[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20201216182335.27227-24-willy@infradead.org>
Date: Wed, 16 Dec 2020 18:23:33 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: linux-fsdevel@...r.kernel.org, linux-mm@...ck.org
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-kernel@...r.kernel.org
Subject: [PATCH 23/25] mm: Add flush_dcache_folio
This is a default implementation which calls flush_dcache_page() on
each page in the folio. If architectures can do better, they should
implement their own version of it.
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
Documentation/core-api/cachetlb.rst | 6 ++++++
include/asm-generic/cacheflush.h | 13 +++++++++++++
2 files changed, 19 insertions(+)
diff --git a/Documentation/core-api/cachetlb.rst b/Documentation/core-api/cachetlb.rst
index a1582cc79f0f..484cf31fcded 100644
--- a/Documentation/core-api/cachetlb.rst
+++ b/Documentation/core-api/cachetlb.rst
@@ -325,6 +325,12 @@ maps this page at its virtual address.
dirty. Again, see sparc64 for examples of how
to deal with this.
+ ``void flush_dcache_folio(struct folio *folio)``
+ This function is called under the same circumstances as
+ flush_dcache_page(). It allows the architecture to
+ optimise for flushing the entire folio of pages instead
+ of flushing one page at a time.
+
``void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long user_vaddr, void *dst, void *src, int len)``
``void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h
index 4a674db4e1fa..5537ea24333d 100644
--- a/include/asm-generic/cacheflush.h
+++ b/include/asm-generic/cacheflush.h
@@ -49,9 +49,22 @@ static inline void flush_cache_page(struct vm_area_struct *vma,
static inline void flush_dcache_page(struct page *page)
{
}
+
+static inline void flush_dcache_folio(struct folio *folio) { }
#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
#endif
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
+static inline void flush_dcache_folio(struct folio *folio)
+{
+ unsigned int n = folio_nr_pages(folio);
+
+ do {
+ flush_dcache_page(&folio->page[--n]);
+ } while (n);
+}
+#endif
#ifndef flush_dcache_mmap_lock
static inline void flush_dcache_mmap_lock(struct address_space *mapping)
--
2.29.2
Powered by blists - more mailing lists