[RFC PATCH 0/7] Extend the reserved PMP entries

[Yu-Chien Peter Lin]

This series extends the number of reserved PMP entry.
The capabilities of the reserved PMP entries include:
- Highest priority
- Allow TOR mode for platform-specific use cases
- Can be consistent across domain context switches
- Allow runtime PMP allocation

A potential use case for reserved PMP entries is parsing gaps in
memory ports marked as PMA_UNSAFE [1] in device-tree. These gaps
may not be able to exactly covered by 1 or 2 NAPOT entries, so TOR
mode PMP can be allocated to save PMP usage. Besides, they don't
need reconfiguration across domains.

This series depends on:
1) https://lore.kernel.org/all/20250815024434.14303-1-peter.lin@sifive.com/
2) https://lore.kernel.org/all/20250814110522.18809-1-peter.lin@sifive.com/

[1] https://patchwork.kernel.org/project/linux-riscv/patch/20241102000843.1301099-2-samuel.holland@sifive.com/

Yu-Chien Peter Lin (7):
  lib: utils: fdt_helper: add fdt_has_isa_extension() helper
  include: sbi: sbi_platform: add reserved_pmp_count field
  platform: generic: platform: introduce
    fw_platform_get_reserved_pmp_count()
  lib: sbi_init: print total and reserved PMP counts
  lib: sbi: riscv_asm: add reserved_pmp_alloc() to allocate a reserved
    PMP
  lib: sbi: sbi_hart: extend PMP handling to support multiple reserved
    entries
  docs: opensbi_config: add description for reserved-pmp-count

 docs/opensbi_config.md             |  4 +++
 include/sbi/riscv_asm.h            |  2 ++
 include/sbi/sbi_hart.h             | 15 --------
 include/sbi/sbi_platform.h         | 15 +++++---
 include/sbi_utils/fdt/fdt_helper.h |  2 ++
 lib/sbi/riscv_asm.c                | 25 +++++++++++++
 lib/sbi/sbi_domain_context.c       |  6 +++-
 lib/sbi/sbi_hart.c                 | 56 ++++++++++++++++++++++--------
 lib/sbi/sbi_init.c                 |  6 ++--
 lib/utils/fdt/fdt_helper.c         | 35 +++++++++++++++++++
 platform/generic/platform.c        | 34 ++++++++++++++++++
 11 files changed, 163 insertions(+), 37 deletions(-)

-- 
2.48.0