/* * 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 #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 #ifdef CONFIG_PPC_BOOK3S_64 /* * partition table and process table for ISA 3.0 */ struct prtb_entry *process_tb; struct patb_entry *partition_tb; /* * page table size */ unsigned long __pte_index_size; EXPORT_SYMBOL(__pte_index_size); unsigned long __pmd_index_size; EXPORT_SYMBOL(__pmd_index_size); unsigned long __pud_index_size; EXPORT_SYMBOL(__pud_index_size); unsigned long __pgd_index_size; EXPORT_SYMBOL(__pgd_index_size); unsigned long __pmd_cache_index; EXPORT_SYMBOL(__pmd_cache_index); unsigned long __pte_table_size; EXPORT_SYMBOL(__pte_table_size); unsigned long __pmd_table_size; EXPORT_SYMBOL(__pmd_table_size); unsigned long __pud_table_size; EXPORT_SYMBOL(__pud_table_size); unsigned long __pgd_table_size; EXPORT_SYMBOL(__pgd_table_size); unsigned long __pmd_val_bits; EXPORT_SYMBOL(__pmd_val_bits); unsigned long __pud_val_bits; EXPORT_SYMBOL(__pud_val_bits); unsigned long __pgd_val_bits; EXPORT_SYMBOL(__pgd_val_bits); #endif unsigned long ioremap_bot = IOREMAP_BASE; /** * __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); /* We don't support the 4K PFN hack with ioremap */ if (flags & H_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 (slab_is_available()) { 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 = pgprot_val(pgprot_noncached(__pgprot(0))); 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 = pgprot_val(pgprot_noncached_wc(__pgprot(0))); 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_WRITE) flags |= _PAGE_DIRTY; /* we don't want to let _PAGE_EXEC leak out */ flags &= ~_PAGE_EXEC; /* * Force kernel mapping. */ #if defined(CONFIG_PPC_BOOK3S_64) flags |= _PAGE_PRIVILEGED; #else flags &= ~_PAGE_USER; #endif #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 (!slab_is_available()) 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 pte_page(pmd_pte(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)) { set_page_count(page, PTE_FRAG_NR); mm->context.pte_frag = ret + PTE_FRAG_SIZE; } spin_unlock(&mm->page_table_lock); return (pte_t *)ret; } pte_t *pte_fragment_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); } #endif /* CONFIG_PPC_64K_PAGES */ void pte_fragment_free(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 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 */ pte_fragment_free(table, 0); 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 */ pte_fragment_free(table, 0); } else { BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); kmem_cache_free(PGT_CACHE(shift), table); } } #endif #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) { __be64 old_be, tmp; unsigned long old; #ifdef CONFIG_DEBUG_VM WARN_ON(!pmd_trans_huge(*pmdp)); assert_spin_locked(&mm->page_table_lock); #endif __asm__ __volatile__( "1: ldarx %0,0,%3\n\ and. %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_be), "=&r" (tmp), "=m" (*pmdp) : "r" (pmdp), "r" (cpu_to_be64(clr)), "m" (*pmdp), "r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set)) : "cc" ); old = be64_to_cpu(old_be); 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; } /* * We currently remove entries from the hashtable regardless of whether * the entry was young or dirty. * * We should be more intelligent about this but for the moment we override * these functions and force a tlb flush unconditionally */ 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 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; } void pmdp_huge_split_prepare(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(REGION_ID(address) != USER_REGION_ID); /* * We can't mark the pmd none here, because that will cause a race * against exit_mmap. We need to continue mark pmd TRANS HUGE, while * we spilt, but at the same time we wan't rest of the ppc64 code * not to insert hash pte on this, because we will be modifying * the deposited pgtable in the caller of this function. Hence * clear the _PAGE_USER so that we move the fault handling to * higher level function and that will serialize against ptl. * We need to flush existing hash pte entries here even though, * the translation is still valid, because we will withdraw * pgtable_t after this. */ pmd_hugepage_update(vma->vm_mm, address, pmdp, 0, _PAGE_PRIVILEGED); } /* * 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(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp))); 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)); } /* * We use this to invalidate a pmdp entry before switching from a * hugepte to regular pmd entry. */ 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); /* * This ensures that generic code that rely on IRQ disabling * to prevent a parallel THP split work as expected. */ kick_all_cpus_sync(); } /* * 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 << PAGE_SHIFT) & PTE_RPN_MASK; 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 &= _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 + 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); /* * 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) { 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 */