Changes in kernel/arch/ia32/src/ddi/ddi.c [6eeb4a3:c5396c1] in mainline

File:

• kernel/arch/ia32/src/ddi/ddi.c (modified) (1 diff)

kernel/arch/ia32/src/ddi/ddi.c

@@ -45 +45 @@
 #include <arch.h>
 #include <align.h>
+
+/** Enable I/O space range for task.
+ *
+ * Interrupts are disabled and task is locked.
+ *
+ * @param task   Task.
+ * @param ioaddr Startign I/O space address.
+ * @param size   Size of the enabled I/O range.
+ *
+ * @return 0 on success or an error code from errno.h.
+ *
+ */
+int ddi_iospace_enable_arch(task_t *task, uintptr_t ioaddr, size_t size)
+{
+        size_t elements = ioaddr + size;
+        if (elements > IO_PORTS)
+                return ENOENT;
+        
+        if (task->arch.iomap.elements < elements) {
+                /*
+                 * The I/O permission bitmap is too small and needs to be grown.
+                 */
+                
+                void *store = malloc(bitmap_size(elements), FRAME_ATOMIC);
+                if (!store)
+                        return ENOMEM;
+                
+                bitmap_t oldiomap;
+                bitmap_initialize(&oldiomap, task->arch.iomap.elements,
+                    task->arch.iomap.bits);
+                
+                bitmap_initialize(&task->arch.iomap, elements, store);
+                
+                /*
+                 * Mark the new range inaccessible.
+                 */
+                bitmap_set_range(&task->arch.iomap, oldiomap.elements,
+                    elements - oldiomap.elements);
+                
+                /*
+                 * In case there really existed smaller iomap,
+                 * copy its contents and deallocate it.
+                 */
+                if (oldiomap.bits) {
+                        bitmap_copy(&task->arch.iomap, &oldiomap,
+                            oldiomap.elements);
+                        
+                        free(oldiomap.bits);
+                }
+        }
+        
+        /*
+         * Enable the range and we are done.
+         */
+        bitmap_clear_range(&task->arch.iomap, (size_t) ioaddr, size);
+        
+        /*
+         * Increment I/O Permission bitmap generation counter.
+         */
+        task->arch.iomapver++;
+        
+        return 0;
+}
 
 /** Install I/O Permission bitmap.