SBI system suspend (SUSP) extension

index c0a5505423bf..b43f26cfe3a0 100644
@@ -26,6 +26,15 @@
 #include <sbi/sbi_timer.h>
 #include <sbi/sbi_console.h>
 
+#define __sbi_hsm_hart_change_state(hdata, oldstate, newstate)		\
+({									\
+	long state = atomic_cmpxchg(&(hdata)->state, oldstate, newstate); \
+	if (state != (oldstate))					\
+		sbi_printf("%s: ERR: The hart is in invalid state [%lu]\n", \
+			   __func__, state);				\
+	state == (oldstate);						\
+})
+
 static const struct sbi_hsm_device *hsm_dev = NULL;
 static unsigned long hart_data_offset;
 

@@ -95,13 +104,11 @@ int sbi_hsm_hart_interruptible_mask(const struct sbi_domain *dom,
 
 void sbi_hsm_prepare_next_jump(struct sbi_scratch *scratch, u32 hartid)
 {
-	u32 oldstate;
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);
 
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_START_PENDING,
-				  SBI_HSM_STATE_STARTED);
-	if (oldstate != SBI_HSM_STATE_START_PENDING)
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_START_PENDING,
+					 SBI_HSM_STATE_STARTED))
 		sbi_hart_hang();
 }
 

@@ -217,14 +224,12 @@ int sbi_hsm_init(struct sbi_scratch *scratch, u32 hartid, bool cold_boot)
 
 void __noreturn sbi_hsm_exit(struct sbi_scratch *scratch)
 {
-	u32 hstate;
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);
 	void (*jump_warmboot)(void) = (void (*)(void))scratch->warmboot_addr;
 
-	hstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_STOP_PENDING,
-				SBI_HSM_STATE_STOPPED);
-	if (hstate != SBI_HSM_STATE_STOP_PENDING)
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_STOP_PENDING,
+					 SBI_HSM_STATE_STOPPED))
 		goto fail_exit;
 
 	if (hsm_device_has_hart_hotplug()) {

@@ -299,7 +304,6 @@ int sbi_hsm_hart_start(struct sbi_scratch *scratch,
 
 int sbi_hsm_hart_stop(struct sbi_scratch *scratch, bool exitnow)
 {
-	int oldstate;
 	const struct sbi_domain *dom = sbi_domain_thishart_ptr();
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);

@@ -307,13 +311,9 @@ int sbi_hsm_hart_stop(struct sbi_scratch *scratch, bool exitnow)
 	if (!dom)
 		return SBI_EFAIL;
 
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_STARTED,
-				  SBI_HSM_STATE_STOP_PENDING);
-	if (oldstate != SBI_HSM_STATE_STARTED) {
-		sbi_printf("%s: ERR: The hart is in invalid state [%u]\n",
-			   __func__, oldstate);
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_STARTED,
+					 SBI_HSM_STATE_STOP_PENDING))
 		return SBI_EFAIL;
-	}
 
 	if (exitnow)
 		sbi_exit(scratch);

@@ -363,36 +363,26 @@ static void __sbi_hsm_suspend_non_ret_restore(struct sbi_scratch *scratch)
 
 void sbi_hsm_hart_resume_start(struct sbi_scratch *scratch)
 {
-	int oldstate;
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);
 
 	/* If current HART was SUSPENDED then set RESUME_PENDING state */
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_SUSPENDED,
-			SBI_HSM_STATE_RESUME_PENDING);
-	if (oldstate != SBI_HSM_STATE_SUSPENDED) {
-		sbi_printf("%s: ERR: The hart is in invalid state [%u]\n",
-			   __func__, oldstate);
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_SUSPENDED,
+					 SBI_HSM_STATE_RESUME_PENDING))
 		sbi_hart_hang();
-	}
 
 	hsm_device_hart_resume();
 }
 
 void sbi_hsm_hart_resume_finish(struct sbi_scratch *scratch)
 {
-	u32 oldstate;
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);
 
 	/* If current HART was RESUME_PENDING then set STARTED state */
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_RESUME_PENDING,
-				  SBI_HSM_STATE_STARTED);
-	if (oldstate != SBI_HSM_STATE_RESUME_PENDING) {
-		sbi_printf("%s: ERR: The hart is in invalid state [%u]\n",
-			   __func__, oldstate);
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_RESUME_PENDING,
+					 SBI_HSM_STATE_STARTED))
 		sbi_hart_hang();
-	}
 
 	/*
 	 * Restore some of the M-mode CSRs which we are re-configured by

@@ -404,7 +394,7 @@ void sbi_hsm_hart_resume_finish(struct sbi_scratch *scratch)
 int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 			 ulong raddr, ulong rmode, ulong arg1)
 {
-	int oldstate, ret;
+	int ret;
 	const struct sbi_domain *dom = sbi_domain_thishart_ptr();
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);

@@ -438,11 +428,8 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 	scratch->next_mode = rmode;
 
 	/* Directly move from STARTED to SUSPENDED state */
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_STARTED,
-				  SBI_HSM_STATE_SUSPENDED);
-	if (oldstate != SBI_HSM_STATE_STARTED) {
-		sbi_printf("%s: ERR: The hart is in invalid state [%u]\n",
-			   __func__, oldstate);
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_STARTED,
+					 SBI_HSM_STATE_SUSPENDED)) {
 		ret = SBI_EDENIED;
 		goto fail_restore_state;
 	}

@@ -485,13 +472,9 @@ fail_restore_state:
 	 * We might have successfully resumed from retentive suspend
 	 * or suspend failed. In both cases, we restore state of hart.
 	 */
-	oldstate = atomic_cmpxchg(&hdata->state, SBI_HSM_STATE_SUSPENDED,
-				  SBI_HSM_STATE_STARTED);
-	if (oldstate != SBI_HSM_STATE_SUSPENDED) {
-		sbi_printf("%s: ERR: The hart is in invalid state [%u]\n",
-			   __func__, oldstate);
+	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_SUSPENDED,
+					 SBI_HSM_STATE_STARTED))
 		sbi_hart_hang();
-	}
 
 	return ret;
 }

index b43f26cfe3a0..c7454499b2ba 100644
@@ -429,10 +429,8 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 
 	/* Directly move from STARTED to SUSPENDED state */
 	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_STARTED,
-					 SBI_HSM_STATE_SUSPENDED)) {
-		ret = SBI_EDENIED;
-		goto fail_restore_state;
-	}
+					 SBI_HSM_STATE_SUSPENDED))
+		return SBI_EDENIED;
 
 	/* Save the suspend type */
 	hdata->suspend_type = suspend_type;

@@ -467,7 +465,6 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 		jump_warmboot();
 	}
 
-fail_restore_state:
 	/*
 	 * We might have successfully resumed from retentive suspend
 	 * or suspend failed. In both cases, we restore state of hart.

index c7454499b2ba..2fbb0d0afc7e 100644
@@ -403,7 +403,7 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 
 	/* Sanity check on domain assigned to current HART */
 	if (!dom)
-		return SBI_EINVAL;
+		return SBI_EFAIL;
 
 	/* Sanity check on suspend type */
 	if (SBI_HSM_SUSPEND_RET_DEFAULT < suspend_type &&

@@ -416,7 +416,7 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 	/* Additional sanity check for non-retentive suspend */
 	if (suspend_type & SBI_HSM_SUSP_NON_RET_BIT) {
 		if (rmode != PRV_S && rmode != PRV_U)
-			return SBI_EINVAL;
+			return SBI_EFAIL;
 		if (dom && !sbi_domain_check_addr(dom, raddr, rmode,
 						  SBI_DOMAIN_EXECUTE))
 			return SBI_EINVALID_ADDR;

@@ -430,7 +430,7 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 	/* Directly move from STARTED to SUSPENDED state */
 	if (!__sbi_hsm_hart_change_state(hdata, SBI_HSM_STATE_STARTED,
 					 SBI_HSM_STATE_SUSPENDED))
-		return SBI_EDENIED;
+		return SBI_EFAIL;
 
 	/* Save the suspend type */
 	hdata->suspend_type = suspend_type;

index 2fbb0d0afc7e..2eb189a9d7f3 100644
@@ -399,8 +399,6 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);
 
-	/* For now, we only allow suspend from S-mode or U-mode. */
-
 	/* Sanity check on domain assigned to current HART */
 	if (!dom)
 		return SBI_EFAIL;

@@ -415,6 +413,10 @@ int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 
 	/* Additional sanity check for non-retentive suspend */
 	if (suspend_type & SBI_HSM_SUSP_NON_RET_BIT) {
+		/*
+		 * For now, we only allow non-retentive suspend from
+		 * S-mode or U-mode.
+		 */
 		if (rmode != PRV_S && rmode != PRV_U)
 			return SBI_EFAIL;
 		if (dom && !sbi_domain_check_addr(dom, raddr, rmode,

index 703a824493b4..f1b41d073b22 100644
@@ -12,7 +12,6 @@
 #include <sbi/sbi_ecall_interface.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_trap.h>
-#include <sbi/sbi_version.h>
 #include <sbi/sbi_hsm.h>
 #include <sbi/sbi_scratch.h>
 #include <sbi/riscv_asm.h>

@@ -45,7 +44,8 @@ static int sbi_ecall_hsm_handler(unsigned long extid, unsigned long funcid,
 		break;
 	default:
 		ret = SBI_ENOTSUPP;
-	};
+	}
+
 	if (ret >= 0) {
 		*out_val = ret;
 		ret = 0;

index c2a728a4aca5..c730db1810df 100644
@@ -65,9 +65,13 @@ void sbi_hsm_hart_resume_start(struct sbi_scratch *scratch);
 void sbi_hsm_hart_resume_finish(struct sbi_scratch *scratch);
 int sbi_hsm_hart_suspend(struct sbi_scratch *scratch, u32 suspend_type,
 			 ulong raddr, ulong rmode, ulong arg1);
+bool sbi_hsm_hart_change_state(struct sbi_scratch *scratch, long oldstate,
+			       long newstate);
+int __sbi_hsm_hart_get_state(u32 hartid);
 int sbi_hsm_hart_get_state(const struct sbi_domain *dom, u32 hartid);
 int sbi_hsm_hart_interruptible_mask(const struct sbi_domain *dom,
 				    ulong hbase, ulong *out_hmask);
+void __sbi_hsm_suspend_non_ret_save(struct sbi_scratch *scratch);
 void sbi_hsm_prepare_next_jump(struct sbi_scratch *scratch, u32 hartid);
 
 #endif

index 2eb189a9d7f3..3adedff8f232 100644
@@ -46,7 +46,15 @@ struct sbi_hsm_data {
 	unsigned long saved_mip;
 };
 
-static inline int __sbi_hsm_hart_get_state(u32 hartid)
+bool sbi_hsm_hart_change_state(struct sbi_scratch *scratch, long oldstate,
+			       long newstate)
+{
+	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
+							    hart_data_offset);
+	return __sbi_hsm_hart_change_state(hdata, oldstate, newstate);
+}
+
+int __sbi_hsm_hart_get_state(u32 hartid)
 {
 	struct sbi_hsm_data *hdata;
 	struct sbi_scratch *scratch;

@@ -329,7 +337,7 @@ static int __sbi_hsm_suspend_default(struct sbi_scratch *scratch)
 	return 0;
 }
 
-static void __sbi_hsm_suspend_non_ret_save(struct sbi_scratch *scratch)
+void __sbi_hsm_suspend_non_ret_save(struct sbi_scratch *scratch)
 {
 	struct sbi_hsm_data *hdata = sbi_scratch_offset_ptr(scratch,
 							    hart_data_offset);

index a3f2bf4bdf69..98a426a74ec4 100644
@@ -29,6 +29,7 @@
 #define SBI_EXT_HSM				0x48534D
 #define SBI_EXT_SRST				0x53525354
 #define SBI_EXT_PMU				0x504D55
+#define SBI_EXT_SUSP				0x53555350
 
 /* SBI function IDs for BASE extension*/
 #define SBI_EXT_BASE_GET_SPEC_VERSION		0x0

@@ -230,6 +231,13 @@ enum sbi_pmu_ctr_type {
 /* Flags defined for counter stop function */
 #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
 
+/* SBI function IDs for SUSP extension */
+#define SBI_EXT_SUSP_SUSPEND			0x0
+
+#define SBI_SUSP_SLEEP_TYPE_SUSPEND		0x0
+#define SBI_SUSP_SLEEP_TYPE_LAST		SBI_SUSP_SLEEP_TYPE_SUSPEND
+#define SBI_SUSP_PLATFORM_SLEEP_START		0x80000000
+
 /* SBI base specification related macros */
 #define SBI_SPEC_VERSION_MAJOR_OFFSET		24
 #define SBI_SPEC_VERSION_MAJOR_MASK		0x7f

index 84c281383d8c..65ea3d36d6cf 100644
@@ -43,4 +43,21 @@ bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason);
 
 void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason);
 
+/** System suspend device */
+struct sbi_system_suspend_device {
+	/** Name of the system suspend device */
+	char name[32];
+
+	/* Check whether sleep type is supported by the device */
+	int (*system_suspend_check)(u32 sleep_type);
+
+	/** Suspend the system */
+	int (*system_suspend)(u32 sleep_type);
+};
+
+const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void);
+void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev);
+bool sbi_system_suspend_supported(u32 sleep_type);
+int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque);
+
 #endif

48 lines not on this page · raw message

index 259a191051a7..0d8fdfbe9a41 100644
@@ -69,6 +69,7 @@ static void sbi_boot_print_general(struct sbi_scratch *scratch)
 	const struct sbi_timer_device *tdev;
 	const struct sbi_console_device *cdev;
 	const struct sbi_system_reset_device *srdev;
+	const struct sbi_system_suspend_device *susp_dev;
 	const struct sbi_platform *plat = sbi_platform_ptr(scratch);
 
 	if (scratch->options & SBI_SCRATCH_NO_BOOT_PRINTS)

@@ -103,6 +104,9 @@ static void sbi_boot_print_general(struct sbi_scratch *scratch)
 	srdev = sbi_system_reset_get_device(SBI_SRST_RESET_TYPE_SHUTDOWN, 0);
 	sbi_printf("Platform Shutdown Device  : %s\n",
 		   (srdev) ? srdev->name : "---");
+	susp_dev = sbi_system_suspend_get_device();
+	sbi_printf("Platform Suspend Device   : %s\n",
+		   (susp_dev) ? susp_dev->name : "---");
 
 	/* Firmware details */
 	sbi_printf("Firmware Base             : 0x%lx\n", scratch->fw_start);

index f37c811d0bf3..5c123a6c9d8d 100644
@@ -92,3 +92,29 @@ void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
 	/* If platform specific reset did not work then do sbi_exit() */
 	sbi_exit(scratch);
 }
+
+static const struct sbi_system_suspend_device *suspend_dev = NULL;
+
+const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void)
+{
+	return suspend_dev;
+}
+
+void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev)
+{
+	if (!dev || suspend_dev)
+		return;
+
+	suspend_dev = dev;
+}
+
+bool sbi_system_suspend_supported(u32 sleep_type)
+{
+	return suspend_dev && suspend_dev->system_suspend_check &&
+	       suspend_dev->system_suspend_check(sleep_type);
+}
+
+int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque)
+{
+	return 0;
+}

index bbb3effa2449..178221e3711d 100644
@@ -120,6 +120,8 @@ struct sbi_domain {
 	unsigned long next_mode;
 	/** Is domain allowed to reset the system */
 	bool system_reset_allowed;
+	/** Is domain allowed to suspend the system */
+	bool system_suspend_allowed;
 };
 
 /** The root domain instance */

index 60fda012d7b4..f2fe4da6d17f 100644
@@ -34,6 +34,7 @@ struct sbi_domain root = {
 	.possible_harts = &root_hmask,
 	.regions = root_memregs,
 	.system_reset_allowed = true,
+	.system_suspend_allowed = true,
 };
 
 bool sbi_domain_is_assigned_hart(const struct sbi_domain *dom, u32 hartid)

@@ -394,6 +395,9 @@ void sbi_domain_dump(const struct sbi_domain *dom, const char *suffix)
 
 	sbi_printf("Domain%d SysReset    %s: %s\n",
 		   dom->index, suffix, (dom->system_reset_allowed) ? "yes" : "no");
+
+	sbi_printf("Domain%d SysSuspend  %s: %s\n",
+		   dom->index, suffix, (dom->system_suspend_allowed) ? "yes" : "no");
 }
 
 void sbi_domain_dump_all(const char *suffix)

index 2b51a8ebe132..33653e2f555f 100644
@@ -419,6 +419,13 @@ static int __fdt_parse_domain(void *fdt, int domain_offset, void *opaque)
 	else
 		dom->system_reset_allowed = false;
 
+	/* Read "system-suspend-allowed" DT property */
+	if (fdt_get_property(fdt, domain_offset,
+			     "system-suspend-allowed", NULL))
+		dom->system_suspend_allowed = true;
+	else
+		dom->system_suspend_allowed = false;
+
 	/* Find /cpus DT node */
 	cpus_offset = fdt_path_offset(fdt, "/cpus");
 	if (cpus_offset < 0)

index 5c123a6c9d8d..c18562cdcfab 100644
@@ -116,5 +116,60 @@ bool sbi_system_suspend_supported(u32 sleep_type)
 
 int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque)
 {
-	return 0;
+	int ret = SBI_ENOTSUPP;
+	const struct sbi_domain *dom = sbi_domain_thishart_ptr();
+	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
+	void (*jump_warmboot)(void) = (void (*)(void))scratch->warmboot_addr;
+	unsigned int hartid = current_hartid();
+	unsigned long prev_mode;
+	unsigned long i;
+
+	if (!dom || !dom->system_suspend_allowed)
+		return SBI_EFAIL;
+
+	if (!suspend_dev || !suspend_dev->system_suspend)
+		return SBI_EFAIL;
+
+	if (!sbi_system_suspend_supported(sleep_type))
+		return SBI_ENOTSUPP;
+
+	prev_mode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT;
+	if (prev_mode != PRV_S && prev_mode != PRV_U)
+		return SBI_EFAIL;
+
+	sbi_hartmask_for_each_hart(i, &dom->assigned_harts) {
+		if (i == hartid)
+			continue;
+		if (__sbi_hsm_hart_get_state(i) != SBI_HSM_STATE_STOPPED)
+			return SBI_EFAIL;
+	}
+
+	if (!sbi_domain_check_addr(dom, resume_addr, prev_mode,
+				   SBI_DOMAIN_EXECUTE))
+		return SBI_EINVALID_ADDR;
+
+	if (!sbi_hsm_hart_change_state(scratch, SBI_HSM_STATE_STARTED,
+				       SBI_HSM_STATE_SUSPENDED))
+		return SBI_EFAIL;
+
+	/* Prepare for resume */
+	scratch->next_mode = prev_mode;
+	scratch->next_addr = resume_addr;
+	scratch->next_arg1 = opaque;
+
+	__sbi_hsm_suspend_non_ret_save(scratch);
+
+	/* Suspend */
+	ret = suspend_dev->system_suspend(sleep_type);
+	if (ret != SBI_OK) {
+		if (!sbi_hsm_hart_change_state(scratch, SBI_HSM_STATE_SUSPENDED,
+					       SBI_HSM_STATE_STARTED))
+			sbi_hart_hang();
+		return ret;
+	}
+
+	/* Resume */
+	jump_warmboot();
+
+	__builtin_unreachable();
 }

index 65ea3d36d6cf..7d0867f276aa 100644
@@ -57,6 +57,7 @@ struct sbi_system_suspend_device {
 
 const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void);
 void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev);
+void sbi_system_suspend_test_enable(void);
 bool sbi_system_suspend_supported(u32 sleep_type);
 int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque);
 

index c18562cdcfab..3242b21699cb 100644
@@ -17,6 +17,7 @@
 #include <sbi/sbi_system.h>
 #include <sbi/sbi_ipi.h>
 #include <sbi/sbi_init.h>
+#include <sbi/sbi_timer.h>
 
 static SBI_LIST_HEAD(reset_devices_list);
 

@@ -108,6 +109,35 @@ void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev)
 	suspend_dev = dev;
 }
 
+static int sbi_system_suspend_test_check(u32 sleep_type)
+{
+	return sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND;
+}
+
+static int sbi_system_suspend_test_suspend(u32 sleep_type)
+{
+	if (sleep_type != SBI_SUSP_SLEEP_TYPE_SUSPEND)
+		return SBI_EINVAL;
+
+	sbi_timer_mdelay(5000);
+
+	/* Wait for interrupt */
+	wfi();
+
+	return SBI_OK;
+}
+
+static struct sbi_system_suspend_device sbi_system_suspend_test = {
+	.name = "system-suspend-test",
+	.system_suspend_check = sbi_system_suspend_test_check,
+	.system_suspend = sbi_system_suspend_test_suspend,
+};
+
+void sbi_system_suspend_test_enable(void)
+{
+	sbi_system_suspend_set_device(&sbi_system_suspend_test);
+}
+
 bool sbi_system_suspend_supported(u32 sleep_type)
 {
 	return suspend_dev && suspend_dev->system_suspend_check &&

index a34d3b019335..224cadc73a03 100644
@@ -13,6 +13,7 @@
 #include <sbi/sbi_hartmask.h>
 #include <sbi/sbi_platform.h>
 #include <sbi/sbi_string.h>
+#include <sbi/sbi_system.h>
 #include <sbi_utils/fdt/fdt_domain.h>
 #include <sbi_utils/fdt/fdt_fixup.h>
 #include <sbi_utils/fdt/fdt_helper.h>

@@ -226,7 +227,24 @@ static int generic_extensions_init(struct sbi_hart_features *hfeatures)
 
 static int generic_domains_init(void)
 {
-	return fdt_domains_populate(fdt_get_address());
+	void *fdt = fdt_get_address();
+	int offset, ret;
+
+	ret = fdt_domains_populate(fdt);
+	if (ret < 0)
+		return ret;
+
+	offset = fdt_path_offset(fdt, "/chosen");
+
+	if (offset >= 0) {
+		offset = fdt_node_offset_by_compatible(fdt, offset,
+						       "opensbi,domain,config");
+		if (offset >= 0 &&
+		    fdt_get_property(fdt, offset, "system-suspend-test", NULL))
+			sbi_system_suspend_test_enable();
+	}
+
+	return 0;
 }
 
 static u64 generic_tlbr_flush_limit(void)