[PATCH] Remove flush_page_to_ram()

From: Hugh Dickins <hugh@veritas.com>

This patch removes the long deprecated flush_page_to_ram.  We have
two different schemes for doing this cache flushing stuff, the old
flush_page_to_ram way and the not so old flush_dcache_page etc. way:
see DaveM's Documentation/cachetlb.txt.  Keeping flush_page_to_ram
around is confusing, and makes it harder to get this done right.

All architectures are updated, but the only ones where it amounts
to more than deleting a line or two are m68k, mips, mips64 and v850.

I followed a prescription from DaveM (though not to the letter), that
those arches with non-nop flush_page_to_ram need to do what it did
in their clear_user_page and copy_user_page and flush_dcache_page.

Dave is consterned that, in the v850 nb85e case, this patch leaves its
flush_dcache_page as was, uses it in clear_user_page and copy_user_page,
instead of making them all flush icache as well.  That may be wrong:
I'm just hesitant to add cruft blindly, changing a flush_dcache macro
to flush icache too; and naively hope that the necessary flush_icache
calls are already in place.  Miles, please let us know which way is
right for v850 nb85e - thanks.

1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index a971c2a43185..34527fc3df12 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -179,14 +179,18 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in
 
 		flush_cache_page(vma, addr);
 
+		/*
+		 * FIXME!  We used to have flush_page_to_ram() in here, but
+		 * that was wrong.  davem says we need a new per-arch primitive
+		 * to handle this correctly.
+		 */
+
 		maddr = kmap(page);
 		if (write) {
 			memcpy(maddr + offset, buf, bytes);
-			flush_page_to_ram(page);
 			flush_icache_user_range(vma, page, addr, bytes);
 		} else {
 			memcpy(buf, maddr + offset, bytes);
-			flush_page_to_ram(page);
 		}
 		kunmap(page);
 		page_cache_release(page);