lib: Add ipi exit API

We add sbi_ipi_exit() API for exit path handling in sbi_exit()
implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

include/sbi/sbi_ipi.h

@@ -36,4 +36,6 @@ void sbi_ipi_process(struct sbi_scratch *scratch);
 
 int sbi_ipi_init(struct sbi_scratch *scratch, bool cold_boot);
 
+void sbi_ipi_exit(struct sbi_scratch *scratch);
+
 #endif

include/sbi/sbi_platform.h

@@ -116,6 +116,8 @@ struct sbi_platform_operations {
 	void (*ipi_clear)(u32 target_hart);
 	/** Initialize IPI for current HART */
 	int (*ipi_init)(bool cold_boot);
+	/** Exit IPI for current HART */
+	void (*ipi_exit)(void);
 
 	/** Get platform timer value */
 	u64 (*timer_value)(void);
@@ -499,6 +501,17 @@ static inline int sbi_platform_ipi_init(const struct sbi_platform *plat,
 	return 0;
 }
 
+/**
+ * Exit the platform IPI support for current HART
+ *
+ * @param plat pointer to struct sbi_platform
+ */
+static inline void sbi_platform_ipi_exit(const struct sbi_platform *plat)
+{
+	if (plat && sbi_platform_ops(plat)->ipi_exit)
+		sbi_platform_ops(plat)->ipi_exit();
+}
+
 /**
  * Get platform timer value
  *

lib/sbi/sbi_init.c

@@ -207,6 +207,8 @@ void __noreturn sbi_exit(struct sbi_scratch *scratch)
 
 	sbi_timer_exit(scratch);
 
+	sbi_ipi_exit(scratch);
+
 	sbi_platform_final_exit(plat);
 
 	sbi_hart_hang();

lib/sbi/sbi_ipi.c

@@ -160,8 +160,25 @@ int sbi_ipi_init(struct sbi_scratch *scratch, bool cold_boot)
 	if (ret)
 		return ret;
 
+	/* Platform init */
+	ret = sbi_platform_ipi_init(sbi_platform_ptr(scratch), cold_boot);
+	if (ret)
+		return ret;
+
 	/* Enable software interrupts */
 	csr_set(CSR_MIE, MIP_MSIP);
 
-	return sbi_platform_ipi_init(sbi_platform_ptr(scratch), cold_boot);
+	return 0;
+}
+
+void sbi_ipi_exit(struct sbi_scratch *scratch)
+{
+	/* Disable software interrupts */
+	csr_clear(CSR_MIE, MIP_MSIP);
+
+	/* Process pending IPIs */
+	sbi_ipi_process(scratch);
+
+	/* Platform exit */
+	sbi_platform_ipi_exit(sbi_platform_ptr(scratch));
 }