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authorAnshuman Khandual <anshuman.khandual@arm.com>2025-02-27 09:21:19 +0530
committerCatalin Marinas <catalin.marinas@arm.com>2025-03-11 16:57:28 +0000
commit858c7bfcb35e1100b58bb63c9f562d86e09418d9 (patch)
tree66d5f5ed2b5a649be8e58a55ebeb2269a49a108e
parentea37be0773f04420515b8db49e50abedbaa97e23 (diff)
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 <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Rob Herring <robh@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> 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) <robh@kernel.org> Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20250227035119.2025171-1-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--Documentation/arch/arm64/booting.rst22
-rw-r--r--arch/arm64/include/asm/el2_setup.h25
2 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst
index cad6fdc96b98..dee7b6de864f 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 25e162651750..1a0071faf57e 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