[PATCH 13/13] arch, mm: make releasing of memory to page allocator more explicit

Mike Rapoport
2025-03-06T18:54:36Z

The point where the memory is released from memblock to the buddy allocator
is hidden inside arch-specific mem_init()s and the call to
memblock_free_all() is needlessly duplicated in every artiste cure and
after introduction of arch_mm_preinit() hook, mem_init() implementation on
many architecture only contains the call to memblock_free_all().

Pull memblock_free_all() call into mm_core_init() and drop mem_init() on
relevant architectures to make it more explicit where the free memory is
released from memblock to the buddy allocator and to reduce code
duplication in architecture specific code.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
arch/alpha/mm/init.c | 6 ------
arch/arc/mm/init.c | 11 -----------
arch/arm/mm/init.c | 11 -----------
arch/arm64/mm/init.c | 11 -----------
arch/csky/mm/init.c | 5 -----
arch/hexagon/mm/init.c | 18 ------------------
arch/loongarch/kernel/numa.c | 5 -----
arch/loongarch/mm/init.c | 5 -----
arch/m68k/mm/init.c | 2 --
arch/microblaze/mm/init.c | 3 ---
arch/mips/mm/init.c | 5 -----
arch/nios2/mm/init.c | 6 ------
arch/openrisc/mm/init.c | 3 ---
arch/parisc/mm/init.c | 2 --
arch/powerpc/mm/mem.c | 5 -----
arch/riscv/mm/init.c | 5 -----
arch/s390/mm/init.c | 6 ------
arch/sh/mm/init.c | 2 --
arch/sparc/mm/init_32.c | 5 -----
arch/sparc/mm/init_64.c | 2 --
arch/um/kernel/mem.c | 2 --
arch/x86/mm/init_32.c | 3 ---
arch/x86/mm/init_64.c | 2 --
arch/xtensa/mm/init.c | 9 ---------
include/linux/memblock.h | 1 -
mm/internal.h | 3 ++-
mm/mm_init.c | 5 +++++
27 files changed, 7 insertions(+), 136 deletions(-)

diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index 3ab2d2f3c917..2d491b8cdab9 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -273,12 +273,6 @@ srm_paging_stop (void)
}
#endif

-void __init
-mem_init(void)
-{
- memblock_free_all();
-}
-
static const pgprot_t protection_map[16] = {
[VM_NONE] = _PAGE_P(_PAGE_FOE | _PAGE_FOW |
_PAGE_FOR),
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 90715b4a0bfa..a73cc94f806e 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -169,17 +169,6 @@ void __init arch_mm_preinit(void)
BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE);
}

-/*
- * mem_init - initializes memory
- *
- * Frees up bootmem
- * Calculates and displays memory available/used
- */
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
#ifdef CONFIG_HIGHMEM
int pfn_valid(unsigned long pfn)
{
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 7222100b0631..54bdca025c9f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -263,17 +263,6 @@ void __init arch_mm_preinit(void)
#endif
}

-/*
- * mem_init() marks the free areas in the mem_map and tells us how much
- * memory is free. This is done after various parts of the system have
- * claimed their memory after the kernel image.
- */
-void __init mem_init(void)
-{
- /* this will put all unused low memory onto the freelists */
- memblock_free_all();
-}
-
#ifdef CONFIG_STRICT_KERNEL_RWX
struct section_perm {
const char *name;
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 8eff6a6eb11e..510695107233 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -411,17 +411,6 @@ void __init arch_mm_preinit(void)
}
}

-/*
- * mem_init() marks the free areas in the mem_map and tells us how much memory
- * is free. This is done after various parts of the system have claimed their
- * memory after the kernel image.
- */
-void __init mem_init(void)
-{
- /* this will put all unused low memory onto the freelists */
- memblock_free_all();
-}
-
void free_initmem(void)
{
void *lm_init_begin = lm_alias(__init_begin);
diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
index 3914c2b873da..573da66b2543 100644
--- a/arch/csky/mm/init.c
+++ b/arch/csky/mm/init.c
@@ -42,11 +42,6 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
__page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_initmem(void)
{
free_initmem_default(-1);
diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c
index d412c2314509..34eb9d424b96 100644
--- a/arch/hexagon/mm/init.c
+++ b/arch/hexagon/mm/init.c
@@ -43,24 +43,6 @@ DEFINE_SPINLOCK(kmap_gen_lock);
/* checkpatch says don't init this to 0. */
unsigned long long kmap_generation;

-/*
- * mem_init - initializes memory
- *
- * Frees up bootmem
- * Fixes up more stuff for HIGHMEM
- * Calculates and displays memory available/used
- */
-void __init mem_init(void)
-{
- /* No idea where this is actually declared. Seems to evade LXR. */
- memblock_free_all();
-
- /*
- * To-Do: someone somewhere should wipe out the bootmem map
- * after we're done?
- */
-}
-
void sync_icache_dcache(pte_t pte)
{
unsigned long addr;
diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
index 8eb489725b1a..30a72fd528c0 100644
--- a/arch/loongarch/kernel/numa.c
+++ b/arch/loongarch/kernel/numa.c
@@ -387,11 +387,6 @@ void __init paging_init(void)
free_area_init(zones_size);
}

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
int pcibus_to_node(struct pci_bus *bus)
{
return dev_to_node(&bus->dev);
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index 6affa3609188..fdb7f73ad160 100644
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c
@@ -75,11 +75,6 @@ void __init paging_init(void)

free_area_init(max_zone_pfns);
}
-
-void __init mem_init(void)
-{
- memblock_free_all();
-}
#endif /* !CONFIG_NUMA */

void __ref free_initmem(void)
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index e03ac556c59e..3d9aa9cce144 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -119,7 +119,5 @@ static inline void init_pointer_tables(void)

void __init mem_init(void)
{
- /* this will put all memory onto the freelists */
- memblock_free_all();
init_pointer_tables();
}
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 3e664e0efc33..65f0d1fb8a2a 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -107,9 +107,6 @@ void __init setup_memory(void)

void __init mem_init(void)
{
- /* this will put all memory onto the freelists */
- memblock_free_all();
-
mem_init_done = 1;
}

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 619e2e394392..6ea27bbd387e 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -453,11 +453,6 @@ void __init arch_mm_preinit(void)
}
#endif /* !CONFIG_NUMA */

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_init_pages(const char *what, unsigned long begin, unsigned long end)
{
unsigned long pfn;
diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index 4ba8dfa0d238..94efa3de3933 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -60,12 +60,6 @@ void __init paging_init(void)
(unsigned long)empty_zero_page + PAGE_SIZE);
}

-void __init mem_init(void)
-{
- /* this will put all memory onto the freelists */
- memblock_free_all();
-}
-
void __init mmu_init(void)
{
flush_tlb_all();
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 72c5952607ac..be1c2eb8bb94 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -196,9 +196,6 @@ void __init mem_init(void)
/* clear the zero-page */
memset((void *)empty_zero_page, 0, PAGE_SIZE);

- /* this will put all low memory onto the freelists */
- memblock_free_all();
-
printk("mem_init_done ...........................................\n");
mem_init_done = 1;
return;
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 4fbe354dc9b4..14270715d754 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -562,8 +562,6 @@ void __init mem_init(void)
BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
#endif

- memblock_free_all();
-
#ifdef CONFIG_PA11
if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 68efdaf14e58..d8fe11b64259 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -327,11 +327,6 @@ void __init arch_mm_preinit(void)
#endif /* CONFIG_PPC32 */
}

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_initmem(void)
{
ppc_md.progress = ppc_printk_progress;
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 9efadabf6be1..79b649f6de72 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -196,11 +196,6 @@ void __init arch_mm_preinit(void)
print_vm_layout();
}

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
/* Limit the memory size via mem. */
static phys_addr_t memory_limit;
#ifdef CONFIG_XIP_KERNEL
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6741b38fc864..e8585011fbfc 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -167,12 +167,6 @@ void __init arch_mm_preinit(void)
setup_zero_pages(); /* Setup zeroed pages. */
}

-void __init mem_init(void)
-{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
-}
-
unsigned long memory_block_size_bytes(void)
{
/*
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 6d459ffba4bc..99e302eeeec1 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -330,8 +330,6 @@ unsigned int mem_init_done = 0;

void __init mem_init(void)
{
- memblock_free_all();
-
/* Set this up early, so we can take care of the zero page */
cpu_cache_init();

diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index e16c32c5728f..fdc93dd12c3e 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -264,11 +264,6 @@ void __init arch_mm_preinit(void)
taint_real_pages();
}

-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void sparc_flush_page_to_ram(struct page *page)
{
unsigned long vaddr = (unsigned long)page_address(page);
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 34d46adb9571..760818950464 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -2505,8 +2505,6 @@ static void __init register_page_bootmem_info(void)
}
void __init mem_init(void)
{
- memblock_free_all();
-
/*
* Must be done after boot memory is put on freelist, because here we
* might set fields in deferred struct pages that have not yet been
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index cce387438e60..379f33a1babf 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -71,8 +71,6 @@ void __init arch_mm_preinit(void)

void __init mem_init(void)
{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
kmalloc_ok = 1;
}

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 16664c5464b5..95b2758b4e4d 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -702,9 +702,6 @@ void __init arch_mm_preinit(void)

void __init mem_init(void)
{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
-
after_bootmem = 1;
x86_init.hyper.init_after_bootmem();

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f8981e29633c..451e796427d3 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1357,8 +1357,6 @@ void __init mem_init(void)
{
/* clear_bss() already clear the empty_zero_page */

- /* this will put all memory onto the freelists */
- memblock_free_all();
after_bootmem = 1;
x86_init.hyper.init_after_bootmem();

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 47ecbe28263e..cc52733a0649 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -129,15 +129,6 @@ void __init zones_init(void)
print_vm_layout();
}

-/*
- * Initialize memory pages.
- */
-
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
static void __init parse_memmap_one(char *p)
{
char *oldp;
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index e79eb6ac516f..ef5a1ecc6e59 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -133,7 +133,6 @@ 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);

-void memblock_free_all(void);
void memblock_free(void *ptr, size_t size);
void reset_all_zones_managed_pages(void);

diff --git a/mm/internal.h b/mm/internal.h
index 109ef30fee11..26e2e8cea495 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1407,7 +1407,8 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma,
}

extern bool mirrored_kernelcore;
-extern bool memblock_has_mirror(void);
+bool memblock_has_mirror(void);
+void memblock_free_all(void);

static __always_inline void vma_set_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 9cca3d497bf8..545e11f1a3ba 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2672,6 +2672,10 @@ void __init __weak arch_mm_preinit(void)
{
}

+void __init __weak mem_init(void)
+{
+}
+
/*
* Set up kernel memory allocators
*/
@@ -2693,6 +2697,7 @@ void __init mm_core_init(void)
report_meminit();
kmsan_init_shadow();
stack_depot_early_init();
+ memblock_free_all();
mem_init();
kmem_cache_init();
/*
--
2.47.2