x86: cpa, strict range check in try_preserve_large_page()
[sfrench/cifs-2.6.git] / arch / x86 / mm / pageattr.c
index d18c41d752f349cfb37463973559833ed1073ab1..440210a2277d3d6a710dcb713792e377f8306d89 100644 (file)
@@ -8,15 +8,9 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/interrupt.h>
 
-void clflush_cache_range(void *addr, int size)
-{
-       int i;
-
-       for (i = 0; i < size; i += boot_cpu_data.x86_clflush_size)
-               clflush(addr+i);
-}
-
+#include <asm/e820.h>
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
@@ -24,27 +18,181 @@ void clflush_cache_range(void *addr, int size)
 #include <asm/pgalloc.h>
 
 /*
- * We allow the BIOS range to be executable:
+ * The current flushing context - we pass it instead of 5 arguments:
+ */
+struct cpa_data {
+       unsigned long   vaddr;
+       pgprot_t        mask_set;
+       pgprot_t        mask_clr;
+       int             numpages;
+       int             flushtlb;
+};
+
+static inline int
+within(unsigned long addr, unsigned long start, unsigned long end)
+{
+       return addr >= start && addr < end;
+}
+
+/*
+ * Flushing functions
+ */
+
+/**
+ * clflush_cache_range - flush a cache range with clflush
+ * @addr:      virtual start address
+ * @size:      number of bytes to flush
+ *
+ * clflush is an unordered instruction which needs fencing with mfence
+ * to avoid ordering issues.
+ */
+void clflush_cache_range(void *vaddr, unsigned int size)
+{
+       void *vend = vaddr + size - 1;
+
+       mb();
+
+       for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
+               clflush(vaddr);
+       /*
+        * Flush any possible final partial cacheline:
+        */
+       clflush(vend);
+
+       mb();
+}
+
+static void __cpa_flush_all(void *arg)
+{
+       unsigned long cache = (unsigned long)arg;
+
+       /*
+        * Flush all to work around Errata in early athlons regarding
+        * large page flushing.
+        */
+       __flush_tlb_all();
+
+       if (cache && boot_cpu_data.x86_model >= 4)
+               wbinvd();
+}
+
+static void cpa_flush_all(unsigned long cache)
+{
+       BUG_ON(irqs_disabled());
+
+       on_each_cpu(__cpa_flush_all, (void *) cache, 1, 1);
+}
+
+static void __cpa_flush_range(void *arg)
+{
+       /*
+        * We could optimize that further and do individual per page
+        * tlb invalidates for a low number of pages. Caveat: we must
+        * flush the high aliases on 64bit as well.
+        */
+       __flush_tlb_all();
+}
+
+static void cpa_flush_range(unsigned long start, int numpages, int cache)
+{
+       unsigned int i, level;
+       unsigned long addr;
+
+       BUG_ON(irqs_disabled());
+       WARN_ON(PAGE_ALIGN(start) != start);
+
+       on_each_cpu(__cpa_flush_range, NULL, 1, 1);
+
+       if (!cache)
+               return;
+
+       /*
+        * We only need to flush on one CPU,
+        * clflush is a MESI-coherent instruction that
+        * will cause all other CPUs to flush the same
+        * cachelines:
+        */
+       for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
+               pte_t *pte = lookup_address(addr, &level);
+
+               /*
+                * Only flush present addresses:
+                */
+               if (pte && (pte_val(*pte) & _PAGE_PRESENT))
+                       clflush_cache_range((void *) addr, PAGE_SIZE);
+       }
+}
+
+#define HIGH_MAP_START __START_KERNEL_map
+#define HIGH_MAP_END   (__START_KERNEL_map + KERNEL_TEXT_SIZE)
+
+
+/*
+ * Converts a virtual address to a X86-64 highmap address
  */
-#define BIOS_BEGIN             0x000a0000
-#define BIOS_END               0x00100000
+static unsigned long virt_to_highmap(void *address)
+{
+#ifdef CONFIG_X86_64
+       return __pa((unsigned long)address) + HIGH_MAP_START - phys_base;
+#else
+       return (unsigned long)address;
+#endif
+}
 
-static inline pgprot_t check_exec(pgprot_t prot, unsigned long address)
+/*
+ * Certain areas of memory on x86 require very specific protection flags,
+ * for example the BIOS area or kernel text. Callers don't always get this
+ * right (again, ioremap() on BIOS memory is not uncommon) so this function
+ * checks and fixes these known static required protection bits.
+ */
+static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
 {
-       if (__pa(address) >= BIOS_BEGIN && __pa(address) < BIOS_END)
-               pgprot_val(prot) &= ~_PAGE_NX;
+       pgprot_t forbidden = __pgprot(0);
+
        /*
-        * Better fail early if someone sets the kernel text to NX.
-        * Does not cover __inittext
+        * The BIOS area between 640k and 1Mb needs to be executable for
+        * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
         */
-       BUG_ON(address >= (unsigned long)&_text &&
-               address < (unsigned long)&_etext &&
-              (pgprot_val(prot) & _PAGE_NX));
+       if (within(__pa(address), BIOS_BEGIN, BIOS_END))
+               pgprot_val(forbidden) |= _PAGE_NX;
+
+       /*
+        * The kernel text needs to be executable for obvious reasons
+        * Does not cover __inittext since that is gone later on
+        */
+       if (within(address, (unsigned long)_text, (unsigned long)_etext))
+               pgprot_val(forbidden) |= _PAGE_NX;
+       /*
+        * Do the same for the x86-64 high kernel mapping
+        */
+       if (within(address, virt_to_highmap(_text), virt_to_highmap(_etext)))
+               pgprot_val(forbidden) |= _PAGE_NX;
+
+       /* The .rodata section needs to be read-only */
+       if (within(address, (unsigned long)__start_rodata,
+                               (unsigned long)__end_rodata))
+               pgprot_val(forbidden) |= _PAGE_RW;
+       /*
+        * Do the same for the x86-64 high kernel mapping
+        */
+       if (within(address, virt_to_highmap(__start_rodata),
+                               virt_to_highmap(__end_rodata)))
+               pgprot_val(forbidden) |= _PAGE_RW;
+
+       prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
 
        return prot;
 }
 
-pte_t *lookup_address(unsigned long address, int *level)
+/*
+ * Lookup the page table entry for a virtual address. Return a pointer
+ * to the entry and the level of the mapping.
+ *
+ * Note: We return pud and pmd either when the entry is marked large
+ * or when the present bit is not set. Otherwise we would return a
+ * pointer to a nonexisting mapping.
+ */
+pte_t *lookup_address(unsigned long address, unsigned int *level)
 {
        pgd_t *pgd = pgd_offset_k(address);
        pud_t *pud;
@@ -54,21 +202,31 @@ pte_t *lookup_address(unsigned long address, int *level)
 
        if (pgd_none(*pgd))
                return NULL;
+
        pud = pud_offset(pgd, address);
        if (pud_none(*pud))
                return NULL;
+
+       *level = PG_LEVEL_1G;
+       if (pud_large(*pud) || !pud_present(*pud))
+               return (pte_t *)pud;
+
        pmd = pmd_offset(pud, address);
        if (pmd_none(*pmd))
                return NULL;
 
        *level = PG_LEVEL_2M;
-       if (pmd_large(*pmd))
+       if (pmd_large(*pmd) || !pmd_present(*pmd))
                return (pte_t *)pmd;
 
        *level = PG_LEVEL_4K;
+
        return pte_offset_kernel(pmd, address);
 }
 
+/*
+ * Set the new pmd in all the pgds we know about:
+ */
 static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 {
        /* change init_mm */
@@ -77,7 +235,7 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
        if (!SHARED_KERNEL_PMD) {
                struct page *page;
 
-               for (page = pgd_list; page; page = (struct page *)page->index) {
+               list_for_each_entry(page, &pgd_list, lru) {
                        pgd_t *pgd;
                        pud_t *pud;
                        pmd_t *pmd;
@@ -91,70 +249,269 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 #endif
 }
 
+static int
+try_preserve_large_page(pte_t *kpte, unsigned long address,
+                       struct cpa_data *cpa)
+{
+       unsigned long nextpage_addr, numpages, pmask, psize, flags, addr;
+       pte_t new_pte, old_pte, *tmp;
+       pgprot_t old_prot, new_prot;
+       int i, do_split = 1;
+       unsigned int level;
+
+       spin_lock_irqsave(&pgd_lock, flags);
+       /*
+        * Check for races, another CPU might have split this page
+        * up already:
+        */
+       tmp = lookup_address(address, &level);
+       if (tmp != kpte)
+               goto out_unlock;
+
+       switch (level) {
+       case PG_LEVEL_2M:
+               psize = PMD_PAGE_SIZE;
+               pmask = PMD_PAGE_MASK;
+               break;
+#ifdef CONFIG_X86_64
+       case PG_LEVEL_1G:
+               psize = PMD_PAGE_SIZE;
+               pmask = PMD_PAGE_MASK;
+               break;
+#endif
+       default:
+               do_split = -EINVAL;
+               goto out_unlock;
+       }
+
+       /*
+        * Calculate the number of pages, which fit into this large
+        * page starting at address:
+        */
+       nextpage_addr = (address + psize) & pmask;
+       numpages = (nextpage_addr - address) >> PAGE_SHIFT;
+       if (numpages < cpa->numpages)
+               cpa->numpages = numpages;
+
+       /*
+        * We are safe now. Check whether the new pgprot is the same:
+        */
+       old_pte = *kpte;
+       old_prot = new_prot = pte_pgprot(old_pte);
+
+       pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
+       pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
+       new_prot = static_protections(new_prot, address);
+
+       /*
+        * We need to check the full range, whether
+        * static_protection() requires a different pgprot for one of
+        * the pages in the range we try to preserve:
+        */
+       addr = address + PAGE_SIZE;
+       for (i = 1; i < cpa->numpages; i++, addr += PAGE_SIZE) {
+               pgprot_t chk_prot = static_protections(new_prot, addr);
+
+               if (pgprot_val(chk_prot) != pgprot_val(new_prot))
+                       goto out_unlock;
+       }
+
+       /*
+        * If there are no changes, return. maxpages has been updated
+        * above:
+        */
+       if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
+               do_split = 0;
+               goto out_unlock;
+       }
+
+       /*
+        * We need to change the attributes. Check, whether we can
+        * change the large page in one go. We request a split, when
+        * the address is not aligned and the number of pages is
+        * smaller than the number of pages in the large page. Note
+        * that we limited the number of possible pages already to
+        * the number of pages in the large page.
+        */
+       if (address == (nextpage_addr - psize) && cpa->numpages == numpages) {
+               /*
+                * The address is aligned and the number of pages
+                * covers the full page.
+                */
+               new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
+               __set_pmd_pte(kpte, address, new_pte);
+               cpa->flushtlb = 1;
+               do_split = 0;
+       }
+
+out_unlock:
+       spin_unlock_irqrestore(&pgd_lock, flags);
+
+       return do_split;
+}
+
+static LIST_HEAD(page_pool);
+static unsigned long pool_size, pool_pages, pool_low;
+static unsigned long pool_used, pool_failed, pool_refill;
+
+static void cpa_fill_pool(void)
+{
+       struct page *p;
+       gfp_t gfp = GFP_KERNEL;
+
+       /* Do not allocate from interrupt context */
+       if (in_irq() || irqs_disabled())
+               return;
+       /*
+        * Check unlocked. I does not matter when we have one more
+        * page in the pool. The bit lock avoids recursive pool
+        * allocations:
+        */
+       if (pool_pages >= pool_size || test_and_set_bit_lock(0, &pool_refill))
+               return;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       /*
+        * We could do:
+        * gfp = in_atomic() ? GFP_ATOMIC : GFP_KERNEL;
+        * but this fails on !PREEMPT kernels
+        */
+       gfp =  GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
+#endif
+
+       while (pool_pages < pool_size) {
+               p = alloc_pages(gfp, 0);
+               if (!p) {
+                       pool_failed++;
+                       break;
+               }
+               spin_lock_irq(&pgd_lock);
+               list_add(&p->lru, &page_pool);
+               pool_pages++;
+               spin_unlock_irq(&pgd_lock);
+       }
+       clear_bit_unlock(0, &pool_refill);
+}
+
+#define SHIFT_MB               (20 - PAGE_SHIFT)
+#define ROUND_MB_GB            ((1 << 10) - 1)
+#define SHIFT_MB_GB            10
+#define POOL_PAGES_PER_GB      16
+
+void __init cpa_init(void)
+{
+       struct sysinfo si;
+       unsigned long gb;
+
+       si_meminfo(&si);
+       /*
+        * Calculate the number of pool pages:
+        *
+        * Convert totalram (nr of pages) to MiB and round to the next
+        * GiB. Shift MiB to Gib and multiply the result by
+        * POOL_PAGES_PER_GB:
+        */
+       gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB;
+       pool_size = POOL_PAGES_PER_GB * gb;
+       pool_low = pool_size;
+
+       cpa_fill_pool();
+       printk(KERN_DEBUG
+              "CPA: page pool initialized %lu of %lu pages preallocated\n",
+              pool_pages, pool_size);
+}
+
 static int split_large_page(pte_t *kpte, unsigned long address)
 {
-       pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
-       gfp_t gfp_flags = GFP_KERNEL;
-       unsigned long flags;
-       unsigned long addr;
+       unsigned long flags, pfn, pfninc = 1;
+       unsigned int i, level;
        pte_t *pbase, *tmp;
+       pgprot_t ref_prot;
        struct page *base;
-       int i, level;
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
-       gfp_flags = GFP_ATOMIC;
-#endif
-       base = alloc_pages(gfp_flags, 0);
-       if (!base)
+       /*
+        * Get a page from the pool. The pool list is protected by the
+        * pgd_lock, which we have to take anyway for the split
+        * operation:
+        */
+       spin_lock_irqsave(&pgd_lock, flags);
+       if (list_empty(&page_pool)) {
+               spin_unlock_irqrestore(&pgd_lock, flags);
                return -ENOMEM;
+       }
+
+       base = list_first_entry(&page_pool, struct page, lru);
+       list_del(&base->lru);
+       pool_pages--;
+
+       if (pool_pages < pool_low)
+               pool_low = pool_pages;
 
-       spin_lock_irqsave(&pgd_lock, flags);
        /*
         * Check for races, another CPU might have split this page
         * up for us already:
         */
        tmp = lookup_address(address, &level);
-       if (tmp != kpte) {
-               WARN_ON_ONCE(1);
+       if (tmp != kpte)
                goto out_unlock;
-       }
 
-       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
+       ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+
+#ifdef CONFIG_X86_64
+       if (level == PG_LEVEL_1G) {
+               pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
+               pgprot_val(ref_prot) |= _PAGE_PSE;
+       }
+#endif
 
-       for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE)
-               set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot));
+       /*
+        * Get the target pfn from the original entry:
+        */
+       pfn = pte_pfn(*kpte);
+       for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
+               set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
 
        /*
-        * Install the new, split up pagetable:
+        * Install the new, split up pagetable. Important details here:
+        *
+        * On Intel the NX bit of all levels must be cleared to make a
+        * page executable. See section 4.13.2 of Intel 64 and IA-32
+        * Architectures Software Developer's Manual).
+        *
+        * Mark the entry present. The current mapping might be
+        * set to not present, which we preserved above.
         */
+       ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
+       pgprot_val(ref_prot) |= _PAGE_PRESENT;
        __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
        base = NULL;
 
 out_unlock:
+       /*
+        * If we dropped out via the lookup_address check under
+        * pgd_lock then stick the page back into the pool:
+        */
+       if (base) {
+               list_add(&base->lru, &page_pool);
+               pool_pages++;
+       } else
+               pool_used++;
        spin_unlock_irqrestore(&pgd_lock, flags);
 
-       if (base)
-               __free_pages(base, 0);
-
        return 0;
 }
 
-static int
-__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot)
+static int __change_page_attr(unsigned long address, struct cpa_data *cpa)
 {
+       int do_split, err;
+       unsigned int level;
        struct page *kpte_page;
-       int level, err = 0;
        pte_t *kpte;
 
-#ifdef CONFIG_X86_32
-       BUG_ON(pfn > max_low_pfn);
-#endif
-
 repeat:
        kpte = lookup_address(address, &level);
        if (!kpte)
@@ -164,22 +521,69 @@ repeat:
        BUG_ON(PageLRU(kpte_page));
        BUG_ON(PageCompound(kpte_page));
 
-       prot = check_exec(prot, address);
-
        if (level == PG_LEVEL_4K) {
-               set_pte_atomic(kpte, pfn_pte(pfn, canon_pgprot(prot)));
-       } else {
-               err = split_large_page(kpte, address);
-               if (!err)
-                       goto repeat;
+               pte_t new_pte, old_pte = *kpte;
+               pgprot_t new_prot = pte_pgprot(old_pte);
+
+               if(!pte_val(old_pte)) {
+                       printk(KERN_WARNING "CPA: called for zero pte. "
+                              "vaddr = %lx cpa->vaddr = %lx\n", address,
+                               cpa->vaddr);
+                       WARN_ON(1);
+                       return -EINVAL;
+               }
+
+               pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
+               pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
+
+               new_prot = static_protections(new_prot, address);
+
+               /*
+                * We need to keep the pfn from the existing PTE,
+                * after all we're only going to change it's attributes
+                * not the memory it points to
+                */
+               new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
+
+               /*
+                * Do we really change anything ?
+                */
+               if (pte_val(old_pte) != pte_val(new_pte)) {
+                       set_pte_atomic(kpte, new_pte);
+                       cpa->flushtlb = 1;
+               }
+               cpa->numpages = 1;
+               return 0;
+       }
+
+       /*
+        * Check, whether we can keep the large page intact
+        * and just change the pte:
+        */
+       do_split = try_preserve_large_page(kpte, address, cpa);
+       /*
+        * When the range fits into the existing large page,
+        * return. cp->numpages and cpa->tlbflush have been updated in
+        * try_large_page:
+        */
+       if (do_split <= 0)
+               return do_split;
+
+       /*
+        * We have to split the large page:
+        */
+       err = split_large_page(kpte, address);
+       if (!err) {
+               cpa->flushtlb = 1;
+               goto repeat;
        }
+
        return err;
 }
 
 /**
  * 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_*)
  *
  * Change page attributes of a page in the direct mapping. This is a variant
@@ -187,98 +591,260 @@ repeat:
  * mem_map entry (pfn_valid() is false).
  *
  * See change_page_attr() documentation for more details.
+ *
+ * Modules and drivers should use the set_memory_* APIs instead.
  */
-
-int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
+static int change_page_attr_addr(struct cpa_data *cpa)
 {
-       int err = 0, kernel_map = 0, i;
+       int err;
+       unsigned long address = cpa->vaddr;
 
 #ifdef CONFIG_X86_64
-       if (address >= __START_KERNEL_map &&
-                       address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
+       unsigned long phys_addr = __pa(address);
 
-               address = (unsigned long)__va(__pa(address));
-               kernel_map = 1;
-       }
+       /*
+        * If we are inside the high mapped kernel range, then we
+        * fixup the low mapping first. __va() returns the virtual
+        * address in the linear mapping:
+        */
+       if (within(address, HIGH_MAP_START, HIGH_MAP_END))
+               address = (unsigned long) __va(phys_addr);
 #endif
 
-       for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
-               unsigned long pfn = __pa(address) >> PAGE_SHIFT;
+       err = __change_page_attr(address, cpa);
+       if (err)
+               return err;
 
-               if (!kernel_map || pte_present(pfn_pte(0, prot))) {
-                       err = __change_page_attr(address, pfn, prot);
-                       if (err)
-                               break;
-               }
 #ifdef CONFIG_X86_64
+       /*
+        * If the physical address is inside the kernel map, we need
+        * to touch the high mapped kernel as well:
+        */
+       if (within(phys_addr, 0, KERNEL_TEXT_SIZE)) {
                /*
-                * Handle kernel mapping too which aliases part of
-                * lowmem:
+                * Calc the high mapping address. See __phys_addr()
+                * for the non obvious details.
+                *
+                * Note that NX and other required permissions are
+                * checked in static_protections().
                 */
-               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, prot2);
-               }
-#endif
-       }
+               address = phys_addr + HIGH_MAP_START - phys_base;
 
+               /*
+                * Our high aliases are imprecise, because we check
+                * everything between 0 and KERNEL_TEXT_SIZE, so do
+                * not propagate lookup failures back to users:
+                */
+               __change_page_attr(address, cpa);
+       }
+#endif
        return err;
 }
 
-/**
- * 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)
+static int __change_page_attr_set_clr(struct cpa_data *cpa)
 {
-       unsigned long addr = (unsigned long)page_address(page);
+       int ret, numpages = cpa->numpages;
+
+       while (numpages) {
+               /*
+                * Store the remaining nr of pages for the large page
+                * preservation check.
+                */
+               cpa->numpages = numpages;
+               ret = change_page_attr_addr(cpa);
+               if (ret)
+                       return ret;
+
+               /*
+                * Adjust the number of pages with the result of the
+                * CPA operation. Either a large page has been
+                * preserved or a single page update happened.
+                */
+               BUG_ON(cpa->numpages > numpages);
+               numpages -= cpa->numpages;
+               cpa->vaddr += cpa->numpages * PAGE_SIZE;
+       }
+       return 0;
+}
 
-       return change_page_attr_addr(addr, numpages, prot);
+static inline int cache_attr(pgprot_t attr)
+{
+       return pgprot_val(attr) &
+               (_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
 }
-EXPORT_SYMBOL(change_page_attr);
 
-static void flush_kernel_map(void *arg)
+static int change_page_attr_set_clr(unsigned long addr, int numpages,
+                                   pgprot_t mask_set, pgprot_t mask_clr)
 {
+       struct cpa_data cpa;
+       int ret, cache;
+
        /*
-        * Flush all to work around Errata in early athlons regarding
-        * large page flushing.
+        * Check, if we are requested to change a not supported
+        * feature:
         */
-       __flush_tlb_all();
+       mask_set = canon_pgprot(mask_set);
+       mask_clr = canon_pgprot(mask_clr);
+       if (!pgprot_val(mask_set) && !pgprot_val(mask_clr))
+               return 0;
 
-       if (boot_cpu_data.x86_model >= 4)
-               wbinvd();
+       cpa.vaddr = addr;
+       cpa.numpages = numpages;
+       cpa.mask_set = mask_set;
+       cpa.mask_clr = mask_clr;
+       cpa.flushtlb = 0;
+
+       ret = __change_page_attr_set_clr(&cpa);
+
+       /*
+        * Check whether we really changed something:
+        */
+       if (!cpa.flushtlb)
+               goto out;
+
+       /*
+        * No need to flush, when we did not set any of the caching
+        * attributes:
+        */
+       cache = cache_attr(mask_set);
+
+       /*
+        * On success we use clflush, when the CPU supports it to
+        * avoid the wbindv. If the CPU does not support it and in the
+        * error case we fall back to cpa_flush_all (which uses
+        * wbindv):
+        */
+       if (!ret && cpu_has_clflush)
+               cpa_flush_range(addr, numpages, cache);
+       else
+               cpa_flush_all(cache);
+
+out:
+       cpa_fill_pool();
+       return ret;
 }
 
-void global_flush_tlb(void)
+static inline int change_page_attr_set(unsigned long addr, int numpages,
+                                      pgprot_t mask)
 {
-       BUG_ON(irqs_disabled());
+       return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0));
+}
+
+static inline int change_page_attr_clear(unsigned long addr, int numpages,
+                                        pgprot_t mask)
+{
+       return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask);
+}
+
+int set_memory_uc(unsigned long addr, int numpages)
+{
+       return change_page_attr_set(addr, numpages,
+                                   __pgprot(_PAGE_PCD | _PAGE_PWT));
+}
+EXPORT_SYMBOL(set_memory_uc);
+
+int set_memory_wb(unsigned long addr, int numpages)
+{
+       return change_page_attr_clear(addr, numpages,
+                                     __pgprot(_PAGE_PCD | _PAGE_PWT));
+}
+EXPORT_SYMBOL(set_memory_wb);
 
-       on_each_cpu(flush_kernel_map, NULL, 1, 1);
+int set_memory_x(unsigned long addr, int numpages)
+{
+       return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_NX));
+}
+EXPORT_SYMBOL(set_memory_x);
+
+int set_memory_nx(unsigned long addr, int numpages)
+{
+       return change_page_attr_set(addr, numpages, __pgprot(_PAGE_NX));
+}
+EXPORT_SYMBOL(set_memory_nx);
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+       return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_RW));
+}
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+       return change_page_attr_set(addr, numpages, __pgprot(_PAGE_RW));
+}
+
+int set_memory_np(unsigned long addr, int numpages)
+{
+       return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
+}
+
+int set_pages_uc(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_uc(addr, numpages);
+}
+EXPORT_SYMBOL(set_pages_uc);
+
+int set_pages_wb(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_wb(addr, numpages);
+}
+EXPORT_SYMBOL(set_pages_wb);
+
+int set_pages_x(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_x(addr, numpages);
+}
+EXPORT_SYMBOL(set_pages_x);
+
+int set_pages_nx(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_nx(addr, numpages);
+}
+EXPORT_SYMBOL(set_pages_nx);
+
+int set_pages_ro(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_ro(addr, numpages);
+}
+
+int set_pages_rw(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_rw(addr, numpages);
 }
-EXPORT_SYMBOL(global_flush_tlb);
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
+
+static int __set_pages_p(struct page *page, int numpages)
+{
+       struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+                               .numpages = numpages,
+                               .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
+                               .mask_clr = __pgprot(0)};
+
+       return __change_page_attr_set_clr(&cpa);
+}
+
+static int __set_pages_np(struct page *page, int numpages)
+{
+       struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+                               .numpages = numpages,
+                               .mask_set = __pgprot(0),
+                               .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW)};
+
+       return __change_page_attr_set_clr(&cpa);
+}
+
 void kernel_map_pages(struct page *page, int numpages, int enable)
 {
        if (PageHighMem(page))
@@ -298,12 +864,29 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
         * The return value is ignored - the calls cannot fail,
         * large pages are disabled at boot time:
         */
-       change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
+       if (enable)
+               __set_pages_p(page, numpages);
+       else
+               __set_pages_np(page, numpages);
 
        /*
         * We should perform an IPI and flush all tlbs,
         * but that can deadlock->flush only current cpu:
         */
        __flush_tlb_all();
+
+       /*
+        * Try to refill the page pool here. We can do this only after
+        * the tlb flush.
+        */
+       cpa_fill_pool();
 }
 #endif
+
+/*
+ * The testcases use internal knowledge of the implementation that shouldn't
+ * be exposed to the rest of the kernel. Include these directly here.
+ */
+#ifdef CONFIG_CPA_DEBUG
+#include "pageattr-test.c"
+#endif