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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/uio.h
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/linux/uio.h')
-rw-r--r--include/linux/uio.h66
1 files changed, 66 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h
new file mode 100644
index 000000000000..9af8bbcd8963
--- /dev/null
+++ b/include/linux/uio.h
@@ -0,0 +1,66 @@
+#ifndef __LINUX_UIO_H
+#define __LINUX_UIO_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+/*
+ * Berkeley style UIO structures - Alan Cox 1994.
+ *
+ * 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.
+ */
+
+
+/* A word of warning: Our uio structure will clash with the C library one (which is now obsolete). Remove the C
+ library one from sys/uio.h if you have a very old library set */
+
+struct iovec
+{
+ void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */
+ __kernel_size_t iov_len; /* Must be size_t (1003.1g) */
+};
+
+#ifdef __KERNEL__
+
+struct kvec {
+ void *iov_base; /* and that should *never* hold a userland pointer */
+ size_t iov_len;
+};
+
+#endif
+
+/*
+ * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
+ */
+
+#define UIO_FASTIOV 8
+#define UIO_MAXIOV 1024
+#if 0
+#define UIO_MAXIOV 16 /* Maximum iovec's in one operation
+ 16 matches BSD */
+ /* Beg pardon: BSD has 1024 --ANK */
+#endif
+
+/*
+ * Total number of bytes covered by an iovec.
+ *
+ * NOTE that it is not safe to use this function until all the iovec's
+ * segment lengths have been validated. Because the individual lengths can
+ * overflow a size_t when added together.
+ */
+static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
+{
+ unsigned long seg;
+ size_t ret = 0;
+
+ for (seg = 0; seg < nr_segs; seg++)
+ ret += iov[seg].iov_len;
+ return ret;
+}
+
+unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
+
+#endif