| /* |
| * Copyright IBM Corp. 2007, 2011 |
| * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/gfp.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/smp.h> |
| #include <linux/highmem.h> |
| #include <linux/pagemap.h> |
| #include <linux/spinlock.h> |
| #include <linux/module.h> |
| #include <linux/quicklist.h> |
| #include <linux/rcupdate.h> |
| #include <linux/slab.h> |
| |
| #include <asm/pgtable.h> |
| #include <asm/pgalloc.h> |
| #include <asm/tlb.h> |
| #include <asm/tlbflush.h> |
| #include <asm/mmu_context.h> |
| |
| #ifndef CONFIG_64BIT |
| #define ALLOC_ORDER 1 |
| #define FRAG_MASK 0x0f |
| #else |
| #define ALLOC_ORDER 2 |
| #define FRAG_MASK 0x03 |
| #endif |
| |
| |
| unsigned long *crst_table_alloc(struct mm_struct *mm) |
| { |
| struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); |
| |
| if (!page) |
| return NULL; |
| return (unsigned long *) page_to_phys(page); |
| } |
| |
| void crst_table_free(struct mm_struct *mm, unsigned long *table) |
| { |
| free_pages((unsigned long) table, ALLOC_ORDER); |
| } |
| |
| #ifdef CONFIG_64BIT |
| int crst_table_upgrade(struct mm_struct *mm, unsigned long limit) |
| { |
| unsigned long *table, *pgd; |
| unsigned long entry; |
| |
| BUG_ON(limit > (1UL << 53)); |
| repeat: |
| table = crst_table_alloc(mm); |
| if (!table) |
| return -ENOMEM; |
| spin_lock_bh(&mm->page_table_lock); |
| if (mm->context.asce_limit < limit) { |
| pgd = (unsigned long *) mm->pgd; |
| if (mm->context.asce_limit <= (1UL << 31)) { |
| entry = _REGION3_ENTRY_EMPTY; |
| mm->context.asce_limit = 1UL << 42; |
| mm->context.asce_bits = _ASCE_TABLE_LENGTH | |
| _ASCE_USER_BITS | |
| _ASCE_TYPE_REGION3; |
| } else { |
| entry = _REGION2_ENTRY_EMPTY; |
| mm->context.asce_limit = 1UL << 53; |
| mm->context.asce_bits = _ASCE_TABLE_LENGTH | |
| _ASCE_USER_BITS | |
| _ASCE_TYPE_REGION2; |
| } |
| crst_table_init(table, entry); |
| pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd); |
| mm->pgd = (pgd_t *) table; |
| mm->task_size = mm->context.asce_limit; |
| table = NULL; |
| } |
| spin_unlock_bh(&mm->page_table_lock); |
| if (table) |
| crst_table_free(mm, table); |
| if (mm->context.asce_limit < limit) |
| goto repeat; |
| return 0; |
| } |
| |
| void crst_table_downgrade(struct mm_struct *mm, unsigned long limit) |
| { |
| pgd_t *pgd; |
| |
| while (mm->context.asce_limit > limit) { |
| pgd = mm->pgd; |
| switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) { |
| case _REGION_ENTRY_TYPE_R2: |
| mm->context.asce_limit = 1UL << 42; |
| mm->context.asce_bits = _ASCE_TABLE_LENGTH | |
| _ASCE_USER_BITS | |
| _ASCE_TYPE_REGION3; |
| break; |
| case _REGION_ENTRY_TYPE_R3: |
| mm->context.asce_limit = 1UL << 31; |
| mm->context.asce_bits = _ASCE_TABLE_LENGTH | |
| _ASCE_USER_BITS | |
| _ASCE_TYPE_SEGMENT; |
| break; |
| default: |
| BUG(); |
| } |
| mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN); |
| mm->task_size = mm->context.asce_limit; |
| crst_table_free(mm, (unsigned long *) pgd); |
| } |
| } |
| #endif |
| |
| #ifdef CONFIG_PGSTE |
| |
| /** |
| * gmap_alloc - allocate a guest address space |
| * @mm: pointer to the parent mm_struct |
| * |
| * Returns a guest address space structure. |
| */ |
| struct gmap *gmap_alloc(struct mm_struct *mm) |
| { |
| struct gmap *gmap; |
| struct page *page; |
| unsigned long *table; |
| |
| gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL); |
| if (!gmap) |
| goto out; |
| INIT_LIST_HEAD(&gmap->crst_list); |
| gmap->mm = mm; |
| page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); |
| if (!page) |
| goto out_free; |
| list_add(&page->lru, &gmap->crst_list); |
| table = (unsigned long *) page_to_phys(page); |
| crst_table_init(table, _REGION1_ENTRY_EMPTY); |
| gmap->table = table; |
| gmap->asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH | |
| _ASCE_USER_BITS | __pa(table); |
| list_add(&gmap->list, &mm->context.gmap_list); |
| return gmap; |
| |
| out_free: |
| kfree(gmap); |
| out: |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(gmap_alloc); |
| |
| static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table) |
| { |
| struct gmap_pgtable *mp; |
| struct gmap_rmap *rmap; |
| struct page *page; |
| |
| if (*table & _SEGMENT_ENTRY_INVALID) |
| return 0; |
| page = pfn_to_page(*table >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| list_for_each_entry(rmap, &mp->mapper, list) { |
| if (rmap->entry != table) |
| continue; |
| list_del(&rmap->list); |
| kfree(rmap); |
| break; |
| } |
| *table = mp->vmaddr | _SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_PROTECT; |
| return 1; |
| } |
| |
| static void gmap_flush_tlb(struct gmap *gmap) |
| { |
| if (MACHINE_HAS_IDTE) |
| __tlb_flush_idte((unsigned long) gmap->table | |
| _ASCE_TYPE_REGION1); |
| else |
| __tlb_flush_global(); |
| } |
| |
| /** |
| * gmap_free - free a guest address space |
| * @gmap: pointer to the guest address space structure |
| */ |
| void gmap_free(struct gmap *gmap) |
| { |
| struct page *page, *next; |
| unsigned long *table; |
| int i; |
| |
| |
| /* Flush tlb. */ |
| if (MACHINE_HAS_IDTE) |
| __tlb_flush_idte((unsigned long) gmap->table | |
| _ASCE_TYPE_REGION1); |
| else |
| __tlb_flush_global(); |
| |
| /* Free all segment & region tables. */ |
| down_read(&gmap->mm->mmap_sem); |
| spin_lock(&gmap->mm->page_table_lock); |
| list_for_each_entry_safe(page, next, &gmap->crst_list, lru) { |
| table = (unsigned long *) page_to_phys(page); |
| if ((*table & _REGION_ENTRY_TYPE_MASK) == 0) |
| /* Remove gmap rmap structures for segment table. */ |
| for (i = 0; i < PTRS_PER_PMD; i++, table++) |
| gmap_unlink_segment(gmap, table); |
| __free_pages(page, ALLOC_ORDER); |
| } |
| spin_unlock(&gmap->mm->page_table_lock); |
| up_read(&gmap->mm->mmap_sem); |
| list_del(&gmap->list); |
| kfree(gmap); |
| } |
| EXPORT_SYMBOL_GPL(gmap_free); |
| |
| /** |
| * gmap_enable - switch primary space to the guest address space |
| * @gmap: pointer to the guest address space structure |
| */ |
| void gmap_enable(struct gmap *gmap) |
| { |
| S390_lowcore.gmap = (unsigned long) gmap; |
| } |
| EXPORT_SYMBOL_GPL(gmap_enable); |
| |
| /** |
| * gmap_disable - switch back to the standard primary address space |
| * @gmap: pointer to the guest address space structure |
| */ |
| void gmap_disable(struct gmap *gmap) |
| { |
| S390_lowcore.gmap = 0UL; |
| } |
| EXPORT_SYMBOL_GPL(gmap_disable); |
| |
| /* |
| * gmap_alloc_table is assumed to be called with mmap_sem held |
| */ |
| static int gmap_alloc_table(struct gmap *gmap, |
| unsigned long *table, unsigned long init) |
| { |
| struct page *page; |
| unsigned long *new; |
| |
| /* since we dont free the gmap table until gmap_free we can unlock */ |
| spin_unlock(&gmap->mm->page_table_lock); |
| page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); |
| spin_lock(&gmap->mm->page_table_lock); |
| if (!page) |
| return -ENOMEM; |
| new = (unsigned long *) page_to_phys(page); |
| crst_table_init(new, init); |
| if (*table & _REGION_ENTRY_INVALID) { |
| list_add(&page->lru, &gmap->crst_list); |
| *table = (unsigned long) new | _REGION_ENTRY_LENGTH | |
| (*table & _REGION_ENTRY_TYPE_MASK); |
| } else |
| __free_pages(page, ALLOC_ORDER); |
| return 0; |
| } |
| |
| /** |
| * gmap_unmap_segment - unmap segment from the guest address space |
| * @gmap: pointer to the guest address space structure |
| * @addr: address in the guest address space |
| * @len: length of the memory area to unmap |
| * |
| * Returns 0 if the unmap succeded, -EINVAL if not. |
| */ |
| int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len) |
| { |
| unsigned long *table; |
| unsigned long off; |
| int flush; |
| |
| if ((to | len) & (PMD_SIZE - 1)) |
| return -EINVAL; |
| if (len == 0 || to + len < to) |
| return -EINVAL; |
| |
| flush = 0; |
| down_read(&gmap->mm->mmap_sem); |
| spin_lock(&gmap->mm->page_table_lock); |
| for (off = 0; off < len; off += PMD_SIZE) { |
| /* Walk the guest addr space page table */ |
| table = gmap->table + (((to + off) >> 53) & 0x7ff); |
| if (*table & _REGION_ENTRY_INVALID) |
| goto out; |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 42) & 0x7ff); |
| if (*table & _REGION_ENTRY_INVALID) |
| goto out; |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 31) & 0x7ff); |
| if (*table & _REGION_ENTRY_INVALID) |
| goto out; |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 20) & 0x7ff); |
| |
| /* Clear segment table entry in guest address space. */ |
| flush |= gmap_unlink_segment(gmap, table); |
| *table = _SEGMENT_ENTRY_INVALID; |
| } |
| out: |
| spin_unlock(&gmap->mm->page_table_lock); |
| up_read(&gmap->mm->mmap_sem); |
| if (flush) |
| gmap_flush_tlb(gmap); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(gmap_unmap_segment); |
| |
| /** |
| * gmap_mmap_segment - map a segment to the guest address space |
| * @gmap: pointer to the guest address space structure |
| * @from: source address in the parent address space |
| * @to: target address in the guest address space |
| * |
| * Returns 0 if the mmap succeded, -EINVAL or -ENOMEM if not. |
| */ |
| int gmap_map_segment(struct gmap *gmap, unsigned long from, |
| unsigned long to, unsigned long len) |
| { |
| unsigned long *table; |
| unsigned long off; |
| int flush; |
| |
| if ((from | to | len) & (PMD_SIZE - 1)) |
| return -EINVAL; |
| if (len == 0 || from + len > PGDIR_SIZE || |
| from + len < from || to + len < to) |
| return -EINVAL; |
| |
| flush = 0; |
| down_read(&gmap->mm->mmap_sem); |
| spin_lock(&gmap->mm->page_table_lock); |
| for (off = 0; off < len; off += PMD_SIZE) { |
| /* Walk the gmap address space page table */ |
| table = gmap->table + (((to + off) >> 53) & 0x7ff); |
| if ((*table & _REGION_ENTRY_INVALID) && |
| gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY)) |
| goto out_unmap; |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 42) & 0x7ff); |
| if ((*table & _REGION_ENTRY_INVALID) && |
| gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY)) |
| goto out_unmap; |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 31) & 0x7ff); |
| if ((*table & _REGION_ENTRY_INVALID) && |
| gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY)) |
| goto out_unmap; |
| table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN); |
| table = table + (((to + off) >> 20) & 0x7ff); |
| |
| /* Store 'from' address in an invalid segment table entry. */ |
| flush |= gmap_unlink_segment(gmap, table); |
| *table = (from + off) | (_SEGMENT_ENTRY_INVALID | |
| _SEGMENT_ENTRY_PROTECT); |
| } |
| spin_unlock(&gmap->mm->page_table_lock); |
| up_read(&gmap->mm->mmap_sem); |
| if (flush) |
| gmap_flush_tlb(gmap); |
| return 0; |
| |
| out_unmap: |
| spin_unlock(&gmap->mm->page_table_lock); |
| up_read(&gmap->mm->mmap_sem); |
| gmap_unmap_segment(gmap, to, len); |
| return -ENOMEM; |
| } |
| EXPORT_SYMBOL_GPL(gmap_map_segment); |
| |
| static unsigned long *gmap_table_walk(unsigned long address, struct gmap *gmap) |
| { |
| unsigned long *table; |
| |
| table = gmap->table + ((address >> 53) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) |
| return ERR_PTR(-EFAULT); |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 42) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) |
| return ERR_PTR(-EFAULT); |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 31) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) |
| return ERR_PTR(-EFAULT); |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 20) & 0x7ff); |
| return table; |
| } |
| |
| /** |
| * __gmap_translate - translate a guest address to a user space address |
| * @address: guest address |
| * @gmap: pointer to guest mapping meta data structure |
| * |
| * Returns user space address which corresponds to the guest address or |
| * -EFAULT if no such mapping exists. |
| * This function does not establish potentially missing page table entries. |
| * The mmap_sem of the mm that belongs to the address space must be held |
| * when this function gets called. |
| */ |
| unsigned long __gmap_translate(unsigned long address, struct gmap *gmap) |
| { |
| unsigned long *segment_ptr, vmaddr, segment; |
| struct gmap_pgtable *mp; |
| struct page *page; |
| |
| current->thread.gmap_addr = address; |
| segment_ptr = gmap_table_walk(address, gmap); |
| if (IS_ERR(segment_ptr)) |
| return PTR_ERR(segment_ptr); |
| /* Convert the gmap address to an mm address. */ |
| segment = *segment_ptr; |
| if (!(segment & _SEGMENT_ENTRY_INVALID)) { |
| page = pfn_to_page(segment >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| return mp->vmaddr | (address & ~PMD_MASK); |
| } else if (segment & _SEGMENT_ENTRY_PROTECT) { |
| vmaddr = segment & _SEGMENT_ENTRY_ORIGIN; |
| return vmaddr | (address & ~PMD_MASK); |
| } |
| return -EFAULT; |
| } |
| EXPORT_SYMBOL_GPL(__gmap_translate); |
| |
| /** |
| * gmap_translate - translate a guest address to a user space address |
| * @address: guest address |
| * @gmap: pointer to guest mapping meta data structure |
| * |
| * Returns user space address which corresponds to the guest address or |
| * -EFAULT if no such mapping exists. |
| * This function does not establish potentially missing page table entries. |
| */ |
| unsigned long gmap_translate(unsigned long address, struct gmap *gmap) |
| { |
| unsigned long rc; |
| |
| down_read(&gmap->mm->mmap_sem); |
| rc = __gmap_translate(address, gmap); |
| up_read(&gmap->mm->mmap_sem); |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(gmap_translate); |
| |
| static int gmap_connect_pgtable(unsigned long address, unsigned long segment, |
| unsigned long *segment_ptr, struct gmap *gmap) |
| { |
| unsigned long vmaddr; |
| struct vm_area_struct *vma; |
| struct gmap_pgtable *mp; |
| struct gmap_rmap *rmap; |
| struct mm_struct *mm; |
| struct page *page; |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| |
| mm = gmap->mm; |
| vmaddr = segment & _SEGMENT_ENTRY_ORIGIN; |
| vma = find_vma(mm, vmaddr); |
| if (!vma || vma->vm_start > vmaddr) |
| return -EFAULT; |
| /* Walk the parent mm page table */ |
| pgd = pgd_offset(mm, vmaddr); |
| pud = pud_alloc(mm, pgd, vmaddr); |
| if (!pud) |
| return -ENOMEM; |
| pmd = pmd_alloc(mm, pud, vmaddr); |
| if (!pmd) |
| return -ENOMEM; |
| if (!pmd_present(*pmd) && |
| __pte_alloc(mm, vma, pmd, vmaddr)) |
| return -ENOMEM; |
| /* pmd now points to a valid segment table entry. */ |
| rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT); |
| if (!rmap) |
| return -ENOMEM; |
| /* Link gmap segment table entry location to page table. */ |
| page = pmd_page(*pmd); |
| mp = (struct gmap_pgtable *) page->index; |
| rmap->gmap = gmap; |
| rmap->entry = segment_ptr; |
| rmap->vmaddr = address & PMD_MASK; |
| spin_lock(&mm->page_table_lock); |
| if (*segment_ptr == segment) { |
| list_add(&rmap->list, &mp->mapper); |
| /* Set gmap segment table entry to page table. */ |
| *segment_ptr = pmd_val(*pmd) & PAGE_MASK; |
| rmap = NULL; |
| } |
| spin_unlock(&mm->page_table_lock); |
| kfree(rmap); |
| return 0; |
| } |
| |
| static void gmap_disconnect_pgtable(struct mm_struct *mm, unsigned long *table) |
| { |
| struct gmap_rmap *rmap, *next; |
| struct gmap_pgtable *mp; |
| struct page *page; |
| int flush; |
| |
| flush = 0; |
| spin_lock(&mm->page_table_lock); |
| page = pfn_to_page(__pa(table) >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| list_for_each_entry_safe(rmap, next, &mp->mapper, list) { |
| *rmap->entry = mp->vmaddr | (_SEGMENT_ENTRY_INVALID | |
| _SEGMENT_ENTRY_PROTECT); |
| list_del(&rmap->list); |
| kfree(rmap); |
| flush = 1; |
| } |
| spin_unlock(&mm->page_table_lock); |
| if (flush) |
| __tlb_flush_global(); |
| } |
| |
| /* |
| * this function is assumed to be called with mmap_sem held |
| */ |
| unsigned long __gmap_fault(unsigned long address, struct gmap *gmap) |
| { |
| unsigned long *segment_ptr, segment; |
| struct gmap_pgtable *mp; |
| struct page *page; |
| int rc; |
| |
| current->thread.gmap_addr = address; |
| segment_ptr = gmap_table_walk(address, gmap); |
| if (IS_ERR(segment_ptr)) |
| return -EFAULT; |
| /* Convert the gmap address to an mm address. */ |
| while (1) { |
| segment = *segment_ptr; |
| if (!(segment & _SEGMENT_ENTRY_INVALID)) { |
| /* Page table is present */ |
| page = pfn_to_page(segment >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| return mp->vmaddr | (address & ~PMD_MASK); |
| } |
| if (!(segment & _SEGMENT_ENTRY_PROTECT)) |
| /* Nothing mapped in the gmap address space. */ |
| break; |
| rc = gmap_connect_pgtable(address, segment, segment_ptr, gmap); |
| if (rc) |
| return rc; |
| } |
| return -EFAULT; |
| } |
| |
| unsigned long gmap_fault(unsigned long address, struct gmap *gmap) |
| { |
| unsigned long rc; |
| |
| down_read(&gmap->mm->mmap_sem); |
| rc = __gmap_fault(address, gmap); |
| up_read(&gmap->mm->mmap_sem); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(gmap_fault); |
| |
| void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap) |
| { |
| |
| unsigned long *table, address, size; |
| struct vm_area_struct *vma; |
| struct gmap_pgtable *mp; |
| struct page *page; |
| |
| down_read(&gmap->mm->mmap_sem); |
| address = from; |
| while (address < to) { |
| /* Walk the gmap address space page table */ |
| table = gmap->table + ((address >> 53) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) { |
| address = (address + PMD_SIZE) & PMD_MASK; |
| continue; |
| } |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 42) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) { |
| address = (address + PMD_SIZE) & PMD_MASK; |
| continue; |
| } |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 31) & 0x7ff); |
| if (unlikely(*table & _REGION_ENTRY_INVALID)) { |
| address = (address + PMD_SIZE) & PMD_MASK; |
| continue; |
| } |
| table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| table = table + ((address >> 20) & 0x7ff); |
| if (unlikely(*table & _SEGMENT_ENTRY_INVALID)) { |
| address = (address + PMD_SIZE) & PMD_MASK; |
| continue; |
| } |
| page = pfn_to_page(*table >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| vma = find_vma(gmap->mm, mp->vmaddr); |
| size = min(to - address, PMD_SIZE - (address & ~PMD_MASK)); |
| zap_page_range(vma, mp->vmaddr | (address & ~PMD_MASK), |
| size, NULL); |
| address = (address + PMD_SIZE) & PMD_MASK; |
| } |
| up_read(&gmap->mm->mmap_sem); |
| } |
| EXPORT_SYMBOL_GPL(gmap_discard); |
| |
| static LIST_HEAD(gmap_notifier_list); |
| static DEFINE_SPINLOCK(gmap_notifier_lock); |
| |
| /** |
| * gmap_register_ipte_notifier - register a pte invalidation callback |
| * @nb: pointer to the gmap notifier block |
| */ |
| void gmap_register_ipte_notifier(struct gmap_notifier *nb) |
| { |
| spin_lock(&gmap_notifier_lock); |
| list_add(&nb->list, &gmap_notifier_list); |
| spin_unlock(&gmap_notifier_lock); |
| } |
| EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier); |
| |
| /** |
| * gmap_unregister_ipte_notifier - remove a pte invalidation callback |
| * @nb: pointer to the gmap notifier block |
| */ |
| void gmap_unregister_ipte_notifier(struct gmap_notifier *nb) |
| { |
| spin_lock(&gmap_notifier_lock); |
| list_del_init(&nb->list); |
| spin_unlock(&gmap_notifier_lock); |
| } |
| EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier); |
| |
| /** |
| * gmap_ipte_notify - mark a range of ptes for invalidation notification |
| * @gmap: pointer to guest mapping meta data structure |
| * @address: virtual address in the guest address space |
| * @len: size of area |
| * |
| * Returns 0 if for each page in the given range a gmap mapping exists and |
| * the invalidation notification could be set. If the gmap mapping is missing |
| * for one or more pages -EFAULT is returned. If no memory could be allocated |
| * -ENOMEM is returned. This function establishes missing page table entries. |
| */ |
| int gmap_ipte_notify(struct gmap *gmap, unsigned long start, unsigned long len) |
| { |
| unsigned long addr; |
| spinlock_t *ptl; |
| pte_t *ptep, entry; |
| pgste_t pgste; |
| int rc = 0; |
| |
| if ((start & ~PAGE_MASK) || (len & ~PAGE_MASK)) |
| return -EINVAL; |
| down_read(&gmap->mm->mmap_sem); |
| while (len) { |
| /* Convert gmap address and connect the page tables */ |
| addr = __gmap_fault(start, gmap); |
| if (IS_ERR_VALUE(addr)) { |
| rc = addr; |
| break; |
| } |
| /* Get the page mapped */ |
| if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE)) { |
| rc = -EFAULT; |
| break; |
| } |
| /* Walk the process page table, lock and get pte pointer */ |
| ptep = get_locked_pte(gmap->mm, addr, &ptl); |
| if (unlikely(!ptep)) |
| continue; |
| /* Set notification bit in the pgste of the pte */ |
| entry = *ptep; |
| if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) { |
| pgste = pgste_get_lock(ptep); |
| pgste_val(pgste) |= PGSTE_IN_BIT; |
| pgste_set_unlock(ptep, pgste); |
| start += PAGE_SIZE; |
| len -= PAGE_SIZE; |
| } |
| spin_unlock(ptl); |
| } |
| up_read(&gmap->mm->mmap_sem); |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(gmap_ipte_notify); |
| |
| /** |
| * gmap_do_ipte_notify - call all invalidation callbacks for a specific pte. |
| * @mm: pointer to the process mm_struct |
| * @addr: virtual address in the process address space |
| * @pte: pointer to the page table entry |
| * |
| * This function is assumed to be called with the page table lock held |
| * for the pte to notify. |
| */ |
| void gmap_do_ipte_notify(struct mm_struct *mm, unsigned long addr, pte_t *pte) |
| { |
| unsigned long segment_offset; |
| struct gmap_notifier *nb; |
| struct gmap_pgtable *mp; |
| struct gmap_rmap *rmap; |
| struct page *page; |
| |
| segment_offset = ((unsigned long) pte) & (255 * sizeof(pte_t)); |
| segment_offset = segment_offset * (4096 / sizeof(pte_t)); |
| page = pfn_to_page(__pa(pte) >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| spin_lock(&gmap_notifier_lock); |
| list_for_each_entry(rmap, &mp->mapper, list) { |
| list_for_each_entry(nb, &gmap_notifier_list, list) |
| nb->notifier_call(rmap->gmap, |
| rmap->vmaddr + segment_offset); |
| } |
| spin_unlock(&gmap_notifier_lock); |
| } |
| |
| static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, |
| unsigned long vmaddr) |
| { |
| struct page *page; |
| unsigned long *table; |
| struct gmap_pgtable *mp; |
| |
| page = alloc_page(GFP_KERNEL|__GFP_REPEAT); |
| if (!page) |
| return NULL; |
| mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT); |
| if (!mp) { |
| __free_page(page); |
| return NULL; |
| } |
| pgtable_page_ctor(page); |
| mp->vmaddr = vmaddr & PMD_MASK; |
| INIT_LIST_HEAD(&mp->mapper); |
| page->index = (unsigned long) mp; |
| atomic_set(&page->_mapcount, 3); |
| table = (unsigned long *) page_to_phys(page); |
| clear_table(table, _PAGE_INVALID, PAGE_SIZE/2); |
| clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2); |
| return table; |
| } |
| |
| static inline void page_table_free_pgste(unsigned long *table) |
| { |
| struct page *page; |
| struct gmap_pgtable *mp; |
| |
| page = pfn_to_page(__pa(table) >> PAGE_SHIFT); |
| mp = (struct gmap_pgtable *) page->index; |
| BUG_ON(!list_empty(&mp->mapper)); |
| pgtable_page_dtor(page); |
| atomic_set(&page->_mapcount, -1); |
| kfree(mp); |
| __free_page(page); |
| } |
| |
| int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, |
| unsigned long key, bool nq) |
| { |
| spinlock_t *ptl; |
| pgste_t old, new; |
| pte_t *ptep; |
| |
| down_read(&mm->mmap_sem); |
| ptep = get_locked_pte(current->mm, addr, &ptl); |
| if (unlikely(!ptep)) { |
| up_read(&mm->mmap_sem); |
| return -EFAULT; |
| } |
| |
| new = old = pgste_get_lock(ptep); |
| pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | |
| PGSTE_ACC_BITS | PGSTE_FP_BIT); |
| pgste_val(new) |= (key & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48; |
| pgste_val(new) |= (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; |
| if (!(pte_val(*ptep) & _PAGE_INVALID)) { |
| unsigned long address, bits; |
| unsigned char skey; |
| |
| address = pte_val(*ptep) & PAGE_MASK; |
| skey = page_get_storage_key(address); |
| bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); |
| /* Set storage key ACC and FP */ |
| page_set_storage_key(address, |
| (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)), |
| !nq); |
| |
| /* Merge host changed & referenced into pgste */ |
| pgste_val(new) |= bits << 52; |
| /* Transfer skey changed & referenced bit to kvm user bits */ |
| pgste_val(new) |= bits << 45; /* PGSTE_UR_BIT & PGSTE_UC_BIT */ |
| } |
| /* changing the guest storage key is considered a change of the page */ |
| if ((pgste_val(new) ^ pgste_val(old)) & |
| (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT)) |
| pgste_val(new) |= PGSTE_UC_BIT; |
| |
| pgste_set_unlock(ptep, new); |
| pte_unmap_unlock(*ptep, ptl); |
| up_read(&mm->mmap_sem); |
| return 0; |
| } |
| EXPORT_SYMBOL(set_guest_storage_key); |
| |
| #else /* CONFIG_PGSTE */ |
| |
| static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, |
| unsigned long vmaddr) |
| { |
| return NULL; |
| } |
| |
| static inline void page_table_free_pgste(unsigned long *table) |
| { |
| } |
| |
| static inline void gmap_disconnect_pgtable(struct mm_struct *mm, |
| unsigned long *table) |
| { |
| } |
| |
| #endif /* CONFIG_PGSTE */ |
| |
| static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits) |
| { |
| unsigned int old, new; |
| |
| do { |
| old = atomic_read(v); |
| new = old ^ bits; |
| } while (atomic_cmpxchg(v, old, new) != old); |
| return new; |
| } |
| |
| /* |
| * page table entry allocation/free routines. |
| */ |
| unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr) |
| { |
| unsigned long *uninitialized_var(table); |
| struct page *uninitialized_var(page); |
| unsigned int mask, bit; |
| |
| if (mm_has_pgste(mm)) |
| return page_table_alloc_pgste(mm, vmaddr); |
| /* Allocate fragments of a 4K page as 1K/2K page table */ |
| spin_lock_bh(&mm->context.list_lock); |
| mask = FRAG_MASK; |
| if (!list_empty(&mm->context.pgtable_list)) { |
| page = list_first_entry(&mm->context.pgtable_list, |
| struct page, lru); |
| table = (unsigned long *) page_to_phys(page); |
| mask = atomic_read(&page->_mapcount); |
| mask = mask | (mask >> 4); |
| } |
| if ((mask & FRAG_MASK) == FRAG_MASK) { |
| spin_unlock_bh(&mm->context.list_lock); |
| page = alloc_page(GFP_KERNEL|__GFP_REPEAT); |
| if (!page) |
| return NULL; |
| pgtable_page_ctor(page); |
| atomic_set(&page->_mapcount, 1); |
| table = (unsigned long *) page_to_phys(page); |
| clear_table(table, _PAGE_INVALID, PAGE_SIZE); |
| spin_lock_bh(&mm->context.list_lock); |
| list_add(&page->lru, &mm->context.pgtable_list); |
| } else { |
| for (bit = 1; mask & bit; bit <<= 1) |
| table += PTRS_PER_PTE; |
| mask = atomic_xor_bits(&page->_mapcount, bit); |
| if ((mask & FRAG_MASK) == FRAG_MASK) |
| list_del(&page->lru); |
| } |
| spin_unlock_bh(&mm->context.list_lock); |
| return table; |
| } |
| |
| void page_table_free(struct mm_struct *mm, unsigned long *table) |
| { |
| struct page *page; |
| unsigned int bit, mask; |
| |
| if (mm_has_pgste(mm)) { |
| gmap_disconnect_pgtable(mm, table); |
| return page_table_free_pgste(table); |
| } |
| /* Free 1K/2K page table fragment of a 4K page */ |
| page = pfn_to_page(__pa(table) >> PAGE_SHIFT); |
| bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t))); |
| spin_lock_bh(&mm->context.list_lock); |
| if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK) |
| list_del(&page->lru); |
| mask = atomic_xor_bits(&page->_mapcount, bit); |
| if (mask & FRAG_MASK) |
| list_add(&page->lru, &mm->context.pgtable_list); |
| spin_unlock_bh(&mm->context.list_lock); |
| if (mask == 0) { |
| pgtable_page_dtor(page); |
| atomic_set(&page->_mapcount, -1); |
| __free_page(page); |
| } |
| } |
| |
| static void __page_table_free_rcu(void *table, unsigned bit) |
| { |
| struct page *page; |
| |
| if (bit == FRAG_MASK) |
| return page_table_free_pgste(table); |
| /* Free 1K/2K page table fragment of a 4K page */ |
| page = pfn_to_page(__pa(table) >> PAGE_SHIFT); |
| if (atomic_xor_bits(&page->_mapcount, bit) == 0) { |
| pgtable_page_dtor(page); |
| atomic_set(&page->_mapcount, -1); |
| __free_page(page); |
| } |
| } |
| |
| void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table) |
| { |
| struct mm_struct *mm; |
| struct page *page; |
| unsigned int bit, mask; |
| |
| mm = tlb->mm; |
| if (mm_has_pgste(mm)) { |
| gmap_disconnect_pgtable(mm, table); |
| table = (unsigned long *) (__pa(table) | FRAG_MASK); |
| tlb_remove_table(tlb, table); |
| return; |
| } |
| bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t))); |
| page = pfn_to_page(__pa(table) >> PAGE_SHIFT); |
| spin_lock_bh(&mm->context.list_lock); |
| if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK) |
| list_del(&page->lru); |
| mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4)); |
| if (mask & FRAG_MASK) |
| list_add_tail(&page->lru, &mm->context.pgtable_list); |
| spin_unlock_bh(&mm->context.list_lock); |
| table = (unsigned long *) (__pa(table) | (bit << 4)); |
| tlb_remove_table(tlb, table); |
| } |
| |
| void __tlb_remove_table(void *_table) |
| { |
| const unsigned long mask = (FRAG_MASK << 4) | FRAG_MASK; |
| void *table = (void *)((unsigned long) _table & ~mask); |
| unsigned type = (unsigned long) _table & mask; |
| |
| if (type) |
| __page_table_free_rcu(table, type); |
| else |
| free_pages((unsigned long) table, ALLOC_ORDER); |
| } |
| |
| static void tlb_remove_table_smp_sync(void *arg) |
| { |
| /* Simply deliver the interrupt */ |
| } |
| |
| static void tlb_remove_table_one(void *table) |
| { |
| /* |
| * This isn't an RCU grace period and hence the page-tables cannot be |
| * assumed to be actually RCU-freed. |
| * |
| * It is however sufficient for software page-table walkers that rely |
| * on IRQ disabling. See the comment near struct mmu_table_batch. |
| */ |
| smp_call_function(tlb_remove_table_smp_sync, NULL, 1); |
| __tlb_remove_table(table); |
| } |
| |
| static void tlb_remove_table_rcu(struct rcu_head *head) |
| { |
| struct mmu_table_batch *batch; |
| int i; |
| |
| batch = container_of(head, struct mmu_table_batch, rcu); |
| |
| for (i = 0; i < batch->nr; i++) |
| __tlb_remove_table(batch->tables[i]); |
| |
| free_page((unsigned long)batch); |
| } |
| |
| void tlb_table_flush(struct mmu_gather *tlb) |
| { |
| struct mmu_table_batch **batch = &tlb->batch; |
| |
| if (*batch) { |
| __tlb_flush_mm(tlb->mm); |
| call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); |
| *batch = NULL; |
| } |
| } |
| |
| void tlb_remove_table(struct mmu_gather *tlb, void *table) |
| { |
| struct mmu_table_batch **batch = &tlb->batch; |
| |
| if (*batch == NULL) { |
| *batch = (struct mmu_table_batch *) |
| __get_free_page(GFP_NOWAIT | __GFP_NOWARN); |
| if (*batch == NULL) { |
| __tlb_flush_mm(tlb->mm); |
| tlb_remove_table_one(table); |
| return; |
| } |
| (*batch)->nr = 0; |
| } |
| (*batch)->tables[(*batch)->nr++] = table; |
| if ((*batch)->nr == MAX_TABLE_BATCH) |
| tlb_table_flush(tlb); |
| } |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| void thp_split_vma(struct vm_area_struct *vma) |
| { |
| unsigned long addr; |
| struct page *page; |
| |
| for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) { |
| page = follow_page(vma, addr, FOLL_SPLIT); |
| } |
| } |
| |
| void thp_split_mm(struct mm_struct *mm) |
| { |
| struct vm_area_struct *vma = mm->mmap; |
| |
| while (vma != NULL) { |
| thp_split_vma(vma); |
| vma->vm_flags &= ~VM_HUGEPAGE; |
| vma->vm_flags |= VM_NOHUGEPAGE; |
| vma = vma->vm_next; |
| } |
| } |
| #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
| |
| /* |
| * switch on pgstes for its userspace process (for kvm) |
| */ |
| int s390_enable_sie(void) |
| { |
| struct task_struct *tsk = current; |
| struct mm_struct *mm, *old_mm; |
| |
| /* Do we have switched amode? If no, we cannot do sie */ |
| if (s390_user_mode == HOME_SPACE_MODE) |
| return -EINVAL; |
| |
| /* Do we have pgstes? if yes, we are done */ |
| if (mm_has_pgste(tsk->mm)) |
| return 0; |
| |
| /* lets check if we are allowed to replace the mm */ |
| task_lock(tsk); |
| if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 || |
| #ifdef CONFIG_AIO |
| !hlist_empty(&tsk->mm->ioctx_list) || |
| #endif |
| tsk->mm != tsk->active_mm) { |
| task_unlock(tsk); |
| return -EINVAL; |
| } |
| task_unlock(tsk); |
| |
| /* we copy the mm and let dup_mm create the page tables with_pgstes */ |
| tsk->mm->context.alloc_pgste = 1; |
| /* make sure that both mms have a correct rss state */ |
| sync_mm_rss(tsk->mm); |
| mm = dup_mm(tsk); |
| tsk->mm->context.alloc_pgste = 0; |
| if (!mm) |
| return -ENOMEM; |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| /* split thp mappings and disable thp for future mappings */ |
| thp_split_mm(mm); |
| mm->def_flags |= VM_NOHUGEPAGE; |
| #endif |
| |
| /* Now lets check again if something happened */ |
| task_lock(tsk); |
| if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 || |
| #ifdef CONFIG_AIO |
| !hlist_empty(&tsk->mm->ioctx_list) || |
| #endif |
| tsk->mm != tsk->active_mm) { |
| mmput(mm); |
| task_unlock(tsk); |
| return -EINVAL; |
| } |
| |
| /* ok, we are alone. No ptrace, no threads, etc. */ |
| old_mm = tsk->mm; |
| tsk->mm = tsk->active_mm = mm; |
| preempt_disable(); |
| update_mm(mm, tsk); |
| atomic_inc(&mm->context.attach_count); |
| atomic_dec(&old_mm->context.attach_count); |
| cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); |
| preempt_enable(); |
| task_unlock(tsk); |
| mmput(old_mm); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(s390_enable_sie); |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| int pmdp_clear_flush_young(struct vm_area_struct *vma, unsigned long address, |
| pmd_t *pmdp) |
| { |
| VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
| /* No need to flush TLB |
| * On s390 reference bits are in storage key and never in TLB */ |
| return pmdp_test_and_clear_young(vma, address, pmdp); |
| } |
| |
| int pmdp_set_access_flags(struct vm_area_struct *vma, |
| unsigned long address, pmd_t *pmdp, |
| pmd_t entry, int dirty) |
| { |
| VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
| |
| if (pmd_same(*pmdp, entry)) |
| return 0; |
| pmdp_invalidate(vma, address, pmdp); |
| set_pmd_at(vma->vm_mm, address, pmdp, entry); |
| return 1; |
| } |
| |
| static void pmdp_splitting_flush_sync(void *arg) |
| { |
| /* Simply deliver the interrupt */ |
| } |
| |
| void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, |
| pmd_t *pmdp) |
| { |
| VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
| if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT, |
| (unsigned long *) pmdp)) { |
| /* need to serialize against gup-fast (IRQ disabled) */ |
| smp_call_function(pmdp_splitting_flush_sync, NULL, 1); |
| } |
| } |
| |
| void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, |
| pgtable_t pgtable) |
| { |
| struct list_head *lh = (struct list_head *) pgtable; |
| |
| assert_spin_locked(&mm->page_table_lock); |
| |
| /* FIFO */ |
| if (!mm->pmd_huge_pte) |
| INIT_LIST_HEAD(lh); |
| else |
| list_add(lh, (struct list_head *) mm->pmd_huge_pte); |
| mm->pmd_huge_pte = pgtable; |
| } |
| |
| pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) |
| { |
| struct list_head *lh; |
| pgtable_t pgtable; |
| pte_t *ptep; |
| |
| assert_spin_locked(&mm->page_table_lock); |
| |
| /* FIFO */ |
| pgtable = mm->pmd_huge_pte; |
| lh = (struct list_head *) pgtable; |
| if (list_empty(lh)) |
| mm->pmd_huge_pte = NULL; |
| else { |
| mm->pmd_huge_pte = (pgtable_t) lh->next; |
| list_del(lh); |
| } |
| ptep = (pte_t *) pgtable; |
| pte_val(*ptep) = _PAGE_INVALID; |
| ptep++; |
| pte_val(*ptep) = _PAGE_INVALID; |
| return pgtable; |
| } |
| #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |