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From: Tony Luck <tony.luck@intel.com>
To: Fenghua Yu <fenghuay@nvidia.com>,
	Reinette Chatre <reinette.chatre@intel.com>,
	Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>,
	Peter Newman <peternewman@google.com>,
	James Morse <james.morse@arm.com>,
	Babu Moger <babu.moger@amd.com>,
	Drew Fustini <dfustini@baylibre.com>,
	Dave Martin <Dave.Martin@arm.com>, Chen Yu <yu.c.chen@intel.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	patches@lists.linux.dev, Tony Luck <tony.luck@intel.com>
Subject: [RFC PATCH v2 02/11] x86/resctrl: Disable symmetric L2 CAT on Panther Lake
Date: Tue,  3 Nov 2026 13:22:45 -0800	[thread overview]
Message-ID: <20261103212254.18314-3-tony.luck@intel.com> (raw)
In-Reply-To: <20261103212254.18314-1-tony.luck@intel.com>

Panther Lake reports L2 CAT in the symmetric CPUID leaf even though the
feature differs between P-cores and E-cores.

Disable the symmetric l2cat option for Panther Lake so resctrl does not
enumerate this asymmetric feature as symmetric.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/kernel/cpu/resctrl/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 7951cfd20da4..709075ffc706 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -1128,6 +1128,9 @@ static __init void __check_quirks_intel(void)
 	case INTEL_BROADWELL_X:
 		intel_rdt_mbm_apply_quirk();
 		break;
+	case INTEL_PANTHERLAKE_L:
+		set_rdt_options("!l2cat");
+		break;
 	}
 }
 
-- 
2.56.0


  parent reply	other threads:[~2026-11-03 21:23 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-03 21:22 [RFC PATCH v2 00/11] x86/resctrl: Support asymmetric L2 CAT on hybrid CPUs Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 01/11] fs/resctrl: Change UI of "max" file (merge back into earlier patches) Tony Luck
2026-11-03 21:22 ` Tony Luck [this message]
2026-11-03 21:22 ` [RFC PATCH v2 03/11] x86/cpuid: Define Intel RDT enumeration leaves Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 04/11] x86/resctrl: Add asymmetric L2 CAT feature bits and boot options Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 05/11] x86/resctrl: Handle cache allocation setup failures Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 06/11] x86/resctrl: Pass the CPUID leaf to rdt_get_cache_alloc_cfg() Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 07/11] arm,x86,fs/resctrl: Store cache bitmask length per control domain Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 08/11] x86/resctrl: Use cpu_feature_enabled() for RDT allocation Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 09/11] x86/resctrl: Accept asymmetric RDT allocation features Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 10/11] x86/resctrl: Enable asymmetric CAT from CPUID leaf 0x28 Tony Luck
2026-11-03 21:22 ` [RFC PATCH v2 11/11] fs/resctrl: Document asymmetric L2 allocation options Tony Luck

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