diff options
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 2 | ||||
| -rw-r--r-- | arch/s390/mm/pgtable.c | 107 |
2 files changed, 87 insertions, 22 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 4a2930844d43..75b8750a16ff 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -759,6 +759,8 @@ void gmap_disable(struct gmap *gmap); int gmap_map_segment(struct gmap *gmap, unsigned long from, unsigned long to, unsigned long length); int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len); +unsigned long __gmap_translate(unsigned long address, struct gmap *); +unsigned long gmap_translate(unsigned long address, struct gmap *); unsigned long __gmap_fault(unsigned long address, struct gmap *); unsigned long gmap_fault(unsigned long address, struct gmap *); void gmap_discard(unsigned long from, unsigned long to, struct gmap *); diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index ae44d2a34313..2accf7113d13 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -379,45 +379,108 @@ out_unmap: } 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_INV)) + return ERR_PTR(-EFAULT); + table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); + table = table + ((address >> 42) & 0x7ff); + if (unlikely(*table & _REGION_ENTRY_INV)) + return ERR_PTR(-EFAULT); + table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); + table = table + ((address >> 31) & 0x7ff); + if (unlikely(*table & _REGION_ENTRY_INV)) + 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_INV)) { + page = pfn_to_page(segment >> PAGE_SHIFT); + mp = (struct gmap_pgtable *) page->index; + return mp->vmaddr | (address & ~PMD_MASK); + } else if (segment & _SEGMENT_ENTRY_RO) { + 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); + /* * this function is assumed to be called with mmap_sem held */ unsigned long __gmap_fault(unsigned long address, struct gmap *gmap) { - unsigned long *table, vmaddr, segment; - struct mm_struct *mm; + unsigned long *segment_ptr, vmaddr, segment; + struct vm_area_struct *vma; struct gmap_pgtable *mp; struct gmap_rmap *rmap; - struct vm_area_struct *vma; + struct mm_struct *mm; struct page *page; pgd_t *pgd; pud_t *pud; pmd_t *pmd; current->thread.gmap_addr = address; - mm = gmap->mm; - /* Walk the gmap address space page table */ - table = gmap->table + ((address >> 53) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INV)) - return -EFAULT; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - table = table + ((address >> 42) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INV)) + segment_ptr = gmap_table_walk(address, gmap); + if (IS_ERR(segment_ptr)) return -EFAULT; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - table = table + ((address >> 31) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INV)) - return -EFAULT; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - table = table + ((address >> 20) & 0x7ff); - /* Convert the gmap address to an mm address. */ - segment = *table; - if (likely(!(segment & _SEGMENT_ENTRY_INV))) { + segment = *segment_ptr; + if (!(segment & _SEGMENT_ENTRY_INV)) { page = pfn_to_page(segment >> PAGE_SHIFT); mp = (struct gmap_pgtable *) page->index; return mp->vmaddr | (address & ~PMD_MASK); } else if (segment & _SEGMENT_ENTRY_RO) { + mm = gmap->mm; vmaddr = segment & _SEGMENT_ENTRY_ORIGIN; vma = find_vma(mm, vmaddr); if (!vma || vma->vm_start > vmaddr) @@ -441,12 +504,12 @@ unsigned long __gmap_fault(unsigned long address, struct gmap *gmap) /* Link gmap segment table entry location to page table. */ page = pmd_page(*pmd); mp = (struct gmap_pgtable *) page->index; - rmap->entry = table; + rmap->entry = segment_ptr; spin_lock(&mm->page_table_lock); list_add(&rmap->list, &mp->mapper); spin_unlock(&mm->page_table_lock); /* Set gmap segment table entry to page table. */ - *table = pmd_val(*pmd) & PAGE_MASK; + *segment_ptr = pmd_val(*pmd) & PAGE_MASK; return vmaddr | (address & ~PMD_MASK); } return -EFAULT; |