Add fw_smepmp_ids bitmap to track PMP entries that protect firmware
regions. Allow us to preserve these critical entries across domain
transitions and check inconsistent firmware entry allocation.
Also add sbi_hart_smepmp_is_fw_region() helper function to query
whether a given SmePMP entry protects firmware regions.
Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20251008084444.3525615-8-peter.lin@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
During domain context switches, all PMP entries are reconfigured
which can clear firmware access permissions, causing M-mode access
faults under SmePMP.
Sort domain regions to place firmware regions first, ensuring
consistent firmware PMP entries so they won't be revoked during
domain context switches.
Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20251008084444.3525615-7-peter.lin@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Previously, when memory regions exceed available PMP entries,
some regions were silently ignored. If the last entry that covers
the full 64-bit address space is not added to a domain, the next
stage S-mode software won't have permission to access and fetch
instructions from its memory. So return early with error message
to catch such situation.
Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20251008084444.3525615-5-peter.lin@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
