mm: remove flush_kernel_dcache_page

flush_kernel_dcache_page is a rather confusing interface that implements a
subset of flush_dcache_page by not being able to properly handle page
cache mapped pages.

The only callers left are in the exec code as all other previous callers
were incorrect as they could have dealt with page cache pages.  Replace
the calls to flush_kernel_dcache_page with calls to flush_dcache_page,
which for all architectures does either exactly the same thing, can
contains one or more of the following:

 1) an optimization to defer the cache flush for page cache pages not
    mapped into userspace
 2) additional flushing for mapped page cache pages if cache aliases
    are possible

Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 9 deletions

diff --git a/Documentation/translations/zh_CN/core-api/cachetlb.rst b/Documentation/translations/zh_CN/core-api/cachetlb.rst
index 8376485a534d..55827b8a7c53 100644
--- a/Documentation/translations/zh_CN/core-api/cachetlb.rst
+++ b/Documentation/translations/zh_CN/core-api/cachetlb.rst
@@ -298,15 +298,6 @@ HyperSparc cpu就是这样一个具有这种属性的cpu。
 	用。默认的实现是nop（对于所有相干的架构应该保持这样）。对于不一致性
 	的架构，它应该刷新vmaddr处的页面缓存。
 
-  ``void flush_kernel_dcache_page(struct page *page)``
-
-	当内核需要修改一个用kmap获得的用户页时，它会在所有修改完成后（但在
-	kunmapping之前）调用这个函数，以使底层页面达到最新状态。这里假定用
-	户没有不一致性的缓存副本（即原始页面是从类似get_user_pages()的机制
-	中获得的）。默认的实现是一个nop，在所有相干的架构上都应该如此。在不
-	一致性的架构上，这应该刷新内核缓存中的页面（使用page_address(page)）。
-
-
   ``void flush_icache_range(unsigned long start, unsigned long end)``
 
 	当内核存储到它将执行的地址中时（例如在加载模块时），这个函数被调用。