core/platform: Add an explicit fast-reboot type

The OPAL_CEC_REBOOT2 OPAL call allows a specific type of reboot to be
requested. We can use this to allow the OS to request a fast-reboot
explicitly rather than relying on nvram hacks to change the default
behaviour.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

core/platform.c

@@ -116,6 +116,10 @@ static int64_t opal_cec_reboot2(uint32_t reboot_type, char *diag)
 			opal_cec_reboot();
 		for (;;);
 		break;
+	case OPAL_REBOOT_FAST:
+		prlog(PR_NOTICE, "Reboot: Fast reboot requested by OS\n");
+		fast_reboot();
+		break;
 	default:
 		prlog(PR_NOTICE, "OPAL: Unsupported reboot request %d\n", reboot_type);
 		return OPAL_UNSUPPORTED;

include/opal-api.h

@@ -1135,6 +1135,7 @@ enum {
 	OPAL_REBOOT_PLATFORM_ERROR,
 	OPAL_REBOOT_FULL_IPL,
 	OPAL_REBOOT_MPIPL,
+	OPAL_REBOOT_FAST,
 };
 
 /* Argument to OPAL_PCI_TCE_KILL */