patch-2.4.20 linux-2.4.20/include/linux/highmem.h

• Lines: 66
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/linux/highmem.h
• Orig date: Fri Aug 2 17:39:45 2002

diff -urN linux-2.4.19/include/linux/highmem.h linux-2.4.20/include/linux/highmem.h
@@ -13,8 +13,7 @@
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 
-extern struct buffer_head * create_bounce(int rw, struct buffer_head * bh_orig);
-
+extern struct buffer_head *create_bounce(int rw, struct buffer_head * bh_orig);
 
 static inline char *bh_kmap(struct buffer_head *bh)
 {
@@ -26,6 +25,42 @@
 	kunmap(bh->b_page);
 }
 
+/*
+ * remember to add offset! and never ever reenable interrupts between a
+ * bh_kmap_irq and bh_kunmap_irq!!
+ */
+static inline char *bh_kmap_irq(struct buffer_head *bh, unsigned long *flags)
+{
+	unsigned long addr;
+
+	__save_flags(*flags);
+
+	/*
+	 * could be low
+	 */
+	if (!PageHighMem(bh->b_page))
+		return bh->b_data;
+
+	/*
+	 * it's a highmem page
+	 */
+	__cli();
+	addr = (unsigned long) kmap_atomic(bh->b_page, KM_BH_IRQ);
+
+	if (addr & ~PAGE_MASK)
+		BUG();
+
+	return (char *) addr + bh_offset(bh);
+}
+
+static inline void bh_kunmap_irq(char *buffer, unsigned long *flags)
+{
+	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
+
+	kunmap_atomic((void *) ptr, KM_BH_IRQ);
+	__restore_flags(*flags);
+}
+
 #else /* CONFIG_HIGHMEM */
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -37,8 +72,10 @@
 #define kmap_atomic(page,idx)		kmap(page)
 #define kunmap_atomic(page,idx)		kunmap(page)
 
-#define bh_kmap(bh)	((bh)->b_data)
-#define bh_kunmap(bh)	do { } while (0)
+#define bh_kmap(bh)			((bh)->b_data)
+#define bh_kunmap(bh)			do { } while (0)
+#define bh_kmap_irq(bh, flags)		((bh)->b_data)
+#define bh_kunmap_irq(bh, flags)	do { *(flags) = 0; } while (0)
 
 #endif /* CONFIG_HIGHMEM */