Replace the sparc32-private sp_banks memory description with memblock.
The first two patches convert the SRMMU consumers that already run after
bootmem_init() has populated memblock. The third patch moves memblock
population to prom_meminit() and applies the mem= limit there. Patch 4
removes an unused address bitmap before patch 5 moves the early memory
setup into setup_32.c. Patch 6 removes the now-unused sp_banks array.
This work is based on an earlier eight-patch series by Sam Ravnborg.
Patch 2 directly carries over Sam's memblock sizing conversion. The series
has otherwise been substantially reorganized and reworked for the current
kernel. It retains the sparc32 mem= command-line option by using
memblock_enforce_memory_limit() and uses memblock's exclusive range-end
semantics throughout.
The series applies on top of the sparc32 phys_base and Viking fixes,
rebased onto Linux 7.3-rc1. The prerequisite tip is recorded below as the
base commit. setup_memory() preserves relocated-kernel handling by
removing RAM below the physical address to which PAGE_OFFSET maps.
Link: https://lore.kernel.org/sparclinux/20260816075141.3489194-1-linmag7@gmail.com/T/#t
The v1 series was boot tested on a Sun SPARCstation 20 with dual
SuperSPARC-II CPUs (SM71).
The v2 series was boot tested on a Sun SPARCstation 20 with dual
ROSS HyperSPARC (RT626) CPUs.
The v3 series was cross-compiled with the SPARCstation 20 and LEON
configurations as well as boot tested on a Sun SPARCstation 20
with dual ROSS HyperSPARC (RT626) CPUs.
The v4 series was cross-compiled with the SPARCstation 20 SMP configuration
and a sparc32_defconfig-derived LEON configuration, both with HIGHMEM
enabled. Boot tested on a SPARCstation 20 SMP (ROSS)
Changes in v4:
- Use max_pfn in LEON's _pfn_valid() check, preserving the bounds of
last_valid_pfn instead of restricting the check to lowmem, as requested
by Andreas Larsson.
- Correct the description: LEON systems can use highmem.
- Carry Sam's Reviewed-by tag on patch 5; all six patches now retain his
review tags.
- Rebase onto Linux 7.3-rc1 plus the three prerequisite patches; adjust
patch 6's context without changing its code changes.
Changes in v3:
- Add Sam's Reviewed-by tag to patch 4.
- Initialize max_pfn in patch 5 and use it as the highmem zone limit.
- Use PHYS_PFN() instead of open-coded PAGE_SHIFT conversions in patch 5.
- Remove the obsolete highstart_pfn and highend_pfn declarations.
- Use the generic PFN limit declarations from linux/memblock.h.
- Document removal of the duplicate private HIGHMEM summary.
Changes in v2:
- Add Sam's Reviewed-by tags to patches 1-3 and 6. Patch 6 is the
unchanged source change from patch 5 in v1, renumbered by the new patch.
- Drop the unused sparc_valid_addr_bitmap in a preparation patch.
- Use for_each_mem_pfn_range() and the standard max_low_pfn variable in
the early memory setup. The change to LEON's PFN check made in v2 is
corrected in v4 to preserve its original bounds.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20260817153237.GA702187@ravnborg.org
Link: https://lore.kernel.org/r/20260901214611.60560-1-linmag7@gmail.com
Magnus Lindholm (6):
sparc32: use memblock when mapping the kernel
sparc32: use memblock to find available system memory
sparc32: populate memblock from the PROM memory map
sparc32: drop unused valid address bitmap
sparc32: move early memory setup to setup_arch
sparc32: drop sp_banks
arch/sparc/include/asm/highmem.h | 3 -
arch/sparc/include/asm/leon.h | 2 +-
arch/sparc/include/asm/page_32.h | 16 ---
arch/sparc/include/asm/pgtable_32.h | 3 +-
arch/sparc/include/asm/pgtsrmmu.h | 1 -
arch/sparc/kernel/setup_32.c | 112 ++++++++++---------
arch/sparc/mm/init_32.c | 167 +---------------------------
arch/sparc/mm/leon_mm.c | 1 +
arch/sparc/mm/srmmu.c | 69 ++++--------
arch/sparc/prom/memory.c | 51 ++-------
10 files changed, 98 insertions(+), 327 deletions(-)
base-commit: ff3cbaedcebcb60f8f13fa4dd667116f29cd53e4
--
2.43.0