arm_gic: Mask the un-supported priority bits

The GICv2 allows the implementation to implement a variable number
of priority bits; unimplemented bits in the priority registers
are read as zeros, writes ignored. We were previously always
implementing a full 8 bits of priority, which is allowed but not
what the real hardware typically does (which is usually to have
4 or 5 bits of priority).

Add a new device property to allow the number of implemented
property bits to be specified.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Message-id: 1582537164-764-2-git-send-email-sai.pavan.boddu@xilinx.com
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: improved commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Sai Pavan Boddu 2020-02-24 15:09:22 +05:30 committed by Peter Maydell
parent 5df2cfbc8b
commit 11411489da
4 changed files with 35 additions and 2 deletions

View file

@ -96,6 +96,7 @@ typedef struct GICState {
uint16_t priority_mask[GIC_NCPU_VCPU];
uint16_t running_priority[GIC_NCPU_VCPU];
uint16_t current_pending[GIC_NCPU_VCPU];
uint32_t n_prio_bits;
/* If we present the GICv2 without security extensions to a guest,
* the guest can configure the GICC_CTLR to configure group 1 binary point