From 858c7bfcb35e1100b58bb63c9f562d86e09418d9 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 27 Feb 2025 09:21:19 +0530 Subject: [PATCH] arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9 FEAT_PMUv3p9 registers such as PMICNTR_EL0, PMICFILTR_EL0, and PMUACR_EL1 access from EL1 requires appropriate EL2 fine grained trap configuration via FEAT_FGT2 based trap control registers HDFGRTR2_EL2 and HDFGWTR2_EL2. Otherwise such register accesses will result in traps into EL2. Add a new helper __init_el2_fgt2() which initializes FEAT_FGT2 based fine grained trap control registers HDFGRTR2_EL2 and HDFGWTR2_EL2 (setting the bits nPMICNTR_EL0, nPMICFILTR_EL0 and nPMUACR_EL1) to enable access into PMICNTR_EL0, PMICFILTR_EL0, and PMUACR_EL1 registers. Also update booting.rst with SCR_EL3.FGTEn2 requirement for all FEAT_FGT2 based registers to be accessible in EL2. Cc: Will Deacon Cc: Mark Rutland Cc: Rob Herring Cc: Jonathan Corbet Cc: Marc Zyngier Cc: Oliver Upton Cc: linux-arm-kernel@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: kvmarm@lists.linux.dev Fixes: 0bbff9ed8165 ("perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control") Fixes: d8226d8cfbaf ("perf: arm_pmuv3: Add support for Armv9.4 PMU instruction counter") Tested-by: Rob Herring (Arm) Reviewed-by: Rob Herring (Arm) Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/20250227035119.2025171-1-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas --- Documentation/arch/arm64/booting.rst | 22 ++++++++++++++++++++++ arch/arm64/include/asm/el2_setup.h | 25 +++++++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index cad6fdc96b98b..dee7b6de864fc 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -288,6 +288,12 @@ Before jumping into the kernel, the following conditions must be met: - SCR_EL3.FGTEn (bit 27) must be initialised to 0b1. + For CPUs with the Fine Grained Traps 2 (FEAT_FGT2) extension present: + + - If EL3 is present and the kernel is entered at EL2: + + - SCR_EL3.FGTEn2 (bit 59) must be initialised to 0b1. + For CPUs with support for HCRX_EL2 (FEAT_HCX) present: - If EL3 is present and the kernel is entered at EL2: @@ -382,6 +388,22 @@ Before jumping into the kernel, the following conditions must be met: - SMCR_EL2.EZT0 (bit 30) must be initialised to 0b1. + For CPUs with the Performance Monitors Extension (FEAT_PMUv3p9): + + - If EL3 is present: + + - MDCR_EL3.EnPM2 (bit 7) must be initialised to 0b1. + + - If the kernel is entered at EL1 and EL2 is present: + + - HDFGRTR2_EL2.nPMICNTR_EL0 (bit 2) must be initialised to 0b1. + - HDFGRTR2_EL2.nPMICFILTR_EL0 (bit 3) must be initialised to 0b1. + - HDFGRTR2_EL2.nPMUACR_EL1 (bit 4) must be initialised to 0b1. + + - HDFGWTR2_EL2.nPMICNTR_EL0 (bit 2) must be initialised to 0b1. + - HDFGWTR2_EL2.nPMICFILTR_EL0 (bit 3) must be initialised to 0b1. + - HDFGWTR2_EL2.nPMUACR_EL1 (bit 4) must be initialised to 0b1. + For CPUs with Memory Copy and Memory Set instructions (FEAT_MOPS): - If the kernel is entered at EL1 and EL2 is present: diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index 25e1626517500..1a0071faf57ec 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -233,6 +233,30 @@ .Lskip_fgt_\@: .endm +.macro __init_el2_fgt2 + mrs x1, id_aa64mmfr0_el1 + ubfx x1, x1, #ID_AA64MMFR0_EL1_FGT_SHIFT, #4 + cmp x1, #ID_AA64MMFR0_EL1_FGT_FGT2 + b.lt .Lskip_fgt2_\@ + + mov x0, xzr + mrs x1, id_aa64dfr0_el1 + ubfx x1, x1, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4 + cmp x1, #ID_AA64DFR0_EL1_PMUVer_V3P9 + b.lt .Lskip_pmuv3p9_\@ + + orr x0, x0, #HDFGRTR2_EL2_nPMICNTR_EL0 + orr x0, x0, #HDFGRTR2_EL2_nPMICFILTR_EL0 + orr x0, x0, #HDFGRTR2_EL2_nPMUACR_EL1 +.Lskip_pmuv3p9_\@: + msr_s SYS_HDFGRTR2_EL2, x0 + msr_s SYS_HDFGWTR2_EL2, x0 + msr_s SYS_HFGRTR2_EL2, xzr + msr_s SYS_HFGWTR2_EL2, xzr + msr_s SYS_HFGITR2_EL2, xzr +.Lskip_fgt2_\@: +.endm + .macro __init_el2_gcs mrs_s x1, SYS_ID_AA64PFR1_EL1 ubfx x1, x1, #ID_AA64PFR1_EL1_GCS_SHIFT, #4 @@ -283,6 +307,7 @@ __init_el2_nvhe_idregs __init_el2_cptr __init_el2_fgt + __init_el2_fgt2 __init_el2_gcs .endm