mm: simplify free_highmem_page() and free_reserved_page()

adjust_managed_page_count() as called by free_reserved_page() properly
handles pages in a highmem zone, so we can reuse it for
free_highmem_page().

We can now get rid of totalhigh_pages_inc() and simplify
free_reserved_page().

Link: https://lkml.kernel.org/r/20210126182113.19892-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/highmem-internal.h

@@ -127,11 +127,6 @@ static inline unsigned long totalhigh_pages(void)
 	return (unsigned long)atomic_long_read(&_totalhigh_pages);
 }
 
-static inline void totalhigh_pages_inc(void)
-{
-	atomic_long_inc(&_totalhigh_pages);
-}
-
 static inline void totalhigh_pages_add(long count)
 {
 	atomic_long_add(count, &_totalhigh_pages);

include/linux/mm.h

@@ -2310,32 +2310,20 @@ extern void free_initmem(void);
 extern unsigned long free_reserved_area(void *start, void *end,
 					int poison, const char *s);
 
-#ifdef	CONFIG_HIGHMEM
-/*
- * Free a highmem page into the buddy system, adjusting totalhigh_pages
- * and totalram_pages.
- */
-extern void free_highmem_page(struct page *page);
-#endif
-
 extern void adjust_managed_page_count(struct page *page, long count);
 extern void mem_init_print_info(const char *str);
 
 extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
 
 /* Free the reserved page into the buddy system, so it gets managed. */
-static inline void __free_reserved_page(struct page *page)
+static inline void free_reserved_page(struct page *page)
 {
 	ClearPageReserved(page);
 	init_page_count(page);
 	__free_page(page);
-}
-
-static inline void free_reserved_page(struct page *page)
-{
-	__free_reserved_page(page);
 	adjust_managed_page_count(page, 1);
 }
+#define free_highmem_page(page) free_reserved_page(page)
 
 static inline void mark_page_reserved(struct page *page)
 {

mm/page_alloc.c

@@ -7691,17 +7691,6 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
 	return pages;
 }
 
-#ifdef	CONFIG_HIGHMEM
-void free_highmem_page(struct page *page)
-{
-	__free_reserved_page(page);
-	totalram_pages_inc();
-	atomic_long_inc(&page_zone(page)->managed_pages);
-	totalhigh_pages_inc();
-}
-#endif
-
-
 void __init mem_init_print_info(const char *str)
 {
 	unsigned long physpages, codesize, datasize, rosize, bss_size;