[PATCH 01/71] arc: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

From: Kirill A. Shutemov
Date: Sun Mar 20 2016 - 14:42:00 EST

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago
with promise that one day it will be possible to implement page cache with
bigger chunks than PAGE_SIZE.

This promise never materialized. And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_*
or PAGE_* constant should be used in a particular case, especially on the
border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special. They are not.

The changes are pretty straight-forward:

- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;


- page_cache_get() -> get_page();

- page_cache_release() -> put_page();

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
arch/arc/mm/cache.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index b65f797e9ad6..d9bacb4199ea 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -621,7 +621,7 @@ void flush_dcache_page(struct page *page)

/* kernel reading from page with U-mapping */
phys_addr_t paddr = (unsigned long)page_address(page);
- unsigned long vaddr = page->index << PAGE_CACHE_SHIFT;
+ unsigned long vaddr = page->index << PAGE_SHIFT;

if (addr_not_cache_congruent(paddr, vaddr))
__flush_dcache_page(paddr, vaddr);