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         /* AUX area */
  39         local_t                         aux_head;
  40         local_t                         aux_nest;
  41         unsigned long                   aux_pgoff;
  42         int                             aux_nr_pages;
  43         int                             aux_overwrite;
  44         atomic_t                        aux_mmap_count;
  45         unsigned long                   aux_mmap_locked;
  46         void                            (*free_aux)(void *);
  47         atomic_t                        aux_refcount;
  48         void                            **aux_pages;
  49         void                            *aux_priv;
  50
  51         struct perf_event_mmap_page     *user_page;
  52         void                            *data_pages[0];
  53 };
  54
  55 extern void rb_free(struct ring_buffer *rb);
  56 extern struct ring_buffer *
  57 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  58 extern void perf_event_wakeup(struct perf_event *event);
  59 extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
  60                         pgoff_t pgoff, int nr_pages, int flags);
  61 extern void rb_free_aux(struct ring_buffer *rb);
  62 extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
  63 extern void ring_buffer_put(struct ring_buffer *rb);
  64
  65 static inline bool rb_has_aux(struct ring_buffer *rb)
  66 {
  67         return !!rb->aux_nr_pages;
  68 }
  69
  70 void perf_event_aux_event(struct perf_event *event, unsigned long head,
  71                           unsigned long size, u64 flags);
  72
  73 extern void
  74 perf_event_header__init_id(struct perf_event_header *header,
  75                            struct perf_sample_data *data,
  76                            struct perf_event *event);
  77 extern void
  78 perf_event__output_id_sample(struct perf_event *event,
  79                              struct perf_output_handle *handle,
  80                              struct perf_sample_data *sample);
  81
  82 extern struct page *
  83 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  84
  85 #ifdef CONFIG_PERF_USE_VMALLOC
  86 /*
  87  * Back perf_mmap() with vmalloc memory.
  88  *
  89  * Required for architectures that have d-cache aliasing issues.
  90  */
  91
  92 static inline int page_order(struct ring_buffer *rb)
  93 {
  94         return rb->page_order;
  95 }
  96
  97 #else
  98
  99 static inline int page_order(struct ring_buffer *rb)
 100 {
 101         return 0;
 102 }
 103 #endif
 104
 105 static inline unsigned long perf_data_size(struct ring_buffer *rb)
 106 {
 107         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 108 }
 109
 110 static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 111 {
 112         return rb->aux_nr_pages << PAGE_SHIFT;
 113 }
 114
 115 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
 116 static inline unsigned long                                             \
 117 func_name(struct perf_output_handle *handle,                            \
 118           const void *buf, unsigned long len)                           \
 119 {                                                                       \
 120         unsigned long size, written;                                    \
 121                                                                         \
 122         do {                                                            \
 123                 size    = min(handle->size, len);                       \
 124                 written = memcpy_func(handle->addr, buf, size);         \
 125                 written = size - written;                               \
 126                                                                         \
 127                 len -= written;                                         \
 128                 handle->addr += written;                                \
 129                 buf += written;                                         \
 130                 handle->size -= written;                                \
 131                 if (!handle->size) {                                    \
 132                         struct ring_buffer *rb = handle->rb;            \
 133                                                                         \
 134                         handle->page++;                                 \
 135                         handle->page &= rb->nr_pages - 1;               \
 136                         handle->addr = rb->data_pages[handle->page];    \
 137                         handle->size = PAGE_SIZE << page_order(rb);     \
 138                 }                                                       \
 139         } while (len && written == size);                               \
 140                                                                         \
 141         return len;                                                     \
 142 }
 143
 144 static inline unsigned long
 145 memcpy_common(void *dst, const void *src, unsigned long n)
 146 {
 147         memcpy(dst, src, n);
 148         return 0;
 149 }
 150
 151 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 152
 153 static inline unsigned long
 154 memcpy_skip(void *dst, const void *src, unsigned long n)
 155 {
 156         return 0;
 157 }
 158
 159 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 160
 161 #ifndef arch_perf_out_copy_user
 162 #define arch_perf_out_copy_user arch_perf_out_copy_user
 163
 164 static inline unsigned long
 165 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 166 {
 167         unsigned long ret;
 168
 169         pagefault_disable();
 170         ret = __copy_from_user_inatomic(dst, src, n);
 171         pagefault_enable();
 172
 173         return ret;
 174 }
 175 #endif
 176
 177 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 178
 179 /* Callchain handling */
 180 extern struct perf_callchain_entry *
 181 perf_callchain(struct perf_event *event, struct pt_regs *regs);
 182 extern int get_callchain_buffers(void);
 183 extern void put_callchain_buffers(void);
 184
 185 static inline int get_recursion_context(int *recursion)
 186 {
 187         int rctx;
 188
 189         if (in_nmi())
 190                 rctx = 3;
 191         else if (in_irq())
 192                 rctx = 2;
 193         else if (in_softirq())
 194                 rctx = 1;
 195         else
 196                 rctx = 0;
 197
 198         if (recursion[rctx])
 199                 return -1;
 200
 201         recursion[rctx]++;
 202         barrier();
 203
 204         return rctx;
 205 }
 206
 207 static inline void put_recursion_context(int *recursion, int rctx)
 208 {
 209         barrier();
 210         recursion[rctx]--;
 211 }
 212
 213 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 214 static inline bool arch_perf_have_user_stack_dump(void)
 215 {
 216         return true;
 217 }
 218
 219 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 220 #else
 221 static inline bool arch_perf_have_user_stack_dump(void)
 222 {
 223         return false;
 224 }
 225
 226 #define perf_user_stack_pointer(regs) 0
 227 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 228
 229 #endif /* _KERNEL_EVENTS_INTERNAL_H */