[PATCH v2 2/9] powerpc: fadump: pair alloc_pages_exact() with free_pages_exact()

Mike Rapoport
2026-03-23T07:49:12Z

fadump allocates buffers with alloc_pages_exact(), but then marks them
as reserved and frees using free_reserved_area().

This is completely unnecessary and the pages allocated with
alloc_pages_exact() can be naturally freed with free_pages_exact().

Replace freeing of memory in fadump_free_buffer() with
free_pages_exact() and simplify allocation code so that it won't mark
allocated pages as reserved.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
arch/powerpc/kernel/fadump.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 4ebc333dd786..501d43bf18f3 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -775,24 +775,12 @@ void __init fadump_update_elfcore_header(char *bufp)

static void *__init fadump_alloc_buffer(unsigned long size)
{
- unsigned long count, i;
- struct page *page;
- void *vaddr;
-
- vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
- if (!vaddr)
- return NULL;
-
- count = PAGE_ALIGN(size) / PAGE_SIZE;
- page = virt_to_page(vaddr);
- for (i = 0; i < count; i++)
- mark_page_reserved(page + i);
- return vaddr;
+ return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
}

static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
{
- free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
+ free_pages_exact((void *)vaddr, size);
}

s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
--
2.53.0