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         atomic_t                        mmap_count;
  35         unsigned long                   mmap_locked;
  36         struct user_struct              *mmap_user;
  37
  38         struct perf_event_mmap_page     *user_page;
  39         void                            *data_pages[0];
  40 };
  41
  42 extern void rb_free(struct ring_buffer *rb);
  43 extern struct ring_buffer *
  44 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  45 extern void perf_event_wakeup(struct perf_event *event);
  46
  47 extern void
  48 perf_event_header__init_id(struct perf_event_header *header,
  49                            struct perf_sample_data *data,
  50                            struct perf_event *event);
  51 extern void
  52 perf_event__output_id_sample(struct perf_event *event,
  53                              struct perf_output_handle *handle,
  54                              struct perf_sample_data *sample);
  55
  56 extern struct page *
  57 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  58
  59 #ifdef CONFIG_PERF_USE_VMALLOC
  60 /*
  61  * Back perf_mmap() with vmalloc memory.
  62  *
  63  * Required for architectures that have d-cache aliasing issues.
  64  */
  65
  66 static inline int page_order(struct ring_buffer *rb)
  67 {
  68         return rb->page_order;
  69 }
  70
  71 #else
  72
  73 static inline int page_order(struct ring_buffer *rb)
  74 {
  75         return 0;
  76 }
  77 #endif
  78
  79 static inline unsigned long perf_data_size(struct ring_buffer *rb)
  80 {
  81         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
  82 }
  83
  84 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
  85 static inline unsigned long                                             \
  86 func_name(struct perf_output_handle *handle,                            \
  87           const void *buf, unsigned long len)                           \
  88 {                                                                       \
  89         unsigned long size, written;                                    \
  90                                                                         \
  91         do {                                                            \
  92                 size    = min(handle->size, len);                       \
  93                 written = memcpy_func(handle->addr, buf, size);         \
  94                 written = size - written;                               \
  95                                                                         \
  96                 len -= written;                                         \
  97                 handle->addr += written;                                \
  98                 buf += written;                                         \
  99                 handle->size -= written;                                \
 100                 if (!handle->size) {                                    \
 101                         struct ring_buffer *rb = handle->rb;            \
 102                                                                         \
 103                         handle->page++;                                 \
 104                         handle->page &= rb->nr_pages - 1;               \
 105                         handle->addr = rb->data_pages[handle->page];    \
 106                         handle->size = PAGE_SIZE << page_order(rb);     \
 107                 }                                                       \
 108         } while (len && written == size);                               \
 109                                                                         \
 110         return len;                                                     \
 111 }
 112
 113 static inline unsigned long
 114 memcpy_common(void *dst, const void *src, unsigned long n)
 115 {
 116         memcpy(dst, src, n);
 117         return 0;
 118 }
 119
 120 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 121
 122 static inline unsigned long
 123 memcpy_skip(void *dst, const void *src, unsigned long n)
 124 {
 125         return 0;
 126 }
 127
 128 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 129
 130 #ifndef arch_perf_out_copy_user
 131 #define arch_perf_out_copy_user arch_perf_out_copy_user
 132
 133 static inline unsigned long
 134 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 135 {
 136         unsigned long ret;
 137
 138         pagefault_disable();
 139         ret = __copy_from_user_inatomic(dst, src, n);
 140         pagefault_enable();
 141
 142         return ret;
 143 }
 144 #endif
 145
 146 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 147
 148 /* Callchain handling */
 149 extern struct perf_callchain_entry *
 150 perf_callchain(struct perf_event *event, struct pt_regs *regs);
 151 extern int get_callchain_buffers(void);
 152 extern void put_callchain_buffers(void);
 153
 154 static inline int get_recursion_context(int *recursion)
 155 {
 156         int rctx;
 157
 158         if (in_nmi())
 159                 rctx = 3;
 160         else if (in_irq())
 161                 rctx = 2;
 162         else if (in_softirq())
 163                 rctx = 1;
 164         else
 165                 rctx = 0;
 166
 167         if (recursion[rctx])
 168                 return -1;
 169
 170         recursion[rctx]++;
 171         barrier();
 172
 173         return rctx;
 174 }
 175
 176 static inline void put_recursion_context(int *recursion, int rctx)
 177 {
 178         barrier();
 179         recursion[rctx]--;
 180 }
 181
 182 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 183 static inline bool arch_perf_have_user_stack_dump(void)
 184 {
 185         return true;
 186 }
 187
 188 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 189 #else
 190 static inline bool arch_perf_have_user_stack_dump(void)
 191 {
 192         return false;
 193 }
 194
 195 #define perf_user_stack_pointer(regs) 0
 196 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 197
 198 #endif /* _KERNEL_EVENTS_INTERNAL_H */