Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / arch / arm / mm / copypage-v6.c

diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index e6a139e..269ce69 100644 (file)
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -15,34 +15,63 @@
 #include <asm/pgtable.h>
 #include <asm/shmparam.h>
 #include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
 
 #if SHMLBA > 16384
 #error FIX ME
 #endif
 
 #define from_address   (0xffff8000)
-#define from_pgprot    PAGE_KERNEL
 #define to_address     (0xffffc000)
-#define to_pgprot      PAGE_KERNEL
 
-static pte_t *from_pte;
-static pte_t *to_pte;
-static spinlock_t v6_lock = SPIN_LOCK_UNLOCKED;
+#define TOP_PTE(x)     pte_offset_kernel(top_pmd, x)
 
-#define DCACHE_COLOUR(vaddr) ((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
+static DEFINE_SPINLOCK(v6_lock);
+
+/*
+ * Copy the user page.  No aliasing to deal with so we can just
+ * attack the kernel's existing mapping of these pages.
+ */
+static void v6_copy_user_page_nonaliasing(void *kto, const void *kfrom, unsigned long vaddr)
+{
+       copy_page(kto, kfrom);
+}
+
+/*
+ * Clear the user page.  No aliasing to deal with so we can just
+ * attack the kernel's existing mapping of this page.
+ */
+static void v6_clear_user_page_nonaliasing(void *kaddr, unsigned long vaddr)
+{
+       clear_page(kaddr);
+}
 
 /*
  * Copy the page, taking account of the cache colour.
  */
-void v6_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
+static void v6_copy_user_page_aliasing(void *kto, const void *kfrom, unsigned long vaddr)
 {
-       unsigned int offset = DCACHE_COLOUR(vaddr);
+       unsigned int offset = CACHE_COLOUR(vaddr);
        unsigned long from, to;
 
+       /*
+        * Discard data in the kernel mapping for the new page.
+        * FIXME: needs this MCRR to be supported.
+        */
+       __asm__("mcrr   p15, 0, %1, %0, c6      @ 0xec401f06"
+          :
+          : "r" (kto),
+            "r" ((unsigned long)kto + PAGE_SIZE - L1_CACHE_BYTES)
+          : "cc");
+
+       /*
+        * Now copy the page using the same cache colour as the
+        * pages ultimate destination.
+        */
        spin_lock(&v6_lock);
 
-       set_pte(from_pte + offset, pfn_pte(__pa(kfrom) >> PAGE_SHIFT, from_pgprot));
-       set_pte(to_pte + offset, pfn_pte(__pa(kto) >> PAGE_SHIFT, to_pgprot));
+       set_pte(TOP_PTE(from_address) + offset, pfn_pte(__pa(kfrom) >> PAGE_SHIFT, PAGE_KERNEL));
+       set_pte(TOP_PTE(to_address) + offset, pfn_pte(__pa(kto) >> PAGE_SHIFT, PAGE_KERNEL));
 
        from = from_address + (offset << PAGE_SHIFT);
        to   = to_address + (offset << PAGE_SHIFT);
@@ -55,14 +84,33 @@ void v6_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
        spin_unlock(&v6_lock);
 }
 
-void v6_clear_user_page(void *kaddr, unsigned long vaddr)
+/*
+ * Clear the user page.  We need to deal with the aliasing issues,
+ * so remap the kernel page into the same cache colour as the user
+ * page.
+ */
+static void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr)
 {
-       unsigned int offset = DCACHE_COLOUR(vaddr);
+       unsigned int offset = CACHE_COLOUR(vaddr);
        unsigned long to = to_address + (offset << PAGE_SHIFT);
 
+       /*
+        * Discard data in the kernel mapping for the new page
+        * FIXME: needs this MCRR to be supported.
+        */
+       __asm__("mcrr   p15, 0, %1, %0, c6      @ 0xec401f06"
+          :
+          : "r" (kaddr),
+            "r" ((unsigned long)kaddr + PAGE_SIZE - L1_CACHE_BYTES)
+          : "cc");
+
+       /*
+        * Now clear the page using the same cache colour as
+        * the pages ultimate destination.
+        */
        spin_lock(&v6_lock);
 
-       set_pte(to_pte + offset, pfn_pte(__pa(kaddr) >> PAGE_SHIFT, to_pgprot));
+       set_pte(TOP_PTE(to_address) + offset, pfn_pte(__pa(kaddr) >> PAGE_SHIFT, PAGE_KERNEL));
        flush_tlb_kernel_page(to);
        clear_page((void *)to);
 
@@ -70,29 +118,18 @@ void v6_clear_user_page(void *kaddr, unsigned long vaddr)
 }
 
 struct cpu_user_fns v6_user_fns __initdata = {
-       .cpu_clear_user_page    = v6_clear_user_page,
-       .cpu_copy_user_page     = v6_copy_user_page,
+       .cpu_clear_user_page    = v6_clear_user_page_nonaliasing,
+       .cpu_copy_user_page     = v6_copy_user_page_nonaliasing,
 };
 
 static int __init v6_userpage_init(void)
 {
-       pgd_t *pgd;
-       pmd_t *pmd;
-
-       pgd = pgd_offset_k(from_address);
-       pmd = pmd_alloc(&init_mm, pgd, from_address);
-       if (!pmd)
-               BUG();
-       from_pte = pte_alloc_kernel(&init_mm, pmd, from_address);
-       if (!from_pte)
-               BUG();
-
-       to_pte = pte_alloc_kernel(&init_mm, pmd, to_address);
-       if (!to_pte)
-               BUG();
+       if (cache_is_vipt_aliasing()) {
+               cpu_user.cpu_clear_user_page = v6_clear_user_page_aliasing;
+               cpu_user.cpu_copy_user_page = v6_copy_user_page_aliasing;
+       }
 
        return 0;
 }
 
-__initcall(v6_userpage_init);
-
+core_initcall(v6_userpage_init);