Commit bef58716 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

cma: split reservation of fixed area into a helper function 

Move the check that verifies that reservation of fixed area does not cross
HIGHMEM boundary and the actual memblock_resrve() call into a helper
function.

This makes code more readable and decouples logic related to
CONFIG_HIGHMEM from the core functionality of
__cma_declare_contiguous_nid().

Link: https://lkml.kernel.org/r/20250703184711.3485940-3-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: default avatarOscar Salvador <osalvador@suse.de>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 20089ebd

mm/cma.c

+27 −13
Original line number Diff line number Diff line
@@ -353,6 +353,30 @@ static void __init list_insert_sorted( 
	}

}



static int __init cma_fixed_reserve(phys_addr_t base, phys_addr_t size)

{

	if (IS_ENABLED(CONFIG_HIGHMEM)) {

		phys_addr_t highmem_start = __pa(high_memory - 1) + 1;



		/*

		 * If allocating at a fixed base the request region must not

		 * cross the low/high memory boundary.

		 */

		if (base < highmem_start && base + size > highmem_start) {

			pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",

			       &base, &highmem_start);

			return -EINVAL;

		}

	}



	if (memblock_is_region_reserved(base, size) ||

	    memblock_reserve(base, size) < 0) {

		return -EBUSY;

	}



	return 0;

}



static int __init __cma_declare_contiguous_nid(phys_addr_t *basep,

			phys_addr_t size, phys_addr_t limit,

			phys_addr_t alignment, unsigned int order_per_bit,
@@ -408,15 +432,6 @@ static int __init __cma_declare_contiguous_nid(phys_addr_t *basep, 
	if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))

		return -EINVAL;



	/*

	 * If allocating at a fixed base the request region must not cross the

	 * low/high memory boundary.

	 */

	if (fixed && base < highmem_start && base + size > highmem_start) {

		pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",

			&base, &highmem_start);

		return -EINVAL;

	}



	/*

	 * If the limit is unspecified or above the memblock end, its effective
@@ -434,10 +449,9 @@ static int __init __cma_declare_contiguous_nid(phys_addr_t *basep, 


	/* Reserve memory */

	if (fixed) {

		if (memblock_is_region_reserved(base, size) ||

		    memblock_reserve(base, size) < 0) {

			return -EBUSY;

		}

		ret = cma_fixed_reserve(base, size);

		if (ret)

			return ret;

	} else {

		phys_addr_t addr = 0;