mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 23:50:53 +07:00
tools: Adopt rounddown_pow_of_two and deps
Will be used to make sure we pass a power of two when automatically setting up the perf_mmap addr range length, as the kernel code validating input on /proc/sys/kernel/perf_event_mlock_kb accepts any integer, if we plain use it to set up the mmap lenght, we may get an EINVAL when passing a non power of two. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-zflvep0q01dmkruf4o291l4p@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo
parent
afcd4f6235
commit
fa37c025c5
@ -12,6 +12,30 @@
|
||||
#ifndef _TOOLS_LINUX_LOG2_H
|
||||
#define _TOOLS_LINUX_LOG2_H
|
||||
|
||||
/*
|
||||
* deal with unrepresentable constant logarithms
|
||||
*/
|
||||
extern __attribute__((const, noreturn))
|
||||
int ____ilog2_NaN(void);
|
||||
|
||||
/*
|
||||
* non-constant log of base 2 calculators
|
||||
* - the arch may override these in asm/bitops.h if they can be implemented
|
||||
* more efficiently than using fls() and fls64()
|
||||
* - the arch is not required to handle n==0 if implementing the fallback
|
||||
*/
|
||||
static inline __attribute__((const))
|
||||
int __ilog2_u32(u32 n)
|
||||
{
|
||||
return fls(n) - 1;
|
||||
}
|
||||
|
||||
static inline __attribute__((const))
|
||||
int __ilog2_u64(u64 n)
|
||||
{
|
||||
return fls64(n) - 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Determine whether some value is a power of two, where zero is
|
||||
* *not* considered a power of two.
|
||||
@ -23,4 +47,114 @@ bool is_power_of_2(unsigned long n)
|
||||
return (n != 0 && ((n & (n - 1)) == 0));
|
||||
}
|
||||
|
||||
/*
|
||||
* round down to nearest power of two
|
||||
*/
|
||||
static inline __attribute__((const))
|
||||
unsigned long __rounddown_pow_of_two(unsigned long n)
|
||||
{
|
||||
return 1UL << (fls_long(n) - 1);
|
||||
}
|
||||
|
||||
/**
|
||||
* ilog2 - log of base 2 of 32-bit or a 64-bit unsigned value
|
||||
* @n - parameter
|
||||
*
|
||||
* constant-capable log of base 2 calculation
|
||||
* - this can be used to initialise global variables from constant data, hence
|
||||
* the massive ternary operator construction
|
||||
*
|
||||
* selects the appropriately-sized optimised version depending on sizeof(n)
|
||||
*/
|
||||
#define ilog2(n) \
|
||||
( \
|
||||
__builtin_constant_p(n) ? ( \
|
||||
(n) < 1 ? ____ilog2_NaN() : \
|
||||
(n) & (1ULL << 63) ? 63 : \
|
||||
(n) & (1ULL << 62) ? 62 : \
|
||||
(n) & (1ULL << 61) ? 61 : \
|
||||
(n) & (1ULL << 60) ? 60 : \
|
||||
(n) & (1ULL << 59) ? 59 : \
|
||||
(n) & (1ULL << 58) ? 58 : \
|
||||
(n) & (1ULL << 57) ? 57 : \
|
||||
(n) & (1ULL << 56) ? 56 : \
|
||||
(n) & (1ULL << 55) ? 55 : \
|
||||
(n) & (1ULL << 54) ? 54 : \
|
||||
(n) & (1ULL << 53) ? 53 : \
|
||||
(n) & (1ULL << 52) ? 52 : \
|
||||
(n) & (1ULL << 51) ? 51 : \
|
||||
(n) & (1ULL << 50) ? 50 : \
|
||||
(n) & (1ULL << 49) ? 49 : \
|
||||
(n) & (1ULL << 48) ? 48 : \
|
||||
(n) & (1ULL << 47) ? 47 : \
|
||||
(n) & (1ULL << 46) ? 46 : \
|
||||
(n) & (1ULL << 45) ? 45 : \
|
||||
(n) & (1ULL << 44) ? 44 : \
|
||||
(n) & (1ULL << 43) ? 43 : \
|
||||
(n) & (1ULL << 42) ? 42 : \
|
||||
(n) & (1ULL << 41) ? 41 : \
|
||||
(n) & (1ULL << 40) ? 40 : \
|
||||
(n) & (1ULL << 39) ? 39 : \
|
||||
(n) & (1ULL << 38) ? 38 : \
|
||||
(n) & (1ULL << 37) ? 37 : \
|
||||
(n) & (1ULL << 36) ? 36 : \
|
||||
(n) & (1ULL << 35) ? 35 : \
|
||||
(n) & (1ULL << 34) ? 34 : \
|
||||
(n) & (1ULL << 33) ? 33 : \
|
||||
(n) & (1ULL << 32) ? 32 : \
|
||||
(n) & (1ULL << 31) ? 31 : \
|
||||
(n) & (1ULL << 30) ? 30 : \
|
||||
(n) & (1ULL << 29) ? 29 : \
|
||||
(n) & (1ULL << 28) ? 28 : \
|
||||
(n) & (1ULL << 27) ? 27 : \
|
||||
(n) & (1ULL << 26) ? 26 : \
|
||||
(n) & (1ULL << 25) ? 25 : \
|
||||
(n) & (1ULL << 24) ? 24 : \
|
||||
(n) & (1ULL << 23) ? 23 : \
|
||||
(n) & (1ULL << 22) ? 22 : \
|
||||
(n) & (1ULL << 21) ? 21 : \
|
||||
(n) & (1ULL << 20) ? 20 : \
|
||||
(n) & (1ULL << 19) ? 19 : \
|
||||
(n) & (1ULL << 18) ? 18 : \
|
||||
(n) & (1ULL << 17) ? 17 : \
|
||||
(n) & (1ULL << 16) ? 16 : \
|
||||
(n) & (1ULL << 15) ? 15 : \
|
||||
(n) & (1ULL << 14) ? 14 : \
|
||||
(n) & (1ULL << 13) ? 13 : \
|
||||
(n) & (1ULL << 12) ? 12 : \
|
||||
(n) & (1ULL << 11) ? 11 : \
|
||||
(n) & (1ULL << 10) ? 10 : \
|
||||
(n) & (1ULL << 9) ? 9 : \
|
||||
(n) & (1ULL << 8) ? 8 : \
|
||||
(n) & (1ULL << 7) ? 7 : \
|
||||
(n) & (1ULL << 6) ? 6 : \
|
||||
(n) & (1ULL << 5) ? 5 : \
|
||||
(n) & (1ULL << 4) ? 4 : \
|
||||
(n) & (1ULL << 3) ? 3 : \
|
||||
(n) & (1ULL << 2) ? 2 : \
|
||||
(n) & (1ULL << 1) ? 1 : \
|
||||
(n) & (1ULL << 0) ? 0 : \
|
||||
____ilog2_NaN() \
|
||||
) : \
|
||||
(sizeof(n) <= 4) ? \
|
||||
__ilog2_u32(n) : \
|
||||
__ilog2_u64(n) \
|
||||
)
|
||||
|
||||
|
||||
/**
|
||||
* rounddown_pow_of_two - round the given value down to nearest power of two
|
||||
* @n - parameter
|
||||
*
|
||||
* round the given value down to the nearest power of two
|
||||
* - the result is undefined when n == 0
|
||||
* - this can be used to initialise global variables from constant data
|
||||
*/
|
||||
#define rounddown_pow_of_two(n) \
|
||||
( \
|
||||
__builtin_constant_p(n) ? ( \
|
||||
(1UL << ilog2(n))) : \
|
||||
__rounddown_pow_of_two(n) \
|
||||
)
|
||||
|
||||
#endif /* _TOOLS_LINUX_LOG2_H */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user