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