linux/kernel/events/internal.h
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   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
  11struct 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
  58extern void rb_free(struct ring_buffer *rb);
  59
  60static 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
  68extern struct ring_buffer *
  69rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  70extern void perf_event_wakeup(struct perf_event *event);
  71extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
  72                        pgoff_t pgoff, int nr_pages, long watermark, int flags);
  73extern void rb_free_aux(struct ring_buffer *rb);
  74extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
  75extern void ring_buffer_put(struct ring_buffer *rb);
  76
  77static inline bool rb_has_aux(struct ring_buffer *rb)
  78{
  79        return !!rb->aux_nr_pages;
  80}
  81
  82void perf_event_aux_event(struct perf_event *event, unsigned long head,
  83                          unsigned long size, u64 flags);
  84
  85extern struct page *
  86perf_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
  95static inline int page_order(struct ring_buffer *rb)
  96{
  97        return rb->page_order;
  98}
  99
 100#else
 101
 102static inline int page_order(struct ring_buffer *rb)
 103{
 104        return 0;
 105}
 106#endif
 107
 108static inline unsigned long perf_data_size(struct ring_buffer *rb)
 109{
 110        return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 111}
 112
 113static 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)                      \
 119static inline unsigned long                                             \
 120func_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
 147static inline unsigned long
 148memcpy_common(void *dst, const void *src, unsigned long n)
 149{
 150        memcpy(dst, src, n);
 151        return 0;
 152}
 153
 154DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 155
 156static inline unsigned long
 157memcpy_skip(void *dst, const void *src, unsigned long n)
 158{
 159        return 0;
 160}
 161
 162DEFINE_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
 167static inline unsigned long
 168arch_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
 180DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 181
 182/* Callchain handling */
 183extern struct perf_callchain_entry *
 184perf_callchain(struct perf_event *event, struct pt_regs *regs);
 185
 186static 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
 208static 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
 215static 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
 222static 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 */
 231