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authorMark Brown <broonie@kernel.org>2021-04-01 21:09:40 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2021-04-08 20:39:18 +0300
commit31c00d2aeaa2da89361f5b64a64ca831433be5fc (patch)
treeee5b9c2400bebe5d0182c971f140220107168876 /arch/arm64/include/asm/el2_setup.h
parent3e237387bb76cbbd254e82fb1e996e2f3af9e6a7 (diff)
downloadlinux-31c00d2aeaa2da89361f5b64a64ca831433be5fc.tar.xz
arm64: Disable fine grained traps on boot
The arm64 FEAT_FGT extension introduces a set of traps to EL2 for accesses to small sets of registers and instructions from EL1 and EL0. Currently Linux makes no use of this feature, ensure that it is not active at boot by disabling the traps during EL2 setup. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210401180942.35815-3-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/el2_setup.h')
-rw-r--r--arch/arm64/include/asm/el2_setup.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index d77d358f9395..b3f2d3bb0938 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -131,6 +131,26 @@
.Lskip_sve_\@:
.endm
+/* Disable any fine grained traps */
+.macro __init_el2_fgt
+ mrs x1, id_aa64mmfr0_el1
+ ubfx x1, x1, #ID_AA64MMFR0_FGT_SHIFT, #4
+ cbz x1, .Lskip_fgt_\@
+
+ msr_s SYS_HDFGRTR_EL2, xzr
+ msr_s SYS_HDFGWTR_EL2, xzr
+ msr_s SYS_HFGRTR_EL2, xzr
+ msr_s SYS_HFGWTR_EL2, xzr
+ msr_s SYS_HFGITR_EL2, xzr
+
+ mrs x1, id_aa64pfr0_el1 // AMU traps UNDEF without AMU
+ ubfx x1, x1, #ID_AA64PFR0_AMU_SHIFT, #4
+ cbz x1, .Lskip_fgt_\@
+
+ msr_s SYS_HAFGRTR_EL2, xzr
+.Lskip_fgt_\@:
+.endm
+
.macro __init_el2_nvhe_prepare_eret
mov x0, #INIT_PSTATE_EL1
msr spsr_el2, x0
@@ -155,6 +175,7 @@
__init_el2_nvhe_idregs
__init_el2_nvhe_cptr
__init_el2_nvhe_sve
+ __init_el2_fgt
__init_el2_nvhe_prepare_eret
.endm