:: commit e847d6091044c6d972faf448e1bf2be178e5d77f
riscv: implement feature dectection
diff --git a/common/entry.s3.c b/common/entry.s3.c
index da91b4cc..56559a28 100644
--- a/common/entry.s3.c
+++ b/common/entry.s3.c
@@ -22,6 +22,7 @@
#include <drivers/disk.h>
#include <sys/lapic.h>
#include <lib/readline.h>
+#include <sys/cpu.h>
void stage3_common(void);
@@ -130,6 +131,18 @@ noreturn void stage3_common(void) {
init_io_apics();
#endif
+#if defined (__riscv)
+#if defined (UEFI)
+ RISCV_EFI_BOOT_PROTOCOL *rv_proto = get_riscv_boot_protocol();
+ if (rv_proto == NULL || rv_proto->GetBootHartId(rv_proto, &bsp_hartid) != EFI_SUCCESS) {
+ panic(false, "failed to get BSP's hartid");
+ }
+#else
+#error riscv: only UEFI is supported
+#endif
+ init_riscv();
+#endif
+
term_notready();
menu(true);
diff --git a/common/sys/cpu.h b/common/sys/cpu.h
index 12d48137..bd8609dd 100644
--- a/common/sys/cpu.h
+++ b/common/sys/cpu.h
@@ -320,6 +320,30 @@ inline uint64_t rdtsc(void) {
locked_read__ret; \
})
+extern size_t bsp_hartid;
+
+struct riscv_hart {
+ struct riscv_hart *next;
+ const char *isa_string;
+ size_t hartid;
+ uint32_t acpi_uid;
+ uint8_t mmu_type;
+ uint8_t flags;
+};
+
+#define RISCV_HART_COPROC ((uint8_t)1 << 0) // is a coprocessor
+#define RISCV_HART_HAS_MMU ((uint8_t)1 << 1) // `mmu_type` field is valid
+
+extern struct riscv_hart *hart_list;
+
+bool riscv_check_isa_extension_for(size_t hartid, const char *ext, size_t *maj, size_t *min);
+
+static inline bool riscv_check_isa_extension(const char *ext, size_t *maj, size_t *min) {
+ return riscv_check_isa_extension_for(bsp_hartid, ext, maj, min);
+}
+
+void init_riscv(void);
+
#else
#error Unknown architecture
#endif
diff --git a/common/sys/cpu_riscv.c b/common/sys/cpu_riscv.c
new file mode 100644
index 00000000..37dcff90
--- /dev/null
+++ b/common/sys/cpu_riscv.c
@@ -0,0 +1,255 @@
+
+#if defined(__riscv)
+
+#include <lib/acpi.h>
+#include <lib/misc.h>
+#include <lib/print.h>
+#include <mm/pmm.h>
+#include <stddef.h>
+#include <stdint.h>
+
+// ACPI RISC-V Hart Capabilities Table
+struct rhct {
+ struct sdt header;
+ uint32_t flags;
+ uint64_t time_base_frequency;
+ uint32_t nodes_len;
+ uint32_t nodes_offset;
+ uint8_t nodes[];
+} __attribute__((packed));
+
+#define RHCT_ISA_STRING 0
+#define RHCT_CMO 1
+#define RHCT_MMU 2
+#define RHCT_HART_INFO 65535
+
+struct rhct_header {
+ uint16_t type; // node type
+ uint16_t size; // node size (bytes)
+ uint16_t revision; // node revision
+} __attribute__((packed));
+
+// One `struct rhct_hart_info` structure exists per hart in the system.
+// The `offsets` array points to other entries in the RHCT associated with the
+// hart.
+struct rhct_hart_info {
+ struct rhct_header header;
+ uint16_t offsets_len;
+ uint32_t acpi_processor_uid;
+ uint32_t offsets[];
+} __attribute__((packed));
+
+struct rhct_isa_string {
+ struct rhct_header header;
+ uint16_t isa_string_len;
+ const char isa_string[];
+} __attribute__((packed));
+
+#define RISCV_MMU_TYPE_SV39 0
+#define RISCV_MMU_TYPE_SV48 1
+#define RISCV_MMU_TYPE_SV57 2
+
+struct rhct_mmu {
+ struct rhct_header header;
+ uint8_t reserved0;
+ uint8_t mmu_type;
+} __attribute__((packed));
+
+size_t bsp_hartid;
+struct riscv_hart *hart_list;
+static struct riscv_hart *bsp_hart;
+
+static struct riscv_hart *riscv_get_hart(size_t hartid) {
+ for (struct riscv_hart *hart = hart_list; hart != NULL; hart = hart->next) {
+ if (hart->hartid == hartid) {
+ return hart;
+ }
+ }
+ panic(false, "no `struct riscv_hart` for hartid %u", hartid);
+}
+
+static inline struct rhct_hart_info *rhct_get_hart_info(struct rhct *rhct, uint32_t acpi_uid) {
+ uint32_t offset = rhct->nodes_offset;
+ for (uint32_t i = 0; i < rhct->nodes_len; i++) {
+ struct rhct_hart_info *node = (void *)((uintptr_t)rhct + offset);
+ if (node->header.type == RHCT_HART_INFO && node->acpi_processor_uid == acpi_uid) {
+ return node;
+ }
+ offset += node->header.size;
+ }
+ return NULL;
+}
+
+void riscv_init(void) {
+ struct madt *madt = acpi_get_table("APIC", 0);
+ struct rhct *rhct = acpi_get_table("RHCT", 0);
+ if (madt == NULL || rhct == NULL) {
+ panic(false, "riscv: requires acpi");
+ }
+
+ for (uint8_t *madt_ptr = (uint8_t *)madt->madt_entries_begin;
+ (uintptr_t)madt_ptr < (uintptr_t)madt + madt->header.length; madt_ptr += *(madt_ptr + 1)) {
+ if (*madt_ptr != 0x18) {
+ continue;
+ }
+ struct madt_riscv_intc *intc = (struct madt_riscv_intc *)madt_ptr;
+
+ // Ignore harts we can't do anything with.
+ if (!(intc->flags & MADT_RISCV_INTC_ENABLED ||
+ intc->flags & MADT_RISCV_INTC_ONLINE_CAPABLE)) {
+ continue;
+ }
+
+ uint32_t acpi_uid = intc->acpi_processor_uid;
+ size_t hartid = intc->hartid;
+
+ struct rhct_hart_info *hart_info = rhct_get_hart_info(rhct, acpi_uid);
+ if (hart_info == NULL) {
+ panic(false, "riscv: missing rhct node for hartid %u", hartid);
+ }
+
+ const char *isa_string = NULL;
+ uint8_t mmu_type = 0;
+ uint8_t flags = 0;
+
+ for (uint32_t i = 0; i < hart_info->offsets_len; i++) {
+ const struct rhct_header *node = (void *)((uintptr_t)rhct + hart_info->offsets[i]);
+ switch (node->type) {
+ case RHCT_ISA_STRING:
+ isa_string = ((struct rhct_isa_string *)node)->isa_string;
+ break;
+ case RHCT_MMU:
+ mmu_type = ((struct rhct_mmu *)node)->mmu_type;
+ flags |= RISCV_HART_HAS_MMU;
+ break;
+ }
+ }
+
+ if (isa_string == NULL) {
+ print("riscv: missing isa string for hartid %u, skipping.\n", hartid);
+ continue;
+ }
+
+ struct riscv_hart *hart = ext_mem_alloc(sizeof(struct riscv_hart));
+ if (hart == NULL) {
+ panic(false, "out of memory");
+ }
+
+ hart->hartid = hartid;
+ hart->acpi_uid = acpi_uid;
+ hart->isa_string = isa_string;
+ hart->mmu_type = mmu_type;
+ hart->flags = flags;
+
+ hart->next = hart_list;
+ hart_list = hart;
+
+ if (hart->hartid == bsp_hartid) {
+ bsp_hart = hart;
+ }
+ }
+
+ if (bsp_hart == NULL) {
+ panic(false, "riscv: missing `struct riscv_hart` for BSP");
+ }
+
+ if (strncasecmp(bsp_hart->isa_string, "rv64i", 5)) {
+ panic(false, "unsupported cpu: %s", bsp_hart->isa_string);
+ }
+
+ for (struct riscv_hart *hart = hart_list; hart != NULL; hart = hart->next) {
+ if (hart != bsp_hart && strcmp(bsp_hart->isa_string, hart->isa_string)) {
+ hart->flags |= RISCV_HART_COPROC;
+ }
+ }
+}
+
+struct isa_extension {
+ const char *name;
+ size_t name_len;
+ uint32_t ver_maj;
+ uint32_t ver_min;
+};
+
+// Parse the next sequence of digit characters into an integer.
+static bool parse_number(const char **s, size_t *_n) {
+ size_t n = 0;
+ bool parsed = false;
+ while (isdigit(**s)) {
+ n *= 10;
+ n += *(*s)++ - '0';
+ parsed = true;
+ }
+ *_n = n;
+ return parsed;
+}
+
+// Parse the next extension from an ISA string.
+static bool parse_extension(const char **s, struct isa_extension *ext) {
+ if (**s == '\0') {
+ return false;
+ }
+
+ const char *name = *s;
+ size_t name_len = 1;
+ if (**s == 's' || **s == 'S' || **s == 'x' || **s == 'X' || **s == 'z' || **s == 'Z') {
+ while (isalpha((*s)[name_len])) {
+ name_len++;
+ }
+ }
+ *s += name_len;
+
+ size_t maj = 0, min = 0;
+ if (parse_number(s, &maj)) {
+ if (**s == 'p') {
+ *s += 1;
+ parse_number(s, &min);
+ }
+ }
+
+ while (**s == '_') {
+ *s += 1;
+ }
+
+ if (ext) {
+ ext->name = name;
+ ext->name_len = name_len;
+ ext->ver_maj = maj;
+ ext->ver_min = min;
+ }
+ return true;
+}
+
+static bool extension_matches(const struct isa_extension *ext, const char *name) {
+ for (size_t i = ext->name_len; i > 0; i--) {
+ const char c1 = tolower(ext->name[i]);
+ const char c2 = tolower(*name++);
+ if (c2 == '\0' || c1 != c2) {
+ return false;
+ }
+ }
+ // Make sure `name` is not longer.
+ return *name == '\0';
+}
+
+bool riscv_check_isa_extension_for(size_t hartid, const char *name, size_t *maj, size_t *min) {
+ const char *isa_string = riscv_get_hart(hartid)->isa_string;
+
+ struct isa_extension ext;
+ while (parse_extension(&isa_string, &ext)) {
+ if (!extension_matches(&ext, name)) {
+ continue;
+ }
+ if (maj) {
+ *maj = ext.ver_maj;
+ }
+ if (min) {
+ *min = ext.ver_min;
+ }
+ return true;
+ }
+
+ return false;
+}
+
+#endif
\ No newline at end of file
