[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.

Documentation/cachetlb.txt

@@ -75,7 +75,7 @@ changes occur:
 	Platform developers note that generic code will always
 	invoke this interface with mm->page_table_lock held.
 
-4) void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+4) void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
 
 	This time we need to remove the PAGE_SIZE sized translation
 	from the TLB.  The 'vma' is the backing structure used by
@@ -87,9 +87,9 @@ changes occur:
 
 	After running, this interface must make sure that any previous
 	page table modification for address space 'vma->vm_mm' for
-	user virtual address 'page' will be visible to the cpu.  That
+	user virtual address 'addr' will be visible to the cpu.  That
 	is, after running, there will be no entries in the TLB for
-	'vma->vm_mm' for virtual address 'page'.
+	'vma->vm_mm' for virtual address 'addr'.
 
 	This is used primarily during fault processing.
 
@@ -144,9 +144,9 @@ the sequence will be in one of the following forms:
 	   change_range_of_page_tables(mm, start, end);
 	   flush_tlb_range(vma, start, end);
 
-	3) flush_cache_page(vma, page);
+	3) flush_cache_page(vma, addr);
 	   set_pte(pte_pointer, new_pte_val);
-	   flush_tlb_page(vma, page);
+	   flush_tlb_page(vma, addr);
 
 The cache level flush will always be first, because this allows
 us to properly handle systems whose caches are strict and require
@@ -200,7 +200,7 @@ Here are the routines, one by one:
 	call flush_cache_page (see below) for each entry which may be
 	modified.
 
-4) void flush_cache_page(struct vm_area_struct *vma, unsigned long page)
+4) void flush_cache_page(struct vm_area_struct *vma, unsigned long addr)
 
 	This time we need to remove a PAGE_SIZE sized range
 	from the cache.  The 'vma' is the backing structure used by
@@ -211,7 +211,7 @@ Here are the routines, one by one:
 	"Harvard" type cache layouts).
 
 	After running, there will be no entries in the cache for
-	'vma->vm_mm' for virtual address 'page'.
+	'vma->vm_mm' for virtual address 'addr'.
 
 	This is used primarily during fault processing.
 
@@ -235,7 +235,7 @@ this value.
 NOTE: This does not fix shared mmaps, check out the sparc64 port for
 one way to solve this (in particular SPARC_FLAG_MMAPSHARED).
 
-Next, you have two methods to solve the D-cache aliasing issue for all
+Next, you have to solve the D-cache aliasing issue for all
 other cases.  Please keep in mind that fact that, for a given page
 mapped into some user address space, there is always at least one more
 mapping, that of the kernel in it's linear mapping starting at
@@ -244,35 +244,8 @@ physical page into its address space, by implication the D-cache
 aliasing problem has the potential to exist since the kernel already
 maps this page at its virtual address.
 
-First, I describe the old method to deal with this problem.  I am
-describing it for documentation purposes, but it is deprecated and the
-latter method I describe next should be used by all new ports and all
-existing ports should move over to the new mechanism as well.
-
-  flush_page_to_ram(struct page *page)
-
-	The physical page 'page' is about to be place into the
-	user address space of a process.  If it is possible for
-	stores done recently by the kernel into this physical
-	page, to not be visible to an arbitrary mapping in userspace,
-	you must flush this page from the D-cache.
-
-	If the D-cache is writeback in nature, the dirty data (if
-	any) for this physical page must be written back to main
-	memory before the cache lines are invalidated.
-
-Admittedly, the author did not think very much when designing this
-interface.  It does not give the architecture enough information about
-what exactly is going on, and there is no context to base a judgment
-on about whether an alias is possible at all.  The new interfaces to
-deal with D-cache aliasing are meant to address this by telling the
-architecture specific code exactly which is going on at the proper points
-in time.
-
-Here is the new interface:
-
-  void copy_user_page(void *to, void *from, unsigned long address)
-  void clear_user_page(void *to, unsigned long address)
+  void copy_user_page(void *to, void *from, unsigned long addr, struct page *page)
+  void clear_user_page(void *to, unsigned long addr, struct page *page)
 
 	These two routines store data in user anonymous or COW
 	pages.  It allows a port to efficiently avoid D-cache alias
@@ -285,8 +258,9 @@ Here is the new interface:
 	of the same "color" as the user mapping of the page.  Sparc64
 	for example, uses this technique.
 
-	The "address" parameter tells the virtual address where the
-	user will ultimately have this page mapped.
+	The 'addr' parameter tells the virtual address where the
+	user will ultimately have this page mapped, and the 'page'
+	parameter gives a pointer to the struct page of the target.
 
 	If D-cache aliasing is not an issue, these two routines may
 	simply call memcpy/memset directly and do nothing more.
@@ -363,5 +337,5 @@ Here is the new interface:
 
   void flush_icache_page(struct vm_area_struct *vma, struct page *page)
 	All the functionality of flush_icache_page can be implemented in
-	flush_dcache_page and update_mmu_cache. In 2.5 the hope is to
+	flush_dcache_page and update_mmu_cache. In 2.7 the hope is to
 	remove this interface completely.

arch/ia64/mm/init.c

@@ -251,7 +251,6 @@ put_gate_page (struct page *page, unsigned long address)
 			pte_unmap(pte);
 			goto out;
 		}
-		flush_page_to_ram(page);
 		set_pte(pte, mk_pte(page, PAGE_GATE));
 		pte_unmap(pte);
 	}

arch/mips64/kernel/linux32.c

@@ -195,7 +195,7 @@ int copy_strings32(int argc, u32 * argv, struct linux_binprm *bprm)
 			}
 			err = copy_from_user(kaddr + offset, (char *)A(str),
 			                     bytes_to_copy);
-			flush_page_to_ram(page);
+			flush_dcache_page(page);
 			kunmap(page);
 
 			if (err)

arch/parisc/kernel/sys_parisc32.c

@@ -183,7 +183,6 @@ static int copy_strings32(int argc, u32 *argv, struct linux_binprm *bprm)
 			}
 			err = copy_from_user(kaddr + offset, (char *)A(str), bytes_to_copy);
 			flush_dcache_page(page);
-			flush_page_to_ram(page);
 			kunmap(page);
 
 			if (err)

arch/ppc64/kernel/sys_ppc32.c

@@ -2077,7 +2077,6 @@ static int copy_strings32(int argc, u32 * argv, struct linux_binprm *bprm)
 
 			err = copy_from_user(kaddr + offset, (char *)A(str),
 					     bytes_to_copy);
-			flush_page_to_ram(page);
 			kunmap((unsigned long)kaddr);
 
 			if (err)

arch/s390x/kernel/linux32.c

@@ -1888,7 +1888,6 @@ static int copy_strings32(int argc, u32 * argv, struct linux_binprm *bprm)
 
 			err = copy_from_user(kaddr + offset, (char *)A(str),
 					     bytes_to_copy);
-			flush_page_to_ram(page);
 			kunmap(page);
 
 			if (err)

fs/binfmt_elf.c

@@ -1378,7 +1378,6 @@ static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file)
 					flush_cache_page(vma, addr);
 					kaddr = kmap(page);
 					DUMP_WRITE(kaddr, PAGE_SIZE);
-					flush_page_to_ram(page);
 					kunmap(page);
 				}
 				page_cache_release(page);

fs/exec.c

@@ -314,7 +314,6 @@ void put_dirty_page(struct task_struct * tsk, struct page *page, unsigned long a
 	}
 	lru_cache_add_active(page);
 	flush_dcache_page(page);
-	flush_page_to_ram(page);
 	set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(page, PAGE_COPY))));
 	pte_chain = page_add_rmap(page, pte, pte_chain);
 	pte_unmap(pte);

include/asm-alpha/cacheflush.h

@@ -9,7 +9,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 
 /* Note that the following two definitions are _highly_ dependent

include/asm-arm/proc-armo/cache.h

@@ -13,7 +13,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma,start,end)	do { } while (0)
 #define flush_cache_page(vma,vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 
 #define invalidate_dcache_range(start,end)	do { } while (0)
 #define clean_dcache_range(start,end)		do { } while (0)

include/asm-arm/proc-armv/cache.h

@@ -70,13 +70,6 @@
 	cpu_cache_clean_invalidate_range((unsigned long)start, \
 					 ((unsigned long)start) + size, 0);
 
-/*
- * This is an obsolete interface; the functionality that was provided by this
- * function is now merged into our flush_dcache_page, flush_icache_page,
- * copy_user_page and clear_user_page functions.
- */
-#define flush_page_to_ram(page)	do { } while (0)
-
 /*
  * flush_dcache_page is used when the kernel has written to the page
  * cache page at virtual address page->virtual.

include/asm-cris/pgtable.h

@@ -121,7 +121,6 @@ extern void paging_init(void);
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)                 do { } while (0)
 #define flush_icache_range(start, end)          do { } while (0)
 #define flush_icache_page(vma,pg)               do { } while (0)

include/asm-i386/cacheflush.h

@@ -9,7 +9,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start, end)		do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)

include/asm-ia64/cacheflush.h

@@ -20,7 +20,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_icache_page(vma,page)		do { } while (0)
 
 #define flush_dcache_page(page)			\

include/asm-m68k/cacheflush.h

@@ -106,7 +106,6 @@ extern inline void flush_cache_page(struct vm_area_struct *vma,
 
 /* Push the page at kernel virtual address and clear the icache */
 /* RZ: use cpush %bc instead of cpush %dc, cinv %ic */
-#define flush_page_to_ram(page) __flush_page_to_ram(page_address(page))
 extern inline void __flush_page_to_ram(void *vaddr)
 {
 	if (CPU_IS_040_OR_060) {
@@ -125,7 +124,7 @@ extern inline void __flush_page_to_ram(void *vaddr)
 	}
 }
 
-#define flush_dcache_page(page)			do { } while (0)
+#define flush_dcache_page(page)	__flush_page_to_ram(page_address(page))
 #define flush_icache_page(vma,pg)              do { } while (0)
 #define flush_icache_user_range(vma,pg,adr,len)	do { } while (0)
 

include/asm-m68k/page.h

@@ -79,8 +79,14 @@ static inline void clear_page(void *page)
 #define copy_page(to,from)	memcpy((to), (from), PAGE_SIZE)
 #endif
 
-#define clear_user_page(page, vaddr, pg)	clear_page(page)
-#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
+#define clear_user_page(addr, vaddr, page)	\
+	do { 	clear_page(addr);		\
+		flush_dcache_page(page);	\
+	} while (0)
+#define copy_user_page(to, from, vaddr, page)	\
+	do {	copy_page(to, from);		\
+		flush_dcache_page(page);	\
+	} while (0)
 
 /*
  * These are used to make use of C type-checking..

include/asm-m68knommu/cacheflush.h

@@ -10,7 +10,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_range(start,len)		do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start,len)		__flush_cache_all()

include/asm-mips/page.h

@@ -25,8 +25,15 @@ extern void (*_copy_page)(void * to, void * from);
 
 #define clear_page(page)	_clear_page(page)
 #define copy_page(to, from)	_copy_page(to, from)
-#define clear_user_page(page, vaddr)	clear_page(page)
-#define copy_user_page(to, from, vaddr)	copy_page(to, from)
+
+#define clear_user_page(addr, vaddr, page)	\
+	do { 	clear_page(addr);		\
+		flush_dcache_page(page);	\
+	} while (0)
+#define copy_user_page(to, from, vaddr, page)	\
+	do {	copy_page(to, from);		\
+		flush_dcache_page(page);	\
+	} while (0)
 
 /*
  * These are used to make use of C type-checking..

include/asm-mips/pgtable.h

@@ -24,7 +24,6 @@
  *  - flush_cache_mm(mm) flushes the specified mm context's cache lines
  *  - flush_cache_page(mm, vmaddr) flushes a single page
  *  - flush_cache_range(vma, start, end) flushes a range of pages
- *  - flush_page_to_ram(page) write back kernel page to ram
  *  - flush_icache_range(start, end) flush a range of instructions
  */
 extern void (*_flush_cache_all)(void);
@@ -39,15 +38,13 @@ extern void (*_flush_icache_range)(unsigned long start, unsigned long end);
 extern void (*_flush_icache_page)(struct vm_area_struct *vma,
                                   struct page *page);
 
-#define flush_dcache_page(page)			do { } while (0)
-
 #define flush_cache_all()		_flush_cache_all()
 #define __flush_cache_all()		___flush_cache_all()
 #define flush_cache_mm(mm)		_flush_cache_mm(mm)
 #define flush_cache_range(vma,start,end) _flush_cache_range(vma,start,end)
 #define flush_cache_page(vma,page)	_flush_cache_page(vma, page)
 #define flush_cache_sigtramp(addr)	_flush_cache_sigtramp(addr)
-#define flush_page_to_ram(page)		_flush_page_to_ram(page)
+#define flush_dcache_page(page)		_flush_page_to_ram(page)
 
 #define flush_icache_range(start, end)	_flush_icache_range(start,end)
 #define flush_icache_page(vma, page) 	_flush_icache_page(vma, page)

include/asm-mips64/page.h

@@ -25,8 +25,15 @@ extern void (*_copy_page)(void * to, void * from);
 
 #define clear_page(page)	_clear_page(page)
 #define copy_page(to, from)	_copy_page(to, from)
-#define clear_user_page(page, vaddr)	clear_page(page)
-#define copy_user_page(to, from, vaddr)	copy_page(to, from)
+
+#define clear_user_page(addr, vaddr, page)	\
+	do { 	clear_page(addr);		\
+		flush_dcache_page(page);	\
+	} while (0)
+#define copy_user_page(to, from, vaddr, page)	\
+	do {	copy_page(to, from);		\
+		flush_dcache_page(page);	\
+	} while (0)
 
 /*
  * These are used to make use of C type-checking..

include/asm-mips64/pgtable.h

@@ -25,7 +25,6 @@
  *  - flush_cache_mm(mm) flushes the specified mm context's cache lines
  *  - flush_cache_page(mm, vmaddr) flushes a single page
  *  - flush_cache_range(vma, start, end) flushes a range of pages
- *  - flush_page_to_ram(page) write back kernel page to ram
  */
 extern void (*_flush_cache_mm)(struct mm_struct *mm);
 extern void (*_flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
@@ -34,14 +33,12 @@ extern void (*_flush_cache_page)(struct vm_area_struct *vma, unsigned long page)
 extern void (*_flush_page_to_ram)(struct page * page);
 
 #define flush_cache_all()		do { } while(0)
-#define flush_dcache_page(page)		do { } while (0)
 
 #ifndef CONFIG_CPU_R10000
 #define flush_cache_mm(mm)		_flush_cache_mm(mm)
 #define flush_cache_range(vma,start,end) _flush_cache_range(vma,start,end)
 #define flush_cache_page(vma,page)	_flush_cache_page(vma, page)
-#define flush_page_to_ram(page)		_flush_page_to_ram(page)
-
+#define flush_dcache_page(page)		_flush_page_to_ram(page)
 #define flush_icache_range(start, end)	_flush_cache_l1()
 #define flush_icache_user_range(vma, page, addr, len)	\
 					flush_icache_page((vma), (page))
@@ -66,7 +63,7 @@ extern void andes_flush_icache_page(unsigned long);
 #define flush_cache_mm(mm)		do { } while(0)
 #define flush_cache_range(vma,start,end) do { } while(0)
 #define flush_cache_page(vma,page)	do { } while(0)
-#define flush_page_to_ram(page)		do { } while(0)
+#define flush_dcache_page(page)		do { } while(0)
 #define flush_icache_range(start, end)	_flush_cache_l1()
 #define flush_icache_user_range(vma, page, addr, len)	\
 					flush_icache_page((vma), (page))

include/asm-parisc/cacheflush.h

@@ -18,11 +18,6 @@
 #define flush_kernel_dcache_range(start,size) \
 	flush_kernel_dcache_range_asm((start), (start)+(size));
 
-static inline void
-flush_page_to_ram(struct page *page)
-{
-}
-
 extern void flush_cache_all_local(void);
 
 static inline void cacheflush_h_tmp_function(void *dummy)

include/asm-ppc/cacheflush.h

@@ -23,7 +23,6 @@
 #define flush_cache_mm(mm)		do { } while (0)
 #define flush_cache_range(vma, a, b)	do { } while (0)
 #define flush_cache_page(vma, p)	do { } while (0)
-#define flush_page_to_ram(page)		do { } while (0)
 #define flush_icache_page(vma, page)	do { } while (0)
 
 extern void flush_dcache_page(struct page *page);

include/asm-ppc64/cacheflush.h

@@ -13,7 +13,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_icache_page(vma, page)		do { } while (0)
 
 extern void flush_dcache_page(struct page *page);

include/asm-s390/cacheflush.h

@@ -9,7 +9,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start, end)		do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)

include/asm-s390x/cacheflush.h

@@ -9,7 +9,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start, end)		do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)

include/asm-sh/pgtable.h

@@ -26,7 +26,6 @@ extern void paging_init(void);
  *  - flush_cache_range(vma, start, end) flushes a range of pages
  *
  *  - flush_dcache_page(pg) flushes(wback&invalidates) a page for dcache
- *  - flush_page_to_ram(page) write back kernel page to ram
  *  - flush_icache_range(start, end) flushes(invalidates) a range for icache
  *  - flush_icache_page(vma, pg) flushes(invalidates) a page for icache
  *
@@ -37,7 +36,6 @@ extern void paging_init(void);
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start, end)		do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)
@@ -63,7 +61,6 @@ extern void flush_dcache_page(struct page *pg);
 extern void flush_icache_range(unsigned long start, unsigned long end);
 extern void flush_cache_sigtramp(unsigned long addr);
 
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)
 #define flush_icache_user_range(vma,pg,adr,len)	do { } while (0)
 

include/asm-sparc/cacheflush.h

@@ -64,7 +64,6 @@ BTFIXUPDEF_CALL(void, flush_sig_insns, struct mm_struct *, unsigned long)
 
 extern void sparc_flush_page_to_ram(struct page *page);
 
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			sparc_flush_page_to_ram(page)
 
 #endif /* _SPARC_CACHEFLUSH_H */

include/asm-sparc64/cacheflush.h

@@ -50,7 +50,4 @@ extern void smp_flush_cache_all(void);
 
 extern void flush_dcache_page(struct page *page);
 
-/* This is unnecessary on the SpitFire since D-CACHE is write-through. */
-#define flush_page_to_ram(page)			do { } while (0)
-
 #endif /* _SPARC64_CACHEFLUSH_H */

include/asm-v850/cacheflush.h

@@ -29,7 +29,6 @@
 #define flush_cache_mm(mm)			((void)0)
 #define flush_cache_range(vma, start, end)	((void)0)
 #define flush_cache_page(vma, vmaddr)		((void)0)
-#define flush_page_to_ram(page)			((void)0)
 #define flush_dcache_page(page)			((void)0)
 #define flush_icache()				((void)0)
 #define flush_icache_range(start, end)		((void)0)

include/asm-v850/nb85e_cache.h

@@ -62,7 +62,6 @@ extern void nb85e_cache_flush_icache_user_range (struct vm_area_struct *vma,
 						 unsigned long adr, int len);
 extern void nb85e_cache_flush_sigtramp (unsigned long addr);
 
-#define flush_page_to_ram(x)	((void)0)
 #define flush_cache_all		nb85e_cache_flush_all
 #define flush_cache_mm		nb85e_cache_flush_mm
 #define flush_cache_range	nb85e_cache_flush_range

include/asm-v850/page.h

@@ -40,8 +40,14 @@
 #define clear_page(page)	memset ((void *)(page), 0, PAGE_SIZE)
 #define copy_page(to, from)	memcpy ((void *)(to), (void *)from, PAGE_SIZE)
 
-#define clear_user_page(page, vaddr, pg)	clear_page (page)
-#define copy_user_page(to, from, vaddr,pg)	copy_page (to, from)
+#define clear_user_page(addr, vaddr, page)	\
+	do { 	clear_page(addr);		\
+		flush_dcache_page(page);	\
+	} while (0)
+#define copy_user_page(to, from, vaddr, page)	\
+	do {	copy_page(to, from);		\
+		flush_dcache_page(page);	\
+	} while (0)
 
 #ifdef STRICT_MM_TYPECHECKS
 /*

include/asm-x86_64/cacheflush.h

@@ -9,7 +9,6 @@
 #define flush_cache_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
-#define flush_page_to_ram(page)			do { } while (0)
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_icache_range(start, end)		do { } while (0)
 #define flush_icache_page(vma,pg)		do { } while (0)

include/linux/highmem.h

@@ -67,7 +67,6 @@ static inline void memclear_highpage_flush(struct page *page, unsigned int offse
 	kaddr = kmap_atomic(page, KM_USER0);
 	memset((char *)kaddr + offset, 0, size);
 	flush_dcache_page(page);
-	flush_page_to_ram(page);
 	kunmap_atomic(kaddr, KM_USER0);
 }
 

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);

mm/filemap.c

@@ -1008,11 +1008,9 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 
 success:
 	/*
-	 * Found the page and have a reference on it, need to check sharing
-	 * and possibly copy it over to another page..
+	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
-	flush_page_to_ram(page);
 	return page;
 
 no_cached_page:
@@ -1124,12 +1122,9 @@ static struct page * filemap_getpage(struct file *file, unsigned long pgoff,
 
 success:
 	/*
-	 * Found the page and have a reference on it, need to check sharing
-	 * and possibly copy it over to another page..
+	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
-	flush_page_to_ram(page);
-
 	return page;
 
 no_cached_page:

mm/fremap.c

@@ -78,7 +78,6 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	flush = zap_pte(mm, vma, addr, pte);
 
 	mm->rss++;
-	flush_page_to_ram(page);
 	flush_icache_page(vma, page);
 	set_pte(pte, mk_pte(page, prot));
 	pte_chain = page_add_rmap(page, pte, pte_chain);

mm/memory.c

@@ -916,7 +916,6 @@ static inline void break_cow(struct vm_area_struct * vma, struct page * new_page
 		pte_t *page_table)
 {
 	invalidate_vcache(address, vma->vm_mm, new_page);
-	flush_page_to_ram(new_page);
 	flush_cache_page(vma, address);
 	establish_pte(vma, address, page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot))));
 }
@@ -1206,7 +1205,6 @@ static int do_swap_page(struct mm_struct * mm,
 		pte = pte_mkdirty(pte_mkwrite(pte));
 	unlock_page(page);
 
-	flush_page_to_ram(page);
 	flush_icache_page(vma, page);
 	set_pte(page_table, pte);
 	pte_chain = page_add_rmap(page, page_table, pte_chain);
@@ -1271,7 +1269,6 @@ do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			goto out;
 		}
 		mm->rss++;
-		flush_page_to_ram(page);
 		entry = pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
 		lru_cache_add_active(page);
 		mark_page_accessed(page);
@@ -1365,7 +1362,6 @@ do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	/* Only go through if we didn't race with anybody else... */
 	if (pte_none(*page_table)) {
 		++mm->rss;
-		flush_page_to_ram(new_page);
 		flush_icache_page(vma, new_page);
 		entry = mk_pte(new_page, vma->vm_page_prot);
 		if (write_access)

mm/shmem.c

@@ -832,7 +832,6 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **p
 			shmem_swp_unmap(entry);
 			delete_from_swap_cache(swappage);
 			spin_unlock(&info->lock);
-			flush_page_to_ram(swappage);
 			copy_highpage(filepage, swappage);
 			unlock_page(swappage);
 			page_cache_release(swappage);
@@ -953,7 +952,6 @@ struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long address, int
 		return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS;
 
 	mark_page_accessed(page);
-	flush_page_to_ram(page);
 	return page;
 }
 
@@ -981,7 +979,6 @@ static int shmem_populate(struct vm_area_struct *vma,
 			return err;
 		if (page) {
 			mark_page_accessed(page);
-			flush_page_to_ram(page);
 			err = install_page(mm, vma, addr, page, prot);
 			if (err) {
 				page_cache_release(page);

mm/swapfile.c

@@ -641,7 +641,6 @@ static int try_to_unuse(unsigned int type)
 		shmem = 0;
 		swcount = *swap_map;
 		if (swcount > 1) {
-			flush_page_to_ram(page);
 			if (start_mm == &init_mm)
 				shmem = shmem_unuse(entry, page);
 			else