#define DCACHE_COLOUR(vaddr) ((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
+/*
+ * Copy the user page. No aliasing to deal with so we can just
+ * attack the kernel's existing mapping of these pages.
+ */
+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.
+ */
+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)
+void v6_copy_user_page_aliasing(void *kto, const void *kfrom, unsigned long vaddr)
{
unsigned int offset = DCACHE_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));
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.
+ */
+void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr)
{
unsigned int offset = DCACHE_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));
}
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()) {
+ 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();
+
+ cpu_user.cpu_clear_user_page = v6_clear_user_page_aliasing;
+ cpu_user.cpu_copy_user_page = v6_copy_user_page_aliasing;
+ }
return 0;
}