diff options
| -rw-r--r-- | arch/riscv/include/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/riscv/kernel/cpufeature.c | 78 |
2 files changed, 75 insertions, 4 deletions
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index a20e4ade1b53..e3cda14a486b 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -76,6 +76,7 @@ unsigned long riscv_get_elf_hwcap(void); struct riscv_isa_ext_data { const unsigned int id; const char *name; + const char *property; }; extern const struct riscv_isa_ext_data riscv_isa_ext[]; diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 7c661b12ac8d..fdc71e52dc2b 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -101,6 +101,7 @@ static bool riscv_isa_extension_check(int id) #define __RISCV_ISA_EXT_DATA(_name, _id) { \ .name = #_name, \ + .property = #_name, \ .id = _id, \ } @@ -414,11 +415,69 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) 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; +} + void __init riscv_fill_hwcap(void) { char print_str[NUM_ALPHA_EXTS + 1]; - int i, j; unsigned long isa2hwcap[26] = {0}; + int i, j; isa2hwcap['i' - 'a'] = COMPAT_HWCAP_ISA_I; isa2hwcap['m' - 'a'] = COMPAT_HWCAP_ISA_M; @@ -428,10 +487,21 @@ void __init riscv_fill_hwcap(void) isa2hwcap['c' - 'a'] = COMPAT_HWCAP_ISA_C; isa2hwcap['v' - 'a'] = COMPAT_HWCAP_ISA_V; - riscv_fill_hwcap_from_isa_string(isa2hwcap); + if (!acpi_disabled) { + riscv_fill_hwcap_from_isa_string(isa2hwcap); + } else { + int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); - /* We don't support systems with F but without D, so mask those out - * here. */ + if (ret) { + 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; |