EXPORT_SYMBOL(__iounmap);
EXPORT_SYMBOL(__iounmap_at);
+/*
+ * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
+ * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
+ */
+struct page *pmd_page(pmd_t pmd)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ if (pmd_trans_huge(pmd))
+ return pfn_to_page(pmd_pfn(pmd));
+#endif
+ return virt_to_page(pmd_page_vaddr(pmd));
+}
+
#ifdef CONFIG_PPC_64K_PAGES
static pte_t *get_from_cache(struct mm_struct *mm)
{
}
#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 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\
+ stdcx. %1,0,%3 \n\
+ bne- 1b"
+ : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
+ : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY)
+ : "cc" );
+#else
+ old = pmd_val(*pmdp);
+ *pmdp = __pmd(old & ~clr);
+#endif
+ if (old & _PAGE_HASHPTE)
+ hpte_do_hugepage_flush(mm, addr, pmdp);
+ return old;
+}
+
+pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_t pmd;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ if (pmd_trans_huge(*pmdp)) {
+ pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+ } else {
+ /*
+ * khugepaged calls this for normal pmd
+ */
+ 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 mark the pmd splitting and invalidate all the hpte
+ * entries for this hugepage.
+ */
+void pmdp_splitting_flush(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ unsigned long old, tmp;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+#ifdef CONFIG_DEBUG_VM
+ WARN_ON(!pmd_trans_huge(*pmdp));
+ assert_spin_locked(&vma->vm_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\
+ ori %1,%0,%4 \n\
+ stdcx. %1,0,%3 \n\
+ bne- 1b"
+ : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
+ : "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY)
+ : "cc" );
+#else
+ old = pmd_val(*pmdp);
+ *pmdp = __pmd(old | _PAGE_SPLITTING);
+#endif
+ /*
+ * If we didn't had the splitting flag set, go and flush the
+ * HPTE entries.
+ */
+ if (!(old & _PAGE_SPLITTING)) {
+ /* We need to flush the hpte */
+ if (old & _PAGE_HASHPTE)
+ hpte_do_hugepage_flush(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 + 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 + 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, 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_none(*pmdp));
+ assert_spin_locked(&mm->page_table_lock);
+ WARN_ON(!pmd_trans_huge(pmd));
+#endif
+ 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, _PAGE_PRESENT);
+}
+
+/*
+ * 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)
+{
+ int ssize, i;
+ unsigned long s_addr;
+ int max_hpte_count;
+ unsigned int psize, valid;
+ unsigned char *hpte_slot_array;
+ unsigned long hidx, vpn, vsid, hash, shift, slot;
+
+ /*
+ * Flush all the hptes mapping this hugepage
+ */
+ s_addr = addr & HPAGE_PMD_MASK;
+ hpte_slot_array = get_hpte_slot_array(pmdp);
+ /*
+ * IF we try to do a HUGE PTE update after a withdraw is done.
+ * we will find the below NULL. This happens when we do
+ * split_huge_page_pmd
+ */
+ if (!hpte_slot_array)
+ return;
+
+ /* get the base page size */
+ psize = get_slice_psize(mm, s_addr);
+
+ if (ppc_md.hugepage_invalidate)
+ return ppc_md.hugepage_invalidate(mm, hpte_slot_array,
+ s_addr, psize);
+ /*
+ * No bluk hpte removal support, invalidate each entry
+ */
+ shift = mmu_psize_defs[psize].shift;
+ max_hpte_count = HPAGE_PMD_SIZE >> shift;
+ for (i = 0; i < max_hpte_count; i++) {
+ /*
+ * 8 bits per each hpte entries
+ * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
+ */
+ valid = hpte_valid(hpte_slot_array, i);
+ if (!valid)
+ continue;
+ hidx = hpte_hash_index(hpte_slot_array, i);
+
+ /* get the vpn */
+ addr = s_addr + (i * (1ul << shift));
+ 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;
+ }
+
+ vpn = hpt_vpn(addr, vsid, ssize);
+ hash = hpt_hash(vpn, shift, ssize);
+ if (hidx & _PTEIDX_SECONDARY)
+ hash = ~hash;
+
+ slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+ slot += hidx & _PTEIDX_GROUP_IX;
+ ppc_md.hpte_invalidate(slot, vpn, psize,
+ MMU_PAGE_16M, ssize, 0);
+ }
+}
+
+static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
+{
+ pmd_val(pmd) |= pgprot_val(pgprot);
+ return pmd;
+}
+
+pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+ pmd_t pmd;
+ /*
+ * For a valid pte, we would have _PAGE_PRESENT or _PAGE_FILE always
+ * set. We use this to check THP page at pmd level.
+ * leaf pte for huge page, bottom two bits != 00
+ */
+ pmd_val(pmd) = pfn << PTE_RPN_SHIFT;
+ pmd_val(pmd) |= _PAGE_THP_HUGE;
+ pmd = pmd_set_protbits(pmd, pgprot);
+ return pmd;
+}
+
+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)
+{
+
+ pmd_val(pmd) &= _HPAGE_CHG_MASK;
+ pmd = pmd_set_protbits(pmd, newprot);
+ return pmd;
+}
+
+/*
+ * 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_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);
+ 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 + PTRS_PER_PMD;
+ pgtable = *pgtable_slot;
+ /*
+ * Let's zero out old valid and hash index details
+ * hash fault look at them.
+ */
+ memset(pgtable, 0, PTE_FRAG_SIZE);
+ return old_pmd;
+}
+
+int has_transparent_hugepage(void)
+{
+ 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 != 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 */
projects / linux-2.6-block.git / blobdiff