powerpc/mm: implement set_memory_attr()

[linux-2.6-microblaze.git] / arch / powerpc / mm / pageattr.c

diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c
index 5e5ae50..0876216 100644 (file)
--- a/arch/powerpc/mm/pageattr.c
+++ b/arch/powerpc/mm/pageattr.c
@@ -99,3 +99,36 @@ int change_memory_attr(unsigned long addr, int numpages, long action)
        return apply_to_existing_page_range(&init_mm, start, size,
                                            change_page_attr, (void *)action);
 }
+
+/*
+ * Set the attributes of a page:
+ *
+ * This function is used by PPC32 at the end of init to set final kernel memory
+ * protection. It includes changing the maping of the page it is executing from
+ * and data pages it is using.
+ */
+static int set_page_attr(pte_t *ptep, unsigned long addr, void *data)
+{
+       pgprot_t prot = __pgprot((unsigned long)data);
+
+       spin_lock(&init_mm.page_table_lock);
+
+       set_pte_at(&init_mm, addr, ptep, pte_modify(*ptep, prot));
+       flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+
+       spin_unlock(&init_mm.page_table_lock);
+
+       return 0;
+}
+
+int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot)
+{
+       unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE);
+       unsigned long sz = numpages * PAGE_SIZE;
+
+       if (numpages <= 0)
+               return 0;
+
+       return apply_to_existing_page_range(&init_mm, start, sz, set_page_attr,
+                                           (void *)pgprot_val(prot));
+}