@@ -208,6 +208,21 @@
msr spsr_el2, x0
.endm
+.macro __init_el2_mpam
+#ifdef CONFIG_ARM64_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, #17, .Lskip_mpam_\@ // skip if no MPAMHCR reg
+ msr_s SYS_MPAMHCR_EL2, xzr // clear TRAP_MPAMIDR_EL1 -> EL2
+.Lskip_mpam_\@:
+#endif /* CONFIG_ARM64_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
@@ -225,6 +240,7 @@
__init_el2_stage2
__init_el2_gicv3
__init_el2_hstr
+ __init_el2_mpam
__init_el2_nvhe_idregs
__init_el2_cptr
__init_el2_fgt
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> --- arch/arm64/include/asm/el2_setup.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)