diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /include/linux/tnum.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/tnum.h')
-rw-r--r-- | include/linux/tnum.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/include/linux/tnum.h b/include/linux/tnum.h new file mode 100644 index 000000000..1c3948a1d --- /dev/null +++ b/include/linux/tnum.h @@ -0,0 +1,117 @@ +/* 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. + */ + +#ifndef _LINUX_TNUM_H +#define _LINUX_TNUM_H + +#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; +/* An unknown value that is a superset of @min <= value <= @max. + * + * Could include values outside the range of [@min, @max]. + * For example tnum_range(0, 2) is represented by {0, 1, 2, *3*}, + * rather than the intended set of {0, 1, 2}. + */ +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 (rsh) a tnum right (by a fixed shift) */ +struct tnum tnum_rshift(struct tnum a, u8 shift); +/* Shift (arsh) a tnum right (by a fixed min_shift) */ +struct tnum tnum_arshift(struct tnum a, u8 min_shift, u8 insn_bitness); +/* 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. + * + * Note that using tnum_range() as @a requires extra cautions as tnum_in() may + * return true unexpectedly due to tnum limited ability to represent tight + * range, e.g. + * + * tnum_in(tnum_range(0, 2), tnum_const(3)) == true + * + * As a rule of thumb, if @a is explicitly coded rather than coming from + * reg->var_off, it should be in form of tnum_const(), tnum_range(0, 2**n - 1), + * or tnum_range(2**n, 2**(n+1) - 1). + */ +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); + +/* Returns the 32-bit subreg */ +struct tnum tnum_subreg(struct tnum a); +/* Returns the tnum with the lower 32-bit subreg cleared */ +struct tnum tnum_clear_subreg(struct tnum a); +/* Returns the tnum with the lower 32-bit subreg set to value */ +struct tnum tnum_const_subreg(struct tnum a, u32 value); +/* Returns true if 32-bit subreg @a is a known constant*/ +static inline bool tnum_subreg_is_const(struct tnum a) +{ + return !(tnum_subreg(a)).mask; +} + +#endif /* _LINUX_TNUM_H */ |