diff options
Diffstat (limited to 'arch/x86/kernel/acpi/cstate.c')
| -rw-r--r-- | arch/x86/kernel/acpi/cstate.c | 27 |
1 files changed, 3 insertions, 24 deletions
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index d2b7f27781b..4b28159e042 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -87,7 +87,9 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK; retval = 0; - if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) { + /* If the HW does not support any sub-states in this C-state */ + if (num_cstate_subtype == 0) { + pr_warn(FW_BUG "ACPI MWAIT C-state 0x%x not supported by HW (0x%x)\n", cx->address, edx_part); retval = -1; goto out; } @@ -150,29 +152,6 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, } EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe); -/* - * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, - * which can obviate IPI to trigger checking of need_resched. - * We execute MONITOR against need_resched and enter optimized wait state - * through MWAIT. Whenever someone changes need_resched, we would be woken - * up from MWAIT (without an IPI). - * - * New with Core Duo processors, MWAIT can take some hints based on CPU - * capability. - */ -void mwait_idle_with_hints(unsigned long ax, unsigned long cx) -{ - if (!need_resched()) { - if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) - clflush((void *)¤t_thread_info()->flags); - - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __mwait(ax, cx); - } -} - void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cx) { unsigned int cpu = smp_processor_id(); |