WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/as.c

  * @param as Address space.
  * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
  * @param size New size of the virtual memory block starting at address.
  * @param flags Flags influencing the remap operation. Currently unused.
+ *
- * @return address on success, (__address) -1 otherwise.
+ * @return Zero on success or a value from @ref errno.h otherwise.
  */
-__address as_area_resize(as_t *as, __address address, size_t size, int flags)
+int as_area_resize(as_t *as, __address address, size_t size, int flags)
+{
-    as_area_t *area = NULL;
+    as_area_t *area;
     ipl_t ipl;
     size_t pages;
     ipl = interrupts_disable();
     spinlock_lock(&as->lock);
      */
     area = find_area_and_lock(as, address);
     if (!area) {
         spinlock_unlock(&as->lock);
         interrupts_restore(ipl);
-        return (__address) -1;
+        return ENOENT;
+    }
     if (area->flags & AS_AREA_DEVICE) {
         /*
          * Remapping of address space areas associated
          * with memory mapped devices is not supported.
          */
         spinlock_unlock(&area->lock);
         spinlock_unlock(&as->lock);
         interrupts_restore(ipl);
-        return (__address) -1;
+        return ENOTSUP;
+    }
     pages = SIZE2FRAMES((address - area->base) + size);
     if (!pages) {
         /*
          * Zero size address space areas are not allowed.
          */
         spinlock_unlock(&area->lock);
         spinlock_unlock(&as->lock);
         interrupts_restore(ipl);
-        return (__address) -1;
+        return EPERM;
+    }
     if (pages < area->pages) {
         int i;
          */
         if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
             spinlock_unlock(&area->lock);
             spinlock_unlock(&as->lock);
             interrupts_restore(ipl);
-            return (__address) -1;
+            return EADDRNOTAVAIL;
+        }
+    }
     area->pages = pages;
     spinlock_unlock(&area->lock);
     spinlock_unlock(&as->lock);
     interrupts_restore(ipl);
+    return 0;
+}
+/** Destroy address space area.
+ *
+ * @param as Address space.
+ * @param address Address withing the area to be deleted.
+ *
+ * @return Zero on success or a value from @ref errno.h on failure.
+ */
+int as_area_destroy(as_t *as, __address address)
+{
+    as_area_t *area;
+    __address base;
+    ipl_t ipl;
+    int i;
+    ipl = interrupts_disable();
+    spinlock_lock(&as->lock);
+    area = find_area_and_lock(as, address);
+    if (!area) {
+        spinlock_unlock(&as->lock);
+        interrupts_restore(ipl);
-    return address;
+        return ENOENT;
+    }
+    base = area->base;
+    for (i = 0; i < area->pages; i++) {
+        pte_t *pte;
+        /*
+         * Releasing physical memory.
+         * Areas mapping memory-mapped devices are treated differently than
+         * areas backing frame_alloc()'ed memory.
+         */
+        page_table_lock(as, false);
+        pte = page_mapping_find(as, area->base + i*PAGE_SIZE);
+        if (pte && PTE_VALID(pte)) {
+            ASSERT(PTE_PRESENT(pte));
+            page_mapping_remove(as, area->base + i*PAGE_SIZE);
+            if (area->flags & AS_AREA_DEVICE) {
+                __address frame;
+                frame = PTE_GET_FRAME(pte);
+                frame_free(ADDR2PFN(frame));
+            }
+            page_table_unlock(as, false);
+        } else {
+            page_table_unlock(as, false);
+        }
+    }
+    /*
+     * Invalidate TLB's.
+     */
+    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
+    tlb_invalidate_pages(AS->asid, area->base, area->pages);
+    tlb_shootdown_finalize();
+    spinlock_unlock(&area->lock);
+    /*
+     * Remove the empty area from address space.
+     */
+    btree_remove(&AS->as_area_btree, base, NULL);
+    spinlock_unlock(&AS->lock);
+    interrupts_restore(ipl);
+    return 0;
+}
 /** Send address space area to another task.
+ *
  * Address space area is sent to the specified task.
  * space area and any associated mapping is preserved.
+ *
  * @param dst_id Task ID of the accepting task.
  * @param src_base Base address of the source address space area.
+ *
- * @return 0 on success or ENOENT if there is no such task or
+ * @return Zero on success or ENOENT if there is no such task or
  *     if there is no such address space area,
  *     EPERM if there was a problem in accepting the area or
  *     ENOMEM if there was a problem in allocating destination
  *     address space area.
  */
+}
 /** Wrapper for as_area_resize. */
 __native sys_as_area_resize(__address address, size_t size, int flags)
+{
-    return as_area_resize(AS, address, size, 0);
+    return (__native) as_area_resize(AS, address, size, 0);
+}
+/** Wrapper for as_area_destroy. */
+__native sys_as_area_destroy(__address address)
+{
+    return (__native) as_area_destroy(AS, address);
+}
 /** Prepare task for accepting address space area from another task.
+ *
  * @param uspace_accept_arg Accept structure passed from userspace.

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/mm/as.c – Rev 1288 → 1306