xen: import arch generic part of xencomm

On xen/ia64 and xen/powerpc hypercall arguments are passed by pseudo
physical address (guest physical address) so that it's necessary to
convert from virtual address into pseudo physical address. The frame
work is called xencomm.
Import arch generic part of xencomm.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 77 insertions, 0 deletions

diff --git a/include/xen/xencomm.h b/include/xen/xencomm.h
new file mode 100644
index 000000000000..e43b039be112
--- /dev/null
+++ b/include/xen/xencomm.h
@@ -0,0 +1,77 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * Copyright (C) IBM Corp. 2006
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ *          Jerone Young <jyoung5@us.ibm.com>
+ */
+
+#ifndef _LINUX_XENCOMM_H_
+#define _LINUX_XENCOMM_H_
+
+#include <xen/interface/xencomm.h>
+
+#define XENCOMM_MINI_ADDRS 3
+struct xencomm_mini {
+	struct xencomm_desc _desc;
+	uint64_t address[XENCOMM_MINI_ADDRS];
+};
+
+/* To avoid additionnal virt to phys conversion, an opaque structure is
+   presented.  */
+struct xencomm_handle;
+
+extern void xencomm_free(struct xencomm_handle *desc);
+extern struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes);
+extern struct xencomm_handle *__xencomm_map_no_alloc(void *ptr,
+			unsigned long bytes,  struct xencomm_mini *xc_area);
+
+#if 0
+#define XENCOMM_MINI_ALIGNED(xc_desc, n)				\
+	struct xencomm_mini xc_desc ## _base[(n)]			\
+	__attribute__((__aligned__(sizeof(struct xencomm_mini))));	\
+	struct xencomm_mini *xc_desc = &xc_desc ## _base[0];
+#else
+/*
+ * gcc bug workaround:
+ * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660
+ * gcc doesn't handle properly stack variable with
+ * __attribute__((__align__(sizeof(struct xencomm_mini))))
+ */
+#define XENCOMM_MINI_ALIGNED(xc_desc, n)				\
+	unsigned char xc_desc ## _base[((n) + 1 ) *			\
+				       sizeof(struct xencomm_mini)];	\
+	struct xencomm_mini *xc_desc = (struct xencomm_mini *)		\
+		((unsigned long)xc_desc ## _base +			\
+		 (sizeof(struct xencomm_mini) -				\
+		  ((unsigned long)xc_desc ## _base) %			\
+		  sizeof(struct xencomm_mini)));
+#endif
+#define xencomm_map_no_alloc(ptr, bytes)			\
+	({ XENCOMM_MINI_ALIGNED(xc_desc, 1);			\
+		__xencomm_map_no_alloc(ptr, bytes, xc_desc); })
+
+/* provided by architecture code: */
+extern unsigned long xencomm_vtop(unsigned long vaddr);
+
+static inline void *xencomm_pa(void *ptr)
+{
+	return (void *)xencomm_vtop((unsigned long)ptr);
+}
+
+#define xen_guest_handle(hnd)  ((hnd).p)
+
+#endif /* _LINUX_XENCOMM_H_ */