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arm64: Disable fine grained traps on boot

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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>
This commit is contained in:
Mark Brown 2021-04-01 19:09:40 +01:00 committed by Catalin Marinas
parent 3e237387bb
commit 31c00d2aea
2 changed files with 27 additions and 0 deletions
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21
arch/arm64/include/asm/el2_setup.h
View file

@ -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

6
arch/arm64/include/asm/sysreg.h
View file

@ -475,9 +475,15 @@
#define SYS_PMCCFILTR_EL0 sys_reg(3, 3, 14, 15, 7)
#define SYS_SCTLR_EL2 sys_reg(3, 4, 1, 0, 0)
#define SYS_HFGRTR_EL2 sys_reg(3, 4, 1, 1, 4)
#define SYS_HFGWTR_EL2 sys_reg(3, 4, 1, 1, 5)
#define SYS_HFGITR_EL2 sys_reg(3, 4, 1, 1, 6)
#define SYS_ZCR_EL2 sys_reg(3, 4, 1, 2, 0)
#define SYS_TRFCR_EL2 sys_reg(3, 4, 1, 2, 1)
#define SYS_DACR32_EL2 sys_reg(3, 4, 3, 0, 0)
#define SYS_HDFGRTR_EL2 sys_reg(3, 4, 3, 1, 4)
#define SYS_HDFGWTR_EL2 sys_reg(3, 4, 3, 1, 5)
#define SYS_HAFGRTR_EL2 sys_reg(3, 4, 3, 1, 6)
#define SYS_SPSR_EL2 sys_reg(3, 4, 4, 0, 0)
#define SYS_ELR_EL2 sys_reg(3, 4, 4, 0, 1)
#define SYS_IFSR32_EL2 sys_reg(3, 4, 5, 0, 1)