powerpc: fadump: pair alloc_pages_exact() with free_pages_exact()

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.

Link: https://patch.msgid.link/20260323074836.3653702-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 4ebc333dd786f605ffaa26d9eeb80a7c86edfa90..501d43bf18f3a171d4b4c0dce5deeecf2bfb1d59 100644 (file)
--- 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)