Pileus Git - ~andy/linux/blob - kernel/events/internal.h

   1 #ifndef _KERNEL_EVENTS_INTERNAL_H
   2 #define _KERNEL_EVENTS_INTERNAL_H
   3
   4 #include <linux/hardirq.h>
   5
   6 /* Buffer handling */
   7
   8 #define RING_BUFFER_WRITABLE            0x01
   9
  10 struct ring_buffer {
  11         atomic_t                        refcount;
  12         struct rcu_head                 rcu_head;
  13 #ifdef CONFIG_PERF_USE_VMALLOC
  14         struct work_struct              work;
  15         int                             page_order;     /* allocation order  */
  16 #endif
  17         int                             nr_pages;       /* nr of data pages  */
  18         int                             writable;       /* are we writable   */
  19
  20         atomic_t                        poll;           /* POLL_ for wakeups */
  21
  22         local_t                         head;           /* write position    */
  23         local_t                         nest;           /* nested writers    */
  24         local_t                         events;         /* event limit       */
  25         local_t                         wakeup;         /* wakeup stamp      */
  26         local_t                         lost;           /* nr records lost   */
  27
  28         long                            watermark;      /* wakeup watermark  */
  29
  30         struct perf_event_mmap_page     *user_page;
  31         void                            *data_pages[0];
  32 };
  33
  34 extern void rb_free(struct ring_buffer *rb);
  35 extern struct ring_buffer *
  36 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  37 extern void perf_event_wakeup(struct perf_event *event);
  38
  39 extern void
  40 perf_event_header__init_id(struct perf_event_header *header,
  41                            struct perf_sample_data *data,
  42                            struct perf_event *event);
  43 extern void
  44 perf_event__output_id_sample(struct perf_event *event,
  45                              struct perf_output_handle *handle,
  46                              struct perf_sample_data *sample);
  47
  48 extern struct page *
  49 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  50
  51 #ifdef CONFIG_PERF_USE_VMALLOC
  52 /*
  53  * Back perf_mmap() with vmalloc memory.
  54  *
  55  * Required for architectures that have d-cache aliasing issues.
  56  */
  57
  58 static inline int page_order(struct ring_buffer *rb)
  59 {
  60         return rb->page_order;
  61 }
  62
  63 #else
  64
  65 static inline int page_order(struct ring_buffer *rb)
  66 {
  67         return 0;
  68 }
  69 #endif
  70
  71 static inline unsigned long perf_data_size(struct ring_buffer *rb)
  72 {
  73         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  74 }
  75
  76 static inline void
  77 __output_copy(struct perf_output_handle *handle,
  78                    const void *buf, unsigned int len)
  79 {
  80         do {
  81                 unsigned long size = min_t(unsigned long, handle->size, len);
  82
  83                 memcpy(handle->addr, buf, size);
  84
  85                 len -= size;
  86                 handle->addr += size;
  87                 buf += size;
  88                 handle->size -= size;
  89                 if (!handle->size) {
  90                         struct ring_buffer *rb = handle->rb;
  91
  92                         handle->page++;
  93                         handle->page &= rb->nr_pages - 1;
  94                         handle->addr = rb->data_pages[handle->page];
  95                         handle->size = PAGE_SIZE << page_order(rb);
  96                 }
  97         } while (len);
  98 }
  99
 100 /* Callchain handling */
 101 extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
 102 extern int get_callchain_buffers(void);
 103 extern void put_callchain_buffers(void);
 104
 105 static inline int get_recursion_context(int *recursion)
 106 {
 107         int rctx;
 108
 109         if (in_nmi())
 110                 rctx = 3;
 111         else if (in_irq())
 112                 rctx = 2;
 113         else if (in_softirq())
 114                 rctx = 1;
 115         else
 116                 rctx = 0;
 117
 118         if (recursion[rctx])
 119                 return -1;
 120
 121         recursion[rctx]++;
 122         barrier();
 123
 124         return rctx;
 125 }
 126
 127 static inline void put_recursion_context(int *recursion, int rctx)
 128 {
 129         barrier();
 130         recursion[rctx]--;
 131 }
 132
 133 #endif /* _KERNEL_EVENTS_INTERNAL_H */