Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
arch/powerpc/mm/pgtable-hash64.c | 341 +++++++++++++++++++++++++++++++++++++++
arch/powerpc/mm/pgtable_64.c | 341 ---------------------------------------
2 files changed, 341 insertions(+), 341 deletions(-)
diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c
index 35127acdb8c6..6c9c16b37033 100644
--- a/arch/powerpc/mm/pgtable-hash64.c
+++ b/arch/powerpc/mm/pgtable-hash64.c
@@ -21,6 +21,9 @@
#include "mmu_decl.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/thp.h>
+
#if H_PGTABLE_RANGE > USER_VSID_RANGE
#warning Limited user VSID range means pagetable space is wasted
#endif
@@ -244,3 +247,341 @@ void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep,
/* Perform the setting of the PTE */
__set_pte_at(mm, addr, ptep, pte, 0);
}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/*
+ * This is called when relaxing access to a hugepage. It's also called in the
page
+ * fault path when we don't hit any of the major fault cases, ie, a minor
+ * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
+ * handled those two for us, we additionally deal with missing execute
+ * permission here on some processors
+ */
+int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp, pmd_t entry, int dirty)
+{
+ int changed;
+#ifdef CONFIG_DEBUG_VM
+ WARN_ON(!pmd_trans_huge(*pmdp));
+ assert_spin_locked(&vma->vm_mm->page_table_lock);
+#endif
+ changed = !pmd_same(*(pmdp), entry);
+ if (changed) {
+ __ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry));
+ /*
+ * Since we are not supporting SW TLB systems, we don't
+ * have any thing similar to flush_tlb_page_nohash()
+ */
+ }
+ return changed;
+}
+
+unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, unsigned long clr,
+ unsigned long set)
+{
+
+ unsigned long old, tmp;
+
+#ifdef CONFIG_DEBUG_VM
+ WARN_ON(!pmd_trans_huge(*pmdp));
+ assert_spin_locked(&mm->page_table_lock);
+#endif
+
+#ifdef PTE_ATOMIC_UPDATES
+ __asm__ __volatile__(
+ "1: ldarx %0,0,%3\n\
+ andi. %1,%0,%6\n\
+ bne- 1b \n\
+ andc %1,%0,%4 \n\
+ or %1,%1,%7\n\
+ stdcx. %1,0,%3 \n\
+ bne- 1b"
+ : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
+ : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (H_PAGE_BUSY), "r" (set)
+ : "cc" );
+#else
+ old = pmd_val(*pmdp);
+ *pmdp = __pmd((old & ~clr) | set);
+#endif
+ trace_hugepage_update(addr, old, clr, set);
+ if (old & H_PAGE_HASHPTE)
+ hpte_do_hugepage_flush(mm, addr, pmdp, old);
+ return old;
+}
+
+pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_t pmd;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ VM_BUG_ON(pmd_trans_huge(*pmdp));
+
+ pmd = *pmdp;
+ pmd_clear(pmdp);
+ /*
+ * Wait for all pending hash_page to finish. This is needed
+ * in case of subpage collapse. When we collapse normal pages
+ * to hugepage, we first clear the pmd, then invalidate all
+ * the PTE entries. The assumption here is that any low level
+ * page fault will see a none pmd and take the slow path that
+ * will wait on mmap_sem. But we could very well be in a
+ * hash_page with local ptep pointer value. Such a hash page
+ * can result in adding new HPTE entries for normal subpages.
+ * That means we could be modifying the page content as we
+ * copy them to a huge page. So wait for parallel hash_page
+ * to finish before invalidating HPTE entries. We can do this
+ * by sending an IPI to all the cpus and executing a dummy
+ * function there.
+ */
+ kick_all_cpus_sync();
+ /*
+ * Now invalidate the hpte entries in the range
+ * covered by pmd. This make sure we take a
+ * fault and will find the pmd as none, which will
+ * result in a major fault which takes mmap_sem and
+ * hence wait for collapse to complete. Without this
+ * the __collapse_huge_page_copy can result in copying
+ * the old content.
+ */
+ flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
+ return pmd;
+}
+
+int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
+}
+
+/*
+ * We currently remove entries from the hashtable regardless of whether
+ * the entry was young or dirty. The generic routines only flush if the
+ * entry was young or dirty which is not good enough.
+ *
+ * We should be more intelligent about this but for the moment we override
+ * these functions and force a tlb flush unconditionally
+ */
+int pmdp_clear_flush_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
+}
+
+/*
+ * We want to put the pgtable in pmd and use pgtable for tracking
+ * the base page size hptes
+ */
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+ pgtable_t pgtable)
+{
+ pgtable_t *pgtable_slot;
+ assert_spin_locked(&mm->page_table_lock);
+ /*
+ * we store the pgtable in the second half of PMD
+ */
+ pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
+ *pgtable_slot = pgtable;
+ /*
+ * expose the deposited pgtable to other cpus.
+ * before we set the hugepage PTE at pmd level
+ * hash fault code looks at the deposted pgtable
+ * to store hash index values.
+ */
+ smp_wmb();
+}
+
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+ pgtable_t pgtable;
+ pgtable_t *pgtable_slot;
+
+ assert_spin_locked(&mm->page_table_lock);
+ pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
+ pgtable = *pgtable_slot;
+ /*
+ * Once we withdraw, mark the entry NULL.
+ */
+ *pgtable_slot = NULL;
+ /*
+ * We store HPTE information in the deposited PTE fragment.
+ * zero out the content on withdraw.
+ */
+ memset(pgtable, 0, H_PTE_FRAG_SIZE);
+ return pgtable;
+}
+
+/*
+ * set a new huge pmd. We should not be called for updating
+ * an existing pmd entry. That should go via pmd_hugepage_update.
+ */
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t pmd)
+{
+#ifdef CONFIG_DEBUG_VM
+ WARN_ON((pmd_val(*pmdp) & (H_PAGE_PRESENT | H_PAGE_USER)) ==
+ (H_PAGE_PRESENT | H_PAGE_USER));
+ assert_spin_locked(&mm->page_table_lock);
+ WARN_ON(!pmd_trans_huge(pmd));
+#endif
+ trace_hugepage_set_pmd(addr, pmd_val(pmd));
+ return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
+}
+
+void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_hugepage_update(vma->vm_mm, address, pmdp, H_PAGE_PRESENT, 0);
+}
+
+/*
+ * A linux hugepage PMD was changed and the corresponding hash table entries
+ * neesd to be flushed.
+ */
+void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, unsigned long old_pmd)
+{
+ int ssize;
+ unsigned int psize;
+ unsigned long vsid;
+ unsigned long flags = 0;
+ const struct cpumask *tmp;
+
+ /* get the base page size,vsid and segment size */
+#ifdef CONFIG_DEBUG_VM
+ psize = get_slice_psize(mm, addr);
+ BUG_ON(psize == MMU_PAGE_16M);
+#endif
+ if (old_pmd & H_PAGE_COMBO)
+ psize = MMU_PAGE_4K;
+ else
+ psize = MMU_PAGE_64K;
+
+ if (!is_kernel_addr(addr)) {
+ ssize = user_segment_size(addr);
+ vsid = get_vsid(mm->context.id, addr, ssize);
+ WARN_ON(vsid == 0);
+ } else {
+ vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+ ssize = mmu_kernel_ssize;
+ }
+
+ tmp = cpumask_of(smp_processor_id());
+ if (cpumask_equal(mm_cpumask(mm), tmp))
+ flags |= HPTE_LOCAL_UPDATE;
+
+ return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
+}
+
+static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
+{
+ return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
+}
+
+pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+ unsigned long pmdv;
+
+ pmdv = pfn << H_PTE_RPN_SHIFT;
+ return pmd_set_protbits(__pmd(pmdv), pgprot);
+}
+
+pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
+{
+ return pfn_pmd(page_to_pfn(page), pgprot);
+}
+
+pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ unsigned long pmdv;
+
+ pmdv = pmd_val(pmd);
+ pmdv &= H_HPAGE_CHG_MASK;
+ return pmd_set_protbits(__pmd(pmdv), newprot);
+}
+
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a HUGE PMD entry in the linux page
tables.
+ * We use it to preload an HPTE into the hash table corresponding to
+ * the updated linux HUGE PMD entry.
+ */
+void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd)
+{
+ return;
+}
+
+pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pmd_t *pmdp)
+{
+ pmd_t old_pmd;
+ pgtable_t pgtable;
+ unsigned long old;
+ pgtable_t *pgtable_slot;
+
+ old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
+ old_pmd = __pmd(old);
+ /*
+ * We have pmd == none and we are holding page_table_lock.
+ * So we can safely go and clear the pgtable hash
+ * index info.
+ */
+ pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
+ pgtable = *pgtable_slot;
+ /*
+ * Let's zero out old valid and hash index details
+ * hash fault look at them.
+ */
+ memset(pgtable, 0, H_PTE_FRAG_SIZE);
+ /*
+ * Serialize against find_linux_pte_or_hugepte which does lock-less
+ * lookup in page tables with local interrupts disabled. For huge pages
+ * it casts pmd_t to pte_t. Since format of pte_t is different from
+ * pmd_t we want to prevent transit from pmd pointing to page table
+ * to pmd pointing to huge page (and back) while interrupts are
disabled.
+ * We clear pmd to possibly replace it with page table pointer in
+ * different code paths. So make sure we wait for the parallel
+ * find_linux_pte_or_hugepage to finish.
+ */
+ kick_all_cpus_sync();
+ return old_pmd;
+}
+
+int has_transparent_hugepage(void)
+{
+
+ BUILD_BUG_ON_MSG((H_PMD_SHIFT - PAGE_SHIFT) >= MAX_ORDER,
+ "hugepages can't be allocated by the buddy allocator");
+
+ BUILD_BUG_ON_MSG((H_PMD_SHIFT - PAGE_SHIFT) < 2,
+ "We need more than 2 pages to do deferred thp split");
+
+ if (!mmu_has_feature(MMU_FTR_16M_PAGE))
+ return 0;
+ /*
+ * We support THP only if PMD_SIZE is 16MB.
+ */
+ if (mmu_psize_defs[MMU_PAGE_16M].shift != H_PMD_SHIFT)
+ return 0;
+ /*
+ * We need to make sure that we support 16MB hugepage in a segement
+ * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
+ * of 64K.
+ */
+ /*
+ * If we have 64K HPTE, we will be using that by default
+ */
+ if (mmu_psize_defs[MMU_PAGE_64K].shift &&
+ (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
+ return 0;
+ /*
+ * Ok we only have 4K HPTE
+ */
+ if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
+ return 0;
+
+ return 1;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index ff9d388bb311..b642215e51f9 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -55,9 +55,6 @@
#include "mmu_decl.h"
-#define CREATE_TRACE_POINTS
-#include <trace/events/thp.h>
-
#ifdef CONFIG_PPC_STD_MMU_64
#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
#error TASK_SIZE_USER64 exceeds user VSID range
@@ -423,341 +420,3 @@ void pgtable_free_tlb(struct mmu_gather *tlb, void
*table, int shift)
}
#endif
#endif /* CONFIG_PPC_64K_PAGES */
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-
-/*
- * This is called when relaxing access to a hugepage. It's also called in the
page
- * fault path when we don't hit any of the major fault cases, ie, a minor
- * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
- * handled those two for us, we additionally deal with missing execute
- * permission here on some processors
- */
-int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp, pmd_t entry, int dirty)
-{
- int changed;
-#ifdef CONFIG_DEBUG_VM
- WARN_ON(!pmd_trans_huge(*pmdp));
- assert_spin_locked(&vma->vm_mm->page_table_lock);
-#endif
- changed = !pmd_same(*(pmdp), entry);
- if (changed) {
- __ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry));
- /*
- * Since we are not supporting SW TLB systems, we don't
- * have any thing similar to flush_tlb_page_nohash()
- */
- }
- return changed;
-}
-
-unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
- pmd_t *pmdp, unsigned long clr,
- unsigned long set)
-{
-
- unsigned long old, tmp;
-
-#ifdef CONFIG_DEBUG_VM
- WARN_ON(!pmd_trans_huge(*pmdp));
- assert_spin_locked(&mm->page_table_lock);
-#endif
-
-#ifdef PTE_ATOMIC_UPDATES
- __asm__ __volatile__(
- "1: ldarx %0,0,%3\n\
- andi. %1,%0,%6\n\
- bne- 1b \n\
- andc %1,%0,%4 \n\
- or %1,%1,%7\n\
- stdcx. %1,0,%3 \n\
- bne- 1b"
- : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
- : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (H_PAGE_BUSY), "r" (set)
- : "cc" );
-#else
- old = pmd_val(*pmdp);
- *pmdp = __pmd((old & ~clr) | set);
-#endif
- trace_hugepage_update(addr, old, clr, set);
- if (old & H_PAGE_HASHPTE)
- hpte_do_hugepage_flush(mm, addr, pmdp, old);
- return old;
-}
-
-pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp)
-{
- pmd_t pmd;
-
- VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- VM_BUG_ON(pmd_trans_huge(*pmdp));
-
- pmd = *pmdp;
- pmd_clear(pmdp);
- /*
- * Wait for all pending hash_page to finish. This is needed
- * in case of subpage collapse. When we collapse normal pages
- * to hugepage, we first clear the pmd, then invalidate all
- * the PTE entries. The assumption here is that any low level
- * page fault will see a none pmd and take the slow path that
- * will wait on mmap_sem. But we could very well be in a
- * hash_page with local ptep pointer value. Such a hash page
- * can result in adding new HPTE entries for normal subpages.
- * That means we could be modifying the page content as we
- * copy them to a huge page. So wait for parallel hash_page
- * to finish before invalidating HPTE entries. We can do this
- * by sending an IPI to all the cpus and executing a dummy
- * function there.
- */
- kick_all_cpus_sync();
- /*
- * Now invalidate the hpte entries in the range
- * covered by pmd. This make sure we take a
- * fault and will find the pmd as none, which will
- * result in a major fault which takes mmap_sem and
- * hence wait for collapse to complete. Without this
- * the __collapse_huge_page_copy can result in copying
- * the old content.
- */
- flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
- return pmd;
-}
-
-int pmdp_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp)
-{
- return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
-}
-
-/*
- * We currently remove entries from the hashtable regardless of whether
- * the entry was young or dirty. The generic routines only flush if the
- * entry was young or dirty which is not good enough.
- *
- * We should be more intelligent about this but for the moment we override
- * these functions and force a tlb flush unconditionally
- */
-int pmdp_clear_flush_young(struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmdp)
-{
- return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
-}
-
-/*
- * We want to put the pgtable in pmd and use pgtable for tracking
- * the base page size hptes
- */
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
- pgtable_t pgtable)
-{
- pgtable_t *pgtable_slot;
- assert_spin_locked(&mm->page_table_lock);
- /*
- * we store the pgtable in the second half of PMD
- */
- pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
- *pgtable_slot = pgtable;
- /*
- * expose the deposited pgtable to other cpus.
- * before we set the hugepage PTE at pmd level
- * hash fault code looks at the deposted pgtable
- * to store hash index values.
- */
- smp_wmb();
-}
-
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
-{
- pgtable_t pgtable;
- pgtable_t *pgtable_slot;
-
- assert_spin_locked(&mm->page_table_lock);
- pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
- pgtable = *pgtable_slot;
- /*
- * Once we withdraw, mark the entry NULL.
- */
- *pgtable_slot = NULL;
- /*
- * We store HPTE information in the deposited PTE fragment.
- * zero out the content on withdraw.
- */
- memset(pgtable, 0, H_PTE_FRAG_SIZE);
- return pgtable;
-}
-
-/*
- * set a new huge pmd. We should not be called for updating
- * an existing pmd entry. That should go via pmd_hugepage_update.
- */
-void set_pmd_at(struct mm_struct *mm, unsigned long addr,
- pmd_t *pmdp, pmd_t pmd)
-{
-#ifdef CONFIG_DEBUG_VM
- WARN_ON((pmd_val(*pmdp) & (H_PAGE_PRESENT | H_PAGE_USER)) ==
- (H_PAGE_PRESENT | H_PAGE_USER));
- assert_spin_locked(&mm->page_table_lock);
- WARN_ON(!pmd_trans_huge(pmd));
-#endif
- trace_hugepage_set_pmd(addr, pmd_val(pmd));
- return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
-}
-
-void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp)
-{
- pmd_hugepage_update(vma->vm_mm, address, pmdp, H_PAGE_PRESENT, 0);
-}
-
-/*
- * A linux hugepage PMD was changed and the corresponding hash table entries
- * neesd to be flushed.
- */
-void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
- pmd_t *pmdp, unsigned long old_pmd)
-{
- int ssize;
- unsigned int psize;
- unsigned long vsid;
- unsigned long flags = 0;
- const struct cpumask *tmp;
-
- /* get the base page size,vsid and segment size */
-#ifdef CONFIG_DEBUG_VM
- psize = get_slice_psize(mm, addr);
- BUG_ON(psize == MMU_PAGE_16M);
-#endif
- if (old_pmd & H_PAGE_COMBO)
- psize = MMU_PAGE_4K;
- else
- psize = MMU_PAGE_64K;
-
- if (!is_kernel_addr(addr)) {
- ssize = user_segment_size(addr);
- vsid = get_vsid(mm->context.id, addr, ssize);
- WARN_ON(vsid == 0);
- } else {
- vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
- ssize = mmu_kernel_ssize;
- }
-
- tmp = cpumask_of(smp_processor_id());
- if (cpumask_equal(mm_cpumask(mm), tmp))
- flags |= HPTE_LOCAL_UPDATE;
-
- return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
-}
-
-static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
-{
- return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
-}
-
-pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
-{
- unsigned long pmdv;
-
- pmdv = pfn << H_PTE_RPN_SHIFT;
- return pmd_set_protbits(__pmd(pmdv), pgprot);
-}
-
-pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
-{
- return pfn_pmd(page_to_pfn(page), pgprot);
-}
-
-pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
-{
- unsigned long pmdv;
-
- pmdv = pmd_val(pmd);
- pmdv &= H_HPAGE_CHG_MASK;
- return pmd_set_protbits(__pmd(pmdv), newprot);
-}
-
-/*
- * This is called at the end of handling a user page fault, when the
- * fault has been handled by updating a HUGE PMD entry in the linux page
tables.
- * We use it to preload an HPTE into the hash table corresponding to
- * the updated linux HUGE PMD entry.
- */
-void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
- pmd_t *pmd)
-{
- return;
-}
-
-pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
- unsigned long addr, pmd_t *pmdp)
-{
- pmd_t old_pmd;
- pgtable_t pgtable;
- unsigned long old;
- pgtable_t *pgtable_slot;
-
- old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
- old_pmd = __pmd(old);
- /*
- * We have pmd == none and we are holding page_table_lock.
- * So we can safely go and clear the pgtable hash
- * index info.
- */
- pgtable_slot = (pgtable_t *)pmdp + H_PTRS_PER_PMD;
- pgtable = *pgtable_slot;
- /*
- * Let's zero out old valid and hash index details
- * hash fault look at them.
- */
- memset(pgtable, 0, H_PTE_FRAG_SIZE);
- /*
- * Serialize against find_linux_pte_or_hugepte which does lock-less
- * lookup in page tables with local interrupts disabled. For huge pages
- * it casts pmd_t to pte_t. Since format of pte_t is different from
- * pmd_t we want to prevent transit from pmd pointing to page table
- * to pmd pointing to huge page (and back) while interrupts are
disabled.
- * We clear pmd to possibly replace it with page table pointer in
- * different code paths. So make sure we wait for the parallel
- * find_linux_pte_or_hugepage to finish.
- */
- kick_all_cpus_sync();
- return old_pmd;
-}
-
-int has_transparent_hugepage(void)
-{
-
- BUILD_BUG_ON_MSG((H_PMD_SHIFT - PAGE_SHIFT) >= MAX_ORDER,
- "hugepages can't be allocated by the buddy allocator");
-
- BUILD_BUG_ON_MSG((H_PMD_SHIFT - PAGE_SHIFT) < 2,
- "We need more than 2 pages to do deferred thp split");
-
- if (!mmu_has_feature(MMU_FTR_16M_PAGE))
- return 0;
- /*
- * We support THP only if PMD_SIZE is 16MB.
- */
- if (mmu_psize_defs[MMU_PAGE_16M].shift != H_PMD_SHIFT)
- return 0;
- /*
- * We need to make sure that we support 16MB hugepage in a segement
- * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
- * of 64K.
- */
- /*
- * If we have 64K HPTE, we will be using that by default
- */
- if (mmu_psize_defs[MMU_PAGE_64K].shift &&
- (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
- return 0;
- /*
- * Ok we only have 4K HPTE
- */
- if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
- return 0;
-
- return 1;
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
--
2.5.0
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