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Diffstat (limited to 'arch/riscv/kernel/cpu.c')
-rw-r--r--arch/riscv/kernel/cpu.c87
1 files changed, 74 insertions, 13 deletions
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index ca6c81e54e37..3a5a2ee31547 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -14,9 +14,13 @@
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/of.h>
+#include <asm/smp.h>
-/* Return -1 if not a valid hart */
-int riscv_of_processor_hart(struct device_node *node)
+/*
+ * Returns the hart ID of the given device tree node, or -1 if the device tree
+ * node isn't a RISC-V hart.
+ */
+int riscv_of_processor_hartid(struct device_node *node)
{
const char *isa, *status;
u32 hart;
@@ -58,6 +62,64 @@ 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\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++;
+ }
+ }
+ seq_puts(f, "\n");
+
+ /*
+ * 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\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);
@@ -78,21 +140,20 @@ static void c_stop(struct seq_file *m, void *v)
static int c_show(struct seq_file *m, void *v)
{
- unsigned long hart_id = (unsigned long)v - 1;
- struct device_node *node = of_get_cpu_node(hart_id, NULL);
+ unsigned long cpu_id = (unsigned long)v - 1;
+ struct device_node *node = of_get_cpu_node(cpuid_to_hartid_map(cpu_id),
+ NULL);
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);
+ seq_printf(m, "processor\t: %lu\n", cpu_id);
+ seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
+ 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);
+ seq_printf(m, "uarch\t\t: %s\n", compat);
seq_puts(m, "\n");
return 0;