| 1 | #ifndef _ASM_GENERIC_PERCPU_H_
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| 2 | #define _ASM_GENERIC_PERCPU_H_
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| 3 |
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| 4 | #include <linux/compiler.h>
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| 5 | #include <linux/threads.h>
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| 6 | #include <linux/percpu-defs.h>
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| 7 |
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| 8 | #ifdef CONFIG_SMP
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| 9 |
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| 10 | |
| 11 | * per_cpu_offset() is the offset that has to be added to a
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| 12 | * percpu variable to get to the instance for a certain processor.
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| 13 | *
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| 14 | * Most arches use the __per_cpu_offset array for those offsets but
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| 15 | * some arches have their own ways of determining the offset (x86_64, s390).
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| 16 |
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| 17 | #ifndef __per_cpu_offset
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| 18 | extern unsigned long __per_cpu_offset[NR_CPUS];
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| 19 |
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| 20 | #define per_cpu_offset(x) (__per_cpu_offset[x])
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| 21 | #endif
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| 22 |
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| 23 | |
| 24 | * Determine the offset for the currently active processor.
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| 25 | * An arch may define __my_cpu_offset to provide a more effective
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| 26 | * means of obtaining the offset to the per cpu variables of the
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| 27 | * current processor.
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| 28 |
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| 29 | #ifndef __my_cpu_offset
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| 30 | #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
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| 31 | #endif
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| 32 | #ifdef CONFIG_DEBUG_PREEMPT
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| 33 | #define my_cpu_offset per_cpu_offset(smp_processor_id())
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| 34 | #else
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| 35 | #define my_cpu_offset __my_cpu_offset
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| 36 | #endif
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| 37 |
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| 38 | |
| 39 | * Add a offset to a pointer but keep the pointer as is.
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| 40 | *
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| 41 | * Only S390 provides its own means of moving the pointer.
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| 42 |
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| 43 | #ifndef SHIFT_PERCPU_PTR
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| 44 |
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| 45 | #define SHIFT_PERCPU_PTR(__p, __offset) ({ \
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| 46 | __verify_pcpu_ptr((__p)); \
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| 47 | RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \
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| 48 | })
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| 49 | #endif
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| 50 |
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| 51 | |
| 52 | * A percpu variable may point to a discarded regions. The following are
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| 53 | * established ways to produce a usable pointer from the percpu variable
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| 54 | * offset.
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| 55 |
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| 56 | #define per_cpu(var, cpu) \
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| 57 | (*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu)))
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| 58 |
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| 59 | #ifndef __this_cpu_ptr
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| 60 | #define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
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| 61 | #endif
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| 62 | #ifdef CONFIG_DEBUG_PREEMPT
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| 63 | #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
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| 64 | #else
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| 65 | #define this_cpu_ptr(ptr) __this_cpu_ptr(ptr)
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| 66 | #endif
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| 67 |
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| 68 | #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
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| 69 | #define __raw_get_cpu_var(var) (*__this_cpu_ptr(&(var)))
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| 70 |
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| 71 | #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
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| 72 | extern void setup_per_cpu_areas(void);
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| 73 | #endif
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| 74 |
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| 75 | #else
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| 76 |
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| 77 | #define VERIFY_PERCPU_PTR(__p) ({ \
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| 78 | __verify_pcpu_ptr((__p)); \
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| 79 | (typeof(*(__p)) __kernel __force *)(__p); \
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| 80 | })
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| 81 |
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| 82 | #define per_cpu(var, cpu) (*((void)(cpu), VERIFY_PERCPU_PTR(&(var))))
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| 83 | #define __get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
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| 84 | #define __raw_get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
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| 85 | #define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
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| 86 | #define __this_cpu_ptr(ptr) this_cpu_ptr(ptr)
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| 87 |
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| 88 | #endif
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| 89 |
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| 90 | #ifndef PER_CPU_BASE_SECTION
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| 91 | #ifdef CONFIG_SMP
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| 92 | #define PER_CPU_BASE_SECTION ".data..percpu"
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| 93 | #else
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| 94 | #define PER_CPU_BASE_SECTION ".data"
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| 95 | #endif
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| 96 | #endif
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| 97 |
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| 98 | #ifdef CONFIG_SMP
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| 99 |
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| 100 | #ifdef MODULE
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| 101 | #define PER_CPU_SHARED_ALIGNED_SECTION ""
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| 102 | #define PER_CPU_ALIGNED_SECTION ""
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| 103 | #else
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| 104 | #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned"
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| 105 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
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| 106 | #endif
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| 107 | #define PER_CPU_FIRST_SECTION "..first"
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| 108 |
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| 109 | #else
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| 110 |
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| 111 | #define PER_CPU_SHARED_ALIGNED_SECTION ""
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| 112 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned"
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| 113 | #define PER_CPU_FIRST_SECTION ""
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| 114 |
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| 115 | #endif
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| 116 |
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| 117 | #ifndef PER_CPU_ATTRIBUTES
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| 118 | #define PER_CPU_ATTRIBUTES
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| 119 | #endif
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| 120 |
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| 121 | #ifndef PER_CPU_DEF_ATTRIBUTES
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| 122 | #define PER_CPU_DEF_ATTRIBUTES
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| 123 | #endif
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| 124 |
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| 125 | #endif
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