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         struct perf_event_mmap_page     *user_page;
  35         void                            *data_pages[0];
  36 };
  37
  38 extern void rb_free(struct ring_buffer *rb);
  39 extern struct ring_buffer *
  40 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  41 extern void perf_event_wakeup(struct perf_event *event);
  42
  43 extern void
  44 perf_event_header__init_id(struct perf_event_header *header,
  45                            struct perf_sample_data *data,
  46                            struct perf_event *event);
  47 extern void
  48 perf_event__output_id_sample(struct perf_event *event,
  49                              struct perf_output_handle *handle,
  50                              struct perf_sample_data *sample);
  51
  52 extern struct page *
  53 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  54
  55 #ifdef CONFIG_PERF_USE_VMALLOC
  56 /*
  57  * Back perf_mmap() with vmalloc memory.
  58  *
  59  * Required for architectures that have d-cache aliasing issues.
  60  */
  61
  62 static inline int page_order(struct ring_buffer *rb)
  63 {
  64         return rb->page_order;
  65 }
  66
  67 #else
  68
  69 static inline int page_order(struct ring_buffer *rb)
  70 {
  71         return 0;
  72 }
  73 #endif
  74
  75 static inline unsigned long perf_data_size(struct ring_buffer *rb)
  76 {
  77         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  78 }
  79
  80 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
  81 static inline unsigned int                                              \
  82 func_name(struct perf_output_handle *handle,                            \
  83           const void *buf, unsigned int len)                            \
  84 {                                                                       \
  85         unsigned long size, written;                                    \
  86                                                                         \
  87         do {                                                            \
  88                 size = min_t(unsigned long, handle->size, len);         \
  89                                                                         \
  90                 written = memcpy_func(handle->addr, buf, size);         \
  91                                                                         \
  92                 len -= written;                                         \
  93                 handle->addr += written;                                \
  94                 buf += written;                                         \
  95                 handle->size -= written;                                \
  96                 if (!handle->size) {                                    \
  97                         struct ring_buffer *rb = handle->rb;            \
  98                                                                         \
  99                         handle->page++;                                 \
 100                         handle->page &= rb->nr_pages - 1;               \
 101                         handle->addr = rb->data_pages[handle->page];    \
 102                         handle->size = PAGE_SIZE << page_order(rb);     \
 103                 }                                                       \
 104         } while (len && written == size);                               \
 105                                                                         \
 106         return len;                                                     \
 107 }
 108
 109 static inline int memcpy_common(void *dst, const void *src, size_t n)
 110 {
 111         memcpy(dst, src, n);
 112         return n;
 113 }
 114
 115 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 116
 117 #define MEMCPY_SKIP(dst, src, n) (n)
 118
 119 DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP)
 120
 121 #ifndef arch_perf_out_copy_user
 122 #define arch_perf_out_copy_user __copy_from_user_inatomic
 123 #endif
 124
 125 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 126
 127 /* Callchain handling */
 128 extern struct perf_callchain_entry *
 129 perf_callchain(struct perf_event *event, struct pt_regs *regs);
 130 extern int get_callchain_buffers(void);
 131 extern void put_callchain_buffers(void);
 132
 133 static inline int get_recursion_context(int *recursion)
 134 {
 135         int rctx;
 136
 137         if (in_nmi())
 138                 rctx = 3;
 139         else if (in_irq())
 140                 rctx = 2;
 141         else if (in_softirq())
 142                 rctx = 1;
 143         else
 144                 rctx = 0;
 145
 146         if (recursion[rctx])
 147                 return -1;
 148
 149         recursion[rctx]++;
 150         barrier();
 151
 152         return rctx;
 153 }
 154
 155 static inline void put_recursion_context(int *recursion, int rctx)
 156 {
 157         barrier();
 158         recursion[rctx]--;
 159 }
 160
 161 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 162 static inline bool arch_perf_have_user_stack_dump(void)
 163 {
 164         return true;
 165 }
 166
 167 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 168 #else
 169 static inline bool arch_perf_have_user_stack_dump(void)
 170 {
 171         return false;
 172 }
 173
 174 #define perf_user_stack_pointer(regs) 0
 175 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 176
 177 #endif /* _KERNEL_EVENTS_INTERNAL_H */