[PATCH v8 2/4] mm: Introduce memblock_isolate_memory
From: Alexandre Ghiti <hidden>
Date: 2023-03-16 13:20:08
Also in:
linux-devicetree, linux-mm, linux-riscv, lkml
Subsystem:
memblock and memory management initialization, memory management, the rest · Maintainers:
Mike Rapoport, Andrew Morton, Linus Torvalds
This function allows to split a region in memblock.memory and will be useful when setting up the linear mapping with STRICT_KERNEL_RWX: it allows to isolate the kernel text/rodata and then avoid to map those regions with a PUD/P4D/PGD. Signed-off-by: Alexandre Ghiti <redacted> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> --- include/linux/memblock.h | 1 + mm/memblock.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+)
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 50ad19662a32..2f7ef97c0da7 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h@@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); void memblock_free_all(void); void memblock_free(void *ptr, size_t size);
diff --git a/mm/memblock.c b/mm/memblock.c
index 25fd0626a9e7..e8c651a37012 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c@@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, return 0; } +/** + * memblock_isolate_memory - isolate given range in memblock.memory + * @base: base of range to isolate + * @size: size of range to isolate + * + * Isolates the given range in memblock.memory so that it does not share any + * region with other ranges. + * + * Return: + * 0 on success, -errno on failure. + */ + +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) +{ + int start_rgn, end_rgn; + + return memblock_isolate_range(&memblock.memory, base, size, + &start_rgn, &end_rgn); +} + static int __init_memblock memblock_remove_range(struct memblock_type *type, phys_addr_t base, phys_addr_t size) {
--
2.37.2
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