Introduce hart disabled parameter in platform.

As of now, uboot doesn't have support for SMP.
Moreover, unleashed board has a E51 hart which
doesn't not support S mode.

We should only boot only 1 non-zero hart.

Signed-off-by: Atish Patra <atish.patra@wdc.com>

include/sbi/sbi_platform.h

@@ -33,6 +33,7 @@ struct sbi_platform {
 	u64 features;
 	u32 hart_count;
 	u32 hart_stack_size;
+	u64 disabled_hart_mask;
 	int (*cold_early_init)(void);
 	int (*cold_final_init)(void);
 	int (*warm_early_init)(u32 target_hart);
@@ -83,6 +84,13 @@ static inline const char *sbi_platform_name(struct sbi_platform *plat)
 	return NULL;
 }
 
+static inline bool sbi_platform_hart_disabled(struct sbi_platform *plat, u32 hartid)
+{
+	if (plat && (plat->disabled_hart_mask & (1 << hartid)))
+		return 1;
+	else
+		return 0;
+}
 static inline u32 sbi_platform_hart_count(struct sbi_platform *plat)
 {
 	if (plat)

lib/sbi_hart.c

@@ -211,8 +211,6 @@ int sbi_hart_init(struct sbi_scratch *scratch, u32 hartid)
 
 void __attribute__((noreturn)) sbi_hart_hang(void)
 {
-	sbi_printf("\nHART%u Hang !!\n\n", sbi_current_hartid());
-
 	while (1)
 		wfi();
 	__builtin_unreachable();

lib/sbi_init.c

@@ -86,7 +86,6 @@ static void __attribute__((noreturn)) init_coldboot(struct sbi_scratch *scratch,
 	sbi_printf("OpenSBI v%d.%d (%s %s)\n",
 		   OPENSBI_MAJOR, OPENSBI_MINOR,
 		   __DATE__, __TIME__);
-	sbi_printf("Running on Hart %u\n", hartid);
 
 	sbi_printf("%s\n", logo);
 
@@ -95,6 +94,7 @@ static void __attribute__((noreturn)) init_coldboot(struct sbi_scratch *scratch,
 	sbi_printf("Platform HART Features : RV%d%s\n", misa_xlen(), str);
 	sbi_printf("Platform Max HARTs     : %d\n",
 		   sbi_platform_hart_count(plat));
+	sbi_printf("Current Hart           : %u\n", hartid);
 	/* Firmware details */
 	sbi_printf("Firmware Base          : 0x%lx\n", scratch->fw_start);
 	sbi_printf("Firmware Size          : %d KB\n",
@@ -106,11 +106,9 @@ static void __attribute__((noreturn)) init_coldboot(struct sbi_scratch *scratch,
 
 	sbi_hart_pmp_dump(scratch);
 
-	sbi_hart_mark_available(hartid);
-
 	if (!sbi_platform_has_hart_hotplug(plat))
 		sbi_hart_wake_coldboot_harts(scratch, hartid);
-
+	sbi_hart_mark_available(hartid);
 	sbi_hart_switch_mode(hartid, scratch->next_arg1,
 			     scratch->next_addr, scratch->next_mode);
 }
@@ -124,6 +122,9 @@ static void __attribute__((noreturn)) init_warmboot(struct sbi_scratch *scratch,
 	if (!sbi_platform_has_hart_hotplug(plat))
 		sbi_hart_wait_for_coldboot(scratch, hartid);
 
+	if (sbi_platform_hart_disabled(plat, hartid))
+		sbi_hart_hang();
+
 	rc = sbi_system_warm_early_init(scratch, hartid);
 	if (rc)
 		sbi_hart_hang();
@@ -164,6 +165,10 @@ void __attribute__((noreturn)) sbi_init(struct sbi_scratch *scratch)
 {
 	bool coldboot = FALSE;
 	u32 hartid = sbi_current_hartid();
+	struct sbi_platform *plat = sbi_platform_ptr(scratch);
+
+	if (sbi_platform_hart_disabled(plat, hartid))
+		sbi_hart_hang();
 		
 	if (atomic_add_return(&coldboot_lottery, 1) == 1)
 		coldboot = TRUE;

lib/sbi_ipi.c

@@ -28,7 +28,7 @@ int sbi_ipi_send_many(struct sbi_scratch *scratch,
 
 	/* send IPIs to everyone */
 	for (i = 0, m = mask; m; i++, m >>= 1) {
-		if ((m & 1) && (i != hartid)) {
+		if ((m & 1) && (i != hartid) && !sbi_platform_hart_disabled(plat, hartid)) {
 			oth = sbi_hart_id_to_scratch(scratch, i);
 			oth->ipi_type = event;
 			mb();

platform/kendryte/k210/platform.c

@@ -81,6 +81,7 @@ struct sbi_platform platform = {
 
 	.hart_count = PLAT_HART_COUNT,
 	.hart_stack_size = PLAT_HART_STACK_SIZE,
+	.disabled_hart_mask = 0,
 
 	.console_init = k210_console_init,
 	.console_putc = k210_console_putc,

platform/qemu/sifive_u/platform.c

@@ -104,6 +104,7 @@ struct sbi_platform platform = {
 	.features = SBI_PLATFORM_DEFAULT_FEATURES,
 	.hart_count = PLAT_HART_COUNT,
 	.hart_stack_size = PLAT_HART_STACK_SIZE,
+	.disabled_hart_mask = 0,
 	.pmp_region_count = sifive_u_pmp_region_count,
 	.pmp_region_info = sifive_u_pmp_region_info,
 	.cold_final_init = sifive_u_cold_final_init,

platform/qemu/virt/platform.c

@@ -105,6 +105,7 @@ struct sbi_platform platform = {
 	.features = SBI_PLATFORM_DEFAULT_FEATURES,
 	.hart_count = PLAT_HART_COUNT,
 	.hart_stack_size = PLAT_HART_STACK_SIZE,
+	.disabled_hart_mask = 0,
 	.pmp_region_count = virt_pmp_region_count,
 	.pmp_region_info = virt_pmp_region_info,
 	.cold_final_init = virt_cold_final_init,

platform/sifive/hifive_u540/platform.c

@@ -27,6 +27,8 @@
 #define SIFIVE_U_UART1_ADDR			0x10011000
 #define SIFIVE_UART_BAUDRATE			115200
 
+#define SIFIVE_U_HARITD_ENABLED			1
+
 /* PRCI clock related macros */
 //TODO: Do we need a separate driver for this ?
 #define SIFIVE_PRCI_BASE_ADDR			0x10000000
@@ -122,6 +124,7 @@ struct sbi_platform platform = {
 	.features = SBI_PLATFORM_DEFAULT_FEATURES,
 	.hart_count = PLAT_HART_COUNT,
 	.hart_stack_size = PLAT_HART_STACK_SIZE,
+	.disabled_hart_mask = ~(1 << SIFIVE_U_HARITD_ENABLED),
 	.pmp_region_count = sifive_u_pmp_region_count,
 	.pmp_region_info = sifive_u_pmp_region_info,
 	.cold_final_init = sifive_u_cold_final_init,