OSCL-LXR linux-6.0.1/​arch/​x86/​mm/​pat/​set_memory.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2002 Andi Kleen, SuSE Labs.
  * Thanks to Ben LaHaise for precious feedback.
  */
 #include <linux/highmem.h>
 #include <linux/memblock.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/interrupt.h>
 #include <linux/seq_file.h>
 #include <linux/debugfs.h>
 #include <linux/pfn.h>
 #include <linux/percpu.h>
 #include <linux/gfp.h>
 #include <linux/pci.h>
 #include <linux/vmalloc.h>
 #include <linux/libnvdimm.h>
 #include <linux/vmstat.h>
 #include <linux/kernel.h>
 #include <linux/cc_platform.h>
 #include <linux/set_memory.h>
 
 #include <asm/e820/api.h>
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
 #include <linux/uaccess.h>
 #include <asm/pgalloc.h>
 #include <asm/proto.h>
 #include <asm/memtype.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/mshyperv.h>
 
 #include "../mm_internal.h"
 
 /*
  * The current flushing context - we pass it instead of 5 arguments:
  */
 struct cpa_data {
     unsigned long   *vaddr;
     pgd_t       *pgd;
     pgprot_t    mask_set;
     pgprot_t    mask_clr;
     unsigned long   numpages;
     unsigned long   curpage;
     unsigned long   pfn;
     unsigned int    flags;
     unsigned int    force_split     : 1,
             force_static_prot   : 1,
             force_flush_all     : 1;
     struct page **pages;
 };
 
 enum cpa_warn {
     CPA_CONFLICT,
     CPA_PROTECT,
     CPA_DETECT,
 };
 
 static const int cpa_warn_level = CPA_PROTECT;
 
 /*
  * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
  * using cpa_lock. So that we don't allow any other cpu, with stale large tlb
  * entries change the page attribute in parallel to some other cpu
  * splitting a large page entry along with changing the attribute.
  */
 static DEFINE_SPINLOCK(cpa_lock);
 
 #define CPA_FLUSHTLB 1
 #define CPA_ARRAY 2
 #define CPA_PAGES_ARRAY 4
 #define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */
 
 static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm)
 {
     return __pgprot(cachemode2protval(pcm));
 }
 
 #ifdef CONFIG_PROC_FS
 static unsigned long direct_pages_count[PG_LEVEL_NUM];
 
 void update_page_count(int level, unsigned long pages)
 {
     /* Protect against CPA */
     spin_lock(&pgd_lock);
     direct_pages_count[level] += pages;
     spin_unlock(&pgd_lock);
 }
 
 static void split_page_count(int level)
 {
     if (direct_pages_count[level] == 0)
         return;
 
     direct_pages_count[level]--;
     if (system_state == SYSTEM_RUNNING) {
         if (level == PG_LEVEL_2M)
             count_vm_event(DIRECT_MAP_LEVEL2_SPLIT);
         else if (level == PG_LEVEL_1G)
             count_vm_event(DIRECT_MAP_LEVEL3_SPLIT);
     }
     direct_pages_count[level - 1] += PTRS_PER_PTE;
 }
 
 void arch_report_meminfo(struct seq_file *m)
 {
     seq_printf(m, "DirectMap4k:    %8lu kB\n",
             direct_pages_count[PG_LEVEL_4K] << 2);
 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
     seq_printf(m, "DirectMap2M:    %8lu kB\n",
             direct_pages_count[PG_LEVEL_2M] << 11);
 #else
     seq_printf(m, "DirectMap4M:    %8lu kB\n",
             direct_pages_count[PG_LEVEL_2M] << 12);
 #endif
     if (direct_gbpages)
         seq_printf(m, "DirectMap1G:    %8lu kB\n",
             direct_pages_count[PG_LEVEL_1G] << 20);
 }
 #else
 static inline void split_page_count(int level) { }
 #endif
 
 #ifdef CONFIG_X86_CPA_STATISTICS
 
 static unsigned long cpa_1g_checked;
 static unsigned long cpa_1g_sameprot;
 static unsigned long cpa_1g_preserved;
 static unsigned long cpa_2m_checked;
 static unsigned long cpa_2m_sameprot;
 static unsigned long cpa_2m_preserved;
 static unsigned long cpa_4k_install;
 
 static inline void cpa_inc_1g_checked(void)
 {
     cpa_1g_checked++;
 }
 
 static inline void cpa_inc_2m_checked(void)
 {
     cpa_2m_checked++;
 }
 
 static inline void cpa_inc_4k_install(void)
 {
     data_race(cpa_4k_install++);
 }
 
 static inline void cpa_inc_lp_sameprot(int level)
 {
     if (level == PG_LEVEL_1G)
         cpa_1g_sameprot++;
     else
         cpa_2m_sameprot++;
 }
 
 static inline void cpa_inc_lp_preserved(int level)
 {
     if (level == PG_LEVEL_1G)
         cpa_1g_preserved++;
     else
         cpa_2m_preserved++;
 }
 
 static int cpastats_show(struct seq_file *m, void *p)
 {
     seq_printf(m, "1G pages checked:     %16lu\n", cpa_1g_checked);
     seq_printf(m, "1G pages sameprot:    %16lu\n", cpa_1g_sameprot);
     seq_printf(m, "1G pages preserved:   %16lu\n", cpa_1g_preserved);
     seq_printf(m, "2M pages checked:     %16lu\n", cpa_2m_checked);
     seq_printf(m, "2M pages sameprot:    %16lu\n", cpa_2m_sameprot);
     seq_printf(m, "2M pages preserved:   %16lu\n", cpa_2m_preserved);
     seq_printf(m, "4K pages set-checked: %16lu\n", cpa_4k_install);
     return 0;
 }
 
 static int cpastats_open(struct inode *inode, struct file *file)
 {
     return single_open(file, cpastats_show, NULL);
 }
 
 static const struct file_operations cpastats_fops = {
     .open       = cpastats_open,
     .read       = seq_read,
     .llseek     = seq_lseek,
     .release    = single_release,
 };
 
 static int __init cpa_stats_init(void)
 {
     debugfs_create_file("cpa_stats", S_IRUSR, arch_debugfs_dir, NULL,
                 &cpastats_fops);
     return 0;
 }
 late_initcall(cpa_stats_init);
 #else
 static inline void cpa_inc_1g_checked(void) { }
 static inline void cpa_inc_2m_checked(void) { }
 static inline void cpa_inc_4k_install(void) { }
 static inline void cpa_inc_lp_sameprot(int level) { }
 static inline void cpa_inc_lp_preserved(int level) { }
 #endif
 
 
 static inline int
 within(unsigned long addr, unsigned long start, unsigned long end)
 {
     return addr >= start && addr < end;
 }
 
 static inline int
 within_inclusive(unsigned long addr, unsigned long start, unsigned long end)
 {
     return addr >= start && addr <= end;
 }
 
 #ifdef CONFIG_X86_64
 
 static inline unsigned long highmap_start_pfn(void)
 {
     return __pa_symbol(_text) >> PAGE_SHIFT;
 }
 
 static inline unsigned long highmap_end_pfn(void)
 {
     /* Do not reference physical address outside the kernel. */
     return __pa_symbol(roundup(_brk_end, PMD_SIZE) - 1) >> PAGE_SHIFT;
 }
 
 static bool __cpa_pfn_in_highmap(unsigned long pfn)
 {
     /*
      * Kernel text has an alias mapping at a high address, known
      * here as "highmap".
      */
     return within_inclusive(pfn, highmap_start_pfn(), highmap_end_pfn());
 }
 
 #else
 
 static bool __cpa_pfn_in_highmap(unsigned long pfn)
 {
     /* There is no highmap on 32-bit */
     return false;
 }
 
 #endif
 
 /*
  * See set_mce_nospec().
  *
  * Machine check recovery code needs to change cache mode of poisoned pages to
  * UC to avoid speculative access logging another error. But passing the
  * address of the 1:1 mapping to set_memory_uc() is a fine way to encourage a
  * speculative access. So we cheat and flip the top bit of the address. This
  * works fine for the code that updates the page tables. But at the end of the
  * process we need to flush the TLB and cache and the non-canonical address
  * causes a #GP fault when used by the INVLPG and CLFLUSH instructions.
  *
  * But in the common case we already have a canonical address. This code
  * will fix the top bit if needed and is a no-op otherwise.
  */
 static inline unsigned long fix_addr(unsigned long addr)
 {
 #ifdef CONFIG_X86_64
     return (long)(addr << 1) >> 1;
 #else
     return addr;
 #endif
 }
 
 static unsigned long __cpa_addr(struct cpa_data *cpa, unsigned long idx)
 {
     if (cpa->flags & CPA_PAGES_ARRAY) {
         struct page *page = cpa->pages[idx];
 
         if (unlikely(PageHighMem(page)))
             return 0;
 
         return (unsigned long)page_address(page);
     }
 
     if (cpa->flags & CPA_ARRAY)
         return cpa->vaddr[idx];
 
     return *cpa->vaddr + idx * PAGE_SIZE;
 }
 
 /*
  * Flushing functions
  */
 
 static void clflush_cache_range_opt(void *vaddr, unsigned int size)
 {
     const unsigned long clflush_size = boot_cpu_data.x86_clflush_size;
     void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1));
     void *vend = vaddr + size;
 
     if (p >= vend)
         return;
 
     for (; p < vend; p += clflush_size)
         clflushopt(p);
 }
 
 /**
  * clflush_cache_range - flush a cache range with clflush
  * @vaddr:  virtual start address
  * @size:   number of bytes to flush
  *
  * CLFLUSHOPT is an unordered instruction which needs fencing with MFENCE or
  * SFENCE to avoid ordering issues.
  */
 void clflush_cache_range(void *vaddr, unsigned int size)
 {
     mb();
     clflush_cache_range_opt(vaddr, size);
     mb();
 }
 EXPORT_SYMBOL_GPL(clflush_cache_range);
 
 #ifdef CONFIG_ARCH_HAS_PMEM_API
 void arch_invalidate_pmem(void *addr, size_t size)
 {
     clflush_cache_range(addr, size);
 }
 EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
 #endif
 
 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 >= 4)
         wbinvd();
 }
 
 static void cpa_flush_all(unsigned long cache)
 {
     BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
     on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 }
 
 static void __cpa_flush_tlb(void *data)
 {
     struct cpa_data *cpa = data;
     unsigned int i;
 
     for (i = 0; i < cpa->numpages; i++)
         flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i)));
 }
 
 static void cpa_flush(struct cpa_data *data, int cache)
 {
     struct cpa_data *cpa = data;
     unsigned int i;
 
     BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
     if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
         cpa_flush_all(cache);
         return;
     }
 
     if (cpa->force_flush_all || cpa->numpages > tlb_single_page_flush_ceiling)
         flush_tlb_all();
     else
         on_each_cpu(__cpa_flush_tlb, cpa, 1);
 
     if (!cache)
         return;
 
     mb();
     for (i = 0; i < cpa->numpages; i++) {
         unsigned long addr = __cpa_addr(cpa, i);
         unsigned int level;
 
         pte_t *pte = lookup_address(addr, &level);
 
         /*
          * Only flush present addresses:
          */
         if (pte && (pte_val(*pte) & _PAGE_PRESENT))
             clflush_cache_range_opt((void *)fix_addr(addr), PAGE_SIZE);
     }
     mb();
 }
 
 static bool overlaps(unsigned long r1_start, unsigned long r1_end,
              unsigned long r2_start, unsigned long r2_end)
 {
     return (r1_start <= r2_end && r1_end >= r2_start) ||
         (r2_start <= r1_end && r2_end >= r1_start);
 }
 
 #ifdef CONFIG_PCI_BIOS
 /*
  * The BIOS area between 640k and 1Mb needs to be executable for PCI BIOS
  * based config access (CONFIG_PCI_GOBIOS) support.
  */
 #define BIOS_PFN    PFN_DOWN(BIOS_BEGIN)
 #define BIOS_PFN_END    PFN_DOWN(BIOS_END - 1)
 
 static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn)
 {
     if (pcibios_enabled && overlaps(spfn, epfn, BIOS_PFN, BIOS_PFN_END))
         return _PAGE_NX;
     return 0;
 }
 #else
 static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn)
 {
     return 0;
 }
 #endif
 
 /*
  * The .rodata section needs to be read-only. Using the pfn catches all
  * aliases.  This also includes __ro_after_init, so do not enforce until
  * kernel_set_to_readonly is true.
  */
 static pgprotval_t protect_rodata(unsigned long spfn, unsigned long epfn)
 {
     unsigned long epfn_ro, spfn_ro = PFN_DOWN(__pa_symbol(__start_rodata));
 
     /*
      * Note: __end_rodata is at page aligned and not inclusive, so
      * subtract 1 to get the last enforced PFN in the rodata area.
      */
     epfn_ro = PFN_DOWN(__pa_symbol(__end_rodata)) - 1;
 
     if (kernel_set_to_readonly && overlaps(spfn, epfn, spfn_ro, epfn_ro))
         return _PAGE_RW;
     return 0;
 }
 
 /*
  * Protect kernel text against becoming non executable by forbidding
  * _PAGE_NX.  This protects only the high kernel mapping (_text -> _etext)
  * out of which the kernel actually executes.  Do not protect the low
  * mapping.
  *
  * This does not cover __inittext since that is gone after boot.
  */
 static pgprotval_t protect_kernel_text(unsigned long start, unsigned long end)
 {
     unsigned long t_end = (unsigned long)_etext - 1;
     unsigned long t_start = (unsigned long)_text;
 
     if (overlaps(start, end, t_start, t_end))
         return _PAGE_NX;
     return 0;
 }
 
 #if defined(CONFIG_X86_64)
 /*
  * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
  * kernel text mappings for the large page aligned text, rodata sections
  * will be always read-only. For the kernel identity mappings covering the
  * holes caused by this alignment can be anything that user asks.
  *
  * This will preserve the large page mappings for kernel text/data at no
  * extra cost.
  */
 static pgprotval_t protect_kernel_text_ro(unsigned long start,
                       unsigned long end)
 {
     unsigned long t_end = (unsigned long)__end_rodata_hpage_align - 1;
     unsigned long t_start = (unsigned long)_text;
     unsigned int level;
 
     if (!kernel_set_to_readonly || !overlaps(start, end, t_start, t_end))
         return 0;
     /*
      * Don't enforce the !RW mapping for the kernel text mapping, if
      * the current mapping is already using small page mapping.  No
      * need to work hard to preserve large page mappings in this case.
      *
      * This also fixes the Linux Xen paravirt guest boot failure caused
      * by unexpected read-only mappings for kernel identity
      * mappings. In this paravirt guest case, the kernel text mapping
      * and the kernel identity mapping share the same page-table pages,
      * so the protections for kernel text and identity mappings have to
      * be the same.
      */
     if (lookup_address(start, &level) && (level != PG_LEVEL_4K))
         return _PAGE_RW;
     return 0;
 }
 #else
 static pgprotval_t protect_kernel_text_ro(unsigned long start,
                       unsigned long end)
 {
     return 0;
 }
 #endif
 
 static inline bool conflicts(pgprot_t prot, pgprotval_t val)
 {
     return (pgprot_val(prot) & ~val) != pgprot_val(prot);
 }
 
 static inline void check_conflict(int warnlvl, pgprot_t prot, pgprotval_t val,
                   unsigned long start, unsigned long end,
                   unsigned long pfn, const char *txt)
 {
     static const char *lvltxt[] = {
         [CPA_CONFLICT]  = "conflict",
         [CPA_PROTECT]   = "protect",
         [CPA_DETECT]    = "detect",
     };
 
     if (warnlvl > cpa_warn_level || !conflicts(prot, val))
         return;
 
     pr_warn("CPA %8s %10s: 0x%016lx - 0x%016lx PFN %lx req %016llx prevent %016llx\n",
         lvltxt[warnlvl], txt, start, end, pfn, (unsigned long long)pgprot_val(prot),
         (unsigned long long)val);
 }
 
 /*
  * 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 start,
                       unsigned long pfn, unsigned long npg,
                       unsigned long lpsize, int warnlvl)
 {
     pgprotval_t forbidden, res;
     unsigned long end;
 
     /*
      * There is no point in checking RW/NX conflicts when the requested
      * mapping is setting the page !PRESENT.
      */
     if (!(pgprot_val(prot) & _PAGE_PRESENT))
         return prot;
 
     /* Operate on the virtual address */
     end = start + npg * PAGE_SIZE - 1;
 
     res = protect_kernel_text(start, end);
     check_conflict(warnlvl, prot, res, start, end, pfn, "Text NX");
     forbidden = res;
 
     /*
      * Special case to preserve a large page. If the change spawns the
      * full large page mapping then there is no point to split it
      * up. Happens with ftrace and is going to be removed once ftrace
      * switched to text_poke().
      */
     if (lpsize != (npg * PAGE_SIZE) || (start & (lpsize - 1))) {
         res = protect_kernel_text_ro(start, end);
         check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO");
         forbidden |= res;
     }
 
     /* Check the PFN directly */
     res = protect_pci_bios(pfn, pfn + npg - 1);
     check_conflict(warnlvl, prot, res, start, end, pfn, "PCIBIOS NX");
     forbidden |= res;
 
     res = protect_rodata(pfn, pfn + npg - 1);
     check_conflict(warnlvl, prot, res, start, end, pfn, "Rodata RO");
     forbidden |= res;
 
     return __pgprot(pgprot_val(prot) & ~forbidden);
 }
 
 /*
  * Lookup the page table entry for a virtual address in a specific pgd.
  * Return a pointer to the entry and the level of the mapping.
  */
 pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
                  unsigned int *level)
 {
     p4d_t *p4d;
     pud_t *pud;
     pmd_t *pmd;
 
     *level = PG_LEVEL_NONE;
 
     if (pgd_none(*pgd))
         return NULL;
 
     p4d = p4d_offset(pgd, address);
     if (p4d_none(*p4d))
         return NULL;
 
     *level = PG_LEVEL_512G;
     if (p4d_large(*p4d) || !p4d_present(*p4d))
         return (pte_t *)p4d;
 
     pud = pud_offset(p4d, 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) || !pmd_present(*pmd))
         return (pte_t *)pmd;
 
     *level = PG_LEVEL_4K;
 
     return pte_offset_kernel(pmd, address);
 }
 
 /*
  * 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)
 {
     return lookup_address_in_pgd(pgd_offset_k(address), address, level);
 }
 EXPORT_SYMBOL_GPL(lookup_address);
 
 static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,
                   unsigned int *level)
 {
     if (cpa->pgd)
         return lookup_address_in_pgd(cpa->pgd + pgd_index(address),
                            address, level);
 
     return lookup_address(address, level);
 }
 
 /*
  * Lookup the PMD entry for a virtual address. Return a pointer to the entry
  * or NULL if not present.
  */
 pmd_t *lookup_pmd_address(unsigned long address)
 {
     pgd_t *pgd;
     p4d_t *p4d;
     pud_t *pud;
 
     pgd = pgd_offset_k(address);
     if (pgd_none(*pgd))
         return NULL;
 
     p4d = p4d_offset(pgd, address);
     if (p4d_none(*p4d) || p4d_large(*p4d) || !p4d_present(*p4d))
         return NULL;
 
     pud = pud_offset(p4d, address);
     if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud))
         return NULL;
 
     return pmd_offset(pud, address);
 }
 
 /*
  * This is necessary because __pa() does not work on some
  * kinds of memory, like vmalloc() or the alloc_remap()
  * areas on 32-bit NUMA systems.  The percpu areas can
  * end up in this kind of memory, for instance.
  *
  * This could be optimized, but it is only intended to be
  * used at initialization time, and keeping it
  * unoptimized should increase the testing coverage for
  * the more obscure platforms.
  */
 phys_addr_t slow_virt_to_phys(void *__virt_addr)
 {
     unsigned long virt_addr = (unsigned long)__virt_addr;
     phys_addr_t phys_addr;
     unsigned long offset;
     enum pg_level level;
     pte_t *pte;
 
     pte = lookup_address(virt_addr, &level);
     BUG_ON(!pte);
 
     /*
      * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t
      * before being left-shifted PAGE_SHIFT bits -- this trick is to
      * make 32-PAE kernel work correctly.
      */
     switch (level) {
     case PG_LEVEL_1G:
         phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT;
         offset = virt_addr & ~PUD_PAGE_MASK;
         break;
     case PG_LEVEL_2M:
         phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT;
         offset = virt_addr & ~PMD_PAGE_MASK;
         break;
     default:
         phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
         offset = virt_addr & ~PAGE_MASK;
     }
 
     return (phys_addr_t)(phys_addr | offset);
 }
 EXPORT_SYMBOL_GPL(slow_virt_to_phys);
 
 /*
  * 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 */
     set_pte_atomic(kpte, pte);
 #ifdef CONFIG_X86_32
     if (!SHARED_KERNEL_PMD) {
         struct page *page;
 
         list_for_each_entry(page, &pgd_list, lru) {
             pgd_t *pgd;
             p4d_t *p4d;
             pud_t *pud;
             pmd_t *pmd;
 
             pgd = (pgd_t *)page_address(page) + pgd_index(address);
             p4d = p4d_offset(pgd, address);
             pud = pud_offset(p4d, address);
             pmd = pmd_offset(pud, address);
             set_pte_atomic((pte_t *)pmd, pte);
         }
     }
 #endif
 }
 
 static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot)
 {
     /*
      * _PAGE_GLOBAL means "global page" for present PTEs.
      * But, it is also used to indicate _PAGE_PROTNONE
      * for non-present PTEs.
      *
      * This ensures that a _PAGE_GLOBAL PTE going from
      * present to non-present is not confused as
      * _PAGE_PROTNONE.
      */
     if (!(pgprot_val(prot) & _PAGE_PRESENT))
         pgprot_val(prot) &= ~_PAGE_GLOBAL;
 
     return prot;
 }
 
 static int __should_split_large_page(pte_t *kpte, unsigned long address,
                      struct cpa_data *cpa)
 {
     unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn;
     pgprot_t old_prot, new_prot, req_prot, chk_prot;
     pte_t new_pte, *tmp;
     enum pg_level level;
 
     /*
      * Check for races, another CPU might have split this page
      * up already:
      */
     tmp = _lookup_address_cpa(cpa, address, &level);
     if (tmp != kpte)
         return 1;
 
     switch (level) {
     case PG_LEVEL_2M:
         old_prot = pmd_pgprot(*(pmd_t *)kpte);
         old_pfn = pmd_pfn(*(pmd_t *)kpte);
         cpa_inc_2m_checked();
         break;
     case PG_LEVEL_1G:
         old_prot = pud_pgprot(*(pud_t *)kpte);
         old_pfn = pud_pfn(*(pud_t *)kpte);
         cpa_inc_1g_checked();
         break;
     default:
         return -EINVAL;
     }
 
     psize = page_level_size(level);
     pmask = page_level_mask(level);
 
     /*
      * Calculate the number of pages, which fit into this large
      * page starting at address:
      */
     lpaddr = (address + psize) & pmask;
     numpages = (lpaddr - address) >> PAGE_SHIFT;
     if (numpages < cpa->numpages)
         cpa->numpages = numpages;
 
     /*
      * We are safe now. Check whether the new pgprot is the same:
      * Convert protection attributes to 4k-format, as cpa->mask* are set
      * up accordingly.
      */
 
     /* Clear PSE (aka _PAGE_PAT) and move PAT bit to correct position */
     req_prot = pgprot_large_2_4k(old_prot);
 
     pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr);
     pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
 
     /*
      * req_prot is in format of 4k pages. It must be converted to large
      * page format: the caching mode includes the PAT bit located at
      * different bit positions in the two formats.
      */
     req_prot = pgprot_4k_2_large(req_prot);
     req_prot = pgprot_clear_protnone_bits(req_prot);
     if (pgprot_val(req_prot) & _PAGE_PRESENT)
         pgprot_val(req_prot) |= _PAGE_PSE;
 
     /*
      * old_pfn points to the large page base pfn. So we need to add the
      * offset of the virtual address:
      */
     pfn = old_pfn + ((address & (psize - 1)) >> PAGE_SHIFT);
     cpa->pfn = pfn;
 
     /*
      * Calculate the large page base address and the number of 4K pages
      * in the large page
      */
     lpaddr = address & pmask;
     numpages = psize >> PAGE_SHIFT;
 
     /*
      * Sanity check that the existing mapping is correct versus the static
      * protections. static_protections() guards against !PRESENT, so no
      * extra conditional required here.
      */
     chk_prot = static_protections(old_prot, lpaddr, old_pfn, numpages,
                       psize, CPA_CONFLICT);
 
     if (WARN_ON_ONCE(pgprot_val(chk_prot) != pgprot_val(old_prot))) {
         /*
          * Split the large page and tell the split code to
          * enforce static protections.
          */
         cpa->force_static_prot = 1;
         return 1;
     }
 
     /*
      * Optimization: If the requested pgprot is the same as the current
      * pgprot, then the large page can be preserved and no updates are
      * required independent of alignment and length of the requested
      * range. The above already established that the current pgprot is
      * correct, which in consequence makes the requested pgprot correct
      * as well if it is the same. The static protection scan below will
      * not come to a different conclusion.
      */
     if (pgprot_val(req_prot) == pgprot_val(old_prot)) {
         cpa_inc_lp_sameprot(level);
         return 0;
     }
 
     /*
      * If the requested range does not cover the full page, split it up
      */
     if (address != lpaddr || cpa->numpages != numpages)
         return 1;
 
     /*
      * Check whether the requested pgprot is conflicting with a static
      * protection requirement in the large page.
      */
     new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages,
                       psize, CPA_DETECT);
 
     /*
      * If there is a conflict, split the large page.
      *
      * There used to be a 4k wise evaluation trying really hard to
      * preserve the large pages, but experimentation has shown, that this
      * does not help at all. There might be corner cases which would
      * preserve one large page occasionally, but it's really not worth the
      * extra code and cycles for the common case.
      */
     if (pgprot_val(req_prot) != pgprot_val(new_prot))
         return 1;
 
     /* All checks passed. Update the large page mapping. */
     new_pte = pfn_pte(old_pfn, new_prot);
     __set_pmd_pte(kpte, address, new_pte);
     cpa->flags |= CPA_FLUSHTLB;
     cpa_inc_lp_preserved(level);
     return 0;
 }
 
 static int should_split_large_page(pte_t *kpte, unsigned long address,
                    struct cpa_data *cpa)
 {
     int do_split;
 
     if (cpa->force_split)
         return 1;
 
     spin_lock(&pgd_lock);
     do_split = __should_split_large_page(kpte, address, cpa);
     spin_unlock(&pgd_lock);
 
     return do_split;
 }
 
 static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn,
               pgprot_t ref_prot, unsigned long address,
               unsigned long size)
 {
     unsigned int npg = PFN_DOWN(size);
     pgprot_t prot;
 
     /*
      * If should_split_large_page() discovered an inconsistent mapping,
      * remove the invalid protection in the split mapping.
      */
     if (!cpa->force_static_prot)
         goto set;
 
     /* Hand in lpsize = 0 to enforce the protection mechanism */
     prot = static_protections(ref_prot, address, pfn, npg, 0, CPA_PROTECT);
 
     if (pgprot_val(prot) == pgprot_val(ref_prot))
         goto set;
 
     /*
      * If this is splitting a PMD, fix it up. PUD splits cannot be
      * fixed trivially as that would require to rescan the newly
      * installed PMD mappings after returning from split_large_page()
      * so an eventual further split can allocate the necessary PTE
      * pages. Warn for now and revisit it in case this actually
      * happens.
      */
     if (size == PAGE_SIZE)
         ref_prot = prot;
     else
         pr_warn_once("CPA: Cannot fixup static protections for PUD split\n");
 set:
     set_pte(pte, pfn_pte(pfn, ref_prot));
 }
 
 static int
 __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
            struct page *base)
 {
     unsigned long lpaddr, lpinc, ref_pfn, pfn, pfninc = 1;
     pte_t *pbase = (pte_t *)page_address(base);
     unsigned int i, level;
     pgprot_t ref_prot;
     pte_t *tmp;
 
     spin_lock(&pgd_lock);
     /*
      * Check for races, another CPU might have split this page
      * up for us already:
      */
     tmp = _lookup_address_cpa(cpa, address, &level);
     if (tmp != kpte) {
         spin_unlock(&pgd_lock);
         return 1;
     }
 
     paravirt_alloc_pte(&init_mm, page_to_pfn(base));
 
     switch (level) {
     case PG_LEVEL_2M:
         ref_prot = pmd_pgprot(*(pmd_t *)kpte);
         /*
          * Clear PSE (aka _PAGE_PAT) and move
          * PAT bit to correct position.
          */
         ref_prot = pgprot_large_2_4k(ref_prot);
         ref_pfn = pmd_pfn(*(pmd_t *)kpte);
         lpaddr = address & PMD_MASK;
         lpinc = PAGE_SIZE;
         break;
 
     case PG_LEVEL_1G:
         ref_prot = pud_pgprot(*(pud_t *)kpte);
         ref_pfn = pud_pfn(*(pud_t *)kpte);
         pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
         lpaddr = address & PUD_MASK;
         lpinc = PMD_SIZE;
         /*
          * Clear the PSE flags if the PRESENT flag is not set
          * otherwise pmd_present/pmd_huge will return true
          * even on a non present pmd.
          */
         if (!(pgprot_val(ref_prot) & _PAGE_PRESENT))
             pgprot_val(ref_prot) &= ~_PAGE_PSE;
         break;
 
     default:
         spin_unlock(&pgd_lock);
         return 1;
     }
 
     ref_prot = pgprot_clear_protnone_bits(ref_prot);
 
     /*
      * Get the target pfn from the original entry:
      */
     pfn = ref_pfn;
     for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc, lpaddr += lpinc)
         split_set_pte(cpa, pbase + i, pfn, ref_prot, lpaddr, lpinc);
 
     if (virt_addr_valid(address)) {
         unsigned long pfn = PFN_DOWN(__pa(address));
 
         if (pfn_range_is_mapped(pfn, pfn + 1))
             split_page_count(level);
     }
 
     /*
      * Install the new, split up pagetable.
      *
      * We use the standard kernel pagetable protections for the new
      * pagetable protections, the actual ptes set above control the
      * primary protection behavior:
      */
     __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
 
     /*
      * Do a global flush tlb after splitting the large page
      * and before we do the actual change page attribute in the PTE.
      *
      * Without this, we violate the TLB application note, that says:
      * "The TLBs may contain both ordinary and large-page
      *  translations for a 4-KByte range of linear addresses. This
      *  may occur if software modifies the paging structures so that
      *  the page size used for the address range changes. If the two
      *  translations differ with respect to page frame or attributes
      *  (e.g., permissions), processor behavior is undefined and may
      *  be implementation-specific."
      *
      * We do this global tlb flush inside the cpa_lock, so that we
      * don't allow any other cpu, with stale tlb entries change the
      * page attribute in parallel, that also falls into the
      * just split large page entry.
      */
     flush_tlb_all();
     spin_unlock(&pgd_lock);
 
     return 0;
 }
 
 static int split_large_page(struct cpa_data *cpa, pte_t *kpte,
                 unsigned long address)
 {
     struct page *base;
 
     if (!debug_pagealloc_enabled())
         spin_unlock(&cpa_lock);
     base = alloc_pages(GFP_KERNEL, 0);
     if (!debug_pagealloc_enabled())
         spin_lock(&cpa_lock);
     if (!base)
         return -ENOMEM;
 
     if (__split_large_page(cpa, kpte, address, base))
         __free_page(base);
 
     return 0;
 }
 
 static bool try_to_free_pte_page(pte_t *pte)
 {
     int i;
 
     for (i = 0; i < PTRS_PER_PTE; i++)
         if (!pte_none(pte[i]))
             return false;
 
     free_page((unsigned long)pte);
     return true;
 }
 
 static bool try_to_free_pmd_page(pmd_t *pmd)
 {
     int i;
 
     for (i = 0; i < PTRS_PER_PMD; i++)
         if (!pmd_none(pmd[i]))
             return false;
 
     free_page((unsigned long)pmd);
     return true;
 }
 
 static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end)
 {
     pte_t *pte = pte_offset_kernel(pmd, start);
 
     while (start < end) {
         set_pte(pte, __pte(0));
 
         start += PAGE_SIZE;
         pte++;
     }
 
     if (try_to_free_pte_page((pte_t *)pmd_page_vaddr(*pmd))) {
         pmd_clear(pmd);
         return true;
     }
     return false;
 }
 
 static void __unmap_pmd_range(pud_t *pud, pmd_t *pmd,
                   unsigned long start, unsigned long end)
 {
     if (unmap_pte_range(pmd, start, end))
         if (try_to_free_pmd_page(pud_pgtable(*pud)))
             pud_clear(pud);
 }
 
 static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end)
 {
     pmd_t *pmd = pmd_offset(pud, start);
 
     /*
      * Not on a 2MB page boundary?
      */
     if (start & (PMD_SIZE - 1)) {
         unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
         unsigned long pre_end = min_t(unsigned long, end, next_page);
 
         __unmap_pmd_range(pud, pmd, start, pre_end);
 
         start = pre_end;
         pmd++;
     }
 
     /*
      * Try to unmap in 2M chunks.
      */
     while (end - start >= PMD_SIZE) {
         if (pmd_large(*pmd))
             pmd_clear(pmd);
         else
             __unmap_pmd_range(pud, pmd, start, start + PMD_SIZE);
 
         start += PMD_SIZE;
         pmd++;
     }
 
     /*
      * 4K leftovers?
      */
     if (start < end)
         return __unmap_pmd_range(pud, pmd, start, end);
 
     /*
      * Try again to free the PMD page if haven't succeeded above.
      */
     if (!pud_none(*pud))
         if (try_to_free_pmd_page(pud_pgtable(*pud)))
             pud_clear(pud);
 }
 
 static void unmap_pud_range(p4d_t *p4d, unsigned long start, unsigned long end)
 {
     pud_t *pud = pud_offset(p4d, start);
 
     /*
      * Not on a GB page boundary?
      */
     if (start & (PUD_SIZE - 1)) {
         unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
         unsigned long pre_end   = min_t(unsigned long, end, next_page);
 
         unmap_pmd_range(pud, start, pre_end);
 
         start = pre_end;
         pud++;
     }
 
     /*
      * Try to unmap in 1G chunks?
      */
     while (end - start >= PUD_SIZE) {
 
         if (pud_large(*pud))
             pud_clear(pud);
         else
             unmap_pmd_range(pud, start, start + PUD_SIZE);
 
         start += PUD_SIZE;
         pud++;
     }
 
     /*
      * 2M leftovers?
      */
     if (start < end)
         unmap_pmd_range(pud, start, end);
 
     /*
      * No need to try to free the PUD page because we'll free it in
      * populate_pgd's error path
      */
 }
 
 static int alloc_pte_page(pmd_t *pmd)
 {
     pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
     if (!pte)
         return -1;
 
     set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
     return 0;
 }
 
 static int alloc_pmd_page(pud_t *pud)
 {
     pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
     if (!pmd)
         return -1;
 
     set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
     return 0;
 }
 
 static void populate_pte(struct cpa_data *cpa,
              unsigned long start, unsigned long end,
              unsigned num_pages, pmd_t *pmd, pgprot_t pgprot)
 {
     pte_t *pte;
 
     pte = pte_offset_kernel(pmd, start);
 
     pgprot = pgprot_clear_protnone_bits(pgprot);
 
     while (num_pages-- && start < end) {
         set_pte(pte, pfn_pte(cpa->pfn, pgprot));
 
         start    += PAGE_SIZE;
         cpa->pfn++;
         pte++;
     }
 }
 
 static long populate_pmd(struct cpa_data *cpa,
              unsigned long start, unsigned long end,
              unsigned num_pages, pud_t *pud, pgprot_t pgprot)
 {
     long cur_pages = 0;
     pmd_t *pmd;
     pgprot_t pmd_pgprot;
 
     /*
      * Not on a 2M boundary?
      */
     if (start & (PMD_SIZE - 1)) {
         unsigned long pre_end = start + (num_pages << PAGE_SHIFT);
         unsigned long next_page = (start + PMD_SIZE) & PMD_MASK;
 
         pre_end   = min_t(unsigned long, pre_end, next_page);
         cur_pages = (pre_end - start) >> PAGE_SHIFT;
         cur_pages = min_t(unsigned int, num_pages, cur_pages);
 
         /*
          * Need a PTE page?
          */
         pmd = pmd_offset(pud, start);
         if (pmd_none(*pmd))
             if (alloc_pte_page(pmd))
                 return -1;
 
         populate_pte(cpa, start, pre_end, cur_pages, pmd, pgprot);
 
         start = pre_end;
     }
 
     /*
      * We mapped them all?
      */
     if (num_pages == cur_pages)
         return cur_pages;
 
     pmd_pgprot = pgprot_4k_2_large(pgprot);
 
     while (end - start >= PMD_SIZE) {
 
         /*
          * We cannot use a 1G page so allocate a PMD page if needed.
          */
         if (pud_none(*pud))
             if (alloc_pmd_page(pud))
                 return -1;
 
         pmd = pmd_offset(pud, start);
 
         set_pmd(pmd, pmd_mkhuge(pfn_pmd(cpa->pfn,
                     canon_pgprot(pmd_pgprot))));
 
         start     += PMD_SIZE;
         cpa->pfn  += PMD_SIZE >> PAGE_SHIFT;
         cur_pages += PMD_SIZE >> PAGE_SHIFT;
     }
 
     /*
      * Map trailing 4K pages.
      */
     if (start < end) {
         pmd = pmd_offset(pud, start);
         if (pmd_none(*pmd))
             if (alloc_pte_page(pmd))
                 return -1;
 
         populate_pte(cpa, start, end, num_pages - cur_pages,
                  pmd, pgprot);
     }
     return num_pages;
 }
 
 static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d,
             pgprot_t pgprot)
 {
     pud_t *pud;
     unsigned long end;
     long cur_pages = 0;
     pgprot_t pud_pgprot;
 
     end = start + (cpa->numpages << PAGE_SHIFT);
 
     /*
      * Not on a Gb page boundary? => map everything up to it with
      * smaller pages.
      */
     if (start & (PUD_SIZE - 1)) {
         unsigned long pre_end;
         unsigned long next_page = (start + PUD_SIZE) & PUD_MASK;
 
         pre_end   = min_t(unsigned long, end, next_page);
         cur_pages = (pre_end - start) >> PAGE_SHIFT;
         cur_pages = min_t(int, (int)cpa->numpages, cur_pages);
 
         pud = pud_offset(p4d, start);
 
         /*
          * Need a PMD page?
          */
         if (pud_none(*pud))
             if (alloc_pmd_page(pud))
                 return -1;
 
         cur_pages = populate_pmd(cpa, start, pre_end, cur_pages,
                      pud, pgprot);
         if (cur_pages < 0)
             return cur_pages;
 
         start = pre_end;
     }
 
     /* We mapped them all? */
     if (cpa->numpages == cur_pages)
         return cur_pages;
 
     pud = pud_offset(p4d, start);
     pud_pgprot = pgprot_4k_2_large(pgprot);
 
     /*
      * Map everything starting from the Gb boundary, possibly with 1G pages
      */
     while (boot_cpu_has(X86_FEATURE_GBPAGES) && end - start >= PUD_SIZE) {
         set_pud(pud, pud_mkhuge(pfn_pud(cpa->pfn,
                    canon_pgprot(pud_pgprot))));
 
         start     += PUD_SIZE;
         cpa->pfn  += PUD_SIZE >> PAGE_SHIFT;
         cur_pages += PUD_SIZE >> PAGE_SHIFT;
         pud++;
     }
 
     /* Map trailing leftover */
     if (start < end) {
         long tmp;
 
         pud = pud_offset(p4d, start);
         if (pud_none(*pud))
             if (alloc_pmd_page(pud))
                 return -1;
 
         tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages,
                    pud, pgprot);
         if (tmp < 0)
             return cur_pages;
 
         cur_pages += tmp;
     }
     return cur_pages;
 }
 
 /*
  * Restrictions for kernel page table do not necessarily apply when mapping in
  * an alternate PGD.
  */
 static int populate_pgd(struct cpa_data *cpa, unsigned long addr)
 {
     pgprot_t pgprot = __pgprot(_KERNPG_TABLE);
     pud_t *pud = NULL;  /* shut up gcc */
     p4d_t *p4d;
     pgd_t *pgd_entry;
     long ret;
 
     pgd_entry = cpa->pgd + pgd_index(addr);
 
     if (pgd_none(*pgd_entry)) {
         p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL);
         if (!p4d)
             return -1;
 
         set_pgd(pgd_entry, __pgd(__pa(p4d) | _KERNPG_TABLE));
     }
 
     /*
      * Allocate a PUD page and hand it down for mapping.
      */
     p4d = p4d_offset(pgd_entry, addr);
     if (p4d_none(*p4d)) {
         pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
         if (!pud)
             return -1;
 
         set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));
     }
 
     pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr);
     pgprot_val(pgprot) |=  pgprot_val(cpa->mask_set);
 
     ret = populate_pud(cpa, addr, p4d, pgprot);
     if (ret < 0) {
         /*
          * Leave the PUD page in place in case some other CPU or thread
          * already found it, but remove any useless entries we just
          * added to it.
          */
         unmap_pud_range(p4d, addr,
                 addr + (cpa->numpages << PAGE_SHIFT));
         return ret;
     }
 
     cpa->numpages = ret;
     return 0;
 }
 
 static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr,
                    int primary)
 {
     if (cpa->pgd) {
         /*
          * Right now, we only execute this code path when mapping
          * the EFI virtual memory map regions, no other users
          * provide a ->pgd value. This may change in the future.
          */
         return populate_pgd(cpa, vaddr);
     }
 
     /*
      * Ignore all non primary paths.
      */
     if (!primary) {
         cpa->numpages = 1;
         return 0;
     }
 
     /*
      * Ignore the NULL PTE for kernel identity mapping, as it is expected
      * to have holes.
      * Also set numpages to '1' indicating that we processed cpa req for
      * one virtual address page and its pfn. TBD: numpages can be set based
      * on the initial value and the level returned by lookup_address().
      */
     if (within(vaddr, PAGE_OFFSET,
            PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
         cpa->numpages = 1;
         cpa->pfn = __pa(vaddr) >> PAGE_SHIFT;
         return 0;
 
     } else if (__cpa_pfn_in_highmap(cpa->pfn)) {
         /* Faults in the highmap are OK, so do not warn: */
         return -EFAULT;
     } else {
         WARN(1, KERN_WARNING "CPA: called for zero pte. "
             "vaddr = %lx cpa->vaddr = %lx\n", vaddr,
             *cpa->vaddr);
 
         return -EFAULT;
     }
 }
 
 static int __change_page_attr(struct cpa_data *cpa, int primary)
 {
     unsigned long address;
     int do_split, err;
     unsigned int level;
     pte_t *kpte, old_pte;
 
     address = __cpa_addr(cpa, cpa->curpage);
 repeat:
     kpte = _lookup_address_cpa(cpa, address, &level);
     if (!kpte)
         return __cpa_process_fault(cpa, address, primary);
 
     old_pte = *kpte;
     if (pte_none(old_pte))
         return __cpa_process_fault(cpa, address, primary);
 
     if (level == PG_LEVEL_4K) {
         pte_t new_pte;
         pgprot_t new_prot = pte_pgprot(old_pte);
         unsigned long pfn = pte_pfn(old_pte);
 
         pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
         pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
 
         cpa_inc_4k_install();
         /* Hand in lpsize = 0 to enforce the protection mechanism */
         new_prot = static_protections(new_prot, address, pfn, 1, 0,
                           CPA_PROTECT);
 
         new_prot = pgprot_clear_protnone_bits(new_prot);
 
         /*
          * 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(pfn, new_prot);
         cpa->pfn = pfn;
         /*
          * Do we really change anything ?
          */
         if (pte_val(old_pte) != pte_val(new_pte)) {
             set_pte_atomic(kpte, new_pte);
             cpa->flags |= CPA_FLUSHTLB;
         }
         cpa->numpages = 1;
         return 0;
     }
 
     /*
      * Check, whether we can keep the large page intact
      * and just change the pte:
      */
     do_split = should_split_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(cpa, kpte, address);
     if (!err)
         goto repeat;
 
     return err;
 }
 
 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
 
 static int cpa_process_alias(struct cpa_data *cpa)
 {
     struct cpa_data alias_cpa;
     unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT);
     unsigned long vaddr;
     int ret;
 
     if (!pfn_range_is_mapped(cpa->pfn, cpa->pfn + 1))
         return 0;
 
     /*
      * No need to redo, when the primary call touched the direct
      * mapping already:
      */
     vaddr = __cpa_addr(cpa, cpa->curpage);
     if (!(within(vaddr, PAGE_OFFSET,
             PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) {
 
         alias_cpa = *cpa;
         alias_cpa.vaddr = &laddr;
         alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
         alias_cpa.curpage = 0;
 
         cpa->force_flush_all = 1;
 
         ret = __change_page_attr_set_clr(&alias_cpa, 0);
         if (ret)
             return ret;
     }
 
 #ifdef CONFIG_X86_64
     /*
      * If the primary call didn't touch the high mapping already
      * and the physical address is inside the kernel map, we need
      * to touch the high mapped kernel as well:
      */
     if (!within(vaddr, (unsigned long)_text, _brk_end) &&
         __cpa_pfn_in_highmap(cpa->pfn)) {
         unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) +
                            __START_KERNEL_map - phys_base;
         alias_cpa = *cpa;
         alias_cpa.vaddr = &temp_cpa_vaddr;
         alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
         alias_cpa.curpage = 0;
 
         cpa->force_flush_all = 1;
         /*
          * The high mapping range is imprecise, so ignore the
          * return value.
          */
         __change_page_attr_set_clr(&alias_cpa, 0);
     }
 #endif
 
     return 0;
 }
 
 static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
 {
     unsigned long numpages = cpa->numpages;
     unsigned long rempages = numpages;
     int ret = 0;
 
     while (rempages) {
         /*
          * Store the remaining nr of pages for the large page
          * preservation check.
          */
         cpa->numpages = rempages;
         /* for array changes, we can't use large page */
         if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY))
             cpa->numpages = 1;
 
         if (!debug_pagealloc_enabled())
             spin_lock(&cpa_lock);
         ret = __change_page_attr(cpa, checkalias);
         if (!debug_pagealloc_enabled())
             spin_unlock(&cpa_lock);
         if (ret)
             goto out;
 
         if (checkalias) {
             ret = cpa_process_alias(cpa);
             if (ret)
                 goto out;
         }
 
         /*
          * 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 > rempages || !cpa->numpages);
         rempages -= cpa->numpages;
         cpa->curpage += cpa->numpages;
     }
 
 out:
     /* Restore the original numpages */
     cpa->numpages = numpages;
     return ret;
 }
 
 static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                     pgprot_t mask_set, pgprot_t mask_clr,
                     int force_split, int in_flag,
                     struct page **pages)
 {
     struct cpa_data cpa;
     int ret, cache, checkalias;
 
     memset(&cpa, 0, sizeof(cpa));
 
     /*
      * Check, if we are requested to set a not supported
      * feature.  Clearing non-supported features is OK.
      */
     mask_set = canon_pgprot(mask_set);
 
     if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split)
         return 0;
 
     /* Ensure we are PAGE_SIZE aligned */
     if (in_flag & CPA_ARRAY) {
         int i;
         for (i = 0; i < numpages; i++) {
             if (addr[i] & ~PAGE_MASK) {
                 addr[i] &= PAGE_MASK;
                 WARN_ON_ONCE(1);
             }
         }
     } else if (!(in_flag & CPA_PAGES_ARRAY)) {
         /*
          * in_flag of CPA_PAGES_ARRAY implies it is aligned.
          * No need to check in that case
          */
         if (*addr & ~PAGE_MASK) {
             *addr &= PAGE_MASK;
             /*
              * People should not be passing in unaligned addresses:
              */
             WARN_ON_ONCE(1);
         }
     }
 
     /* Must avoid aliasing mappings in the highmem code */
     kmap_flush_unused();
 
     vm_unmap_aliases();
 
     cpa.vaddr = addr;
     cpa.pages = pages;
     cpa.numpages = numpages;
     cpa.mask_set = mask_set;
     cpa.mask_clr = mask_clr;
     cpa.flags = 0;
     cpa.curpage = 0;
     cpa.force_split = force_split;
 
     if (in_flag & (CPA_ARRAY | CPA_PAGES_ARRAY))
         cpa.flags |= in_flag;
 
     /* No alias checking for _NX bit modifications */
     checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
     /* Has caller explicitly disabled alias checking? */
     if (in_flag & CPA_NO_CHECK_ALIAS)
         checkalias = 0;
 
     ret = __change_page_attr_set_clr(&cpa, checkalias);
 
     /*
      * Check whether we really changed something:
      */
     if (!(cpa.flags & CPA_FLUSHTLB))
         goto out;
 
     /*
      * No need to flush, when we did not set any of the caching
      * attributes:
      */
     cache = !!pgprot2cachemode(mask_set);
 
     /*
      * On error; flush everything to be sure.
      */
     if (ret) {
         cpa_flush_all(cache);
         goto out;
     }
 
     cpa_flush(&cpa, cache);
 out:
     return ret;
 }
 
 static inline int change_page_attr_set(unsigned long *addr, int numpages,
                        pgprot_t mask, int array)
 {
     return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0,
         (array ? CPA_ARRAY : 0), NULL);
 }
 
 static inline int change_page_attr_clear(unsigned long *addr, int numpages,
                      pgprot_t mask, int array)
 {
     return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0,
         (array ? CPA_ARRAY : 0), NULL);
 }
 
 static inline int cpa_set_pages_array(struct page **pages, int numpages,
                        pgprot_t mask)
 {
     return change_page_attr_set_clr(NULL, numpages, mask, __pgprot(0), 0,
         CPA_PAGES_ARRAY, pages);
 }
 
 static inline int cpa_clear_pages_array(struct page **pages, int numpages,
                      pgprot_t mask)
 {
     return change_page_attr_set_clr(NULL, numpages, __pgprot(0), mask, 0,
         CPA_PAGES_ARRAY, pages);
 }
 
 /*
  * __set_memory_prot is an internal helper for callers that have been passed
  * a pgprot_t value from upper layers and a reservation has already been taken.
  * If you want to set the pgprot to a specific page protocol, use the
  * set_memory_xx() functions.
  */
 int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot)
 {
     return change_page_attr_set_clr(&addr, numpages, prot,
                     __pgprot(~pgprot_val(prot)), 0, 0,
                     NULL);
 }
 
 int _set_memory_uc(unsigned long addr, int numpages)
 {
     /*
      * for now UC MINUS. see comments in ioremap()
      * If you really need strong UC use ioremap_uc(), but note
      * that you cannot override IO areas with set_memory_*() as
      * these helpers cannot work with IO memory.
      */
     return change_page_attr_set(&addr, numpages,
                     cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS),
                     0);
 }
 
 int set_memory_uc(unsigned long addr, int numpages)
 {
     int ret;
 
     /*
      * for now UC MINUS. see comments in ioremap()
      */
     ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
                   _PAGE_CACHE_MODE_UC_MINUS, NULL);
     if (ret)
         goto out_err;
 
     ret = _set_memory_uc(addr, numpages);
     if (ret)
         goto out_free;
 
     return 0;
 
 out_free:
     memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
 out_err:
     return ret;
 }
 EXPORT_SYMBOL(set_memory_uc);
 
 int _set_memory_wc(unsigned long addr, int numpages)
 {
     int ret;
 
     ret = change_page_attr_set(&addr, numpages,
                    cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS),
                    0);
     if (!ret) {
         ret = change_page_attr_set_clr(&addr, numpages,
                            cachemode2pgprot(_PAGE_CACHE_MODE_WC),
                            __pgprot(_PAGE_CACHE_MASK),
                            0, 0, NULL);
     }
     return ret;
 }
 
 int set_memory_wc(unsigned long addr, int numpages)
 {
     int ret;
 
     ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
         _PAGE_CACHE_MODE_WC, NULL);
     if (ret)
         return ret;
 
     ret = _set_memory_wc(addr, numpages);
     if (ret)
         memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
 
     return ret;
 }
 EXPORT_SYMBOL(set_memory_wc);
 
 int _set_memory_wt(unsigned long addr, int numpages)
 {
     return change_page_attr_set(&addr, numpages,
                     cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0);
 }
 
 int _set_memory_wb(unsigned long addr, int numpages)
 {
     /* WB cache mode is hard wired to all cache attribute bits being 0 */
     return change_page_attr_clear(&addr, numpages,
                       __pgprot(_PAGE_CACHE_MASK), 0);
 }
 
 int set_memory_wb(unsigned long addr, int numpages)
 {
     int ret;
 
     ret = _set_memory_wb(addr, numpages);
     if (ret)
         return ret;
 
     memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
     return 0;
 }
 EXPORT_SYMBOL(set_memory_wb);
 
 /* Prevent speculative access to a page by marking it not-present */
 #ifdef CONFIG_X86_64
 int set_mce_nospec(unsigned long pfn)
 {
     unsigned long decoy_addr;
     int rc;
 
     /* SGX pages are not in the 1:1 map */
     if (arch_is_platform_page(pfn << PAGE_SHIFT))
         return 0;
     /*
      * We would like to just call:
      *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
      * but doing that would radically increase the odds of a
      * speculative access to the poison page because we'd have
      * the virtual address of the kernel 1:1 mapping sitting
      * around in registers.
      * Instead we get tricky.  We create a non-canonical address
      * that looks just like the one we want, but has bit 63 flipped.
      * This relies on set_memory_XX() properly sanitizing any __pa()
      * results with __PHYSICAL_MASK or PTE_PFN_MASK.
      */
     decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
 
     rc = set_memory_np(decoy_addr, 1);
     if (rc)
         pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
     return rc;
 }
 
 static int set_memory_present(unsigned long *addr, int numpages)
 {
     return change_page_attr_set(addr, numpages, __pgprot(_PAGE_PRESENT), 0);
 }
 
 /* Restore full speculative operation to the pfn. */
 int clear_mce_nospec(unsigned long pfn)
 {
     unsigned long addr = (unsigned long) pfn_to_kaddr(pfn);
 
     return set_memory_present(&addr, 1);
 }
 EXPORT_SYMBOL_GPL(clear_mce_nospec);
 #endif /* CONFIG_X86_64 */
 
 int set_memory_x(unsigned long addr, int numpages)
 {
     if (!(__supported_pte_mask & _PAGE_NX))
         return 0;
 
     return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
 
 int set_memory_nx(unsigned long addr, int numpages)
 {
     if (!(__supported_pte_mask & _PAGE_NX))
         return 0;
 
     return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
 
 int set_memory_ro(unsigned long addr, int numpages)
 {
     return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
 }
 
 int set_memory_rw(unsigned long addr, int numpages)
 {
     return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
 }
 
 int set_memory_np(unsigned long addr, int numpages)
 {
     return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
 }
 
 int set_memory_np_noalias(unsigned long addr, int numpages)
 {
     int cpa_flags = CPA_NO_CHECK_ALIAS;
 
     return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
                     __pgprot(_PAGE_PRESENT), 0,
                     cpa_flags, NULL);
 }
 
 int set_memory_4k(unsigned long addr, int numpages)
 {
     return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
                     __pgprot(0), 1, 0, NULL);
 }
 
 int set_memory_nonglobal(unsigned long addr, int numpages)
 {
     return change_page_attr_clear(&addr, numpages,
                       __pgprot(_PAGE_GLOBAL), 0);
 }
 
 int set_memory_global(unsigned long addr, int numpages)
 {
     return change_page_attr_set(&addr, numpages,
                     __pgprot(_PAGE_GLOBAL), 0);
 }
 
 /*
  * __set_memory_enc_pgtable() is used for the hypervisors that get
  * informed about "encryption" status via page tables.
  */
 static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
 {
     pgprot_t empty = __pgprot(0);
     struct cpa_data cpa;
     int ret;
 
     /* Should not be working on unaligned addresses */
     if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
         addr &= PAGE_MASK;
 
     memset(&cpa, 0, sizeof(cpa));
     cpa.vaddr = &addr;
     cpa.numpages = numpages;
     cpa.mask_set = enc ? pgprot_encrypted(empty) : pgprot_decrypted(empty);
     cpa.mask_clr = enc ? pgprot_decrypted(empty) : pgprot_encrypted(empty);
     cpa.pgd = init_mm.pgd;
 
     /* Must avoid aliasing mappings in the highmem code */
     kmap_flush_unused();
     vm_unmap_aliases();
 
     /* Flush the caches as needed before changing the encryption attribute. */
     if (x86_platform.guest.enc_tlb_flush_required(enc))
         cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required());
 
     /* Notify hypervisor that we are about to set/clr encryption attribute. */
     x86_platform.guest.enc_status_change_prepare(addr, numpages, enc);
 
     ret = __change_page_attr_set_clr(&cpa, 1);
 
     /*
      * After changing the encryption attribute, we need to flush TLBs again
      * in case any speculative TLB caching occurred (but no need to flush
      * caches again).  We could just use cpa_flush_all(), but in case TLB
      * flushing gets optimized in the cpa_flush() path use the same logic
      * as above.
      */
     cpa_flush(&cpa, 0);
 
     /* Notify hypervisor that we have successfully set/clr encryption attribute. */
     if (!ret) {
         if (!x86_platform.guest.enc_status_change_finish(addr, numpages, enc))
             ret = -EIO;
     }
 
     return ret;
 }
 
 static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 {
     if (hv_is_isolation_supported())
         return hv_set_mem_host_visibility(addr, numpages, !enc);
 
     if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
         return __set_memory_enc_pgtable(addr, numpages, enc);
 
     return 0;
 }
 
 int set_memory_encrypted(unsigned long addr, int numpages)
 {
     return __set_memory_enc_dec(addr, numpages, true);
 }
 EXPORT_SYMBOL_GPL(set_memory_encrypted);
 
 int set_memory_decrypted(unsigned long addr, int numpages)
 {
     return __set_memory_enc_dec(addr, numpages, false);
 }
 EXPORT_SYMBOL_GPL(set_memory_decrypted);
 
 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);
 
 static int _set_pages_array(struct page **pages, int numpages,
         enum page_cache_mode new_type)
 {
     unsigned long start;
     unsigned long end;
     enum page_cache_mode set_type;
     int i;
     int free_idx;
     int ret;
 
     for (i = 0; i < numpages; i++) {
         if (PageHighMem(pages[i]))
             continue;
         start = page_to_pfn(pages[i]) << PAGE_SHIFT;
         end = start + PAGE_SIZE;
         if (memtype_reserve(start, end, new_type, NULL))
             goto err_out;
     }
 
     /* If WC, set to UC- first and then WC */
     set_type = (new_type == _PAGE_CACHE_MODE_WC) ?
                 _PAGE_CACHE_MODE_UC_MINUS : new_type;
 
     ret = cpa_set_pages_array(pages, numpages,
                   cachemode2pgprot(set_type));
     if (!ret && new_type == _PAGE_CACHE_MODE_WC)
         ret = change_page_attr_set_clr(NULL, numpages,
                            cachemode2pgprot(
                         _PAGE_CACHE_MODE_WC),
                            __pgprot(_PAGE_CACHE_MASK),
                            0, CPA_PAGES_ARRAY, pages);
     if (ret)
         goto err_out;
     return 0; /* Success */
 err_out:
     free_idx = i;
     for (i = 0; i < free_idx; i++) {
         if (PageHighMem(pages[i]))
             continue;
         start = page_to_pfn(pages[i]) << PAGE_SHIFT;
         end = start + PAGE_SIZE;
         memtype_free(start, end);
     }
     return -EINVAL;
 }
 
 int set_pages_array_uc(struct page **pages, int numpages)
 {
     return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_UC_MINUS);
 }
 EXPORT_SYMBOL(set_pages_array_uc);
 
 int set_pages_array_wc(struct page **pages, int numpages)
 {
     return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_WC);
 }
 EXPORT_SYMBOL(set_pages_array_wc);
 
 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_array_wb(struct page **pages, int numpages)
 {
     int retval;
     unsigned long start;
     unsigned long end;
     int i;
 
     /* WB cache mode is hard wired to all cache attribute bits being 0 */
     retval = cpa_clear_pages_array(pages, numpages,
             __pgprot(_PAGE_CACHE_MASK));
     if (retval)
         return retval;
 
     for (i = 0; i < numpages; i++) {
         if (PageHighMem(pages[i]))
             continue;
         start = page_to_pfn(pages[i]) << PAGE_SHIFT;
         end = start + PAGE_SIZE;
         memtype_free(start, end);
     }
 
     return 0;
 }
 EXPORT_SYMBOL(set_pages_array_wb);
 
 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);
 }
 
 static int __set_pages_p(struct page *page, int numpages)
 {
     unsigned long tempaddr = (unsigned long) page_address(page);
     struct cpa_data cpa = { .vaddr = &tempaddr,
                 .pgd = NULL,
                 .numpages = numpages,
                 .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
                 .mask_clr = __pgprot(0),
                 .flags = 0};
 
     /*
      * No alias checking needed for setting present flag. otherwise,
      * we may need to break large pages for 64-bit kernel text
      * mappings (this adds to complexity if we want to do this from
      * atomic context especially). Let's keep it simple!
      */
     return __change_page_attr_set_clr(&cpa, 0);
 }
 
 static int __set_pages_np(struct page *page, int numpages)
 {
     unsigned long tempaddr = (unsigned long) page_address(page);
     struct cpa_data cpa = { .vaddr = &tempaddr,
                 .pgd = NULL,
                 .numpages = numpages,
                 .mask_set = __pgprot(0),
                 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
                 .flags = 0};
 
     /*
      * No alias checking needed for setting not present flag. otherwise,
      * we may need to break large pages for 64-bit kernel text
      * mappings (this adds to complexity if we want to do this from
      * atomic context especially). Let's keep it simple!
      */
     return __change_page_attr_set_clr(&cpa, 0);
 }
 
 int set_direct_map_invalid_noflush(struct page *page)
 {
     return __set_pages_np(page, 1);
 }
 
 int set_direct_map_default_noflush(struct page *page)
 {
     return __set_pages_p(page, 1);
 }
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {
     if (PageHighMem(page))
         return;
     if (!enable) {
         debug_check_no_locks_freed(page_address(page),
                        numpages * PAGE_SIZE);
     }
 
     /*
      * The return value is ignored as the calls cannot fail.
      * Large pages for identity mappings are not used at boot time
      * and hence no memory allocations during large page split.
      */
     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.
      * Preemption needs to be disabled around __flush_tlb_all() due to
      * CR3 reload in __native_flush_tlb().
      */
     preempt_disable();
     __flush_tlb_all();
     preempt_enable();
 
     arch_flush_lazy_mmu_mode();
 }
 #endif /* CONFIG_DEBUG_PAGEALLOC */
 
 bool kernel_page_present(struct page *page)
 {
     unsigned int level;
     pte_t *pte;
 
     if (PageHighMem(page))
         return false;
 
     pte = lookup_address((unsigned long)page_address(page), &level);
     return (pte_val(*pte) & _PAGE_PRESENT);
 }
 
 int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
                    unsigned numpages, unsigned long page_flags)
 {
     int retval = -EINVAL;
 
     struct cpa_data cpa = {
         .vaddr = &address,
         .pfn = pfn,
         .pgd = pgd,
         .numpages = numpages,
         .mask_set = __pgprot(0),
         .mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)),
         .flags = 0,
     };
 
     WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
 
     if (!(__supported_pte_mask & _PAGE_NX))
         goto out;
 
     if (!(page_flags & _PAGE_ENC))
         cpa.mask_clr = pgprot_encrypted(cpa.mask_clr);
 
     cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);
 
     retval = __change_page_attr_set_clr(&cpa, 0);
     __flush_tlb_all();
 
 out:
     return retval;
 }
 
 /*
  * __flush_tlb_all() flushes mappings only on current CPU and hence this
  * function shouldn't be used in an SMP environment. Presently, it's used only
  * during boot (way before smp_init()) by EFI subsystem and hence is ok.
  */
 int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address,
                      unsigned long numpages)
 {
     int retval;
 
     /*
      * The typical sequence for unmapping is to find a pte through
      * lookup_address_in_pgd() (ideally, it should never return NULL because
      * the address is already mapped) and change it's protections. As pfn is
      * the *target* of a mapping, it's not useful while unmapping.
      */
     struct cpa_data cpa = {
         .vaddr      = &address,
         .pfn        = 0,
         .pgd        = pgd,
         .numpages   = numpages,
         .mask_set   = __pgprot(0),
         .mask_clr   = __pgprot(_PAGE_PRESENT | _PAGE_RW),
         .flags      = 0,
     };
 
     WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
 
     retval = __change_page_attr_set_clr(&cpa, 0);
     __flush_tlb_all();
 
     return retval;
 }
 
 /*
  * 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 "cpa-test.c"
 #endif

This page was automatically generated by the 2.1.0 LXR engine. The LXR team