arch-riscv: Support PMP lock feature
The lock feature will let M mode do memory permission check before
R/W/X data. If the lock bit of pmpicfg set, then the pmpicfg and
pmpaddri will ignore the update value later until CPU reset, and
pmpaddri-1 will ignore if the TOR A field is set.
The following is add in CL:
1. Add condition to run PMP check when any lock bit of pmp tables
is set
2. Add PMP_LOCK bit check when try to update pmpaddr and pmpcfg
3. If there is no PMP entry matches and priviledge mode is M,
no fault generated
4. If the address matches PMP entry, return no fault if priviledge
mode is M and lock bit is not set
For more details about PMP, please see RISC-V Spec Volumn II,
Priviledge Archtecture, Ver 1.12, Section 3.7 Physical Memory
Protection
Change-Id: I3e7c5824d6c05f2ea928ee9ec7714f7271e4c58c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/68057
Reviewed-by: Ayaz Akram <yazakram@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Yu-hsin Wang <yuhsingw@google.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
4 files changed
