kernel/events/internal.h

   1 #ifndef _KERNEL_EVENTS_INTERNAL_H
   2 #define _KERNEL_EVENTS_INTERNAL_H
   3
   4 #define RING_BUFFER_WRITABLE            0x01
   5
   6 struct ring_buffer {
   7         atomic_t                        refcount;
   8         struct rcu_head                 rcu_head;
   9 #ifdef CONFIG_PERF_USE_VMALLOC
  10         struct work_struct              work;
  11         int                             page_order;     /* allocation order  */
  12 #endif
  13         int                             nr_pages;       /* nr of data pages  */
  14         int                             writable;       /* are we writable   */
  15
  16         atomic_t                        poll;           /* POLL_ for wakeups */
  17
  18         local_t                         head;           /* write position    */
  19         local_t                         nest;           /* nested writers    */
  20         local_t                         events;         /* event limit       */
  21         local_t                         wakeup;         /* wakeup stamp      */
  22         local_t                         lost;           /* nr records lost   */
  23
  24         long                            watermark;      /* wakeup watermark  */
  25         /* poll crap */
  26         spinlock_t                      event_lock;
  27         struct list_head                event_list;
  28
  29         struct perf_event_mmap_page     *user_page;
  30         void                            *data_pages[0];
  31 };
  32
  33 extern void rb_free(struct ring_buffer *rb);
  34 extern struct ring_buffer *
  35 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  36 extern void perf_event_wakeup(struct perf_event *event);
  37
  38 extern void
  39 perf_event_header__init_id(struct perf_event_header *header,
  40                            struct perf_sample_data *data,
  41                            struct perf_event *event);
  42 extern void
  43 perf_event__output_id_sample(struct perf_event *event,
  44                              struct perf_output_handle *handle,
  45                              struct perf_sample_data *sample);
  46
  47 extern struct page *
  48 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  49
  50 #ifdef CONFIG_PERF_USE_VMALLOC
  51 /*
  52  * Back perf_mmap() with vmalloc memory.
  53  *
  54  * Required for architectures that have d-cache aliasing issues.
  55  */
  56
  57 static inline int page_order(struct ring_buffer *rb)
  58 {
  59         return rb->page_order;
  60 }
  61
  62 #else
  63
  64 static inline int page_order(struct ring_buffer *rb)
  65 {
  66         return 0;
  67 }
  68 #endif
  69
  70 static unsigned long perf_data_size(struct ring_buffer *rb)
  71 {
  72         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  73 }
  74
  75 static inline void
  76 __output_copy(struct perf_output_handle *handle,
  77                    const void *buf, unsigned int len)
  78 {
  79         do {
  80                 unsigned long size = min_t(unsigned long, handle->size, len);
  81
  82                 memcpy(handle->addr, buf, size);
  83
  84                 len -= size;
  85                 handle->addr += size;
  86                 buf += size;
  87                 handle->size -= size;
  88                 if (!handle->size) {
  89                         struct ring_buffer *rb = handle->rb;
  90
  91                         handle->page++;
  92                         handle->page &= rb->nr_pages - 1;
  93                         handle->addr = rb->data_pages[handle->page];
  94                         handle->size = PAGE_SIZE << page_order(rb);
  95                 }
  96         } while (len);
  97 }
  98
  99 #endif /* _KERNEL_EVENTS_INTERNAL_H */