From d7caac991feeef1b871ee6988fd2c9725df09039 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 14 Jun 2022 23:16:04 +0200 Subject: x86/cpu/amd: Add Spectral Chicken Zen2 uarchs have an undocumented, unnamed, MSR that contains a chicken bit for some speculation behaviour. It needs setting. Note: very belatedly AMD released naming; it's now officially called MSR_AMD64_DE_CFG2 and MSR_AMD64_DE_CFG2_SUPPRESS_NOBR_PRED_BIT but shall remain the SPECTRAL CHICKEN. Suggested-by: Andrew Cooper Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/cpu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/cpu/cpu.h') diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 2a8e584fc991..7c9b5893c30a 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -61,6 +61,8 @@ static inline void tsx_init(void) { } static inline void tsx_ap_init(void) { } #endif /* CONFIG_CPU_SUP_INTEL */ +extern void init_spectral_chicken(struct cpuinfo_x86 *c); + extern void get_cpu_cap(struct cpuinfo_x86 *c); extern void get_cpu_address_sizes(struct cpuinfo_x86 *c); extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c); -- cgit v1.2.3