ACPI: processor: Clear C_C2C3_FFH and C_C1_FFH in arch_acpi_set_proc_cap_bits()

Currently arch_acpi_set_proc_cap_bits() clears ACPI_PDC_C_C2C3_FFH bit in
case MWAIT instruction is not supported.

It should also clear ACPI_PDC_C_C1_FFH, as when MWAIT is not supported,
C1 is entered by executing the HLT instruction.

Quote from the C_C1_FFH description:

"If set, OSPM is capable of performing native C State instructions (beyond
halt) for the C1 handler in multi-processor configurations". As without
MWAIT there is no native C-state instructions beyond HALT, this bit
should be toggled off."

Clear ACPI_PDC_C_C1_FFH and ACPI_PDC_C_C2C3_FFH in
arch_acpi_set_proc_cap_bits() in case MWAIT is not supported or
overridden.

Remove setting those bits from the processor_pdc.c code.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index ce5ad6a..d615238 100644 (file)
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -113,11 +113,12 @@ static inline void arch_acpi_set_proc_cap_bits(u32 *cap)
                *cap |= ACPI_PROC_CAP_T_FFH;
 
        /*
-        * If mwait/monitor is unsupported, C2/C3_FFH will be disabled
+        * If mwait/monitor is unsupported, C_C1_FFH and
+        * C2/C3_FFH will be disabled.
         */
-       if (!cpu_has(c, X86_FEATURE_MWAIT))
-               *cap &= ~(ACPI_PROC_CAP_C_C2C3_FFH);
-
+       if (!cpu_has(c, X86_FEATURE_MWAIT) ||
+           boot_option_idle_override == IDLE_NOMWAIT)
+               *cap &= ~(ACPI_PROC_CAP_C_C1_FFH | ACPI_PROC_CAP_C_C2C3_FFH);
 }
 
 static inline bool acpi_has_cpu_in_madt(void)

diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
index 7948b5d..3c60352 100644 (file)
--- a/drivers/acpi/processor_pdc.c
+++ b/drivers/acpi/processor_pdc.c
@@ -74,20 +74,6 @@ acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 {
        acpi_status status = AE_OK;
 
-       if (boot_option_idle_override == IDLE_NOMWAIT) {
-               /*
-                * If mwait is disabled for CPU C-states, the C2C3_FFH access
-                * mode will be disabled in the parameter of _PDC object.
-                * Of course C1_FFH access mode will also be disabled.
-                */
-               union acpi_object *obj;
-               u32 *buffer = NULL;
-
-               obj = pdc_in->pointer;
-               buffer = (u32 *)(obj->buffer.pointer);
-               buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
-
-       }
        status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
 
        if (ACPI_FAILURE(status))