static inline pte_t *lookup_address(unsigned long address)
{
- pgd_t *pgd = pgd_offset_k(address);
+ pgd_t *pgd = pgd_offset_k(address);
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- if (!pgd || !pgd_present(*pgd))
+ if (pgd_none(*pgd))
+ return NULL;
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
return NULL;
- pmd = pmd_offset(pgd, address);
+ pmd = pmd_offset(pud, address);
if (!pmd_present(*pmd))
return NULL;
if (pmd_large(*pmd))
return pte;
}
-static struct page *split_large_page(unsigned long address, pgprot_t prot)
+static struct page *split_large_page(unsigned long address, pgprot_t prot,
+ pgprot_t ref_prot)
{
int i;
unsigned long addr;
pbase = (pte_t *)page_address(base);
for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
pbase[i] = pfn_pte(addr >> PAGE_SHIFT,
- addr == address ? prot : PAGE_KERNEL);
+ addr == address ? prot : ref_prot);
}
return base;
}
asm volatile("clflush (%0)" :: "r" (address + i));
} else
asm volatile("wbinvd":::"memory");
- __flush_tlb_one(address);
+ if (address)
+ __flush_tlb_one(address);
+ else
+ __flush_tlb_all();
}
* No more special protections in this 2/4MB area - revert to a
* large page again.
*/
-static void revert_page(struct page *kpte_page, unsigned long address)
+static void revert_page(unsigned long address, pgprot_t ref_prot)
{
- pgd_t *pgd;
- pmd_t *pmd;
- pte_t large_pte;
-
- pgd = pgd_offset_k(address);
- pmd = pmd_offset(pgd, address);
- BUG_ON(pmd_val(*pmd) & _PAGE_PSE);
- large_pte = mk_pte_phys(__pa(address) & LARGE_PAGE_MASK, PAGE_KERNEL_LARGE);
- set_pte((pte_t *)pmd, large_pte);
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t large_pte;
+
+ pgd = pgd_offset_k(address);
+ BUG_ON(pgd_none(*pgd));
+ pud = pud_offset(pgd,address);
+ BUG_ON(pud_none(*pud));
+ pmd = pmd_offset(pud, address);
+ BUG_ON(pmd_val(*pmd) & _PAGE_PSE);
+ pgprot_val(ref_prot) |= _PAGE_PSE;
+ large_pte = mk_pte_phys(__pa(address) & LARGE_PAGE_MASK, ref_prot);
+ set_pte((pte_t *)pmd, large_pte);
}
static int
-__change_page_attr(unsigned long address, struct page *page, pgprot_t prot)
+__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
+ pgprot_t ref_prot)
{
pte_t *kpte;
struct page *kpte_page;
unsigned kpte_flags;
-
kpte = lookup_address(address);
if (!kpte) return 0;
kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
kpte_flags = pte_val(*kpte);
- if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
+ if (pgprot_val(prot) != pgprot_val(ref_prot)) {
if ((kpte_flags & _PAGE_PSE) == 0) {
- pte_t old = *kpte;
- pte_t standard = mk_pte(page, PAGE_KERNEL);
-
- set_pte(kpte, mk_pte(page, prot));
- if (pte_same(old,standard))
- atomic_inc(&kpte_page->count);
+ set_pte(kpte, pfn_pte(pfn, prot));
} else {
- struct page *split = split_large_page(address, prot);
+ /*
+ * split_large_page will take the reference for this change_page_attr
+ * on the split page.
+ */
+ struct page *split = split_large_page(address, prot, ref_prot);
if (!split)
return -ENOMEM;
- atomic_inc(&kpte_page->count);
- set_pte(kpte,mk_pte(split, PAGE_KERNEL));
+ set_pte(kpte,mk_pte(split, ref_prot));
+ kpte_page = split;
}
+ get_page(kpte_page);
} else if ((kpte_flags & _PAGE_PSE) == 0) {
- set_pte(kpte, mk_pte(page, PAGE_KERNEL));
- atomic_dec(&kpte_page->count);
- }
+ set_pte(kpte, pfn_pte(pfn, ref_prot));
+ __put_page(kpte_page);
+ } else
+ BUG();
+
+ /* on x86-64 the direct mapping set at boot is not using 4k pages */
+ BUG_ON(PageReserved(kpte_page));
- if (atomic_read(&kpte_page->count) == 1) {
+ switch (page_count(kpte_page)) {
+ case 1:
save_page(address, kpte_page);
- revert_page(kpte_page, address);
- }
+ revert_page(address, ref_prot);
+ break;
+ case 0:
+ BUG(); /* memleak and failed 2M page regeneration */
+ }
return 0;
}
*
* Caller must call global_flush_tlb() after this.
*/
-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;
int i;
down_write(&init_mm.mmap_sem);
- for (i = 0; i < numpages; !err && i++, page++) {
- unsigned long address = (unsigned long)page_address(page);
- err = __change_page_attr(address, page, prot);
+ for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
+ unsigned long pfn = __pa(address) >> PAGE_SHIFT;
+
+ err = __change_page_attr(address, pfn, prot, PAGE_KERNEL);
if (err)
break;
- /* Handle kernel mapping too which aliases part of the lowmem */
- if (page_to_phys(page) < KERNEL_TEXT_SIZE) {
- unsigned long addr2 = __START_KERNEL_map + page_to_phys(page);
- err = __change_page_attr(addr2, page, prot);
+ /* Handle kernel mapping too which aliases part of the
+ * lowmem */
+ if (__pa(address) < KERNEL_TEXT_SIZE) {
+ unsigned long addr2;
+ pgprot_t prot2 = prot;
+ addr2 = __START_KERNEL_map + __pa(address);
+ pgprot_val(prot2) &= ~_PAGE_NX;
+ err = __change_page_attr(addr2, pfn, prot2, PAGE_KERNEL_EXEC);
}
}
up_write(&init_mm.mmap_sem);
return err;
}
+/* Don't call this for MMIO areas that may not have a mem_map entry */
+int change_page_attr(struct page *page, int numpages, pgprot_t prot)
+{
+ unsigned long addr = (unsigned long)page_address(page);
+ return change_page_attr_addr(addr, numpages, prot);
+}
+
void global_flush_tlb(void)
{
struct deferred_page *df, *next_df;
down_read(&init_mm.mmap_sem);
df = xchg(&df_list, NULL);
up_read(&init_mm.mmap_sem);
+ if (!df)
+ return;
flush_map((df && !df->next) ? df->address : 0);
for (; df; df = next_df) {
next_df = df->next;