Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 730 insertions, 0 deletions

diff --git a/kernel/include/asm-generic/pgtable.h b/kernel/include/asm-generic/pgtable.h
new file mode 100644
index 000000000..39f1d6a2b
--- /dev/null
+++ b/kernel/include/asm-generic/pgtable.h
@@ -0,0 +1,730 @@
+#ifndef _ASM_GENERIC_PGTABLE_H
+#define _ASM_GENERIC_PGTABLE_H
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_MMU
+
+#include <linux/mm_types.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
+
+#if 4 - defined(__PAGETABLE_PUD_FOLDED) - defined(__PAGETABLE_PMD_FOLDED) != \
+	CONFIG_PGTABLE_LEVELS
+#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{PUD,PMD}_FOLDED
+#endif
+
+/*
+ * On almost all architectures and configurations, 0 can be used as the
+ * upper ceiling to free_pgtables(): on many architectures it has the same
+ * effect as using TASK_SIZE.  However, there is one configuration which
+ * must impose a more careful limit, to avoid freeing kernel pgtables.
+ */
+#ifndef USER_PGTABLES_CEILING
+#define USER_PGTABLES_CEILING	0UL
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+extern int ptep_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pte_t *ptep,
+				 pte_t entry, int dirty);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+extern int pmdp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp,
+				 pmd_t entry, int dirty);
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pte_t *ptep)
+{
+	pte_t pte = *ptep;
+	int r = 1;
+	if (!pte_young(pte))
+		r = 0;
+	else
+		set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
+	return r;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pmd_t *pmdp)
+{
+	pmd_t pmd = *pmdp;
+	int r = 1;
+	if (!pmd_young(pmd))
+		r = 0;
+	else
+		set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
+	return r;
+}
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pmd_t *pmdp)
+{
+	BUG();
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+int ptep_clear_flush_young(struct vm_area_struct *vma,
+			   unsigned long address, pte_t *ptep);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
+int pmdp_clear_flush_young(struct vm_area_struct *vma,
+			   unsigned long address, pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
+				       unsigned long address,
+				       pte_t *ptep)
+{
+	pte_t pte = *ptep;
+	pte_clear(mm, address, ptep);
+	return pte;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
+				       unsigned long address,
+				       pmd_t *pmdp)
+{
+	pmd_t pmd = *pmdp;
+	pmd_clear(pmdp);
+	return pmd;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm,
+					    unsigned long address, pmd_t *pmdp,
+					    int full)
+{
+	return pmdp_get_and_clear(mm, address, pmdp);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
+static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
+					    unsigned long address, pte_t *ptep,
+					    int full)
+{
+	pte_t pte;
+	pte = ptep_get_and_clear(mm, address, ptep);
+	return pte;
+}
+#endif
+
+/*
+ * Some architectures may be able to avoid expensive synchronization
+ * primitives when modifications are made to PTE's which are already
+ * not present, or in the process of an address space destruction.
+ */
+#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
+static inline void pte_clear_not_present_full(struct mm_struct *mm,
+					      unsigned long address,
+					      pte_t *ptep,
+					      int full)
+{
+	pte_clear(mm, address, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
+extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pte_t *ptep);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
+extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
+struct mm_struct;
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
+{
+	pte_t old_pte = *ptep;
+	set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline void pmdp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pmd_t *pmdp)
+{
+	pmd_t old_pmd = *pmdp;
+	set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
+}
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline void pmdp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pmd_t *pmdp)
+{
+	BUG();
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+extern void pmdp_splitting_flush(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				       pgtable_t pgtable);
+#endif
+
+#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PTE_SAME
+static inline int pte_same(pte_t pte_a, pte_t pte_b)
+{
+	return pte_val(pte_a) == pte_val(pte_b);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTE_UNUSED
+/*
+ * Some architectures provide facilities to virtualization guests
+ * so that they can flag allocated pages as unused. This allows the
+ * host to transparently reclaim unused pages. This function returns
+ * whether the pte's page is unused.
+ */
+static inline int pte_unused(pte_t pte)
+{
+	return 0;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMD_SAME
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
+{
+	return pmd_val(pmd_a) == pmd_val(pmd_b);
+}
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
+{
+	BUG();
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
+#define pgd_offset_gate(mm, addr)	pgd_offset(mm, addr)
+#endif
+
+#ifndef __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr)	(pte)
+#endif
+
+#ifndef pte_accessible
+# define pte_accessible(mm, pte)	((void)(pte), 1)
+#endif
+
+#ifndef flush_tlb_fix_spurious_fault
+#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
+#endif
+
+#ifndef pgprot_noncached
+#define pgprot_noncached(prot)	(prot)
+#endif
+
+#ifndef pgprot_writecombine
+#define pgprot_writecombine pgprot_noncached
+#endif
+
+#ifndef pgprot_device
+#define pgprot_device pgprot_noncached
+#endif
+
+#ifndef pgprot_modify
+#define pgprot_modify pgprot_modify
+static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
+{
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
+		newprot = pgprot_noncached(newprot);
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
+		newprot = pgprot_writecombine(newprot);
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
+		newprot = pgprot_device(newprot);
+	return newprot;
+}
+#endif
+
+/*
+ * When walking page tables, get the address of the next boundary,
+ * or the end address of the range if that comes earlier.  Although no
+ * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
+ */
+
+#define pgd_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+
+#ifndef pud_addr_end
+#define pud_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+#endif
+
+#ifndef pmd_addr_end
+#define pmd_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+#endif
+
+/*
+ * When walking page tables, we usually want to skip any p?d_none entries;
+ * and any p?d_bad entries - reporting the error before resetting to none.
+ * Do the tests inline, but report and clear the bad entry in mm/memory.c.
+ */
+void pgd_clear_bad(pgd_t *);
+void pud_clear_bad(pud_t *);
+void pmd_clear_bad(pmd_t *);
+
+static inline int pgd_none_or_clear_bad(pgd_t *pgd)
+{
+	if (pgd_none(*pgd))
+		return 1;
+	if (unlikely(pgd_bad(*pgd))) {
+		pgd_clear_bad(pgd);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pud_none_or_clear_bad(pud_t *pud)
+{
+	if (pud_none(*pud))
+		return 1;
+	if (unlikely(pud_bad(*pud))) {
+		pud_clear_bad(pud);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pmd_none_or_clear_bad(pmd_t *pmd)
+{
+	if (pmd_none(*pmd))
+		return 1;
+	if (unlikely(pmd_bad(*pmd))) {
+		pmd_clear_bad(pmd);
+		return 1;
+	}
+	return 0;
+}
+
+static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
+					     unsigned long addr,
+					     pte_t *ptep)
+{
+	/*
+	 * Get the current pte state, but zero it out to make it
+	 * non-present, preventing the hardware from asynchronously
+	 * updating it.
+	 */
+	return ptep_get_and_clear(mm, addr, ptep);
+}
+
+static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
+					     unsigned long addr,
+					     pte_t *ptep, pte_t pte)
+{
+	/*
+	 * The pte is non-present, so there's no hardware state to
+	 * preserve.
+	 */
+	set_pte_at(mm, addr, ptep, pte);
+}
+
+#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
+/*
+ * Start a pte protection read-modify-write transaction, which
+ * protects against asynchronous hardware modifications to the pte.
+ * The intention is not to prevent the hardware from making pte
+ * updates, but to prevent any updates it may make from being lost.
+ *
+ * This does not protect against other software modifications of the
+ * pte; the appropriate pte lock must be held over the transation.
+ *
+ * Note that this interface is intended to be batchable, meaning that
+ * ptep_modify_prot_commit may not actually update the pte, but merely
+ * queue the update to be done at some later time.  The update must be
+ * actually committed before the pte lock is released, however.
+ */
+static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
+					   unsigned long addr,
+					   pte_t *ptep)
+{
+	return __ptep_modify_prot_start(mm, addr, ptep);
+}
+
+/*
+ * Commit an update to a pte, leaving any hardware-controlled bits in
+ * the PTE unmodified.
+ */
+static inline void ptep_modify_prot_commit(struct mm_struct *mm,
+					   unsigned long addr,
+					   pte_t *ptep, pte_t pte)
+{
+	__ptep_modify_prot_commit(mm, addr, ptep, pte);
+}
+#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
+#endif /* CONFIG_MMU */
+
+/*
+ * A facility to provide lazy MMU batching.  This allows PTE updates and
+ * page invalidations to be delayed until a call to leave lazy MMU mode
+ * is issued.  Some architectures may benefit from doing this, and it is
+ * beneficial for both shadow and direct mode hypervisors, which may batch
+ * the PTE updates which happen during this window.  Note that using this
+ * interface requires that read hazards be removed from the code.  A read
+ * hazard could result in the direct mode hypervisor case, since the actual
+ * write to the page tables may not yet have taken place, so reads though
+ * a raw PTE pointer after it has been modified are not guaranteed to be
+ * up to date.  This mode can only be entered and left under the protection of
+ * the page table locks for all page tables which may be modified.  In the UP
+ * case, this is required so that preemption is disabled, and in the SMP case,
+ * it must synchronize the delayed page table writes properly on other CPUs.
+ */
+#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
+#define arch_enter_lazy_mmu_mode()	do {} while (0)
+#define arch_leave_lazy_mmu_mode()	do {} while (0)
+#define arch_flush_lazy_mmu_mode()	do {} while (0)
+#endif
+
+/*
+ * A facility to provide batching of the reload of page tables and
+ * other process state with the actual context switch code for
+ * paravirtualized guests.  By convention, only one of the batched
+ * update (lazy) modes (CPU, MMU) should be active at any given time,
+ * entry should never be nested, and entry and exits should always be
+ * paired.  This is for sanity of maintaining and reasoning about the
+ * kernel code.  In this case, the exit (end of the context switch) is
+ * in architecture-specific code, and so doesn't need a generic
+ * definition.
+ */
+#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
+#define arch_start_context_switch(prev)	do {} while (0)
+#endif
+
+#ifndef CONFIG_HAVE_ARCH_SOFT_DIRTY
+static inline int pte_soft_dirty(pte_t pte)
+{
+	return 0;
+}
+
+static inline int pmd_soft_dirty(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline pte_t pte_mksoft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline int pte_swp_soft_dirty(pte_t pte)
+{
+	return 0;
+}
+
+static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
+{
+	return pte;
+}
+#endif
+
+#ifndef __HAVE_PFNMAP_TRACKING
+/*
+ * Interfaces that can be used by architecture code to keep track of
+ * memory type of pfn mappings specified by the remap_pfn_range,
+ * vm_insert_pfn.
+ */
+
+/*
+ * track_pfn_remap is called when a _new_ pfn mapping is being established
+ * by remap_pfn_range() for physical range indicated by pfn and size.
+ */
+static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
+				  unsigned long pfn, unsigned long addr,
+				  unsigned long size)
+{
+	return 0;
+}
+
+/*
+ * track_pfn_insert is called when a _new_ single pfn is established
+ * by vm_insert_pfn().
+ */
+static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
+				   unsigned long pfn)
+{
+	return 0;
+}
+
+/*
+ * track_pfn_copy is called when vma that is covering the pfnmap gets
+ * copied through copy_page_range().
+ */
+static inline int track_pfn_copy(struct vm_area_struct *vma)
+{
+	return 0;
+}
+
+/*
+ * untrack_pfn_vma is called while unmapping a pfnmap for a region.
+ * untrack can be called for a specific region indicated by pfn and size or
+ * can be for the entire vma (in which case pfn, size are zero).
+ */
+static inline void untrack_pfn(struct vm_area_struct *vma,
+			       unsigned long pfn, unsigned long size)
+{
+}
+#else
+extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
+			   unsigned long pfn, unsigned long addr,
+			   unsigned long size);
+extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
+			    unsigned long pfn);
+extern int track_pfn_copy(struct vm_area_struct *vma);
+extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
+			unsigned long size);
+#endif
+
+#ifdef __HAVE_COLOR_ZERO_PAGE
+static inline int is_zero_pfn(unsigned long pfn)
+{
+	extern unsigned long zero_pfn;
+	unsigned long offset_from_zero_pfn = pfn - zero_pfn;
+	return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
+}
+
+#define my_zero_pfn(addr)	page_to_pfn(ZERO_PAGE(addr))
+
+#else
+static inline int is_zero_pfn(unsigned long pfn)
+{
+	extern unsigned long zero_pfn;
+	return pfn == zero_pfn;
+}
+
+static inline unsigned long my_zero_pfn(unsigned long addr)
+{
+	extern unsigned long zero_pfn;
+	return zero_pfn;
+}
+#endif
+
+#ifdef CONFIG_MMU
+
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	return 0;
+}
+static inline int pmd_trans_splitting(pmd_t pmd)
+{
+	return 0;
+}
+#ifndef __HAVE_ARCH_PMD_WRITE
+static inline int pmd_write(pmd_t pmd)
+{
+	BUG();
+	return 0;
+}
+#endif /* __HAVE_ARCH_PMD_WRITE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifndef pmd_read_atomic
+static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
+{
+	/*
+	 * Depend on compiler for an atomic pmd read. NOTE: this is
+	 * only going to work, if the pmdval_t isn't larger than
+	 * an unsigned long.
+	 */
+	return *pmdp;
+}
+#endif
+
+#ifndef pmd_move_must_withdraw
+static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
+					 spinlock_t *old_pmd_ptl)
+{
+	/*
+	 * With split pmd lock we also need to move preallocated
+	 * PTE page table if new_pmd is on different PMD page table.
+	 */
+	return new_pmd_ptl != old_pmd_ptl;
+}
+#endif
+
+/*
+ * This function is meant to be used by sites walking pagetables with
+ * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
+ * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
+ * into a null pmd and the transhuge page fault can convert a null pmd
+ * into an hugepmd or into a regular pmd (if the hugepage allocation
+ * fails). While holding the mmap_sem in read mode the pmd becomes
+ * stable and stops changing under us only if it's not null and not a
+ * transhuge pmd. When those races occurs and this function makes a
+ * difference vs the standard pmd_none_or_clear_bad, the result is
+ * undefined so behaving like if the pmd was none is safe (because it
+ * can return none anyway). The compiler level barrier() is critically
+ * important to compute the two checks atomically on the same pmdval.
+ *
+ * For 32bit kernels with a 64bit large pmd_t this automatically takes
+ * care of reading the pmd atomically to avoid SMP race conditions
+ * against pmd_populate() when the mmap_sem is hold for reading by the
+ * caller (a special atomic read not done by "gcc" as in the generic
+ * version above, is also needed when THP is disabled because the page
+ * fault can populate the pmd from under us).
+ */
+static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
+{
+	pmd_t pmdval = pmd_read_atomic(pmd);
+	/*
+	 * The barrier will stabilize the pmdval in a register or on
+	 * the stack so that it will stop changing under the code.
+	 *
+	 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
+	 * pmd_read_atomic is allowed to return a not atomic pmdval
+	 * (for example pointing to an hugepage that has never been
+	 * mapped in the pmd). The below checks will only care about
+	 * the low part of the pmd with 32bit PAE x86 anyway, with the
+	 * exception of pmd_none(). So the important thing is that if
+	 * the low part of the pmd is found null, the high part will
+	 * be also null or the pmd_none() check below would be
+	 * confused.
+	 */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	barrier();
+#endif
+	if (pmd_none(pmdval) || pmd_trans_huge(pmdval))
+		return 1;
+	if (unlikely(pmd_bad(pmdval))) {
+		pmd_clear_bad(pmd);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * This is a noop if Transparent Hugepage Support is not built into
+ * the kernel. Otherwise it is equivalent to
+ * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
+ * places that already verified the pmd is not none and they want to
+ * walk ptes while holding the mmap sem in read mode (write mode don't
+ * need this). If THP is not enabled, the pmd can't go away under the
+ * code even if MADV_DONTNEED runs, but if THP is enabled we need to
+ * run a pmd_trans_unstable before walking the ptes after
+ * split_huge_page_pmd returns (because it may have run when the pmd
+ * become null, but then a page fault can map in a THP and not a
+ * regular page).
+ */
+static inline int pmd_trans_unstable(pmd_t *pmd)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	return pmd_none_or_trans_huge_or_clear_bad(pmd);
+#else
+	return 0;
+#endif
+}
+
+#ifndef CONFIG_NUMA_BALANCING
+/*
+ * Technically a PTE can be PROTNONE even when not doing NUMA balancing but
+ * the only case the kernel cares is for NUMA balancing and is only ever set
+ * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
+ * _PAGE_PROTNONE so by by default, implement the helper as "always no". It
+ * is the responsibility of the caller to distinguish between PROT_NONE
+ * protections and NUMA hinting fault protections.
+ */
+static inline int pte_protnone(pte_t pte)
+{
+	return 0;
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+	return 0;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+#endif /* CONFIG_MMU */
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
+int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
+int pud_clear_huge(pud_t *pud);
+int pmd_clear_huge(pmd_t *pmd);
+#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int pud_clear_huge(pud_t *pud)
+{
+	return 0;
+}
+static inline int pmd_clear_huge(pmd_t *pmd)
+{
+	return 0;
+}
+#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+#endif /* !__ASSEMBLY__ */
+
+#ifndef io_remap_pfn_range
+#define io_remap_pfn_range remap_pfn_range
+#endif
+
+#endif /* _ASM_GENERIC_PGTABLE_H */