diff options
Diffstat (limited to 'arch/x86/kernel/acpi/cstate.c')
| -rw-r--r-- | arch/x86/kernel/acpi/cstate.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index 49ae4e1ac9cd..d28d43d774a2 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -79,6 +79,21 @@ void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags, */ flags->bm_control = 0; } + if (c->x86_vendor == X86_VENDOR_AMD && c->x86 >= 0x17) { + /* + * For all AMD Zen or newer CPUs that support C3, caches + * should not be flushed by software while entering C3 + * type state. Set bm->check to 1 so that kernel doesn't + * need to execute cache flush operation. + */ + flags->bm_check = 1; + /* + * In current AMD C state implementation ARB_DIS is no longer + * used. So set bm_control to zero to indicate ARB_DIS is not + * required while entering C3 type state. + */ + flags->bm_control = 0; + } } EXPORT_SYMBOL(acpi_processor_power_init_bm_check); |