1 #ifndef _ASM_GENERIC_PERCPU_H_
2 #define _ASM_GENERIC_PERCPU_H_
4 #include <linux/compiler.h>
5 #include <linux/threads.h>
6 #include <linux/percpu-defs.h>
11 * per_cpu_offset() is the offset that has to be added to a
12 * percpu variable to get to the instance for a certain processor.
14 * Most arches use the __per_cpu_offset array for those offsets but
15 * some arches have their own ways of determining the offset (x86_64, s390).
17 #ifndef __per_cpu_offset
18 extern unsigned long __per_cpu_offset[NR_CPUS];
20 #define per_cpu_offset(x) (__per_cpu_offset[x])
24 * Determine the offset for the currently active processor.
25 * An arch may define __my_cpu_offset to provide a more effective
26 * means of obtaining the offset to the per cpu variables of the
29 #ifndef __my_cpu_offset
30 #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
32 #ifdef CONFIG_DEBUG_PREEMPT
33 #define my_cpu_offset per_cpu_offset(smp_processor_id())
35 #define my_cpu_offset __my_cpu_offset
39 * Add an offset to a pointer but keep the pointer as-is. Use RELOC_HIDE()
40 * to prevent the compiler from making incorrect assumptions about the
41 * pointer value. The weird cast keeps both GCC and sparse happy.
43 #define SHIFT_PERCPU_PTR(__p, __offset) ({ \
44 __verify_pcpu_ptr((__p)); \
45 RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \
49 * A percpu variable may point to a discarded regions. The following are
50 * established ways to produce a usable pointer from the percpu variable
53 #define per_cpu(var, cpu) \
54 (*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu)))
57 #define raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
59 #ifdef CONFIG_DEBUG_PREEMPT
60 #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
62 #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
65 #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
66 #define __raw_get_cpu_var(var) (*raw_cpu_ptr(&(var)))
68 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
69 extern void setup_per_cpu_areas(void);
74 #define VERIFY_PERCPU_PTR(__p) ({ \
75 __verify_pcpu_ptr((__p)); \
76 (typeof(*(__p)) __kernel __force *)(__p); \
79 #define per_cpu(var, cpu) (*((void)(cpu), VERIFY_PERCPU_PTR(&(var))))
80 #define __get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
81 #define __raw_get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
82 #define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
83 #define raw_cpu_ptr(ptr) this_cpu_ptr(ptr)
87 #ifndef PER_CPU_BASE_SECTION
89 #define PER_CPU_BASE_SECTION ".data..percpu"
91 #define PER_CPU_BASE_SECTION ".data"
98 #define PER_CPU_SHARED_ALIGNED_SECTION ""
99 #define PER_CPU_ALIGNED_SECTION ""
101 #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned"
102 #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
104 #define PER_CPU_FIRST_SECTION "..first"
108 #define PER_CPU_SHARED_ALIGNED_SECTION ""
109 #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
110 #define PER_CPU_FIRST_SECTION ""
114 #ifndef PER_CPU_ATTRIBUTES
115 #define PER_CPU_ATTRIBUTES
118 #ifndef PER_CPU_DEF_ATTRIBUTES
119 #define PER_CPU_DEF_ATTRIBUTES
122 /* Keep until we have removed all uses of __this_cpu_ptr */
123 #define __this_cpu_ptr raw_cpu_ptr
125 #endif /* _ASM_GENERIC_PERCPU_H_ */