1 files changed, 77 insertions, 6 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 5d56c2b95b14..301c84d3b542 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1,5 +1,5 @@
 /*
- *    Copyright IBM Corp. 2007,2009
+ *    Copyright IBM Corp. 2007,2011
  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
@@ -222,6 +222,7 @@ void gmap_free(struct gmap *gmap)
 
         /* 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)
@@ -230,6 +231,7 @@ void gmap_free(struct gmap *gmap)
                                 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);
@@ -256,6 +258,9 @@ void gmap_disable(struct gmap *gmap)
 }
 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)
 {
@@ -267,14 +272,12 @@ static int gmap_alloc_table(struct gmap *gmap,
                 return -ENOMEM;
         new = (unsigned long *) page_to_phys(page);
         crst_table_init(new, init);
-        down_read(&gmap->mm->mmap_sem);
         if (*table & _REGION_ENTRY_INV) {
                 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);
-        up_read(&gmap->mm->mmap_sem);
         return 0;
 }
 
@@ -299,6 +302,7 @@ int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
 
         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);
@@ -320,6 +324,7 @@ int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
                 *table = _SEGMENT_ENTRY_INV;
         }
 out:
+        spin_unlock(&gmap->mm->page_table_lock);
         up_read(&gmap->mm->mmap_sem);
         if (flush)
                 gmap_flush_tlb(gmap);
@@ -350,6 +355,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 
         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);
@@ -373,19 +379,24 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
                 flush |= gmap_unlink_segment(gmap, table);
                 *table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
         }
+        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);
 
-unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
+/*
+ * 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;
@@ -445,16 +456,75 @@ unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
                 page = pmd_page(*pmd);
                 mp = (struct gmap_pgtable *) page->index;
                 rmap->entry = table;
+                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;
                 return vmaddr | (address & ~PMD_MASK);
         }
         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_INV)) {
+                        address = (address + PMD_SIZE) & PMD_MASK;
+                        continue;
+                }
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+                table = table + ((address >> 42) & 0x7ff);
+                if (unlikely(*table & _REGION_ENTRY_INV)) {
+                        address = (address + PMD_SIZE) & PMD_MASK;
+                        continue;
+                }
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+                table = table + ((address >> 31) & 0x7ff);
+                if (unlikely(*table & _REGION_ENTRY_INV)) {
+                        address = (address + PMD_SIZE) & PMD_MASK;
+                        continue;
+                }
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+                table = table + ((address >> 20) & 0x7ff);
+                if (unlikely(*table & _SEGMENT_ENTRY_INV)) {
+                        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);
+
 void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
 {
         struct gmap_rmap *rmap, *next;
@@ -662,8 +732,9 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
 
 void __tlb_remove_table(void *_table)
 {
-        void *table = (void *)((unsigned long) _table & PAGE_MASK);
-        unsigned type = (unsigned long) _table & ~PAGE_MASK;
+        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);