linux-kernel - [PATCH 5.18 086/112] ACPI: bus: Set CPPC _OSC bits for all and when CPPC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220711090552.012032465@linuxfoundation.org>
Date:   Mon, 11 Jul 2022 11:07:26 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Pierre Gondois <pierre.gondois@....com>,
        Sudeep Holla <sudeep.holla@....com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.18 086/112] ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported

From: Pierre Gondois <pierre.gondois@....com>

[ 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@....com>
Reviewed-by: Sudeep Holla <sudeep.holla@....com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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