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-rw-r--r--arch/s390/mm/pgtable.c235
1 files changed, 160 insertions, 75 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index ae44d2a3431..bd954e96f51 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -379,75 +379,183 @@ out_unmap:
}
EXPORT_SYMBOL_GPL(gmap_map_segment);
-/*
- * this function is assumed to be called with mmap_sem held
- */
-unsigned long __gmap_fault(unsigned long address, struct gmap *gmap)
+static unsigned long *gmap_table_walk(unsigned long address, struct gmap *gmap)
{
- unsigned long *table, vmaddr, segment;
- struct mm_struct *mm;
- struct gmap_pgtable *mp;
- struct gmap_rmap *rmap;
- struct vm_area_struct *vma;
- struct page *page;
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
+ unsigned long *table;
- 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;
+ return ERR_PTR(-EFAULT);
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
table = table + ((address >> 42) & 0x7ff);
if (unlikely(*table & _REGION_ENTRY_INV))
- return -EFAULT;
+ return ERR_PTR(-EFAULT);
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
table = table + ((address >> 31) & 0x7ff);
if (unlikely(*table & _REGION_ENTRY_INV))
- return -EFAULT;
+ 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 = *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) {
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->entry = table;
- spin_lock(&mm->page_table_lock);
+ 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 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->entry = segment_ptr;
+ spin_lock(&mm->page_table_lock);
+ if (*segment_ptr == segment) {
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;
- return vmaddr | (address & ~PMD_MASK);
+ *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 =
+ _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
+ 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_INV)) {
+ /* 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_RO))
+ /* Nothing mapped in the gmap address space. */
+ break;
+ rc = gmap_connect_pgtable(segment, segment_ptr, gmap);
+ if (rc)
+ return rc;
}
return -EFAULT;
}
@@ -511,29 +619,6 @@ void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap)
}
EXPORT_SYMBOL_GPL(gmap_discard);
-void gmap_unmap_notifier(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 =
- _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
- list_del(&rmap->list);
- kfree(rmap);
- flush = 1;
- }
- spin_unlock(&mm->page_table_lock);
- if (flush)
- __tlb_flush_global();
-}
-
static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
unsigned long vmaddr)
{
@@ -586,8 +671,8 @@ static inline void page_table_free_pgste(unsigned long *table)
{
}
-static inline void gmap_unmap_notifier(struct mm_struct *mm,
- unsigned long *table)
+static inline void gmap_disconnect_pgtable(struct mm_struct *mm,
+ unsigned long *table)
{
}
@@ -653,7 +738,7 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
unsigned int bit, mask;
if (mm_has_pgste(mm)) {
- gmap_unmap_notifier(mm, table);
+ gmap_disconnect_pgtable(mm, table);
return page_table_free_pgste(table);
}
/* Free 1K/2K page table fragment of a 4K page */
@@ -696,7 +781,7 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
mm = tlb->mm;
if (mm_has_pgste(mm)) {
- gmap_unmap_notifier(mm, table);
+ gmap_disconnect_pgtable(mm, table);
table = (unsigned long *) (__pa(table) | FRAG_MASK);
tlb_remove_table(tlb, table);
return;