78 lines
2.5 KiB
Diff
78 lines
2.5 KiB
Diff
|
From 897da38f243dd23eeaa5e1103bbd9f7d47bc0f7f Mon Sep 17 00:00:00 2001
|
||
|
|
From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
|
||
|
|
Date: Mon, 4 May 2020 14:45:20 +0200
|
||
|
|
Subject: [PATCH] linux/bitfield.h: Add primitives for manipulating bitfields
|
||
|
|
both in host- and fixed-endian
|
||
|
|
|
||
|
|
Imports Al Viro's original Linux commit 00b0c9b82663a, which contains
|
||
|
|
an in depth explanation and two fixes from Johannes Berg:
|
||
|
|
e7d4a95da86e0 "bitfield: fix *_encode_bits()",
|
||
|
|
37a3862e12382 "bitfield: add u8 helpers".
|
||
|
|
|
||
|
|
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
|
||
|
|
[s.nawrocki: added empty lines between functions and macros]
|
||
|
|
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
|
||
|
|
---
|
||
|
|
include/linux/bitfield.h | 50 ++++++++++++++++++++++++++++++++++++++++
|
||
|
|
1 file changed, 50 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
|
||
|
|
index 8b9d6fff00..7acba4c524 100644
|
||
|
|
--- a/include/linux/bitfield.h
|
||
|
|
+++ b/include/linux/bitfield.h
|
||
|
|
@@ -103,4 +103,54 @@
|
||
|
|
(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
|
||
|
|
})
|
||
|
|
|
||
|
|
+extern void __compiletime_error("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_mask(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(u8,u8,,)
|
||
|
|
+__MAKE_OP(16)
|
||
|
|
+__MAKE_OP(32)
|
||
|
|
+__MAKE_OP(64)
|
||
|
|
+
|
||
|
|
+#undef __MAKE_OP
|
||
|
|
+#undef ____MAKE_OP
|
||
|
|
+
|
||
|
|
#endif
|