Backport from current libsdl svn so we can work with newer kernel headers

http://bugs.gentoo.org/159923
http://bugs.gentoo.org/169388

--- configure.in
+++ configure.in
@@ -807,6 +807,7 @@
         ])
         AC_MSG_RESULT($video_fbcon)
         if test x$video_fbcon = xyes; then
+            AC_CHECK_FUNCS(getpagesize)
             AC_DEFINE(SDL_VIDEO_DRIVER_FBCON)
             SOURCES="$SOURCES $srcdir/src/video/fbcon/*.c"
             have_video=yes
--- include/SDL_config.h.in
+++ include/SDL_config.h.in
@@ -302,4 +302,6 @@
 #undef SDL_HERMES_BLITTERS
 #undef SDL_ALTIVEC_BLITTERS
 
+#undef HAVE_GETPAGESIZE
+
 #endif /* _SDL_config_h */
--- src/video/fbcon/SDL_fbvideo.c
+++ src/video/fbcon/SDL_fbvideo.c
@@ -29,7 +29,9 @@
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
+#ifndef HAVE_GETPAGESIZE
 #include <asm/page.h>		/* For definition of PAGE_SIZE */
+#endif
 #include <linux/vt.h>
 
 #include "SDL_video.h"
@@ -149,6 +151,18 @@
                                   struct fb_var_screeninfo *vinfo);
 static void FB_RestorePalette(_THIS);
 
+static int SDL_getpagesize(void)
+{
+#ifdef HAVE_GETPAGESIZE
+    return getpagesize();
+#elif defined(PAGE_SIZE)
+    return PAGE_SIZE;
+#else
+#error Can not determine system page size.
+    return 4096;  /* this is what it USED to be in Linux... */
+#endif
+}
+
 /* Small wrapper for mmap() so we can play nicely with no-mmu hosts
  * (non-mmu hosts disallow the MAP_SHARED flag) */
 
@@ -547,7 +561,7 @@
 
 	/* Memory map the device, compensating for buggy PPC mmap() */
 	mapped_offset = (((long)finfo.smem_start) -
-	                (((long)finfo.smem_start)&~(PAGE_SIZE-1)));
+	                (((long)finfo.smem_start)&~(SDL_getpagesize()-1)));
 	mapped_memlen = finfo.smem_len+mapped_offset;
 	mapped_mem = do_mmap(NULL, mapped_memlen,
 	                  PROT_READ|PROT_WRITE, MAP_SHARED, console_fd, 0);
--- src/video/Xext/Xxf86dga/XF86DGA.c	2007/03/13 23:11:02	1.1
+++ src/video/Xext/Xxf86dga/XF86DGA.c	2007/03/13 23:15:14
@@ -18,7 +18,8 @@ Copyright (c) 1995,1996  The XFree86 Pro
 #define HAS_MMAP_ANON
 #include <sys/types.h>
 #include <sys/mman.h>
-#include <asm/page.h>   /* PAGE_SIZE */
+/* kernel header doesn't work with -ansi */
+/* #include <asm/page.h> */   /* PAGE_SIZE */
 #define HAS_SC_PAGESIZE /* _SC_PAGESIZE may be an enum for Linux */
 #define HAS_GETPAGESIZE
 #endif /* linux */