Changeset 93165be in mainline for arch/amd64/include/mm/page.h

Timestamp:

2006-03-16T23:54:05Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

5fceec7

Parents:

ff14c520

Message:

Add support for more then 2GB of address space for AMD64.

File:

• arch/amd64/include/mm/page.h (modified) (2 diffs)

arch/amd64/include/mm/page.h

@@ -27 +27 @@
  */
 
+/** Paging on AMD64
+ *
+ * The space is divided in positive numbers - userspace and
+ * negative numbers - kernel space. The 'negative' space starting
+ * with 0xffff800000000000 and ending with 0xffffffff80000000
+ * (-2GB) is identically mapped physical memory. The area
+ * (0xffffffff80000000 ... 0xffffffffffffffff is again identically
+ * mapped first 2GB.
+ *
+ * ATTENTION - PA2KA(KA2PA(x)) != x if 'x' is in kernel
+ */
+
 #ifndef __amd64_PAGE_H__
 #define __amd64_PAGE_H__
@@ -43 +55 @@
 
 #ifndef __ASM__
-# define KA2PA(x)      (((__address) (x)) - 0xffffffff80000000)
-# define PA2KA(x)      (((__address) (x)) + 0xffffffff80000000)
+static inline __address ka2pa(__address x)
+{
+        if (x > 0xffffffff80000000)
+                return x - 0xffffffff80000000;
+        else 
+                return x - 0xffff800000000000;
+}
+/* Linker symbol */
+extern int ktext_start;
+extern int kdata_end;
+static inline __address pa2ka(__address x)
+{
+        if (x >= ka2pa((__address)(&kdata_end)) || \
+            x <= ka2pa((__address)&ktext_start))
+                return x + 0xffff800000000000;
+        else 
+                return x + 0xffffffff80000000;
+}
+# define KA2PA(x)      ka2pa((__address)x)
+# define PA2KA(x)      pa2ka((__address)x)
+# define PA2KA_IDENT(x)      (((__address) (x)) + 0xffff800000000000)
+# define PA2KA_CODE(x)      (((__address) (x)) + 0xffffffff80000000)
 #else
 # define KA2PA(x)      ((x) - 0xffffffff80000000)
 # define PA2KA(x)      ((x) + 0xffffffff80000000)
+# define PA2KA_DATA(x)      ((x) + 0xffff800000000000)
 #endif