x86: backmerge 64-bit details into 32-bit pageattr.c

backmerge 64-bit details into 32-bit pageattr.c.

the pageattr_32.c and pageattr_64.c files are now identical.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 87 insertions, 47 deletions

diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c
index 1c7bd81a4194..251613449dd6 100644
--- a/arch/x86/mm/pageattr_32.c
+++ b/arch/x86/mm/pageattr_32.c
@@ -39,23 +39,26 @@ pte_t *lookup_address(unsigned long address, int *level)
 
 static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 {
-        struct page *page;
-
         /* change init_mm */
         set_pte_atomic(kpte, pte);
+#ifdef CONFIG_X86_32
         if (SHARED_KERNEL_PMD)
                 return;
-
-        for (page = pgd_list; page; page = (struct page *)page->index) {
-                pgd_t *pgd;
-                pud_t *pud;
-                pmd_t *pmd;
-
-                pgd = (pgd_t *)page_address(page) + pgd_index(address);
-                pud = pud_offset(pgd, address);
-                pmd = pmd_offset(pud, address);
-                set_pte_atomic((pte_t *)pmd, pte);
+        {
+                struct page *page;
+
+                for (page = pgd_list; page; page = (struct page *)page->index) {
+                        pgd_t *pgd;
+                        pud_t *pud;
+                        pmd_t *pmd;
+
+                        pgd = (pgd_t *)page_address(page) + pgd_index(address);
+                        pud = pud_offset(pgd, address);
+                        pmd = pmd_offset(pud, address);
+                        set_pte_atomic((pte_t *)pmd, pte);
+                }
         }
+#endif
 }
 
 static int split_large_page(pte_t *kpte, unsigned long address)
@@ -89,7 +92,9 @@ static int split_large_page(pte_t *kpte, unsigned long address)
         address = __pa(address);
         addr = address & LARGE_PAGE_MASK;
         pbase = (pte_t *)page_address(base);
+#ifdef CONFIG_X86_32
         paravirt_alloc_pt(&init_mm, page_to_pfn(base));
+#endif
 
         for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE)
                 set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot));
@@ -109,15 +114,14 @@ out_unlock:
         return 0;
 }
 
-static int __change_page_attr(struct page *page, pgprot_t prot)
+static int
+__change_page_attr(unsigned long address, struct page *page, pgprot_t prot)
 {
         struct page *kpte_page;
-        unsigned long address;
         int level, err = 0;
         pte_t *kpte;
 
         BUG_ON(PageHighMem(page));
-        address = (unsigned long)page_address(page);
 
 repeat:
         kpte = lookup_address(address, &level);
@@ -146,51 +150,87 @@ repeat:
         return err;
 }
 
-/*
- * Change the page attributes of an page in the linear mapping.
+/**
+ * change_page_attr_addr - Change page table attributes in linear mapping
+ * @address: Virtual address in linear mapping.
+ * @numpages: Number of pages to change
+ * @prot:    New page table attribute (PAGE_*)
  *
- * This should be used when a page is mapped with a different caching policy
- * than write-back somewhere - some CPUs do not like it when mappings with
- * different caching policies exist. This changes the page attributes of the
- * in kernel linear mapping too.
- *
- * The caller needs to ensure that there are no conflicting mappings elsewhere.
- * This function only deals with the kernel linear map.
+ * Change page attributes of a page in the direct mapping. This is a variant
+ * of change_page_attr() that also works on memory holes that do not have
+ * mem_map entry (pfn_valid() is false).
  *
- * Caller must call global_flush_tlb() after this.
+ * See change_page_attr() documentation for more details.
  */
-int change_page_attr(struct page *page, int numpages, pgprot_t prot)
+
+int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
 {
-        int err = 0, i;
+        int err = 0, kernel_map = 0, i;
+
+#ifdef CONFIG_X86_64
+        if (address >= __START_KERNEL_map &&
+                        address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
 
-        for (i = 0; i < numpages; i++, page++) {
-                err = __change_page_attr(page, prot);
-                if (err)
-                        break;
+                address = (unsigned long)__va(__pa(address));
+                kernel_map = 1;
+        }
+#endif
+
+        for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
+                unsigned long pfn = __pa(address) >> PAGE_SHIFT;
+
+                if (!kernel_map || pte_present(pfn_pte(0, prot))) {
+                        err = __change_page_attr(address, pfn_to_page(pfn), prot);
+                        if (err)
+                                break;
+                }
+#ifdef CONFIG_X86_64
+                /*
+                 * Handle kernel mapping too which aliases part of
+                 * lowmem:
+                 */
+                if (__pa(address) < KERNEL_TEXT_SIZE) {
+                        unsigned long addr2;
+                        pgprot_t prot2;
+
+                        addr2 = __START_KERNEL_map + __pa(address);
+                        /* Make sure the kernel mappings stay executable */
+                        prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
+                        err = __change_page_attr(addr2, pfn_to_page(pfn), prot2);
+                }
+#endif
         }
 
         return err;
 }
-EXPORT_SYMBOL(change_page_attr);
 
-int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot)
+/**
+ * change_page_attr - Change page table attributes in the linear mapping.
+ * @page: First page to change
+ * @numpages: Number of pages to change
+ * @prot: New protection/caching type (PAGE_*)
+ *
+ * Returns 0 on success, otherwise a negated errno.
+ *
+ * This should be used when a page is mapped with a different caching policy
+ * than write-back somewhere - some CPUs do not like it when mappings with
+ * different caching policies exist. This changes the page attributes of the
+ * in kernel linear mapping too.
+ *
+ * Caller must call global_flush_tlb() later to make the changes active.
+ *
+ * The caller needs to ensure that there are no conflicting mappings elsewhere
+ * (e.g. in user space) * This function only deals with the kernel linear map.
+ *
+ * For MMIO areas without mem_map use change_page_attr_addr() instead.
+ */
+int change_page_attr(struct page *page, int numpages, pgprot_t prot)
 {
-        int i;
-        unsigned long pfn = (__pa(addr) >> PAGE_SHIFT);
-
-        for (i = 0; i < numpages; i++) {
-                if (!pfn_valid(pfn + i)) {
-                        WARN_ON_ONCE(1);
-                        break;
-                } else {
-                        int level;
-                        pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level);
-                        BUG_ON(pte && pte_none(*pte));
-                }
-        }
+        unsigned long addr = (unsigned long)page_address(page);
 
-        return change_page_attr(virt_to_page(addr), i, prot);
+        return change_page_attr_addr(addr, numpages, prot);
 }
+EXPORT_SYMBOL(change_page_attr);
 
 static void flush_kernel_map(void *arg)
 {