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
  26         struct perf_event_mmap_page     *user_page;
  27         void                            *data_pages[0];
  28 };
  29
  30 extern void rb_free(struct ring_buffer *rb);
  31 extern struct ring_buffer *
  32 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  33 extern void perf_event_wakeup(struct perf_event *event);
  34
  35 extern void
  36 perf_event_header__init_id(struct perf_event_header *header,
  37                            struct perf_sample_data *data,
  38                            struct perf_event *event);
  39 extern void
  40 perf_event__output_id_sample(struct perf_event *event,
  41                              struct perf_output_handle *handle,
  42                              struct perf_sample_data *sample);
  43
  44 extern struct page *
  45 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  46
  47 #ifdef CONFIG_PERF_USE_VMALLOC
  48 /*
  49  * Back perf_mmap() with vmalloc memory.
  50  *
  51  * Required for architectures that have d-cache aliasing issues.
  52  */
  53
  54 static inline int page_order(struct ring_buffer *rb)
  55 {
  56         return rb->page_order;
  57 }
  58
  59 #else
  60
  61 static inline int page_order(struct ring_buffer *rb)
  62 {
  63         return 0;
  64 }
  65 #endif
  66
  67 static unsigned long perf_data_size(struct ring_buffer *rb)
  68 {
  69         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  70 }
  71
  72 static inline void
  73 __output_copy(struct perf_output_handle *handle,
  74                    const void *buf, unsigned int len)
  75 {
  76         do {
  77                 unsigned long size = min_t(unsigned long, handle->size, len);
  78
  79                 memcpy(handle->addr, buf, size);
  80
  81                 len -= size;
  82                 handle->addr += size;
  83                 buf += size;
  84                 handle->size -= size;
  85                 if (!handle->size) {
  86                         struct ring_buffer *rb = handle->rb;
  87
  88                         handle->page++;
  89                         handle->page &= rb->nr_pages - 1;
  90                         handle->addr = rb->data_pages[handle->page];
  91                         handle->size = PAGE_SIZE << page_order(rb);
  92                 }
  93         } while (len);
  94 }
  95
  96 #endif /* _KERNEL_EVENTS_INTERNAL_H */