[PATCH 5.14 040/432] arm64: Do not trap PMSNEVFR_EL1

Greg Kroah-Hartman
2021-09-16T17:14:19Z

From: Alexandru Elisei <alexandru.elisei@arm.com>

commit 50cb99fa89aa2bec2cab2f9917010bbd7769bfa3 upstream.

Commit 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot") zeroed
the fine grained trap registers to prevent unwanted register traps from
occuring. However, for the PMSNEVFR_EL1 register, the corresponding
HDFG{R,W}TR_EL2.nPMSNEVFR_EL1 fields must be 1 to disable trapping. Set
both fields to 1 if FEAT_SPEv1p2 is detected to disable read and write
traps.

Fixes: 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot")
Cc: <stable@vger.kernel.org> # 5.13.x
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210824154523.906270-1-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/el2_setup.h | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -149,8 +149,17 @@
ubfx x1, x1, #ID_AA64MMFR0_FGT_SHIFT, #4
cbz x1, .Lskip_fgt_\@

- msr_s SYS_HDFGRTR_EL2, xzr
- msr_s SYS_HDFGWTR_EL2, xzr
+ mov x0, xzr
+ mrs x1, id_aa64dfr0_el1
+ ubfx x1, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
+ cmp x1, #3
+ b.lt .Lset_fgt_\@
+ /* Disable PMSNEVFR_EL1 read and write traps */
+ orr x0, x0, #(1 << 62)
+
+.Lset_fgt_\@:
+ msr_s SYS_HDFGRTR_EL2, x0
+ msr_s SYS_HDFGWTR_EL2, x0
msr_s SYS_HFGRTR_EL2, xzr
msr_s SYS_HFGWTR_EL2, xzr
msr_s SYS_HFGITR_EL2, xzr