| /* |
| * 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 <engebret@us.ibm.com> |
| * 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 <linux/signal.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> |
| #include <linux/export.h> |
| #include <linux/types.h> |
| #include <linux/mman.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/stddef.h> |
| #include <linux/vmalloc.h> |
| #include <linux/memblock.h> |
| #include <linux/slab.h> |
| #include <linux/hugetlb.h> |
| |
| #include <asm/pgalloc.h> |
| #include <asm/page.h> |
| #include <asm/prom.h> |
| #include <asm/io.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgtable.h> |
| #include <asm/mmu.h> |
| #include <asm/smp.h> |
| #include <asm/machdep.h> |
| #include <asm/tlb.h> |
| #include <asm/processor.h> |
| #include <asm/cputable.h> |
| #include <asm/sections.h> |
| #include <asm/firmware.h> |
| #include <asm/dma.h> |
| |
| #include "mmu_decl.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/thp.h> |
| |
| /* 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 */ |
| } |
| |
| smp_wmb(); |
| 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 (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 = _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 (!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)) { |
| 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_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 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\ |
| oris %1,%0,%4@h \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) |
| { |
| return __pmd(pmd_val(pmd) | pgprot_val(pgprot)); |
| } |
| |
| pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot) |
| { |
| unsigned long pmdv; |
| |
| pmdv = pfn << 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 &= _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 */ |