@@ -6,8 +6,9 @@
*/
#ifndef _CPUMASK_H_
#define _CPUMASK_H_
-#include <asm/setup.h>
#include <bitops.h>
+#include <limits.h>
+#include <asm/setup.h>
#define CPUMASK_NR_LONGS ((NR_CPUS + BITS_PER_LONG - 1) / BITS_PER_LONG)
@@ -49,46 +50,34 @@ static inline int cpumask_test_and_clear_cpu(int cpu, cpumask_t *mask)
static inline void cpumask_setall(cpumask_t *mask)
{
- int i;
- for (i = 0; i < nr_cpus; i += BITS_PER_LONG)
- cpumask_bits(mask)[BIT_WORD(i)] = ~0UL;
- i -= BITS_PER_LONG;
- if ((nr_cpus - i) < BITS_PER_LONG)
- cpumask_bits(mask)[BIT_WORD(i)] = BIT_MASK(nr_cpus - i) - 1;
+ memset(mask, 0xff, sizeof(*mask));
}
static inline void cpumask_clear(cpumask_t *mask)
{
- int i;
- for (i = 0; i < nr_cpus; i += BITS_PER_LONG)
- cpumask_bits(mask)[BIT_WORD(i)] = 0UL;
+ memset(mask, 0, sizeof(*mask));
}
static inline bool cpumask_empty(const cpumask_t *mask)
{
- int i;
- for (i = 0; i < nr_cpus; i += BITS_PER_LONG) {
- if (i < NR_CPUS) { /* silence crazy compiler warning */
- if (cpumask_bits(mask)[BIT_WORD(i)] != 0UL)
- return false;
- }
- }
- return true;
+ unsigned long lastmask = BIT_MASK(nr_cpus) - 1;
+
+ for (int i = 0; i < BIT_WORD(nr_cpus); ++i)
+ if (cpumask_bits(mask)[i])
+ return false;
+
+ return !lastmask || !(cpumask_bits(mask)[BIT_WORD(nr_cpus)] & lastmask);
}
static inline bool cpumask_full(const cpumask_t *mask)
{
- int i;
- for (i = 0; i < nr_cpus; i += BITS_PER_LONG) {
- if (cpumask_bits(mask)[BIT_WORD(i)] != ~0UL) {
- if ((nr_cpus - i) >= BITS_PER_LONG)
- return false;
- if (cpumask_bits(mask)[BIT_WORD(i)]
- != BIT_MASK(nr_cpus - i) - 1)
- return false;
- }
- }
- return true;
+ unsigned long lastmask = BIT_MASK(nr_cpus) - 1;
+
+ for (int i = 0; i < BIT_WORD(nr_cpus); ++i)
+ if (cpumask_bits(mask)[i] != ULONG_MAX)
+ return false;
+
+ return !lastmask || (cpumask_bits(mask)[BIT_WORD(nr_cpus)] & lastmask) == lastmask;
}
static inline int cpumask_weight(const cpumask_t *mask)
Simplify cpumask_setall and cpumask_clear by just using memset. Also simplify cpumask_empty and cpumask_full. This is a fix for cpumask_empty as it would have reported non-empty for cpumasks that had uninitialized junk following nr_cpus when nr_cpus < NR_CPUS. There aren't currently any users of cpumask_empty though so that bug has never appeared. cpumask_full was just convoluted and can now follow cpumask_empty's new pattern. I've already yelled at a mirror to scold the author of the original implementations! Signed-off-by: Andrew Jones <andrew.jones@linux.dev> --- lib/cpumask.h | 47 ++++++++++++++++++----------------------------- 1 file changed, 18 insertions(+), 29 deletions(-)