4 files changed, 76 insertions, 0 deletions
diff --git a/include/sbi/sbi_error.h b/include/sbi/sbi_error.h
index 4b7dd12..91ba2ee 100644
--- a/include/sbi/sbi_error.h
+++ b/include/sbi/sbi_error.h
@@ -28,6 +28,7 @@
 #define SBI_ETRAP	-13
 #define SBI_EUNKNOWN	-14
 #define SBI_ENOENT	-15
+#define SBI_EALREADY_STARTED	-16
 
 /* clang-format on */
 
diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
index 065cb0c..d88c7de 100644
--- a/include/sbi/sbi_hart.h
+++ b/include/sbi/sbi_hart.h
@@ -22,6 +22,8 @@ void sbi_hart_set_trap_info(struct sbi_scratch *scratch, void *data);
 
 void sbi_hart_delegation_dump(struct sbi_scratch *scratch);
 void sbi_hart_pmp_dump(struct sbi_scratch *scratch);
+int  sbi_hart_pmp_check_addr(struct sbi_scratch *scratch, unsigned long daddr,
+			     unsigned long attr);
 
 void __attribute__((noreturn)) sbi_hart_hang(void);
 
diff --git a/include/sbi/sbi_hsm.h b/include/sbi/sbi_hsm.h
new file mode 100644
index 0000000..2566afb
--- /dev/null
+++ b/include/sbi/sbi_hsm.h
@@ -0,0 +1,30 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#ifndef __SBI_HSM_H__
+#define __SBI_HSM_H__
+
+#include <sbi/sbi_types.h>
+
+/** Hart state values **/
+#define SBI_HART_STOPPED	0
+#define SBI_HART_STOPPING	1
+#define SBI_HART_STARTING	2
+#define SBI_HART_STARTED	3
+
+int sbi_hsm_init(struct sbi_scratch *scratch, u32 hartid, bool cold_boot);
+void __noreturn sbi_hsm_exit(struct sbi_scratch *scratch);
+
+int sbi_hsm_hart_start(struct sbi_scratch *scratch, u32 hartid,
+			   ulong saddr, ulong priv);
+int sbi_hsm_hart_stop(struct sbi_scratch *scratch, bool exitnow);
+int sbi_hsm_hart_get_state(struct sbi_scratch *scratch, u32 hartid);
+bool sbi_hsm_hart_started(struct sbi_scratch *scratch, u32 hartid);
+void sbi_hsm_prepare_next_jump(struct sbi_scratch *scratch, u32 hartid);
+#endif
diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h
index 16ee05c..462006e 100644
--- a/include/sbi/sbi_platform.h
+++ b/include/sbi/sbi_platform.h
@@ -135,6 +135,14 @@ struct sbi_platform_operations {
 	/** Exit platform timer for current HART */
 	void (*timer_exit)(void);
 
+	/** Bringup the given hart from previous stage **/
+	int (*hart_start)(u32 hartid, ulong saddr, ulong priv);
+	/**
+	 *  Stop the current hart from running. This call doesn't expect to
+	 *  return if success.
+	 */
+	int (*hart_stop)(void);
+
 	/** Reboot the platform */
 	int (*system_reboot)(u32 type);
 	/** Shutdown or poweroff the platform */
@@ -285,6 +293,41 @@ static inline u32 sbi_platform_hart_stack_size(const struct sbi_platform *plat)
 }
 
 /**
+ * Bringup a given hart from previous stage. Platform should implement this
+ * operation if they support a custom mechanism to start a hart. Otherwise,
+ * a generic WFI based approach will be used to start/stop a hart in OpenSBI.
+ *
+ * @param plat pointer to struct sbi_platform
+ * @param hartid Hart ID
+ * @param saddr  Physical address in supervisor mode for hart to jump after
+ *		 OpenSBI
+ * @param priv	 A private context data from the caller
+ *
+ * @return 0 if sucessful and negative error code on failure
+ */
+static inline int sbi_platform_hart_start(const struct sbi_platform *plat,
+					  u32 hartid, ulong saddr, ulong priv)
+{
+	if (plat && sbi_platform_ops(plat)->hart_start)
+		return sbi_platform_ops(plat)->hart_start(hartid, saddr, priv);
+	return SBI_ENOTSUPP;
+}
+
+/**
+ * Stop the current hart in OpenSBI.
+ *
+ * @param plat pointer to struct sbi_platform
+ *
+ * @return Negative error code on failure. It doesn't return on success.
+ */
+static inline int sbi_platform_hart_stop(const struct sbi_platform *plat)
+{
+	if (plat && sbi_platform_ops(plat)->hart_stop)
+		return sbi_platform_ops(plat)->hart_stop();
+	return SBI_ENOTSUPP;
+}
+
+/**
  * Early initialization for current HART
  *
  * @param plat pointer to struct sbi_platform