diff options
| -rw-r--r-- | arch/riscv/kernel/cpu.c | 68 |
1 files changed, 61 insertions, 7 deletions
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index ca6c81e54e37..1c0bf6620e65 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -58,6 +58,63 @@ int riscv_of_processor_hart(struct device_node *node) #ifdef CONFIG_PROC_FS +static void print_isa(struct seq_file *f, const char *orig_isa) +{ + static const char *ext = "mafdc"; + const char *isa = orig_isa; + const char *e; + + /* + * Linux doesn't support rv32e or rv128i, and we only support booting + * kernels on harts with the same ISA that the kernel is compiled for. + */ +#if defined(CONFIG_32BIT) + if (strncmp(isa, "rv32i", 5) != 0) + return; +#elif defined(CONFIG_64BIT) + if (strncmp(isa, "rv64i", 5) != 0) + return; +#endif + + /* Print the base ISA, as we already know it's legal. */ + seq_puts(f, "isa\t: "); + seq_write(f, isa, 5); + isa += 5; + + /* + * Check the rest of the ISA string for valid extensions, printing those + * we find. RISC-V ISA strings define an order, so we only print the + * extension bits when they're in order. + */ + for (e = ext; *e != '\0'; ++e) { + if (isa[0] == e[0]) { + seq_write(f, isa, 1); + isa++; + } + } + + /* + * If we were given an unsupported ISA in the device tree then print + * a bit of info describing what went wrong. + */ + if (isa[0] != '\0') + pr_info("unsupported ISA \"%s\" in device tree", orig_isa); +} + +static void print_mmu(struct seq_file *f, const char *mmu_type) +{ +#if defined(CONFIG_32BIT) + if (strcmp(mmu_type, "riscv,sv32") != 0) + return; +#elif defined(CONFIG_64BIT) + if (strcmp(mmu_type, "riscv,sv39") != 0 && + strcmp(mmu_type, "riscv,sv48") != 0) + return; +#endif + + seq_printf(f, "mmu\t: %s\n", mmu_type+6); +} + static void *c_start(struct seq_file *m, loff_t *pos) { *pos = cpumask_next(*pos - 1, cpu_online_mask); @@ -83,13 +140,10 @@ static int c_show(struct seq_file *m, void *v) const char *compat, *isa, *mmu; seq_printf(m, "hart\t: %lu\n", hart_id); - if (!of_property_read_string(node, "riscv,isa", &isa) - && isa[0] == 'r' - && isa[1] == 'v') - seq_printf(m, "isa\t: %s\n", isa); - if (!of_property_read_string(node, "mmu-type", &mmu) - && !strncmp(mmu, "riscv,", 6)) - seq_printf(m, "mmu\t: %s\n", mmu+6); + if (!of_property_read_string(node, "riscv,isa", &isa)) + print_isa(m, isa); + if (!of_property_read_string(node, "mmu-type", &mmu)) + print_mmu(m, mmu); if (!of_property_read_string(node, "compatible", &compat) && strcmp(compat, "riscv")) seq_printf(m, "uarch\t: %s\n", compat); |