[PATCH 5.18 086/112] ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported

From: Greg Kroah-Hartman
Date: Mon Jul 11 2022 - 05:36:00 EST


From: Pierre Gondois <pierre.gondois@xxxxxxx>

[ Upstream commit 72f2ecb7ece7c1d89758d4929d98e95d95fe7199 ]

The _OSC method allows the OS and firmware to communicate about
supported features/capabitlities. It also allows the OS to take
control of some features.

In ACPI 6.4, s6.2.11.2 Platform-Wide OSPM Capabilities, the CPPC
(resp. v2) bit should be set by the OS if it 'supports controlling
processor performance via the interfaces described in the _CPC
object'.

The OS supports CPPC and parses the _CPC object only if
CONFIG_ACPI_CPPC_LIB is set. Replace the x86 specific
boot_cpu_has(X86_FEATURE_HWP) dynamic check with an arch
generic CONFIG_ACPI_CPPC_LIB build-time check.

Note:
CONFIG_X86_INTEL_PSTATE selects CONFIG_ACPI_CPPC_LIB.

Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/acpi/bus.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9eca43d1d941..1fc24f4fbcb4 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -329,10 +329,11 @@ static void acpi_bus_osc_negotiate_platform_control(void)
#endif
#ifdef CONFIG_X86
capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
- if (boot_cpu_has(X86_FEATURE_HWP)) {
- capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
- capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
- }
+#endif
+
+#ifdef CONFIG_ACPI_CPPC_LIB
+ capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
+ capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
#endif

capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_FLEXIBLE_ADR_SPACE;
@@ -357,10 +358,9 @@ static void acpi_bus_osc_negotiate_platform_control(void)
return;
}

-#ifdef CONFIG_X86
- if (boot_cpu_has(X86_FEATURE_HWP))
- osc_sb_cppc_not_supported = !(capbuf_ret[OSC_SUPPORT_DWORD] &
- (OSC_SB_CPC_SUPPORT | OSC_SB_CPCV2_SUPPORT));
+#ifdef CONFIG_ACPI_CPPC_LIB
+ osc_sb_cppc_not_supported = !(capbuf_ret[OSC_SUPPORT_DWORD] &
+ (OSC_SB_CPC_SUPPORT | OSC_SB_CPCV2_SUPPORT));
#endif

/*
--
2.35.1