From: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Date: Mon, 10 Dec 2018 18:07:33 +0000
Subject: arm64: smp: Handle errors reported by the firmware
Git-commit: f357b3a7e17af7736d67d8267edc1ed3d1dd9391
Patch-mainline: v5.0-rc1
References: git-fixes

The __cpu_up() routine ignores the errors reported by the firmware
for a CPU bringup operation and looks for the error status set by the
booting CPU. If the CPU never entered the kernel, we could end up
in assuming stale error status, which otherwise would have been
set/cleared appropriately by the booting CPU.

Reported-by: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ivan T. Ivanov <iivanov@suse.de>
---
 arch/arm64/kernel/smp.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -141,6 +141,7 @@ int __cpu_up(unsigned int cpu, struct ta
 		}
 	} else {
 		pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
+		return ret;
 	}
 
 	secondary_data.task = NULL;