diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cpumask.h | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 72f9c32c12b0..30d59d1d0626 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -75,16 +75,36 @@ * CPU_MASK_NONE Initializer - no bits set * unsigned long *cpus_addr(mask) Array of unsigned long's in mask * + * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t + * variables, and CPUMASK_PTR provides pointers to each field. + * + * The structure should be defined something like this: + * struct my_cpumasks { + * cpumask_t mask1; + * cpumask_t mask2; + * }; + * + * Usage is then: + * CPUMASK_ALLOC(my_cpumasks); + * CPUMASK_PTR(mask1, my_cpumasks); + * CPUMASK_PTR(mask2, my_cpumasks); + * + * --- DO NOT reference cpumask_t pointers until this check --- + * if (my_cpumasks == NULL) + * "kmalloc failed"... + * + * References are now pointers to the cpumask_t variables (*mask1, ...) + * *if NR_CPUS > BITS_PER_LONG * CPUMASK_ALLOC(m) Declares and allocates struct m *m = - * (struct m *)kmalloc(sizeof(*m), ...) - * CPUMASK_FREE(m) Macro for kfree(v) + * kmalloc(sizeof(*m), GFP_KERNEL) + * CPUMASK_FREE(m) Macro for kfree(m) *else * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m * CPUMASK_FREE(m) Nop *endif - * CPUMASK_VAR(v, m) Declares cpumask_t *v = - * m + offset(struct m, v) + * CPUMASK_PTR(v, m) Declares cpumask_t *v = &(m->v) + * ------------------------------------------------------------------------ * * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing * int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask @@ -326,11 +346,10 @@ extern cpumask_t cpu_mask_all; #define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL) #define CPUMASK_FREE(m) kfree(m) #else -#define CPUMASK_ALLOC(m) struct allmasks _m, *m = &_m +#define CPUMASK_ALLOC(m) struct m _m, *m = &_m #define CPUMASK_FREE(m) #endif -#define CPUMASK_VAR(v, m) cpumask_t *v = (cpumask_t *) \ - ((unsigned long)(m) + offsetof(struct m, v)) +#define CPUMASK_PTR(v, m) cpumask_t *v = &(m->v) #define cpumask_scnprintf(buf, len, src) \ __cpumask_scnprintf((buf), (len), &(src), NR_CPUS) |
