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I; @@ -33,8 +76,11 @@ void riscv_fill_hwcap(void) elf_hwcap = 0; + bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX); + for_each_of_cpu_node(node) { unsigned long this_hwcap = 0; + unsigned long this_isa = 0; if (riscv_of_processor_hartid(node) < 0) continue; @@ -44,8 +90,24 @@ void riscv_fill_hwcap(void) continue; } - for (i = 0; i < strlen(isa); ++i) + i = 0; + isa_len = strlen(isa); +#if IS_ENABLED(CONFIG_32BIT) + if (!strncmp(isa, "rv32", 4)) + i += 4; +#elif IS_ENABLED(CONFIG_64BIT) + if (!strncmp(isa, "rv64", 4)) + i += 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')); + } /* * All "okay" hart should have same isa. Set HWCAP based on @@ -56,6 +118,11 @@ void riscv_fill_hwcap(void) elf_hwcap &= this_hwcap; else elf_hwcap = this_hwcap; + + if (riscv_isa[0]) + riscv_isa[0] &= this_isa; + else + riscv_isa[0] = this_isa; } /* We don't support systems with F but without D, so mask those out @@ -65,7 +132,17 @@ void riscv_fill_hwcap(void) elf_hwcap &= ~COMPAT_HWCAP_ISA_F; } - pr_info("elf_hwcap is 0x%lx\n", elf_hwcap); + memset(print_str, 0, sizeof(print_str)); + for (i = 0, j = 0; i < BITS_PER_LONG; i++) + if (riscv_isa[0] & BIT_MASK(i)) + print_str[j++] = (char)('a' + i); + pr_info("riscv: ISA extensions %s\n", print_str); + + memset(print_str, 0, sizeof(print_str)); + for (i = 0, j = 0; i < BITS_PER_LONG; i++) + if (elf_hwcap & BIT_MASK(i)) + print_str[j++] = (char)('a' + i); + pr_info("riscv: ELF capabilities %s\n", print_str); #ifdef CONFIG_FPU if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D)) |