diff options
Diffstat (limited to 'arch/tile/mm/pgtable.c')
| -rw-r--r-- | arch/tile/mm/pgtable.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c new file mode 100644 index 000000000000..335c24621c41 --- /dev/null +++ b/arch/tile/mm/pgtable.c @@ -0,0 +1,529 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * 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, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/spinlock.h> +#include <linux/cpumask.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/vmalloc.h> +#include <linux/smp.h> + +#include <asm/system.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/fixmap.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> +#include <asm/homecache.h> + +#define K(x) ((x) << (PAGE_SHIFT-10)) + +/* + * The normal show_free_areas() is too verbose on Tile, with dozens + * of processors and often four NUMA zones each with high and lowmem. + */ +void show_mem(void) +{ + struct zone *zone; + + pr_err("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu" + " free:%lu\n slab:%lu mapped:%lu pagetables:%lu bounce:%lu" + " pagecache:%lu swap:%lu\n", + (global_page_state(NR_ACTIVE_ANON) + + global_page_state(NR_ACTIVE_FILE)), + (global_page_state(NR_INACTIVE_ANON) + + global_page_state(NR_INACTIVE_FILE)), + global_page_state(NR_FILE_DIRTY), + global_page_state(NR_WRITEBACK), + global_page_state(NR_UNSTABLE_NFS), + global_page_state(NR_FREE_PAGES), + (global_page_state(NR_SLAB_RECLAIMABLE) + + global_page_state(NR_SLAB_UNRECLAIMABLE)), + global_page_state(NR_FILE_MAPPED), + global_page_state(NR_PAGETABLE), + global_page_state(NR_BOUNCE), + global_page_state(NR_FILE_PAGES), + nr_swap_pages); + + for_each_zone(zone) { + unsigned long flags, order, total = 0, largest_order = -1; + + if (!populated_zone(zone)) + continue; + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + int nr = zone->free_area[order].nr_free; + total += nr << order; + if (nr) + largest_order = order; + } + spin_unlock_irqrestore(&zone->lock, flags); + pr_err("Node %d %7s: %lukB (largest %luKb)\n", + zone_to_nid(zone), zone->name, + K(total), largest_order ? K(1UL) << largest_order : 0); + } +} + +/* + * Associate a virtual page frame with a given physical page frame + * and protection flags for that frame. + */ +static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = swapper_pg_dir + pgd_index(vaddr); + if (pgd_none(*pgd)) { + BUG(); + return; + } + pud = pud_offset(pgd, vaddr); + if (pud_none(*pud)) { + BUG(); + return; + } + pmd = pmd_offset(pud, vaddr); + if (pmd_none(*pmd)) { + BUG(); + return; + } + pte = pte_offset_kernel(pmd, vaddr); + /* <pfn,flags> stored as-is, to permit clearing entries */ + set_pte(pte, pfn_pte(pfn, flags)); + + /* + * It's enough to flush this one mapping. + * This appears conservative since it is only called + * from __set_fixmap. + */ + local_flush_tlb_page(NULL, vaddr, PAGE_SIZE); +} + +void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + set_pte_pfn(address, phys >> PAGE_SHIFT, flags); +} + +#if defined(CONFIG_HIGHPTE) +pte_t *_pte_offset_map(pmd_t *dir, unsigned long address, enum km_type type) +{ + pte_t *pte = kmap_atomic(pmd_page(*dir), type) + + (pmd_ptfn(*dir) << HV_LOG2_PAGE_TABLE_ALIGN) & ~PAGE_MASK; + return &pte[pte_index(address)]; +} +#endif + +/* + * List of all pgd's needed so it can invalidate entries in both cached + * and uncached pgd's. This is essentially codepath-based locking + * against pageattr.c; it is the unique case in which a valid change + * of kernel pagetables can't be lazily synchronized by vmalloc faults. + * vmalloc faults work because attached pagetables are never freed. + * The locking scheme was chosen on the basis of manfred's + * recommendations and having no core impact whatsoever. + * -- wli + */ +DEFINE_SPINLOCK(pgd_lock); +LIST_HEAD(pgd_list); + +static inline void pgd_list_add(pgd_t *pgd) +{ + list_add(pgd_to_list(pgd), &pgd_list); +} + +static inline void pgd_list_del(pgd_t *pgd) +{ + list_del(pgd_to_list(pgd)); +} + +#define KERNEL_PGD_INDEX_START pgd_index(PAGE_OFFSET) +#define KERNEL_PGD_PTRS (PTRS_PER_PGD - KERNEL_PGD_INDEX_START) + +static void pgd_ctor(pgd_t *pgd) +{ + unsigned long flags; + + memset(pgd, 0, KERNEL_PGD_INDEX_START*sizeof(pgd_t)); + spin_lock_irqsave(&pgd_lock, flags); + +#ifndef __tilegx__ + /* + * Check that the user interrupt vector has no L2. + * It never should for the swapper, and new page tables + * should always start with an empty user interrupt vector. + */ + BUG_ON(((u64 *)swapper_pg_dir)[pgd_index(MEM_USER_INTRPT)] != 0); +#endif + + clone_pgd_range(pgd + KERNEL_PGD_INDEX_START, + swapper_pg_dir + KERNEL_PGD_INDEX_START, + KERNEL_PGD_PTRS); + + pgd_list_add(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); +} + +static void pgd_dtor(pgd_t *pgd) +{ + unsigned long flags; /* can be called from interrupt context */ + + spin_lock_irqsave(&pgd_lock, flags); + pgd_list_del(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); +} + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL); + if (pgd) + pgd_ctor(pgd); + return pgd; +} + +void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + pgd_dtor(pgd); + kmem_cache_free(pgd_cache, pgd); +} + + +#define L2_USER_PGTABLE_PAGES (1 << L2_USER_PGTABLE_ORDER) + +struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + gfp_t flags = GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO|__GFP_COMP; + struct page *p; + +#ifdef CONFIG_HIGHPTE + flags |= __GFP_HIGHMEM; +#endif + + p = alloc_pages(flags, L2_USER_PGTABLE_ORDER); + if (p == NULL) + return NULL; + + pgtable_page_ctor(p); + return p; +} + +/* + * Free page immediately (used in __pte_alloc if we raced with another + * process). We have to correct whatever pte_alloc_one() did before + * returning the pages to the allocator. + */ +void pte_free(struct mm_struct *mm, struct page *p) +{ + pgtable_page_dtor(p); + __free_pages(p, L2_USER_PGTABLE_ORDER); +} + +void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte, + unsigned long address) +{ + int i; + + pgtable_page_dtor(pte); + tlb->need_flush = 1; + if (tlb_fast_mode(tlb)) { + struct page *pte_pages[L2_USER_PGTABLE_PAGES]; + for (i = 0; i < L2_USER_PGTABLE_PAGES; ++i) + pte_pages[i] = pte + i; + free_pages_and_swap_cache(pte_pages, L2_USER_PGTABLE_PAGES); + return; + } + for (i = 0; i < L2_USER_PGTABLE_PAGES; ++i) { + tlb->pages[tlb->nr++] = pte + i; + if (tlb->nr >= FREE_PTE_NR) + tlb_flush_mmu(tlb, 0, 0); + } +} + +#ifndef __tilegx__ + +/* + * FIXME: needs to be atomic vs hypervisor writes. For now we make the + * window of vulnerability a bit smaller by doing an unlocked 8-bit update. + */ +int ptep_test_and_clear_young(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ +#if HV_PTE_INDEX_ACCESSED < 8 || HV_PTE_INDEX_ACCESSED >= 16 +# error Code assumes HV_PTE "accessed" bit in second byte +#endif + u8 *tmp = (u8 *)ptep; + u8 second_byte = tmp[1]; + if (!(second_byte & (1 << (HV_PTE_INDEX_ACCESSED - 8)))) + return 0; + tmp[1] = second_byte & ~(1 << (HV_PTE_INDEX_ACCESSED - 8)); + return 1; +} + +/* + * This implementation is atomic vs hypervisor writes, since the hypervisor + * always writes the low word (where "accessed" and "dirty" are) and this + * routine only writes the high word. + */ +void ptep_set_wrprotect(struct mm_struct *mm, + unsigned long addr, pte_t *ptep) +{ +#if HV_PTE_INDEX_WRITABLE < 32 +# error Code assumes HV_PTE "writable" bit in high word +#endif + u32 *tmp = (u32 *)ptep; + tmp[1] = tmp[1] & ~(1 << (HV_PTE_INDEX_WRITABLE - 32)); +} + +#endif + +pte_t *virt_to_pte(struct mm_struct* mm, unsigned long addr) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + + if (pgd_addr_invalid(addr)) + return NULL; + + pgd = mm ? pgd_offset(mm, addr) : swapper_pg_dir + pgd_index(addr); + pud = pud_offset(pgd, addr); + if (!pud_present(*pud)) + return NULL; + pmd = pmd_offset(pud, addr); + if (pmd_huge_page(*pmd)) + return (pte_t *)pmd; + if (!pmd_present(*pmd)) + return NULL; + return pte_offset_kernel(pmd, addr); +} + +pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu) +{ + unsigned int width = smp_width; + int x = cpu % width; + int y = cpu / width; + BUG_ON(y >= smp_height); + BUG_ON(hv_pte_get_mode(prot) != HV_PTE_MODE_CACHE_TILE_L3); + BUG_ON(cpu < 0 || cpu >= NR_CPUS); + BUG_ON(!cpu_is_valid_lotar(cpu)); + return hv_pte_set_lotar(prot, HV_XY_TO_LOTAR(x, y)); +} + +int get_remote_cache_cpu(pgprot_t prot) +{ + HV_LOTAR lotar = hv_pte_get_lotar(prot); + int x = HV_LOTAR_X(lotar); + int y = HV_LOTAR_Y(lotar); + BUG_ON(hv_pte_get_mode(prot) != HV_PTE_MODE_CACHE_TILE_L3); + return x + y * smp_width; +} + +void set_pte_order(pte_t *ptep, pte_t pte, int order) +{ + unsigned long pfn = pte_pfn(pte); + struct page *page = pfn_to_page(pfn); + + /* Update the home of a PTE if necessary */ + pte = pte_set_home(pte, page_home(page)); + +#ifdef __tilegx__ + *ptep = pte; +#else + /* + * When setting a PTE, write the high bits first, then write + * the low bits. This sets the "present" bit only after the + * other bits are in place. If a particular PTE update + * involves transitioning from one valid PTE to another, it + * may be necessary to call set_pte_order() more than once, + * transitioning via a suitable intermediate state. + * Note that this sequence also means that if we are transitioning + * from any migrating PTE to a non-migrating one, we will not + * see a half-updated PTE with the migrating bit off. + */ +#if HV_PTE_INDEX_PRESENT >= 32 || HV_PTE_INDEX_MIGRATING >= 32 +# error Must write the present and migrating bits last +#endif + ((u32 *)ptep)[1] = (u32)(pte_val(pte) >> 32); + barrier(); + ((u32 *)ptep)[0] = (u32)(pte_val(pte)); +#endif +} + +/* Can this mm load a PTE with cached_priority set? */ +static inline int mm_is_priority_cached(struct mm_struct *mm) +{ + return mm->context.priority_cached; +} + +/* + * Add a priority mapping to an mm_context and + * notify the hypervisor if this is the first one. + */ +void start_mm_caching(struct mm_struct *mm) +{ + if (!mm_is_priority_cached(mm)) { + mm->context.priority_cached = -1U; + hv_set_caching(-1U); + } +} + +/* + * Validate and return the priority_cached flag. We know if it's zero + * that we don't need to scan, since we immediately set it non-zero + * when we first consider a MAP_CACHE_PRIORITY mapping. + * + * We only _try_ to acquire the mmap_sem semaphore; if we can't acquire it, + * since we're in an interrupt context (servicing switch_mm) we don't + * worry about it and don't unset the "priority_cached" field. + * Presumably we'll come back later and have more luck and clear + * the value then; for now we'll just keep the cache marked for priority. + */ +static unsigned int update_priority_cached(struct mm_struct *mm) +{ + if (mm->context.priority_cached && down_write_trylock(&mm->mmap_sem)) { + struct vm_area_struct *vm; + for (vm = mm->mmap; vm; vm = vm->vm_next) { + if (hv_pte_get_cached_priority(vm->vm_page_prot)) + break; + } + if (vm == NULL) + mm->context.priority_cached = 0; + up_write(&mm->mmap_sem); + } + return mm->context.priority_cached; +} + +/* Set caching correctly for an mm that we are switching to. */ +void check_mm_caching(struct mm_struct *prev, struct mm_struct *next) +{ + if (!mm_is_priority_cached(next)) { + /* + * If the new mm doesn't use priority caching, just see if we + * need the hv_set_caching(), or can assume it's already zero. + */ + if (mm_is_priority_cached(prev)) + hv_set_caching(0); + } else { + hv_set_caching(update_priority_cached(next)); + } +} + +#if CHIP_HAS_MMIO() + +/* Map an arbitrary MMIO address, homed according to pgprot, into VA space. */ +void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size, + pgprot_t home) +{ + void *addr; + struct vm_struct *area; + unsigned long offset, last_addr; + pgprot_t pgprot; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + /* Create a read/write, MMIO VA mapping homed at the requested shim. */ + pgprot = PAGE_KERNEL; + pgprot = hv_pte_set_mode(pgprot, HV_PTE_MODE_MMIO); + pgprot = hv_pte_set_lotar(pgprot, hv_pte_get_lotar(home)); + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr+1) - phys_addr; + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP /* | other flags? */); + if (!area) + return NULL; + area->phys_addr = phys_addr; + addr = area->addr; + if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, + phys_addr, pgprot)) { + remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr)); + return NULL; + } + return (__force void __iomem *) (offset + (char *)addr); +} +EXPORT_SYMBOL(ioremap_prot); + +/* Map a PCI MMIO bus address into VA space. */ +void __iomem *ioremap(resource_size_t phys_addr, unsigned long size) +{ + panic("ioremap for PCI MMIO is not supported"); +} +EXPORT_SYMBOL(ioremap); + +/* Unmap an MMIO VA mapping. */ +void iounmap(volatile void __iomem *addr_in) +{ + volatile void __iomem *addr = (volatile void __iomem *) + (PAGE_MASK & (unsigned long __force)addr_in); +#if 1 + vunmap((void * __force)addr); +#else + /* x86 uses this complicated flow instead of vunmap(). Is + * there any particular reason we should do the same? */ + struct vm_struct *p, *o; + + /* Use the vm area unlocked, assuming the caller + ensures there isn't another iounmap for the same address + in parallel. Reuse of the virtual address is prevented by + leaving it in the global lists until we're done with it. + cpa takes care of the direct mappings. */ + read_lock(&vmlist_lock); + for (p = vmlist; p; p = p->next) { + if (p->addr == addr) + break; + } + read_unlock(&vmlist_lock); + + if (!p) { + pr_err("iounmap: bad address %p\n", addr); + dump_stack(); + return; + } + + /* Finally remove it */ + o = remove_vm_area((void *)addr); + BUG_ON(p != o || o == NULL); + kfree(p); +#endif +} +EXPORT_SYMBOL(iounmap); + +#endif /* CHIP_HAS_MMIO() */ |