This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / xen / xenbus / xenbus_backend_client.c

diff --git a/drivers/xen/xenbus/xenbus_backend_client.c b/drivers/xen/xenbus/xenbus_backend_client.c
new file mode 100644 (file)
index 0000000..b99991c
--- /dev/null
+++ b/drivers/xen/xenbus/xenbus_backend_client.c
@@ -0,0 +1,135 @@
+/******************************************************************************
+ * Backend-client-facing interface for the Xenbus driver.  In other words, the
+ * interface between the Xenbus and the device-specific code in the backend
+ * driver.
+ *
+ * Copyright (C) 2005-2006 XenSource Ltd
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <linux/err.h>
+#include <xen/gnttab.h>
+#include <xen/xenbus.h>
+#include <xen/driver_util.h>
+
+/* Based on Rusty Russell's skeleton driver's map_page */
+struct vm_struct *xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref)
+{
+       struct gnttab_map_grant_ref op;
+       struct vm_struct *area;
+
+       area = alloc_vm_area(PAGE_SIZE);
+       if (!area)
+               return ERR_PTR(-ENOMEM);
+
+       gnttab_set_map_op(&op, (unsigned long)area->addr, GNTMAP_host_map,
+                         gnt_ref, dev->otherend_id);
+       
+       lock_vm_area(area);
+       BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1));
+       unlock_vm_area(area);
+
+       if (op.status != GNTST_okay) {
+               free_vm_area(area);
+               xenbus_dev_fatal(dev, op.status,
+                                "mapping in shared page %d from domain %d",
+                                gnt_ref, dev->otherend_id);
+               BUG_ON(!IS_ERR(ERR_PTR(op.status)));
+               return ERR_PTR(op.status);
+       }
+
+       /* Stuff the handle in an unused field */
+       area->phys_addr = (unsigned long)op.handle;
+
+       return area;
+}
+EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
+
+
+int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
+                  grant_handle_t *handle, void *vaddr)
+{
+       struct gnttab_map_grant_ref op;
+       
+       gnttab_set_map_op(&op, (unsigned long)vaddr, GNTMAP_host_map,
+                         gnt_ref, dev->otherend_id);
+       BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1));
+
+       if (op.status != GNTST_okay) {
+               xenbus_dev_fatal(dev, op.status,
+                                "mapping in shared page %d from domain %d",
+                                gnt_ref, dev->otherend_id);
+       } else
+               *handle = op.handle;
+
+       return op.status;
+}
+EXPORT_SYMBOL_GPL(xenbus_map_ring);
+
+
+/* Based on Rusty Russell's skeleton driver's unmap_page */
+int xenbus_unmap_ring_vfree(struct xenbus_device *dev, struct vm_struct *area)
+{
+       struct gnttab_unmap_grant_ref op;
+
+       gnttab_set_unmap_op(&op, (unsigned long)area->addr, GNTMAP_host_map,
+                           (grant_handle_t)area->phys_addr);
+
+       lock_vm_area(area);
+       BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1));
+       unlock_vm_area(area);
+
+       if (op.status == GNTST_okay)
+               free_vm_area(area);
+       else
+               xenbus_dev_error(dev, op.status,
+                                "unmapping page at handle %d error %d",
+                                (int16_t)area->phys_addr, op.status);
+
+       return op.status;
+}
+EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
+
+
+int xenbus_unmap_ring(struct xenbus_device *dev,
+                    grant_handle_t handle, void *vaddr)
+{
+       struct gnttab_unmap_grant_ref op;
+
+       gnttab_set_unmap_op(&op, (unsigned long)vaddr, GNTMAP_host_map,
+                           handle);
+       BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1));
+
+       if (op.status != GNTST_okay)
+               xenbus_dev_error(dev, op.status,
+                                "unmapping page at handle %d error %d",
+                                handle, op.status);
+
+       return op.status;
+}
+EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
+
+MODULE_LICENSE("Dual BSD/GPL");