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