include/xen/xencomm.h

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  15  *
  16  * Copyright (C) IBM Corp. 2006
  17  *
  18  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  19  *          Jerone Young <jyoung5@us.ibm.com>
  20  */
  21
  22 #ifndef _LINUX_XENCOMM_H_
  23 #define _LINUX_XENCOMM_H_
  24
  25 #include <xen/interface/xencomm.h>
  26
  27 #define XENCOMM_MINI_ADDRS 3
  28 struct xencomm_mini {
  29         struct xencomm_desc _desc;
  30         uint64_t address[XENCOMM_MINI_ADDRS];
  31 };
  32
  33 /* To avoid additionnal virt to phys conversion, an opaque structure is
  34    presented.  */
  35 struct xencomm_handle;
  36
  37 extern void xencomm_free(struct xencomm_handle *desc);
  38 extern struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes);
  39 extern struct xencomm_handle *__xencomm_map_no_alloc(void *ptr,
  40                         unsigned long bytes,  struct xencomm_mini *xc_area);
  41
  42 #if 0
  43 #define XENCOMM_MINI_ALIGNED(xc_desc, n)                                \
  44         struct xencomm_mini xc_desc ## _base[(n)]                       \
  45         __attribute__((__aligned__(sizeof(struct xencomm_mini))));      \
  46         struct xencomm_mini *xc_desc = &xc_desc ## _base[0];
  47 #else
  48 /*
  49  * gcc bug workaround:
  50  * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660
  51  * gcc doesn't handle properly stack variable with
  52  * __attribute__((__align__(sizeof(struct xencomm_mini))))
  53  */
  54 #define XENCOMM_MINI_ALIGNED(xc_desc, n)                                \
  55         unsigned char xc_desc ## _base[((n) + 1 ) *                     \
  56                                        sizeof(struct xencomm_mini)];    \
  57         struct xencomm_mini *xc_desc = (struct xencomm_mini *)          \
  58                 ((unsigned long)xc_desc ## _base +                      \
  59                  (sizeof(struct xencomm_mini) -                         \
  60                   ((unsigned long)xc_desc ## _base) %                   \
  61                   sizeof(struct xencomm_mini)));
  62 #endif
  63 #define xencomm_map_no_alloc(ptr, bytes)                        \
  64         ({ XENCOMM_MINI_ALIGNED(xc_desc, 1);                    \
  65                 __xencomm_map_no_alloc(ptr, bytes, xc_desc); })
  66
  67 /* provided by architecture code: */
  68 extern unsigned long xencomm_vtop(unsigned long vaddr);
  69
  70 static inline void *xencomm_pa(void *ptr)
  71 {
  72         return (void *)xencomm_vtop((unsigned long)ptr);
  73 }
  74
  75 #define xen_guest_handle(hnd)  ((hnd).p)
  76
  77 #endif /* _LINUX_XENCOMM_H_ */