[arch][riscv][sbi] add the pmu extension, tweak boot messages, qemu-virt use reset calls

arch/riscv/arch.c

@@ -88,19 +88,28 @@ void arch_init(void) {
     riscv_init_percpu();
 
     // print some arch info
+    const char *mode_string;
 #if RISCV_M_MODE
-    dprintf(INFO, "RISCV: Machine mode\n");
+    mode_string = "Machine";
+#elif RISCV_S_MODE
+    mode_string = "Supervisor";
+#else
+#error need to define M or S mode
+#endif
+
+    dprintf(INFO, "RISCV: %s mode\n", mode_string);
     dprintf(INFO, "RISCV: mvendorid %#lx marchid %#lx mimpid %#lx mhartid %#x\n",
             riscv_get_mvendorid(), riscv_get_marchid(),
             riscv_get_mimpid(), riscv_current_hart());
+
+#if RISCV_M_MODE
     dprintf(INFO, "RISCV: misa %#lx\n", riscv_csr_read(RISCV_CSR_MISA));
-#else
+#elif RISCV_S_MODE
-    dprintf(INFO, "RISCV: Supervisor mode\n");
+    sbi_init();
 #if RISCV_MMU
     dprintf(INFO, "RISCV: MMU enabled sv%u\n", RISCV_MMU);
     riscv_mmu_init();
 #endif
-    sbi_init();
 #endif
 
 #if WITH_SMP

arch/riscv/include/arch/riscv/sbi.h

@@ -32,6 +32,7 @@ enum sbi_return_code {
     SBI_ERR_INVALID_ADDRESS = -5,
 };
 
+// Legacy SBI extensions (avoid using)
 #define SBI_SET_TIMER               0x00, 0
 #define SBI_CONSOLE_PUTCHAR         0x01, 0
 #define SBI_CONSOLE_GETCHAR         0x02, 0
@@ -42,6 +43,7 @@ enum sbi_return_code {
 #define SBI_REMOTE_SFENCE_VMA_ASID  0x07, 0
 #define SBI_SHUTDOWN                0x08, 0
 
+// Base extension
 #define SBI_GET_SBI_SPEC_VERSION    0x10, 0
 #define SBI_GET_SBI_IMPL_ID         0x10, 1
 #define SBI_GET_SBI_IMPL_VERSION    0x10, 2
@@ -50,11 +52,14 @@ enum sbi_return_code {
 #define SBI_GET_MARCHID             0x10, 5
 #define SBI_GET_MIMPID              0x10, 6
 
-#define SBI_EXT_TIMER_SIG           0x54494d45
+// Extension signatures
-#define SBI_EXT_IPI_SIG             0x00735049
+// use SBI_PROBE_EXTENSION to discover
-#define SBI_EXT_RFENCE_SIG          0x52464e43
+#define SBI_EXT_TIMER_SIG           0x54494d45 // TIME
-#define SBI_EXT_HSM_SIG             0x0048534d
+#define SBI_EXT_IPI_SIG             0x00735049 // sPI
-#define SBI_EXT_SRST_SIG            0x53525354
+#define SBI_EXT_RFENCE_SIG          0x52464e43 // RFNC
+#define SBI_EXT_HSM_SIG             0x0048534d // HSM
+#define SBI_EXT_SRST_SIG            0x53525354 // SRST
+#define SBI_EXT_PMU_SIG            0x00504d55 // PMU
 
 void sbi_early_init(void);
 void sbi_init(void);
@@ -71,6 +76,17 @@ bool sbi_probe_extension(ulong extension);
 struct sbiret sbi_generic_call_2(ulong extension, ulong function);
 struct sbiret sbi_generic_call_3(ulong extension, ulong function);
 
+#define SBI_RESET_TYPE_SHUTDOWN 0
+#define SBI_RESET_TYPE_COLD_REBOOT 1
+#define SBI_RESET_TYPE_WARM_REBOOT 2
+#define SBI_RESET_TYPE_VENDOR_BASE (0xf0000000)
+
+#define SBI_RESET_REASON_NONE 0
+#define SBI_RESET_REASON_SYSTEM_FAILURE 1
+#define SBI_RESET_REASON_SBI_BASE (0xe0000000)
+#define SBI_RESET_REASON_VENDOR_BASE (0xf0000000)
+status_t sbi_system_reset(uint32_t type, uint32_t reason);
+
 #endif
 
 __END_CDECLS

arch/riscv/sbi.c

@@ -25,6 +25,7 @@ enum sbi_extension {
     SBI_EXTENSION_RFENCE,
     SBI_EXTENSION_HSM,
     SBI_EXTENSION_SRST,
+    SBI_EXTENSION_PMU,
 };
 
 static uint sbi_ext;
@@ -110,6 +111,19 @@ void sbi_rfence_vma(const unsigned long *hart_mask, vaddr_t vma, size_t size) {
     }
 }
 
+status_t sbi_system_reset(uint32_t type, uint32_t reason) {
+    if (likely(sbi_ext_present(SBI_EXTENSION_SRST))) {
+        ulong error = sbi_call(SBI_EXT_SRST_SIG, 0, type, reason).error;
+        if (error != 0) {
+            return ERR_GENERIC;
+        }
+        // we really shouldn't get here
+        return NO_ERROR;
+    } else {
+        return ERR_NOT_IMPLEMENTED;
+    }
+}
+
 void sbi_early_init(void) {
     // read the presence of some features
     sbi_ext |= sbi_probe_extension(SBI_EXT_TIMER_SIG) ? (1<<SBI_EXTENSION_TIMER) : 0;
@@ -117,25 +131,26 @@ void sbi_early_init(void) {
     sbi_ext |= sbi_probe_extension(SBI_EXT_RFENCE_SIG) ? (1<<SBI_EXTENSION_RFENCE) : 0;
     sbi_ext |= sbi_probe_extension(SBI_EXT_HSM_SIG) ? (1<<SBI_EXTENSION_HSM) : 0;
     sbi_ext |= sbi_probe_extension(SBI_EXT_SRST_SIG) ? (1<<SBI_EXTENSION_SRST) : 0;
+    sbi_ext |= sbi_probe_extension(SBI_EXT_PMU_SIG) ? (1<<SBI_EXTENSION_PMU) : 0;
 }
 
 void sbi_init(void) {
-    dprintf(INFO, "RISCV: SBI spec version %ld impl id %ld version %ld\n",
+    ulong version = sbi_generic_call_2(SBI_GET_SBI_SPEC_VERSION).value;
-            sbi_generic_call_2(SBI_GET_SBI_SPEC_VERSION).value,
+    dprintf(INFO, "RISCV: SBI spec version %lu.%lu impl id %lu version %lu\n",
+            (version >> 24) & 0x7f, version & ((1UL<<24)-1),
             sbi_generic_call_2(SBI_GET_SBI_IMPL_ID).value,
             sbi_generic_call_2(SBI_GET_SBI_IMPL_VERSION).value);
 
     // print the extensions detected
-    dprintf(INFO, "RISCV: SBI extension TIMER %d\n", sbi_ext_present(SBI_EXTENSION_TIMER));
+    if (LK_DEBUGLEVEL >= INFO) {
-    dprintf(INFO, "RISCV: SBI extension IPI %d\n", sbi_ext_present(SBI_EXTENSION_IPI));
+        dprintf(INFO, "RISCV: SBI extensions: ");
-    dprintf(INFO, "RISCV: SBI extension RFENCE %d\n", sbi_ext_present(SBI_EXTENSION_RFENCE));
+        if (sbi_ext_present(SBI_EXTENSION_TIMER)) dprintf(INFO, "TIMER ");
-    dprintf(INFO, "RISCV: SBI extension HSM %d\n", sbi_ext_present(SBI_EXTENSION_HSM));
+        if (sbi_ext_present(SBI_EXTENSION_IPI)) dprintf(INFO, "IPI ");
-    dprintf(INFO, "RISCV: SBI extension SRST %d\n", sbi_ext_present(SBI_EXTENSION_SRST));
+        if (sbi_ext_present(SBI_EXTENSION_RFENCE)) dprintf(INFO, "RFENCE ");
-
+        if (sbi_ext_present(SBI_EXTENSION_HSM)) dprintf(INFO, "HSM ");
-    // print a line via the console
+        if (sbi_ext_present(SBI_EXTENSION_SRST)) dprintf(INFO, "SRST ");
-    const char test[] = "SBI console test\n\r";
+        if (sbi_ext_present(SBI_EXTENSION_PMU)) dprintf(INFO, "PMU ");
-    for (const char *c = test; *c != 0; c++) {
+        dprintf(INFO, "\n");
-        sbi_call(SBI_CONSOLE_PUTCHAR, *c);
     }
 }
 

platform/qemu-virt-riscv/platform.c

@@ -220,10 +220,17 @@ void platform_halt(platform_halt_action suggested_action,
     switch (suggested_action) {
         case HALT_ACTION_SHUTDOWN:
             dprintf(ALWAYS, "Shutting down... (reason = %d)\n", reason);
+#if RISCV_S_MODE
+            // try to use SBI as a cleaner way to stop
+            sbi_system_reset(SBI_RESET_TYPE_SHUTDOWN, SBI_RESET_REASON_NONE);
+#endif
             *power_reset_reg = 0x5555;
             break;
         case HALT_ACTION_REBOOT:
             dprintf(ALWAYS, "Rebooting... (reason = %d)\n", reason);
+#if RISCV_S_MODE
+            sbi_system_reset(SBI_RESET_TYPE_COLD_REBOOT, SBI_RESET_REASON_NONE);
+#endif
             *power_reset_reg = 0x7777;
             break;
         case HALT_ACTION_HALT: