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>

2 files changed, 118 insertions, 0 deletions

diff --git a/include/xen/interface/xencomm.h b/include/xen/interface/xencomm.h
new file mode 100644
index 000000000000..ac45e0712afa
--- /dev/null
+++ b/include/xen/interface/xencomm.h
@@ -0,0 +1,41 @@
+/*
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (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.
+ *
+ * Copyright (C) IBM Corp. 2006
+ */
+
+#ifndef _XEN_XENCOMM_H_
+#define _XEN_XENCOMM_H_
+
+/* A xencomm descriptor is a scatter/gather list containing physical
+ * addresses corresponding to a virtually contiguous memory area. The
+ * hypervisor translates these physical addresses to machine addresses to copy
+ * to and from the virtually contiguous area.
+ */
+
+#define XENCOMM_MAGIC 0x58434F4D /* 'XCOM' */
+#define XENCOMM_INVALID (~0UL)
+
+struct xencomm_desc {
+    uint32_t magic;
+    uint32_t nr_addrs; /* the number of entries in address[] */
+    uint64_t address[0];
+};
+
+#endif /* _XEN_XENCOMM_H_ */
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_ */