kernel/events/internal.h

   1 #ifndef _KERNEL_EVENTS_INTERNAL_H
   2 #define _KERNEL_EVENTS_INTERNAL_H
   3
   4 #include <linux/hardirq.h>
   5 #include <linux/uaccess.h>
   6
   7 /* Buffer handling */
   8
   9 #define RING_BUFFER_WRITABLE            0x01
  10
  11 struct ring_buffer {
  12         atomic_t                        refcount;
  13         struct rcu_head                 rcu_head;
  14 #ifdef CONFIG_PERF_USE_VMALLOC
  15         struct work_struct              work;
  16         int                             page_order;     /* allocation order  */
  17 #endif
  18         int                             nr_pages;       /* nr of data pages  */
  19         int                             overwrite;      /* can overwrite itself */
  20
  21         atomic_t                        poll;           /* POLL_ for wakeups */
  22
  23         local_t                         head;           /* write position    */
  24         local_t                         nest;           /* nested writers    */
  25         local_t                         events;         /* event limit       */
  26         local_t                         wakeup;         /* wakeup stamp      */
  27         local_t                         lost;           /* nr records lost   */
  28
  29         long                            watermark;      /* wakeup watermark  */
  30         /* poll crap */
  31         spinlock_t                      event_lock;
  32         struct list_head                event_list;
  33
  34         atomic_t                        mmap_count;
  35         unsigned long                   mmap_locked;
  36         struct user_struct              *mmap_user;
  37
  38         /* AUX area */
  39         local_t                         aux_head;
  40         local_t                         aux_nest;
  41         unsigned long                   aux_pgoff;
  42         int                             aux_nr_pages;
  43         atomic_t                        aux_mmap_count;
  44         unsigned long                   aux_mmap_locked;
  45         void                            (*free_aux)(void *);
  46         atomic_t                        aux_refcount;
  47         void                            **aux_pages;
  48         void                            *aux_priv;
  49
  50         struct perf_event_mmap_page     *user_page;
  51         void                            *data_pages[0];
  52 };
  53
  54 extern void rb_free(struct ring_buffer *rb);
  55 extern struct ring_buffer *
  56 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  57 extern void perf_event_wakeup(struct perf_event *event);
  58 extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
  59                         pgoff_t pgoff, int nr_pages, int flags);
  60 extern void rb_free_aux(struct ring_buffer *rb);
  61 extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
  62 extern void ring_buffer_put(struct ring_buffer *rb);
  63
  64 static inline bool rb_has_aux(struct ring_buffer *rb)
  65 {
  66         return !!rb->aux_nr_pages;
  67 }
  68
  69 void perf_event_aux_event(struct perf_event *event, unsigned long head,
  70                           unsigned long size, u64 flags);
  71
  72 extern void
  73 perf_event_header__init_id(struct perf_event_header *header,
  74                            struct perf_sample_data *data,
  75                            struct perf_event *event);
  76 extern void
  77 perf_event__output_id_sample(struct perf_event *event,
  78                              struct perf_output_handle *handle,
  79                              struct perf_sample_data *sample);
  80
  81 extern struct page *
  82 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  83
  84 #ifdef CONFIG_PERF_USE_VMALLOC
  85 /*
  86  * Back perf_mmap() with vmalloc memory.
  87  *
  88  * Required for architectures that have d-cache aliasing issues.
  89  */
  90
  91 static inline int page_order(struct ring_buffer *rb)
  92 {
  93         return rb->page_order;
  94 }
  95
  96 #else
  97
  98 static inline int page_order(struct ring_buffer *rb)
  99 {
 100         return 0;
 101 }
 102 #endif
 103
 104 static inline unsigned long perf_data_size(struct ring_buffer *rb)
 105 {
 106         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 107 }
 108
 109 static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 110 {
 111         return rb->aux_nr_pages << PAGE_SHIFT;
 112 }
 113
 114 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
 115 static inline unsigned long                                             \
 116 func_name(struct perf_output_handle *handle,                            \
 117           const void *buf, unsigned long len)                           \
 118 {                                                                       \
 119         unsigned long size, written;                                    \
 120                                                                         \
 121         do {                                                            \
 122                 size    = min(handle->size, len);                       \
 123                 written = memcpy_func(handle->addr, buf, size);         \
 124                 written = size - written;                               \
 125                                                                         \
 126                 len -= written;                                         \
 127                 handle->addr += written;                                \
 128                 buf += written;                                         \
 129                 handle->size -= written;                                \
 130                 if (!handle->size) {                                    \
 131                         struct ring_buffer *rb = handle->rb;            \
 132                                                                         \
 133                         handle->page++;                                 \
 134                         handle->page &= rb->nr_pages - 1;               \
 135                         handle->addr = rb->data_pages[handle->page];    \
 136                         handle->size = PAGE_SIZE << page_order(rb);     \
 137                 }                                                       \
 138         } while (len && written == size);                               \
 139                                                                         \
 140         return len;                                                     \
 141 }
 142
 143 static inline unsigned long
 144 memcpy_common(void *dst, const void *src, unsigned long n)
 145 {
 146         memcpy(dst, src, n);
 147         return 0;
 148 }
 149
 150 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 151
 152 static inline unsigned long
 153 memcpy_skip(void *dst, const void *src, unsigned long n)
 154 {
 155         return 0;
 156 }
 157
 158 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 159
 160 #ifndef arch_perf_out_copy_user
 161 #define arch_perf_out_copy_user arch_perf_out_copy_user
 162
 163 static inline unsigned long
 164 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 165 {
 166         unsigned long ret;
 167
 168         pagefault_disable();
 169         ret = __copy_from_user_inatomic(dst, src, n);
 170         pagefault_enable();
 171
 172         return ret;
 173 }
 174 #endif
 175
 176 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 177
 178 /* Callchain handling */
 179 extern struct perf_callchain_entry *
 180 perf_callchain(struct perf_event *event, struct pt_regs *regs);
 181 extern int get_callchain_buffers(void);
 182 extern void put_callchain_buffers(void);
 183
 184 static inline int get_recursion_context(int *recursion)
 185 {
 186         int rctx;
 187
 188         if (in_nmi())
 189                 rctx = 3;
 190         else if (in_irq())
 191                 rctx = 2;
 192         else if (in_softirq())
 193                 rctx = 1;
 194         else
 195                 rctx = 0;
 196
 197         if (recursion[rctx])
 198                 return -1;
 199
 200         recursion[rctx]++;
 201         barrier();
 202
 203         return rctx;
 204 }
 205
 206 static inline void put_recursion_context(int *recursion, int rctx)
 207 {
 208         barrier();
 209         recursion[rctx]--;
 210 }
 211
 212 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 213 static inline bool arch_perf_have_user_stack_dump(void)
 214 {
 215         return true;
 216 }
 217
 218 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 219 #else
 220 static inline bool arch_perf_have_user_stack_dump(void)
 221 {
 222         return false;
 223 }
 224
 225 #define perf_user_stack_pointer(regs) 0
 226 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 227
 228 #endif /* _KERNEL_EVENTS_INTERNAL_H */