[PATCH] lib: sbi: sbi_system_reset() if not supported

[Heinrich Schuchardt]

The SBI specification requires that if a reset type or reason is not
supported the system reset function returns SBI_ERR_NOT_SUPPORTED.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
Yet another patch will be needed to return SBI_ERR_FAILED if the reset
did not succeed.
---
 include/sbi/sbi_system.h |  2 +-
 lib/sbi/sbi_system.c     | 22 ++++++++++++++--------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/include/sbi/sbi_system.h b/include/sbi/sbi_system.h
index 84c2813..3c98133 100644
--- a/include/sbi/sbi_system.h
+++ b/include/sbi/sbi_system.h
@@ -41,6 +41,6 @@ void sbi_system_reset_add_device(struct sbi_system_reset_device *dev);
 
 bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason);
 
-void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason);
+void sbi_system_reset(u32 reset_type, u32 reset_reason);
 
 #endif
diff --git a/lib/sbi/sbi_system.c b/lib/sbi/sbi_system.c
index 9cea3c0..5c328fb 100644
--- a/lib/sbi/sbi_system.c
+++ b/lib/sbi/sbi_system.c
@@ -62,12 +62,23 @@ bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason)
 	return !!sbi_system_reset_get_device(reset_type, reset_reason);
 }
 
-void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
+void sbi_system_reset(u32 reset_type, u32 reset_reason)
 {
 	ulong hbase = 0, hmask;
 	u32 cur_hartid = current_hartid();
 	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
+	const struct sbi_system_reset_device *dev =
+		sbi_system_reset_get_device(reset_type, reset_reason);
+
+	/* Check if domain allows system reset */
+	if (!dom->system_reset_allowed)
+		return;
+
+	/* Check if we have a reset device supporting the reset type */
+	dev = sbi_system_reset_get_device(reset_type, reset_reason);
+	if (!dev)
+		return;
 
 	/* Send HALT IPI to every hart other than the current hart */
 	while (!sbi_hsm_hart_interruptible_mask(dom, hbase, &hmask)) {
@@ -81,13 +92,8 @@ void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
 	/* Stop current HART */
 	sbi_hsm_hart_stop(scratch, FALSE);
 
-	/* Platform specific reset if domain allowed system reset */
-	if (dom->system_reset_allowed) {
-		const struct sbi_system_reset_device *dev =
-			sbi_system_reset_get_device(reset_type, reset_reason);
-		if (dev)
-			dev->system_reset(reset_type, reset_reason);
-	}
+	/* Execute platform specific reset */
+	dev->system_reset(reset_type, reset_reason);
 
 	/* If platform specific reset did not work then do sbi_exit() */
 	sbi_exit(scratch);
-- 
2.32.0