lib: utils: Improve fdt_ipi

Remove dummy driver. Optimize fdt_ipi_cold_init to exit the loop
early.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

1 files changed, 21 insertions, 20 deletions

diff --git a/lib/utils/ipi/fdt_ipi.c b/lib/utils/ipi/fdt_ipi.c
index 66dc5108..7762abab 100644
--- a/lib/utils/ipi/fdt_ipi.c
+++ b/lib/utils/ipi/fdt_ipi.c
@@ -16,24 +16,17 @@
 extern struct fdt_ipi *fdt_ipi_drivers[];
 extern unsigned long fdt_ipi_drivers_size;
 
-static struct fdt_ipi dummy = {
-	.match_table = NULL,
-	.cold_init = NULL,
-	.warm_init = NULL,
-	.exit = NULL,
-};
-
-static struct fdt_ipi *current_driver = &dummy;
+static struct fdt_ipi *current_driver = NULL;
 
 void fdt_ipi_exit(void)
 {
-	if (current_driver->exit)
+	if (current_driver && current_driver->exit)
 		current_driver->exit();
 }
 
 static int fdt_ipi_warm_init(void)
 {
-	if (current_driver->warm_init)
+	if (current_driver && current_driver->warm_init)
 		return current_driver->warm_init();
 	return 0;
 }
@@ -51,20 +44,28 @@ static int fdt_ipi_cold_init(void)
 		noff = -1;
 		while ((noff = fdt_find_match(fdt, noff,
 					drv->match_table, &match)) >= 0) {
-			if (drv->cold_init) {
-				rc = drv->cold_init(fdt, noff, match);
-				if (rc == SBI_ENODEV)
-					continue;
-				if (rc)
-					return rc;
-			}
+			/* drv->cold_init must not be NULL */
+			if (drv->cold_init == NULL)
+				return SBI_EFAIL;
+
+			rc = drv->cold_init(fdt, noff, match);
+			if (rc == SBI_ENODEV)
+				continue;
+			if (rc)
+				return rc;
 			current_driver = drv;
-		}
 
-		if (current_driver != &dummy)
-			break;
+			/*
+			 * We will have multiple IPI devices on multi-die or
+			 * multi-socket systems so we cannot break here.
+			 */
+		}
 	}
 
+	/*
+	 * On some single-hart system there is no need for ipi,
+	 * so we cannot return a failure here
+	 */
 	return 0;
 }