The riscv_cpuinfo struct that contains mvendorid and marchid is not populated until all harts are booted which happens after the DT parsing. Use the vendorid/archid values from the DT if available or assume all harts have the same values as the boot hart as a fallback.
Fixes: d82f32202e0d ("RISC-V: Ignore V from the riscv,isa DT property on older T-Head CPUs") Signed-off-by: Charlie Jenkins charlie@rivosinc.com --- arch/riscv/include/asm/sbi.h | 2 ++ arch/riscv/kernel/cpu.c | 36 ++++++++++++++++++++++++++++++++---- arch/riscv/kernel/cpufeature.c | 12 ++++++++++-- 3 files changed, 44 insertions(+), 6 deletions(-)
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 6e68f8dff76b..0fab508a65b3 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -370,6 +370,8 @@ static inline int sbi_remote_fence_i(const struct cpumask *cpu_mask) { return -1 static inline void sbi_init(void) {} #endif /* CONFIG_RISCV_SBI */
+unsigned long riscv_get_mvendorid(void); +unsigned long riscv_get_marchid(void); unsigned long riscv_cached_mvendorid(unsigned int cpu_id); unsigned long riscv_cached_marchid(unsigned int cpu_id); unsigned long riscv_cached_mimpid(unsigned int cpu_id); diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index d11d6320fb0d..8c8250b98752 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -139,6 +139,34 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid) return -1; }
+unsigned long __init riscv_get_marchid(void) +{ + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo); + +#if IS_ENABLED(CONFIG_RISCV_SBI) + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid(); +#elif IS_ENABLED(CONFIG_RISCV_M_MODE) + ci->marchid = csr_read(CSR_MARCHID); +#else + ci->marchid = 0; +#endif + return ci->marchid; +} + +unsigned long __init riscv_get_mvendorid(void) +{ + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo); + +#if IS_ENABLED(CONFIG_RISCV_SBI) + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid(); +#elif IS_ENABLED(CONFIG_RISCV_M_MODE) + ci->mvendorid = csr_read(CSR_MVENDORID); +#else + ci->mvendorid = 0; +#endif + return ci->mvendorid; +} + DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
unsigned long riscv_cached_mvendorid(unsigned int cpu_id) @@ -170,12 +198,12 @@ static int riscv_cpuinfo_starting(unsigned int cpu) struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
#if IS_ENABLED(CONFIG_RISCV_SBI) - ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid(); - ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid(); + ci->mvendorid = ci->mvendorid ? ci->mvendorid : sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid(); + ci->marchid = ci->marchid ? ci->marchid : sbi_spec_is_0_1() ? 0 : sbi_get_marchid(); ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid(); #elif IS_ENABLED(CONFIG_RISCV_M_MODE) - ci->mvendorid = csr_read(CSR_MVENDORID); - ci->marchid = csr_read(CSR_MARCHID); + ci->mvendorid = ci->mvendorid ? ci->mvendorid : csr_read(CSR_MVENDORID); + ci->marchid = ci->marchid ? ci->marchid : csr_read(CSR_MARCHID); ci->mimpid = csr_read(CSR_MIMPID); #else ci->mvendorid = 0; diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 3ed2359eae35..c6e27b45e192 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -490,6 +490,8 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) struct acpi_table_header *rhct; acpi_status status; unsigned int cpu; + u64 boot_vendorid; + u64 boot_archid;
if (!acpi_disabled) { status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct); @@ -497,6 +499,13 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) return; }
+ /* + * Naively assume that all harts have the same mvendorid/marchid as the + * boot hart. + */ + boot_vendorid = riscv_get_mvendorid(); + boot_archid = riscv_get_marchid(); + for_each_possible_cpu(cpu) { struct riscv_isainfo *isainfo = &hart_isa[cpu]; unsigned long this_hwcap = 0; @@ -544,8 +553,7 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) * CPU cores with the ratified spec will contain non-zero * marchid. */ - if (acpi_disabled && riscv_cached_mvendorid(cpu) == THEAD_VENDOR_ID && - riscv_cached_marchid(cpu) == 0x0) { + if (acpi_disabled && boot_vendorid == THEAD_VENDOR_ID && boot_archid == 0x0) { this_hwcap &= ~isa2hwcap[RISCV_ISA_EXT_v]; clear_bit(RISCV_ISA_EXT_v, isainfo->isa); }