ARC: support HIGHMEM even without PAE40

[linux-2.6-block.git] / arch / arc / include / asm / page.h

diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 9a7cf521b95c1a2c428a25b27d2d7df15676a0c7..0d53854884d047557a981fece15936715a4cd950 100644 (file)
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -12,9 +12,6 @@
 
 #ifndef __ASSEMBLY__
 
-#define get_user_page(vaddr)           __get_free_page(GFP_KERNEL)
-#define free_user_page(page, addr)     free_page(addr)
-
 #define clear_page(paddr)              memset((paddr), 0, PAGE_SIZE)
 #define copy_page(to, from)            memcpy((to), (from), PAGE_SIZE)
 
@@ -75,11 +72,20 @@ typedef unsigned long pgprot_t;
 
 typedef pte_t * pgtable_t;
 
+/*
+ * Use virt_to_pfn with caution:
+ * If used in pte or paddr related macros, it could cause truncation
+ * in PAE40 builds
+ * As a rule of thumb, only use it in helpers starting with virt_
+ * You have been warned !
+ */
 #define virt_to_pfn(kaddr)     (__pa(kaddr) >> PAGE_SHIFT)
 
 #define ARCH_PFN_OFFSET                virt_to_pfn(CONFIG_LINUX_LINK_BASE)
 
+#ifdef CONFIG_FLATMEM
 #define pfn_valid(pfn)         (((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
+#endif
 
 /*
  * __pa, __va, virt_to_page (ALERT: deprecated, don't use them)
@@ -88,12 +94,10 @@ typedef pte_t * pgtable_t;
  * virt here means link-address/program-address as embedded in object code.
  * And for ARC, link-addr = physical address
  */
-#define __pa(vaddr)  ((unsigned long)vaddr)
+#define __pa(vaddr)  ((unsigned long)(vaddr))
 #define __va(paddr)  ((void *)((unsigned long)(paddr)))
 
-#define virt_to_page(kaddr)    \
-       (mem_map + virt_to_pfn((kaddr) - CONFIG_LINUX_LINK_BASE))
-
+#define virt_to_page(kaddr)    pfn_to_page(virt_to_pfn(kaddr))
 #define virt_addr_valid(kaddr)  pfn_valid(virt_to_pfn(kaddr))
 
 /* Default Permissions for stack/heaps pages (Non Executable) */