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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 20:25:20 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 20:25:20 +0300
commit19e7b5f99474107e8d0b4b3e4652fa19ddb87efc (patch)
tree49f15b76c07b4c90d6fbd17b49d69017c81a4b58 /include/linux/bitfield.h
parent26064ea409b4d4acb05903a36f3fe2fdccb3d8aa (diff)
parentce4c253573ad184603e0fa77876ba155b0cde46d (diff)
downloadlinux-19e7b5f99474107e8d0b4b3e4652fa19ddb87efc.tar.xz
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro: "All kinds of misc stuff, without any unifying topic, from various people. Neil's d_anon patch, several bugfixes, introduction of kvmalloc analogue of kmemdup_user(), extending bitfield.h to deal with fixed-endians, assorted cleanups all over the place..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) alpha: osf_sys.c: use timespec64 where appropriate alpha: osf_sys.c: fix put_tv32 regression jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path dcache: delete unused d_hash_mask dcache: subtract d_hash_shift from 32 in advance fs/buffer.c: fold init_buffer() into init_page_buffers() fs: fold __inode_permission() into inode_permission() fs: add RWF_APPEND sctp: use vmemdup_user() rather than badly open-coding memdup_user() snd_ctl_elem_init_enum_names(): switch to vmemdup_user() replace_user_tlv(): switch to vmemdup_user() new primitive: vmemdup_user() memdup_user(): switch to GFP_USER eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget() eventfd: fold eventfd_ctx_read() into eventfd_read() eventfd: convert to use anon_inode_getfd() nfs4file: get rid of pointless include of btrfs.h uvc_v4l2: clean copyin/copyout up vme_user: don't use __copy_..._user() usx2y: don't bother with memdup_user() for 16-byte structure ...
Diffstat (limited to 'include/linux/bitfield.h')
-rw-r--r--include/linux/bitfield.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
index 1030651f8309..cf2588d81148 100644
--- a/include/linux/bitfield.h
+++ b/include/linux/bitfield.h
@@ -16,6 +16,7 @@
#define _LINUX_BITFIELD_H
#include <linux/build_bug.h>
+#include <asm/byteorder.h>
/*
* Bitfield access macros
@@ -103,4 +104,49 @@
(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
})
+extern void __compiletime_warning("value doesn't fit into mask")
+__field_overflow(void);
+extern void __compiletime_error("bad bitfield mask")
+__bad_mask(void);
+static __always_inline u64 field_multiplier(u64 field)
+{
+ if ((field | (field - 1)) & ((field | (field - 1)) + 1))
+ __bad_mask();
+ return field & -field;
+}
+static __always_inline u64 field_mask(u64 field)
+{
+ return field / field_multiplier(field);
+}
+#define ____MAKE_OP(type,base,to,from) \
+static __always_inline __##type type##_encode_bits(base v, base field) \
+{ \
+ if (__builtin_constant_p(v) && (v & ~field_multiplier(field))) \
+ __field_overflow(); \
+ return to((v & field_mask(field)) * field_multiplier(field)); \
+} \
+static __always_inline __##type type##_replace_bits(__##type old, \
+ base val, base field) \
+{ \
+ return (old & ~to(field)) | type##_encode_bits(val, field); \
+} \
+static __always_inline void type##p_replace_bits(__##type *p, \
+ base val, base field) \
+{ \
+ *p = (*p & ~to(field)) | type##_encode_bits(val, field); \
+} \
+static __always_inline base type##_get_bits(__##type v, base field) \
+{ \
+ return (from(v) & field)/field_multiplier(field); \
+}
+#define __MAKE_OP(size) \
+ ____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu) \
+ ____MAKE_OP(be##size,u##size,cpu_to_be##size,be##size##_to_cpu) \
+ ____MAKE_OP(u##size,u##size,,)
+__MAKE_OP(16)
+__MAKE_OP(32)
+__MAKE_OP(64)
+#undef __MAKE_OP
+#undef ____MAKE_OP
+
#endif