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| author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-09-29 12:24:10 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-09-29 12:24:10 +0300 |
| commit | cf09e3c904bf424f8b6a8203958e09bf7d9bcbc0 (patch) | |
| tree | 5e9936b3de36aa222b52a9bca366a43d98730ffd /include/linux/tnum.h | |
| parent | d5426f4c2ebac8cf05de43988c3fccddbee13d28 (diff) | |
| parent | e19b205be43d11bff638cad4487008c48d21c103 (diff) | |
| download | linux-cf09e3c904bf424f8b6a8203958e09bf7d9bcbc0.tar.xz | |
Merge tag 'v4.14-rc2' into patchwork
Linux 4.14-rc2
* tag 'v4.14-rc2': (12066 commits)
Linux 4.14-rc2
tpm: ibmvtpm: simplify crq initialization and document crq format
tpm: replace msleep() with usleep_range() in TPM 1.2/2.0 generic drivers
Documentation: tpm: add powered-while-suspended binding documentation
tpm: tpm_crb: constify acpi_device_id.
tpm: vtpm: constify vio_device_id
security: fix description of values returned by cap_inode_need_killpriv
x86/asm: Fix inline asm call constraints for Clang
objtool: Handle another GCC stack pointer adjustment bug
inet: fix improper empty comparison
net: use inet6_rcv_saddr to compare sockets
net: set tb->fast_sk_family
net: orphan frags on stand-alone ptype in dev_queue_xmit_nit
MAINTAINERS: update git tree locations for ieee802154 subsystem
SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags
SMB3: handle new statx fields
arch: remove unused *_segments() macros/functions
parisc: Unbreak bootloader due to gcc-7 optimizations
parisc: Reintroduce option to gzip-compress the kernel
apparmor: fix apparmorfs DAC access permissions
...
Diffstat (limited to 'include/linux/tnum.h')
| -rw-r--r-- | include/linux/tnum.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/include/linux/tnum.h b/include/linux/tnum.h new file mode 100644 index 000000000000..0d2d3da46139 --- /dev/null +++ b/include/linux/tnum.h @@ -0,0 +1,81 @@ +/* tnum: tracked (or tristate) numbers + * + * A tnum tracks knowledge about the bits of a value. Each bit can be either + * known (0 or 1), or unknown (x). Arithmetic operations on tnums will + * propagate the unknown bits such that the tnum result represents all the + * possible results for possible values of the operands. + */ +#include <linux/types.h> + +struct tnum { + u64 value; + u64 mask; +}; + +/* Constructors */ +/* Represent a known constant as a tnum. */ +struct tnum tnum_const(u64 value); +/* A completely unknown value */ +extern const struct tnum tnum_unknown; +/* A value that's unknown except that @min <= value <= @max */ +struct tnum tnum_range(u64 min, u64 max); + +/* Arithmetic and logical ops */ +/* Shift a tnum left (by a fixed shift) */ +struct tnum tnum_lshift(struct tnum a, u8 shift); +/* Shift a tnum right (by a fixed shift) */ +struct tnum tnum_rshift(struct tnum a, u8 shift); +/* Add two tnums, return @a + @b */ +struct tnum tnum_add(struct tnum a, struct tnum b); +/* Subtract two tnums, return @a - @b */ +struct tnum tnum_sub(struct tnum a, struct tnum b); +/* Bitwise-AND, return @a & @b */ +struct tnum tnum_and(struct tnum a, struct tnum b); +/* Bitwise-OR, return @a | @b */ +struct tnum tnum_or(struct tnum a, struct tnum b); +/* Bitwise-XOR, return @a ^ @b */ +struct tnum tnum_xor(struct tnum a, struct tnum b); +/* Multiply two tnums, return @a * @b */ +struct tnum tnum_mul(struct tnum a, struct tnum b); + +/* Return a tnum representing numbers satisfying both @a and @b */ +struct tnum tnum_intersect(struct tnum a, struct tnum b); + +/* Return @a with all but the lowest @size bytes cleared */ +struct tnum tnum_cast(struct tnum a, u8 size); + +/* Returns true if @a is a known constant */ +static inline bool tnum_is_const(struct tnum a) +{ + return !a.mask; +} + +/* Returns true if @a == tnum_const(@b) */ +static inline bool tnum_equals_const(struct tnum a, u64 b) +{ + return tnum_is_const(a) && a.value == b; +} + +/* Returns true if @a is completely unknown */ +static inline bool tnum_is_unknown(struct tnum a) +{ + return !~a.mask; +} + +/* Returns true if @a is known to be a multiple of @size. + * @size must be a power of two. + */ +bool tnum_is_aligned(struct tnum a, u64 size); + +/* Returns true if @b represents a subset of @a. */ +bool tnum_in(struct tnum a, struct tnum b); + +/* Formatting functions. These have snprintf-like semantics: they will write + * up to @size bytes (including the terminating NUL byte), and return the number + * of bytes (excluding the terminating NUL) which would have been written had + * sufficient space been available. (Thus tnum_sbin always returns 64.) + */ +/* Format a tnum as a pair of hex numbers (value; mask) */ +int tnum_strn(char *str, size_t size, struct tnum a); +/* Format a tnum as tristate binary expansion */ +int tnum_sbin(char *str, size_t size, struct tnum a); |
