10 /* Maximum size of any percpu data. */
11 #define PERCPU_OFFSET (4 * sizeof(long))
13 /* Ignore alignment, as CBMC doesn't care about false sharing. */
14 #define alloc_percpu(type) __alloc_percpu(sizeof(type), 1)
16 static inline void *__alloc_percpu(size_t size, size_t align)
22 static inline void free_percpu(void *ptr)
27 #define per_cpu_ptr(ptr, cpu) \
28 ((typeof(ptr)) ((char *) (ptr) + PERCPU_OFFSET * cpu))
30 #define __this_cpu_inc(pcp) __this_cpu_add(pcp, 1)
31 #define __this_cpu_dec(pcp) __this_cpu_sub(pcp, 1)
32 #define __this_cpu_sub(pcp, n) __this_cpu_add(pcp, -(typeof(pcp)) (n))
34 #define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
35 #define this_cpu_dec(pcp) this_cpu_sub(pcp, 1)
36 #define this_cpu_sub(pcp, n) this_cpu_add(pcp, -(typeof(pcp)) (n))
38 /* Make CBMC use atomics to work around bug. */
40 #define THIS_CPU_ADD_HELPER(ptr, x) (*(ptr) += (x))
43 * Split the atomic into a read and a write so that it has the least
46 #define THIS_CPU_ADD_HELPER(ptr, x) \
48 typeof(ptr) this_cpu_add_helper_ptr = (ptr); \
49 typeof(ptr) this_cpu_add_helper_x = (x); \
50 typeof(*ptr) this_cpu_add_helper_temp; \
51 __CPROVER_atomic_begin(); \
52 this_cpu_add_helper_temp = *(this_cpu_add_helper_ptr); \
53 __CPROVER_atomic_end(); \
54 this_cpu_add_helper_temp += this_cpu_add_helper_x; \
55 __CPROVER_atomic_begin(); \
56 *(this_cpu_add_helper_ptr) = this_cpu_add_helper_temp; \
57 __CPROVER_atomic_end(); \
62 * For some reason CBMC needs an atomic operation even though this is percpu
65 #define __this_cpu_add(pcp, n) \
67 BUG_ON(preemptible()); \
68 THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), thread_cpu_id), \
72 #define this_cpu_add(pcp, n) \
74 int this_cpu_add_impl_cpu = get_cpu(); \
75 THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), this_cpu_add_impl_cpu), \
81 * This will cause a compiler warning because of the cast from char[][] to
82 * type*. This will cause a compile time error if type is too big.
84 #define DEFINE_PER_CPU(type, name) \
85 char name[NR_CPUS][PERCPU_OFFSET]; \
86 typedef char percpu_too_big_##name \
87 [sizeof(type) > PERCPU_OFFSET ? -1 : 1]
89 #define for_each_possible_cpu(cpu) \
90 for ((cpu) = 0; (cpu) < NR_CPUS; ++(cpu))