[PATCH 7/8] memblock, treewide: make memblock_free() handle late freeing

Mike Rapoport
2026-03-18T11:00:05Z

It shouldn't be responsibility of memblock users to detect if they free
memory allocated from memblock late and should use memblock_free_late().

Make memblock_free() and memblock_phys_free() take care of late memory
freeing and drop memblock_free_late().

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
arch/sparc/kernel/mdesc.c | 4 +--
arch/x86/kernel/setup.c | 2 +-
arch/x86/platform/efi/memmap.c | 5 +---
arch/x86/platform/efi/quirks.c | 2 +-
drivers/firmware/efi/apple-properties.c | 2 +-
drivers/of/kexec.c | 2 +-
include/linux/memblock.h | 2 --
kernel/dma/swiotlb.c | 6 ++--
lib/bootconfig.c | 2 +-
mm/kfence/core.c | 4 +--
mm/memblock.c | 37 +++++++------------------
11 files changed, 22 insertions(+), 46 deletions(-)

diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index 30f171b7b00c..ecd6c8ae49c7 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -183,14 +183,12 @@ static struct mdesc_handle * __init mdesc_memblock_alloc(unsigned int mdesc_size
static void __init mdesc_memblock_free(struct mdesc_handle *hp)
{
unsigned int alloc_size;
- unsigned long start;

BUG_ON(refcount_read(&hp->refcnt) != 0);
BUG_ON(!list_empty(&hp->list));

alloc_size = PAGE_ALIGN(hp->handle_size);
- start = __pa(hp);
- memblock_free_late(start, alloc_size);
+ memblock_free(hp, alloc_size);
}

static struct mdesc_mem_ops memblock_mdesc_ops = {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index eebcc9db1a1b..46882ce79c3a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -426,7 +426,7 @@ int __init ima_free_kexec_buffer(void)
if (!ima_kexec_buffer_size)
return -ENOENT;

- memblock_free_late(ima_kexec_buffer_phys,
+ memblock_phys_free(ima_kexec_buffer_phys,
ima_kexec_buffer_size);

ima_kexec_buffer_phys = 0;
diff --git a/arch/x86/platform/efi/memmap.c b/arch/x86/platform/efi/memmap.c
index 023697c88910..697a9a26a005 100644
--- a/arch/x86/platform/efi/memmap.c
+++ b/arch/x86/platform/efi/memmap.c
@@ -34,10 +34,7 @@ static
void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags)
{
if (flags & EFI_MEMMAP_MEMBLOCK) {
- if (slab_is_available())
- memblock_free_late(phys, size);
- else
- memblock_phys_free(phys, size);
+ memblock_phys_free(phys, size);
} else if (flags & EFI_MEMMAP_SLAB) {
struct page *p = pfn_to_page(PHYS_PFN(phys));
unsigned int order = get_order(size);
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 35caa5746115..a560bbcaa006 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -372,7 +372,7 @@ void __init efi_reserve_boot_services(void)
* doesn't make sense as far as the firmware is
* concerned, but it does provide us with a way to tag
* those regions that must not be paired with
- * memblock_free_late().
+ * memblock_phys_free().
*/
md->attribute |= EFI_MEMORY_RUNTIME;
}
diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c
index 13ac28754c03..2e525e17fba7 100644
--- a/drivers/firmware/efi/apple-properties.c
+++ b/drivers/firmware/efi/apple-properties.c
@@ -226,7 +226,7 @@ static int __init map_properties(void)
*/
data->len = 0;
memunmap(data);
- memblock_free_late(pa_data + sizeof(*data), data_len);
+ memblock_phys_free(pa_data + sizeof(*data), data_len);

return ret;
}
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index c4cf3552c018..512d9be9d513 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -175,7 +175,7 @@ int __init ima_free_kexec_buffer(void)
if (ret)
return ret;

- memblock_free_late(addr, size);
+ memblock_phys_free(addr, size);
return 0;
}
#endif
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 6ec5e9ac0699..6f6c5b5c4a4b 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -172,8 +172,6 @@ void __next_mem_range_rev(u64 *idx, int nid, enum memblock_flags flags,
struct memblock_type *type_b, phys_addr_t *out_start,
phys_addr_t *out_end, int *out_nid);

-void memblock_free_late(phys_addr_t base, phys_addr_t size);
-
#ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
static inline void __next_physmem_range(u64 *idx, struct memblock_type *type,
phys_addr_t *out_start,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d8e6f1d889d5..e44e039e00d3 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -546,10 +546,10 @@ void __init swiotlb_exit(void)
free_pages(tbl_vaddr, get_order(tbl_size));
free_pages((unsigned long)mem->slots, get_order(slots_size));
} else {
- memblock_free_late(__pa(mem->areas),
+ memblock_free(mem->areas,
array_size(sizeof(*mem->areas), mem->nareas));
- memblock_free_late(mem->start, tbl_size);
- memblock_free_late(__pa(mem->slots), slots_size);
+ memblock_phys_free(mem->start, tbl_size);
+ memblock_free(mem->slots, slots_size);
}

memset(mem, 0, sizeof(*mem));
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 449369a60846..86a75bf636bc 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -64,7 +64,7 @@ static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
if (early)
memblock_free(addr, size);
else if (addr)
- memblock_free_late(__pa(addr), size);
+ memblock_free(addr, size);
}

#else /* !__KERNEL__ */
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 7393957f9a20..5c8268af533e 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -731,10 +731,10 @@ static bool __init kfence_init_pool_early(void)
* fails for the first page, and therefore expect addr==__kfence_pool in
* most failure cases.
*/
- memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool));
+ memblock_free((void *)addr, KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool));
__kfence_pool = NULL;

- memblock_free_late(__pa(kfence_metadata_init), KFENCE_METADATA_SIZE);
+ memblock_free(kfence_metadata_init, KFENCE_METADATA_SIZE);
kfence_metadata_init = NULL;

return false;
diff --git a/mm/memblock.c b/mm/memblock.c
index 9f372a8e82f7..bd5758ff07f2 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -384,26 +384,24 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
*/
void __init memblock_discard(void)
{
- phys_addr_t addr, size;
+ phys_addr_t size;

if (memblock.reserved.regions != memblock_reserved_init_regions) {
- addr = __pa(memblock.reserved.regions);
size = PAGE_ALIGN(sizeof(struct memblock_region) *
memblock.reserved.max);
if (memblock_reserved_in_slab)
kfree(memblock.reserved.regions);
else
- memblock_free_late(addr, size);
+ memblock_free(memblock.reserved.regions, size);
}

if (memblock.memory.regions != memblock_memory_init_regions) {
- addr = __pa(memblock.memory.regions);
size = PAGE_ALIGN(sizeof(struct memblock_region) *
memblock.memory.max);
if (memblock_memory_in_slab)
kfree(memblock.memory.regions);
else
- memblock_free_late(addr, size);
+ memblock_free(memblock.memory.regions, size);
}

memblock_memory = NULL;
@@ -961,7 +959,8 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
* @size: size of the boot memory block in bytes
*
* Free boot memory block previously allocated by memblock_alloc_xx() API.
- * The freeing memory will not be released to the buddy allocator.
+ * If called after the buddy allocator is available, the memory is released to
+ * the buddy allocator.
*/
void __init_memblock memblock_free(void *ptr, size_t size)
{
@@ -975,7 +974,8 @@ void __init_memblock memblock_free(void *ptr, size_t size)
* @size: size of the boot memory block in bytes
*
* Free boot memory block previously allocated by memblock_phys_alloc_xx() API.
- * The freeing memory will not be released to the buddy allocator.
+ * If called after the buddy allocator is available, the memory is released to
+ * the buddy allocator.
*/
int __init_memblock memblock_phys_free(phys_addr_t base, phys_addr_t size)
{
@@ -985,6 +985,9 @@ int __init_memblock memblock_phys_free(phys_addr_t base, phys_addr_t size)
&base, &end, (void *)_RET_IP_);

kmemleak_free_part_phys(base, size);
+ if (slab_is_available())
+ __free_reserved_area(base, base + size, -1);
+
return memblock_remove_range(&memblock.reserved, base, size);
}

@@ -1813,26 +1816,6 @@ void *__init __memblock_alloc_or_panic(phys_addr_t size, phys_addr_t align,
return addr;
}

-/**
- * memblock_free_late - free pages directly to buddy allocator
- * @base: phys starting address of the boot memory block
- * @size: size of the boot memory block in bytes
- *
- * This is only useful when the memblock allocator has already been torn
- * down, but we are still initializing the system. Pages are released directly
- * to the buddy allocator.
- */
-void __init memblock_free_late(phys_addr_t base, phys_addr_t size)
-{
- phys_addr_t end = base + size - 1;
-
- memblock_dbg("%s: [%pa-%pa] %pS\n",
- __func__, &base, &end, (void *)_RET_IP_);
-
- kmemleak_free_part_phys(base, size);
- __free_reserved_area(base, base + size, -1);
-}
-
/*
* Remaining API functions
*/
--
2.51.0