LXR linux/kernel/events/internal.h

   1#ifndef _KERNEL_EVENTS_INTERNAL_H
   2#define _KERNEL_EVENTS_INTERNAL_H
   3
   4#define RING_BUFFER_WRITABLE            0x01
   5
   6struct 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
  30extern void rb_free(struct ring_buffer *rb);
  31extern struct ring_buffer *
  32rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  33extern void perf_event_wakeup(struct perf_event *event);
  34
  35extern void
  36perf_event_header__init_id(struct perf_event_header *header,
  37                           struct perf_sample_data *data,
  38                           struct perf_event *event);
  39extern void
  40perf_event__output_id_sample(struct perf_event *event,
  41                             struct perf_output_handle *handle,
  42                             struct perf_sample_data *sample);
  43
  44extern struct page *
  45perf_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
  54static inline int page_order(struct ring_buffer *rb)
  55{
  56        return rb->page_order;
  57}
  58
  59#else
  60
  61static inline int page_order(struct ring_buffer *rb)
  62{
  63        return 0;
  64}
  65#endif
  66
  67static unsigned long perf_data_size(struct ring_buffer *rb)
  68{
  69        return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  70}
  71
  72static 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 */
  97