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 <[email protected]>
Signed-off-by: Joey Gouly <[email protected]>
Reviewed-by: Gavin Shan <[email protected]>
Tested-by: Shameer Kolothum <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Reviewed-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Oliver Upton <[email protected]>

0 files changed, 0 insertions, 0 deletions