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         int                             paused;         /* can write into ring buffer */
  21
  22         atomic_t                        poll;           /* POLL_ for wakeups */
  23
  24         local_t                         head;           /* write position    */
  25         local_t                         nest;           /* nested writers    */
  26         local_t                         events;         /* event limit       */
  27         local_t                         wakeup;         /* wakeup stamp      */
  28         local_t                         lost;           /* nr records lost   */
  29
  30         long                            watermark;      /* wakeup watermark  */
  31         long                            aux_watermark;
  32         /* poll crap */
  33         spinlock_t                      event_lock;
  34         struct list_head                event_list;
  35
  36         atomic_t                        mmap_count;
  37         unsigned long                   mmap_locked;
  38         struct user_struct              *mmap_user;
  39
  40         /* AUX area */
  41         local_t                         aux_head;
  42         local_t                         aux_nest;
  43         local_t                         aux_wakeup;
  44         unsigned long                   aux_pgoff;
  45         int                             aux_nr_pages;
  46         int                             aux_overwrite;
  47         atomic_t                        aux_mmap_count;
  48         unsigned long                   aux_mmap_locked;
  49         void                            (*free_aux)(void *);
  50         atomic_t                        aux_refcount;
  51         void                            **aux_pages;
  52         void                            *aux_priv;
  53
  54         struct perf_event_mmap_page     *user_page;
  55         void                            *data_pages[0];
  56 };
  57
  58 extern void rb_free(struct ring_buffer *rb);
  59
  60 static inline void rb_free_rcu(struct rcu_head *rcu_head)
  61 {
  62         struct ring_buffer *rb;
  63
  64         rb = container_of(rcu_head, struct ring_buffer, rcu_head);
  65         rb_free(rb);
  66 }
  67
  68 static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
  69 {
  70         if (!pause && rb->nr_pages)
  71                 rb->paused = 0;
  72         else
  73                 rb->paused = 1;
  74 }
  75
  76 extern struct ring_buffer *
  77 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  78 extern void perf_event_wakeup(struct perf_event *event);
  79 extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
  80                         pgoff_t pgoff, int nr_pages, long watermark, int flags);
  81 extern void rb_free_aux(struct ring_buffer *rb);
  82 extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
  83 extern void ring_buffer_put(struct ring_buffer *rb);
  84
  85 static inline bool rb_has_aux(struct ring_buffer *rb)
  86 {
  87         return !!rb->aux_nr_pages;
  88 }
  89
  90 void perf_event_aux_event(struct perf_event *event, unsigned long head,
  91                           unsigned long size, u64 flags);
  92
  93 extern struct page *
  94 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  95
  96 #ifdef CONFIG_PERF_USE_VMALLOC
  97 /*
  98  * Back perf_mmap() with vmalloc memory.
  99  *
 100  * Required for architectures that have d-cache aliasing issues.
 101  */
 102
 103 static inline int page_order(struct ring_buffer *rb)
 104 {
 105         return rb->page_order;
 106 }
 107
 108 #else
 109
 110 static inline int page_order(struct ring_buffer *rb)
 111 {
 112         return 0;
 113 }
 114 #endif
 115
 116 static inline unsigned long perf_data_size(struct ring_buffer *rb)
 117 {
 118         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 119 }
 120
 121 static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 122 {
 123         return rb->aux_nr_pages << PAGE_SHIFT;
 124 }
 125
 126 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)        \
 127 {                                                                       \
 128         unsigned long size, written;                                    \
 129                                                                         \
 130         do {                                                            \
 131                 size    = min(handle->size, len);                       \
 132                 written = memcpy_func(__VA_ARGS__);                     \
 133                 written = size - written;                               \
 134                                                                         \
 135                 len -= written;                                         \
 136                 handle->addr += written;                                \
 137                 if (advance_buf)                                        \
 138                         buf += written;                                 \
 139                 handle->size -= written;                                \
 140                 if (!handle->size) {                                    \
 141                         struct ring_buffer *rb = handle->rb;            \
 142                                                                         \
 143                         handle->page++;                                 \
 144                         handle->page &= rb->nr_pages - 1;               \
 145                         handle->addr = rb->data_pages[handle->page];    \
 146                         handle->size = PAGE_SIZE << page_order(rb);     \
 147                 }                                                       \
 148         } while (len && written == size);                               \
 149                                                                         \
 150         return len;                                                     \
 151 }
 152
 153 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
 154 static inline unsigned long                                             \
 155 func_name(struct perf_output_handle *handle,                            \
 156           const void *buf, unsigned long len)                           \
 157 __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)
 158
 159 static inline unsigned long
 160 __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
 161                 const void *buf, unsigned long len)
 162 {
 163         unsigned long orig_len = len;
 164         __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
 165                                   orig_len - len, size)
 166 }
 167
 168 static inline unsigned long
 169 memcpy_common(void *dst, const void *src, unsigned long n)
 170 {
 171         memcpy(dst, src, n);
 172         return 0;
 173 }
 174
 175 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 176
 177 static inline unsigned long
 178 memcpy_skip(void *dst, const void *src, unsigned long n)
 179 {
 180         return 0;
 181 }
 182
 183 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 184
 185 #ifndef arch_perf_out_copy_user
 186 #define arch_perf_out_copy_user arch_perf_out_copy_user
 187
 188 static inline unsigned long
 189 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 190 {
 191         unsigned long ret;
 192
 193         pagefault_disable();
 194         ret = __copy_from_user_inatomic(dst, src, n);
 195         pagefault_enable();
 196
 197         return ret;
 198 }
 199 #endif
 200
 201 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 202
 203 /* Callchain handling */
 204 extern struct perf_callchain_entry *
 205 perf_callchain(struct perf_event *event, struct pt_regs *regs);
 206
 207 static inline int get_recursion_context(int *recursion)
 208 {
 209         int rctx;
 210
 211         if (in_nmi())
 212                 rctx = 3;
 213         else if (in_irq())
 214                 rctx = 2;
 215         else if (in_softirq())
 216                 rctx = 1;
 217         else
 218                 rctx = 0;
 219
 220         if (recursion[rctx])
 221                 return -1;
 222
 223         recursion[rctx]++;
 224         barrier();
 225
 226         return rctx;
 227 }
 228
 229 static inline void put_recursion_context(int *recursion, int rctx)
 230 {
 231         barrier();
 232         recursion[rctx]--;
 233 }
 234
 235 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 236 static inline bool arch_perf_have_user_stack_dump(void)
 237 {
 238         return true;
 239 }
 240
 241 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 242 #else
 243 static inline bool arch_perf_have_user_stack_dump(void)
 244 {
 245         return false;
 246 }
 247
 248 #define perf_user_stack_pointer(regs) 0
 249 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 250
 251 #endif /* _KERNEL_EVENTS_INTERNAL_H */