From: Pu Wen <puwen@hygon.cn>
Date: Sun, 23 Sep 2018 17:35:50 +0800
Subject: x86/bugs: Add Hygon Dhyana to the respective mitigation machinery
Git-commit: 1a576b23d63794f39a247fb31056eecccbf9a287
Patch-mainline: v4.20-rc1
References: fate#327735
The Hygon Dhyana CPU has the same speculative execution as AMD family
17h, so share AMD spectre mitigation code with Hygon Dhyana.
Also Hygon Dhyana is not affected by meltdown, so add exception for it.
Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Link: https://lkml.kernel.org/r/0861d39c8a103fc0deca15bafbc85d403666d9ef.1537533369.git.puwen@hygon.cn
---
arch/x86/kernel/cpu/bugs.c | 4 +++-
arch/x86/kernel/cpu/common.c | 1 +
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 40bdaea97fe7..b810cc239375 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -312,6 +312,7 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
}
if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_HYGON &&
boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
return SPECTRE_V2_CMD_AUTO;
@@ -371,7 +372,8 @@ static void __init spectre_v2_select_mitigation(void)
return;
retpoline_auto:
- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
retpoline_amd:
if (!boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) {
pr_err("Spectre mitigation: LFENCE not serializing, switching to generic retpoline\n");
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 658c85d16a9b..d14c879ba7ba 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -963,6 +963,7 @@ static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
{ X86_VENDOR_AMD },
+ { X86_VENDOR_HYGON },
{}
};