diff options
| author | James Morse <james.morse@arm.com> | 2024-10-30 16:03:12 +0000 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2024-10-31 18:09:38 +0000 |
| commit | 23b33d1e168cfcc96666f025beb3bccfcb58403a (patch) | |
| tree | d14a2a7cc12f3f54bcb419f93886c5e2317a6ad9 | |
| parent | 83732ce6a056c4bb242d64fd25e1fc78f35e6a74 (diff) | |
arm64: head.S: Initialise MPAM EL2 registers and disable traps
Add code to head.S's el2_setup to detect MPAM and disable any EL2 traps.
This register resets to an unknown value, setting it to the default
parititons/pmg before we enable the MMU is the best thing to do.
Kexec/kdump will depend on this if the previous kernel left the CPU
configured with a restrictive configuration.
If linux is booted at the highest implemented exception level el2_setup
will clear the enable bit, disabling MPAM.
This code can't be enabled until a subsequent patch adds the Kconfig
and cpufeature boiler plate.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241030160317.2528209-3-joey.gouly@arm.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/include/asm/el2_setup.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index e0ffdf13a18b..4cd41464be3f 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -220,6 +220,19 @@ msr spsr_el2, x0 .endm +.macro __init_el2_mpam + /* Memory Partitioning And Monitoring: disable EL2 traps */ + mrs x1, id_aa64pfr0_el1 + ubfx x0, x1, #ID_AA64PFR0_EL1_MPAM_SHIFT, #4 + cbz x0, .Lskip_mpam_\@ // skip if no MPAM + msr_s SYS_MPAM2_EL2, xzr // use the default partition + // and disable lower traps + mrs_s x0, SYS_MPAMIDR_EL1 + tbz x0, #MPAMIDR_EL1_HAS_HCR_SHIFT, .Lskip_mpam_\@ // skip if no MPAMHCR reg + msr_s SYS_MPAMHCR_EL2, xzr // clear TRAP_MPAMIDR_EL1 -> EL2 +.Lskip_mpam_\@: +.endm + /** * Initialize EL2 registers to sane values. This should be called early on all * cores that were booted in EL2. Note that everything gets initialised as @@ -237,6 +250,7 @@ __init_el2_stage2 __init_el2_gicv3 __init_el2_hstr + __init_el2_mpam __init_el2_nvhe_idregs __init_el2_cptr __init_el2_fgt |