| From 1cc29e5eeeea7778d8987b617c8062686121b882 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 11 Nov 2019 04:32:04 +0100 |
| Subject: ARM: 8937/1: spectre-v2: remove Brahma-B53 from hardening |
| |
| From: Doug Berger <opendmb@gmail.com> |
| |
| [ Upstream commit 4ae5061a19b550dfe25397843427ed2ebab16b16 ] |
| |
| When the default processor handling was added to the function |
| cpu_v7_spectre_init() it only excluded other ARM implemented processor |
| cores. The Broadcom Brahma B53 core is not implemented by ARM so it |
| ended up falling through into the set of processors that attempt to use |
| the ARM_SMCCC_ARCH_WORKAROUND_1 service to harden the branch predictor. |
| |
| Since this workaround is not necessary for the Brahma-B53 this commit |
| explicitly checks for it and prevents it from applying a branch |
| predictor hardening workaround. |
| |
| Fixes: 10115105cb3a ("ARM: spectre-v2: add firmware based hardening") |
| Signed-off-by: Doug Berger <opendmb@gmail.com> |
| Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> |
| Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/arm/mm/proc-v7-bugs.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c |
| index 9a07916af8dd..a6554fdb56c5 100644 |
| --- a/arch/arm/mm/proc-v7-bugs.c |
| +++ b/arch/arm/mm/proc-v7-bugs.c |
| @@ -65,6 +65,9 @@ static void cpu_v7_spectre_init(void) |
| break; |
| |
| #ifdef CONFIG_ARM_PSCI |
| + case ARM_CPU_PART_BRAHMA_B53: |
| + /* Requires no workaround */ |
| + break; |
| default: |
| /* Other ARM CPUs require no workaround */ |
| if (read_cpuid_implementor() == ARM_CPU_IMP_ARM) |
| -- |
| 2.20.1 |
| |