1 files changed, 74 insertions, 32 deletions

diff --git a/include/asm-xtensa/page.h b/include/asm-xtensa/page.h
index 1213cde75438..55ce2c9749a3 100644
--- a/include/asm-xtensa/page.h
+++ b/include/asm-xtensa/page.h
@@ -1,11 +1,11 @@
 /*
- * linux/include/asm-xtensa/page.h
+ * include/asm-xtensa/page.h
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version2 as
  * published by the Free Software Foundation.
  *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
  */
 
 #ifndef _XTENSA_PAGE_H
@@ -14,6 +14,12 @@
 #ifdef __KERNEL__
 
 #include <asm/processor.h>
+#include <asm/types.h>
+#include <asm/cache.h>
+
+/*
+ * Fixed TLB translations in the processor.
+ */
 
 #define XCHAL_KSEG_CACHED_VADDR 0xd0000000
 #define XCHAL_KSEG_BYPASS_VADDR 0xd8000000
@@ -26,13 +32,60 @@
  */
 
 #define PAGE_SHIFT              12
-#define PAGE_SIZE               (1 << PAGE_SHIFT)
+#define PAGE_SIZE               (__XTENSA_UL_CONST(1) << PAGE_SHIFT)
 #define PAGE_MASK               (~(PAGE_SIZE-1))
 #define PAGE_ALIGN(addr)        (((addr)+PAGE_SIZE - 1) & PAGE_MASK)
 
 #define PAGE_OFFSET             XCHAL_KSEG_CACHED_VADDR
-#define MAX_MEM_PFN             XCHAL_KSEG_SIZE
-#define PGTABLE_START           0x80000000
+#define MAX_MEM_PFN             XCHAL_KSEG_SIZE
+#define PGTABLE_START           0x80000000
+
+/*
+ * Cache aliasing:
+ *
+ * If the cache size for one way is greater than the page size, we have to
+ * deal with cache aliasing. The cache index is wider than the page size:
+ *
+ * |    |cache| cache index
+ * | pfn  |off| virtual address
+ * |xxxx:X|zzz|
+ * |    : |   |
+ * | \  / |   |
+ * |trans.|   |
+ * | /  \ |   |
+ * |yyyy:Y|zzz| physical address
+ *
+ * When the page number is translated to the physical page address, the lowest
+ * bit(s) (X) that are part of the cache index are also translated (Y).
+ * If this translation changes bit(s) (X), the cache index is also afected,
+ * thus resulting in a different cache line than before.
+ * The kernel does not provide a mechanism to ensure that the page color
+ * (represented by this bit) remains the same when allocated or when pages
+ * are remapped. When user pages are mapped into kernel space, the color of
+ * the page might also change.
+ *
+ * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
+ * to temporarily map a patch so we can match the color.
+ */
+
+#if DCACHE_WAY_SIZE > PAGE_SIZE
+# define DCACHE_ALIAS_ORDER     (DCACHE_WAY_SHIFT - PAGE_SHIFT)
+# define DCACHE_ALIAS_MASK      (PAGE_MASK & (DCACHE_WAY_SIZE - 1))
+# define DCACHE_ALIAS(a)        (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT)
+# define DCACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)
+#else
+# define DCACHE_ALIAS_ORDER     0
+#endif
+
+#if ICACHE_WAY_SIZE > PAGE_SIZE
+# define ICACHE_ALIAS_ORDER     (ICACHE_WAY_SHIFT - PAGE_SHIFT)
+# define ICACHE_ALIAS_MASK      (PAGE_MASK & (ICACHE_WAY_SIZE - 1))
+# define ICACHE_ALIAS(a)        (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT)
+# define ICACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0)
+#else
+# define ICACHE_ALIAS_ORDER     0
+#endif
+
 
 #ifdef __ASSEMBLY__
 
@@ -58,34 +111,23 @@ typedef struct { unsigned long pgprot; } pgprot_t;
 
 /*
  * Pure 2^n version of get_order
+ * Use 'nsau' instructions if supported by the processor or the generic version.
  */
 
-static inline int get_order(unsigned long size)
+#if XCHAL_HAVE_NSA
+
+static inline __attribute_const__ int get_order(unsigned long size)
 {
-        int order;
-#ifndef XCHAL_HAVE_NSU
-        unsigned long x1, x2, x4, x8, x16;
-
-        size = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        x1  = size & 0xAAAAAAAA;
-        x2  = size & 0xCCCCCCCC;
-        x4  = size & 0xF0F0F0F0;
-        x8  = size & 0xFF00FF00;
-        x16 = size & 0xFFFF0000;
-        order = x2 ? 2 : 0;
-        order += (x16 != 0) * 16;
-        order += (x8 != 0) * 8;
-        order += (x4 != 0) * 4;
-        order += (x1 != 0);
-
-        return order;
-#else
-        size = (size - 1) >> PAGE_SHIFT;
-        asm ("nsau %0, %1" : "=r" (order) : "r" (size));
-        return 32 - order;
-#endif
+        int lz;
+        asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
+        return 32 - lz;
 }
 
+#else
+
+# include <asm-generic/page.h>
+
+#endif
 
 struct page;
 extern void clear_page(void *page);
@@ -96,11 +138,11 @@ extern void copy_page(void *to, void *from);
  * some extra work
  */
 
-#if (DCACHE_WAY_SIZE > PAGE_SIZE)
-void clear_user_page(void *addr, unsigned long vaddr, struct page* page);
-void copy_user_page(void *to,void* from,unsigned long vaddr,struct page* page);
+#if DCACHE_WAY_SIZE > PAGE_SIZE
+extern void clear_user_page(void*, unsigned long, struct page*);
+extern void copy_user_page(void*, void*, unsigned long, struct page*);
 #else
-# define clear_user_page(page,vaddr,pg)         clear_page(page)
+# define clear_user_page(page, vaddr, pg)       clear_page(page)
 # define copy_user_page(to, from, vaddr, pg)    copy_page(to, from)
 #endif