/* * This file contains ioremap and related functions for 64-bit machines. * * Derived from arch/ppc64/mm/init.c * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@samba.org) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * Dave Engebretsen * Rework for PPC64 port. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mmu_decl.h" #define CREATE_TRACE_POINTS #include /* Some sanity checking */ #if TASK_SIZE_USER64 > PGTABLE_RANGE #error TASK_SIZE_USER64 exceeds pagetable range #endif #ifdef CONFIG_PPC_STD_MMU_64 #if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT)) #error TASK_SIZE_USER64 exceeds user VSID range #endif #endif unsigned long ioremap_bot = IOREMAP_BASE; #ifdef CONFIG_PPC_MMU_NOHASH static __ref void *early_alloc_pgtable(unsigned long size) { void *pt; pt = __va(memblock_alloc_base(size, size, __pa(MAX_DMA_ADDRESS))); memset(pt, 0, size); return pt; } #endif /* CONFIG_PPC_MMU_NOHASH */ /* * map_kernel_page currently only called by __ioremap * map_kernel_page adds an entry to the ioremap page table * and adds an entry to the HPT, possibly bolting it */ int map_kernel_page(unsigned long ea, unsigned long pa, int flags) { pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp; pte_t *ptep; if (slab_is_available()) { pgdp = pgd_offset_k(ea); pudp = pud_alloc(&init_mm, pgdp, ea); if (!pudp) return -ENOMEM; pmdp = pmd_alloc(&init_mm, pudp, ea); if (!pmdp) return -ENOMEM; ptep = pte_alloc_kernel(pmdp, ea); if (!ptep) return -ENOMEM; set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); } else { #ifdef CONFIG_PPC_MMU_NOHASH pgdp = pgd_offset_k(ea); #ifdef PUD_TABLE_SIZE if (pgd_none(*pgdp)) { pudp = early_alloc_pgtable(PUD_TABLE_SIZE); BUG_ON(pudp == NULL); pgd_populate(&init_mm, pgdp, pudp); } #endif /* PUD_TABLE_SIZE */ pudp = pud_offset(pgdp, ea); if (pud_none(*pudp)) { pmdp = early_alloc_pgtable(PMD_TABLE_SIZE); BUG_ON(pmdp == NULL); pud_populate(&init_mm, pudp, pmdp); } pmdp = pmd_offset(pudp, ea); if (!pmd_present(*pmdp)) { ptep = early_alloc_pgtable(PAGE_SIZE); BUG_ON(ptep == NULL); pmd_populate_kernel(&init_mm, pmdp, ptep); } ptep = pte_offset_kernel(pmdp, ea); set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); #else /* CONFIG_PPC_MMU_NOHASH */ /* * If the mm subsystem is not fully up, we cannot create a * linux page table entry for this mapping. Simply bolt an * entry in the hardware page table. * */ if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags, mmu_io_psize, mmu_kernel_ssize)) { printk(KERN_ERR "Failed to do bolted mapping IO " "memory at %016lx !\n", pa); return -ENOMEM; } #endif /* !CONFIG_PPC_MMU_NOHASH */ } #ifdef CONFIG_PPC_BOOK3E_64 /* * With hardware tablewalk, a sync is needed to ensure that * subsequent accesses see the PTE we just wrote. Unlike userspace * mappings, we can't tolerate spurious faults, so make sure * the new PTE will be seen the first time. */ mb(); #else smp_wmb(); #endif return 0; } /** * __ioremap_at - Low level function to establish the page tables * for an IO mapping */ void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size, unsigned long flags) { unsigned long i; /* Make sure we have the base flags */ if ((flags & _PAGE_PRESENT) == 0) flags |= pgprot_val(PAGE_KERNEL); /* Non-cacheable page cannot be coherent */ if (flags & _PAGE_NO_CACHE) flags &= ~_PAGE_COHERENT; /* We don't support the 4K PFN hack with ioremap */ if (flags & _PAGE_4K_PFN) return NULL; WARN_ON(pa & ~PAGE_MASK); WARN_ON(((unsigned long)ea) & ~PAGE_MASK); WARN_ON(size & ~PAGE_MASK); for (i = 0; i < size; i += PAGE_SIZE) if (map_kernel_page((unsigned long)ea+i, pa+i, flags)) return NULL; return (void __iomem *)ea; } /** * __iounmap_from - Low level function to tear down the page tables * for an IO mapping. This is used for mappings that * are manipulated manually, like partial unmapping of * PCI IOs or ISA space. */ void __iounmap_at(void *ea, unsigned long size) { WARN_ON(((unsigned long)ea) & ~PAGE_MASK); WARN_ON(size & ~PAGE_MASK); unmap_kernel_range((unsigned long)ea, size); } void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, void *caller) { phys_addr_t paligned; void __iomem *ret; /* * Choose an address to map it to. * Once the imalloc system is running, we use it. * Before that, we map using addresses going * up from ioremap_bot. imalloc will use * the addresses from ioremap_bot through * IMALLOC_END * */ paligned = addr & PAGE_MASK; size = PAGE_ALIGN(addr + size) - paligned; if ((size == 0) || (paligned == 0)) return NULL; if (mem_init_done) { struct vm_struct *area; area = __get_vm_area_caller(size, VM_IOREMAP, ioremap_bot, IOREMAP_END, caller); if (area == NULL) return NULL; area->phys_addr = paligned; ret = __ioremap_at(paligned, area->addr, size, flags); if (!ret) vunmap(area->addr); } else { ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags); if (ret) ioremap_bot += size; } if (ret) ret += addr & ~PAGE_MASK; return ret; } void __iomem * __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) { return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); } void __iomem * ioremap(phys_addr_t addr, unsigned long size) { unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED; void *caller = __builtin_return_address(0); if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags, caller); return __ioremap_caller(addr, size, flags, caller); } void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size) { unsigned long flags = _PAGE_NO_CACHE; void *caller = __builtin_return_address(0); if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags, caller); return __ioremap_caller(addr, size, flags, caller); } void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags) { void *caller = __builtin_return_address(0); /* writeable implies dirty for kernel addresses */ if (flags & _PAGE_RW) flags |= _PAGE_DIRTY; /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ flags &= ~(_PAGE_USER | _PAGE_EXEC); #ifdef _PAGE_BAP_SR /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format * which means that we just cleared supervisor access... oops ;-) This * restores it */ flags |= _PAGE_BAP_SR; #endif if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags, caller); return __ioremap_caller(addr, size, flags, caller); } /* * Unmap an IO region and remove it from imalloc'd list. * Access to IO memory should be serialized by driver. */ void __iounmap(volatile void __iomem *token) { void *addr; if (!mem_init_done) return; addr = (void *) ((unsigned long __force) PCI_FIX_ADDR(token) & PAGE_MASK); if ((unsigned long)addr < ioremap_bot) { printk(KERN_WARNING "Attempt to iounmap early bolted mapping" " at 0x%p\n", addr); return; } vunmap(addr); } void iounmap(volatile void __iomem *token) { if (ppc_md.iounmap) ppc_md.iounmap(token); else __iounmap(token); } EXPORT_SYMBOL(ioremap); EXPORT_SYMBOL(ioremap_wc); EXPORT_SYMBOL(ioremap_prot); EXPORT_SYMBOL(__ioremap); EXPORT_SYMBOL(__ioremap_at); EXPORT_SYMBOL(iounmap); EXPORT_SYMBOL(__iounmap); EXPORT_SYMBOL(__iounmap_at); #ifndef __PAGETABLE_PUD_FOLDED /* 4 level page table */ struct page *pgd_page(pgd_t pgd) { if (pgd_huge(pgd)) return pte_page(pgd_pte(pgd)); return virt_to_page(pgd_page_vaddr(pgd)); } #endif struct page *pud_page(pud_t pud) { if (pud_huge(pud)) return pte_page(pud_pte(pud)); return virt_to_page(pud_page_vaddr(pud)); } /* * 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) { if (pmd_trans_huge(pmd) || pmd_huge(pmd)) return pfn_to_page(pmd_pfn(pmd)); return virt_to_page(pmd_page_vaddr(pmd)); } #ifdef CONFIG_PPC_64K_PAGES static pte_t *get_from_cache(struct mm_struct *mm) { void *pte_frag, *ret; spin_lock(&mm->page_table_lock); ret = mm->context.pte_frag; if (ret) { pte_frag = ret + PTE_FRAG_SIZE; /* * If we have taken up all the fragments mark PTE page NULL */ if (((unsigned long)pte_frag & ~PAGE_MASK) == 0) pte_frag = NULL; mm->context.pte_frag = pte_frag; } spin_unlock(&mm->page_table_lock); return (pte_t *)ret; } static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel) { void *ret = NULL; struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO); if (!page) return NULL; if (!kernel && !pgtable_page_ctor(page)) { __free_page(page); return NULL; } ret = page_address(page); spin_lock(&mm->page_table_lock); /* * If we find pgtable_page set, we return * the allocated page with single fragement * count. */ if (likely(!mm->context.pte_frag)) { atomic_set(&page->_count, PTE_FRAG_NR); mm->context.pte_frag = ret + PTE_FRAG_SIZE; } spin_unlock(&mm->page_table_lock); return (pte_t *)ret; } pte_t *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel) { pte_t *pte; pte = get_from_cache(mm); if (pte) return pte; return __alloc_for_cache(mm, kernel); } void page_table_free(struct mm_struct *mm, unsigned long *table, int kernel) { struct page *page = virt_to_page(table); if (put_page_testzero(page)) { if (!kernel) pgtable_page_dtor(page); free_hot_cold_page(page, 0); } } #ifdef CONFIG_SMP static void page_table_free_rcu(void *table) { struct page *page = virt_to_page(table); if (put_page_testzero(page)) { pgtable_page_dtor(page); free_hot_cold_page(page, 0); } } void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) { unsigned long pgf = (unsigned long)table; BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); pgf |= shift; tlb_remove_table(tlb, (void *)pgf); } void __tlb_remove_table(void *_table) { void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE); unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE; if (!shift) /* PTE page needs special handling */ page_table_free_rcu(table); else { BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); kmem_cache_free(PGT_CACHE(shift), table); } } #else void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) { if (!shift) { /* PTE page needs special handling */ struct page *page = virt_to_page(table); if (put_page_testzero(page)) { pgtable_page_dtor(page); free_hot_cold_page(page, 0); } } else { BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); kmem_cache_free(PGT_CACHE(shift), table); } } #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" (_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 & _PAGE_HASHPTE) hpte_do_hugepage_flush(mm, addr, pmdp, old); 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. */ trace_hugepage_splitting(address, old); if (!(old & _PAGE_SPLITTING)) { /* We need to flush the hpte */ if (old & _PAGE_HASHPTE) hpte_do_hugepage_flush(vma->vm_mm, address, pmdp, old); } /* * This ensures that generic code that rely on IRQ disabling * to prevent a parallel THP split work as expected. */ kick_all_cpus_sync(); } /* * 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_val(*pmdp) & (_PAGE_PRESENT | _PAGE_USER)) == (_PAGE_PRESENT | _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, _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 & _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) { 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 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, 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 + 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 */