From a142d0ae9f2ceb0fc7417e19ecfafc8179282e35 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 25 Feb 2026 13:39:48 +0100 Subject: [PATCH] memblock: Permit existing reserved regions to be marked RSRV_KERN Permit existing memblock reservations to be marked as RSRV_KERN. This will be used by the EFI code on x86 to distinguish between reservations of boot services data regions that have actual significance to the kernel and regions that are reserved temporarily to work around buggy firmware. Acked-by: Mike Rapoport (Microsoft) Signed-off-by: Ard Biesheuvel --- include/linux/memblock.h | 1 + mm/memblock.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 6ec5e9ac0699..9eac4f268359 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -155,6 +155,7 @@ 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_reserved_mark_noinit(phys_addr_t base, phys_addr_t size); +int memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size); int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size); int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size); diff --git a/mm/memblock.c b/mm/memblock.c index b3ddfdec7a80..2505ce8b319c 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1115,6 +1115,21 @@ int __init_memblock memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t MEMBLOCK_RSRV_NOINIT); } +/** + * memblock_reserved_mark_kern - Mark a reserved memory region with flag + * MEMBLOCK_RSRV_KERN + * + * @base: the base phys addr of the region + * @size: the size of the region + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.reserved, base, size, 1, + MEMBLOCK_RSRV_KERN); +} + /** * memblock_mark_kho_scratch - Mark a memory region as MEMBLOCK_KHO_SCRATCH. * @base: the base phys addr of the region