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