diff options
| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2021-06-14 14:14:25 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-06-15 17:46:48 +0200 |
| commit | 293649307ef9abcd4f83f6dac4d4400dfd97c936 (patch) | |
| tree | 745286c3c1d2ef6bc847a92046bb619bb47d02f0 | |
| parent | ad3c2e174938d72fded674acead42e2464a3b460 (diff) | |
x86/tsx: Clear CPUID bits when TSX always force aborts
As a result of TSX deprecation, some processors always abort TSX
transactions by default after a microcode update.
When TSX feature cannot be used it is better to hide it. Clear CPUID.RTM
and CPUID.HLE bits when TSX transactions always abort.
[ bp: Massage commit message and comments. ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Link: https://lkml.kernel.org/r/5209b3d72ffe5bd3cafdcc803f5b883f785329c3.1623704845.git-series.pawan.kumar.gupta@linux.intel.com
| -rw-r--r-- | arch/x86/kernel/cpu/cpu.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/tsx.c | 37 |
3 files changed, 40 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 67944128876d..95521302630d 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -48,6 +48,7 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[], enum tsx_ctrl_states { TSX_CTRL_ENABLE, TSX_CTRL_DISABLE, + TSX_CTRL_RTM_ALWAYS_ABORT, TSX_CTRL_NOT_SUPPORTED, }; @@ -56,6 +57,7 @@ extern __ro_after_init enum tsx_ctrl_states tsx_ctrl_state; extern void __init tsx_init(void); extern void tsx_enable(void); extern void tsx_disable(void); +extern void tsx_clear_cpuid(void); #else static inline void tsx_init(void) { } #endif /* CONFIG_CPU_SUP_INTEL */ diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 8adffc17fa8b..861e919eba9a 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -717,8 +717,10 @@ static void init_intel(struct cpuinfo_x86 *c) if (tsx_ctrl_state == TSX_CTRL_ENABLE) tsx_enable(); - if (tsx_ctrl_state == TSX_CTRL_DISABLE) + else if (tsx_ctrl_state == TSX_CTRL_DISABLE) tsx_disable(); + else if (tsx_ctrl_state == TSX_CTRL_RTM_ALWAYS_ABORT) + tsx_clear_cpuid(); split_lock_init(); bus_lock_init(); diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c index e2ad30e474f8..9c7a5f049292 100644 --- a/arch/x86/kernel/cpu/tsx.c +++ b/arch/x86/kernel/cpu/tsx.c @@ -2,7 +2,7 @@ /* * Intel Transactional Synchronization Extensions (TSX) control. * - * Copyright (C) 2019 Intel Corporation + * Copyright (C) 2019-2021 Intel Corporation * * Author: * Pawan Gupta <pawan.kumar.gupta@linux.intel.com> @@ -84,13 +84,46 @@ static enum tsx_ctrl_states x86_get_tsx_auto_mode(void) return TSX_CTRL_ENABLE; } +void tsx_clear_cpuid(void) +{ + u64 msr; + + /* + * MSR_TFA_TSX_CPUID_CLEAR bit is only present when both CPUID + * bits RTM_ALWAYS_ABORT and TSX_FORCE_ABORT are present. + */ + if (boot_cpu_has(X86_FEATURE_RTM_ALWAYS_ABORT) && + boot_cpu_has(X86_FEATURE_TSX_FORCE_ABORT)) { + rdmsrl(MSR_TSX_FORCE_ABORT, msr); + msr |= MSR_TFA_TSX_CPUID_CLEAR; + wrmsrl(MSR_TSX_FORCE_ABORT, msr); + } +} + void __init tsx_init(void) { char arg[5] = {}; int ret; - if (!tsx_ctrl_is_supported()) + /* + * Hardware will always abort a TSX transaction if both CPUID bits + * RTM_ALWAYS_ABORT and TSX_FORCE_ABORT are set. In this case, it is + * better not to enumerate CPUID.RTM and CPUID.HLE bits. Clear them + * here. + */ + if (boot_cpu_has(X86_FEATURE_RTM_ALWAYS_ABORT) && + boot_cpu_has(X86_FEATURE_TSX_FORCE_ABORT)) { + tsx_ctrl_state = TSX_CTRL_RTM_ALWAYS_ABORT; + tsx_clear_cpuid(); + setup_clear_cpu_cap(X86_FEATURE_RTM); + setup_clear_cpu_cap(X86_FEATURE_HLE); return; + } + + if (!tsx_ctrl_is_supported()) { + tsx_ctrl_state = TSX_CTRL_NOT_SUPPORTED; + return; + } ret = cmdline_find_option(boot_command_line, "tsx", arg, sizeof(arg)); if (ret >= 0) { |