+
+/**
+ * Static (compile-time) assertion.
+ * Basically, use COND to dimension an array. If COND is false/zero the
+ * array size will be -1 and we'll get a compilation error.
+ */
+#define STATIC_ASSERT(COND) \
+ do { \
+ (void) sizeof(char [1 - 2*!(COND)]); \
+ } while (0)
+
+
+#include <sys/mman.h>
+
+#if defined(ANDROID)
+#include <errno.h> /* for EINVAL */
+
+extern void *__mmap2(void *, size_t, int, int, int, size_t);
+
+static inline void *drm_mmap(void *addr, size_t length, int prot, int flags,
+ int fd, loff_t offset)
+{
+ /* offset must be aligned to 4096 (not necessarily the page size) */
+ if (offset & 4095) {
+ errno = EINVAL;
+ return MAP_FAILED;
+ }
+
+ return __mmap2(addr, length, prot, flags, fd, (size_t) (offset >> 12));
+}
+
+# define drm_munmap(addr, length) \
+ munmap(addr, length)
+
+
+#else
+
+/* assume large file support exists */
+# define drm_mmap(addr, length, prot, flags, fd, offset) \
+ mmap(addr, length, prot, flags, fd, offset)
+
+
+static inline int drm_munmap(void *addr, size_t length)
+{
+ /* Copied from configure code generated by AC_SYS_LARGEFILE */
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + \
+ (((off_t) 1 << 31) << 31))
+ STATIC_ASSERT(LARGE_OFF_T % 2147483629 == 721 &&
+ LARGE_OFF_T % 2147483647 == 1);
+#undef LARGE_OFF_T
+
+ return munmap(addr, length);
+}
+#endif
+