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From: Pierre Gondois <pierre.gondois@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Ionela.Voinescu@arm.com, Dietmar.Eggemann@arm.com,
	Pierre Gondois <pierre.gondois@arm.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Robert Moore <robert.moore@intel.com>,
	linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org,
	devel@acpica.org
Subject: [PATCH v1 2/5] ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported
Date: Wed, 11 May 2022 15:45:56 +0200	[thread overview]
Message-ID: <20220511134559.1466925-2-pierre.gondois@arm.com> (raw)
In-Reply-To: <20220511134559.1466925-1-pierre.gondois@arm.com>

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@arm.com>
---
 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 a5d08de5d1e9..4fd0ea779441 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_SP;
@@ -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
 
 	/*
-- 
2.25.1


  reply	other threads:[~2022-05-11 13:46 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-11 13:45 [PATCH v1 1/5] ACPI: CPPC: Check _OSC for flexible address space Pierre Gondois
2022-05-11 13:45 ` Pierre Gondois [this message]
2022-05-11 14:22   ` [PATCH v1 2/5] ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported Sudeep Holla
2022-05-11 13:45 ` [PATCH v1 3/5] ACPI: CPPC: Assume no transition latency if no PCCT Pierre Gondois
2022-05-11 14:30   ` Sudeep Holla
2022-05-12 15:04     ` Rafael J. Wysocki
2022-05-11 13:45 ` [PATCH v1 4/5] cpufreq: CPPC: Enable fast_switch Pierre Gondois
2022-05-11 14:41   ` Sudeep Holla
2022-05-12  7:46   ` Viresh Kumar
2022-05-11 13:45 ` [PATCH v1 5/5] cpufreq: CPPC: Enable dvfs_possible_from_any_cpu Pierre Gondois
2022-05-11 14:50   ` Sudeep Holla
2022-05-12  7:47   ` Viresh Kumar
2022-05-11 14:17 ` [PATCH v1 1/5] ACPI: CPPC: Check _OSC for flexible address space Sudeep Holla
2022-05-12 15:03   ` Rafael J. Wysocki

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