arm64: Do not trap PMSNEVFR_EL1

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>

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 21fa330..29bcd79 100644 (file)
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -150,8 +150,17 @@
        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