s390/mm: implement software dirty bits

[deliverable/linux.git] / arch / s390 / include / asm / page.h

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index a86ad4084073c85b2f6307f780d07336e470db5b..75ce9b065f9f321f6b0ef3eb3c010c10e58802e6 100644 (file)
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -154,28 +154,6 @@ static inline int page_reset_referenced(unsigned long addr)
 #define _PAGE_FP_BIT           0x08    /* HW fetch protection bit      */
 #define _PAGE_ACC_BITS         0xf0    /* HW access control bits       */
 
-/*
- * Test and clear dirty bit in storage key.
- * We can't clear the changed bit atomically. This is a potential
- * race against modification of the referenced bit. This function
- * should therefore only be called if it is not mapped in any
- * address space.
- *
- * Note that the bit gets set whenever page content is changed. That means
- * also when the page is modified by DMA or from inside the kernel.
- */
-#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
-static inline int page_test_and_clear_dirty(unsigned long pfn, int mapped)
-{
-       unsigned char skey;
-
-       skey = page_get_storage_key(pfn << PAGE_SHIFT);
-       if (!(skey & _PAGE_CHANGED))
-               return 0;
-       page_set_storage_key(pfn << PAGE_SHIFT, skey & ~_PAGE_CHANGED, mapped);
-       return 1;
-}
-
 /*
  * Test and clear referenced bit in storage key.
  */