kernel/events/internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _KERNEL_EVENTS_INTERNAL_H
   3 #define _KERNEL_EVENTS_INTERNAL_H
   4
   5 #include <linux/hardirq.h>
   6 #include <linux/uaccess.h>
   7 #include <linux/refcount.h>
   8
   9 /* Buffer handling */
  10
  11 #define RING_BUFFER_WRITABLE            0x01
  12
  13 struct ring_buffer {
  14         refcount_t                      refcount;
  15         struct rcu_head                 rcu_head;
  16 #ifdef CONFIG_PERF_USE_VMALLOC
  17         struct work_struct              work;
  18         int                             page_order;     /* allocation order  */
  19 #endif
  20         int                             nr_pages;       /* nr of data pages  */
  21         int                             overwrite;      /* can overwrite itself */
  22         int                             paused;         /* can write into ring buffer */
  23
  24         atomic_t                        poll;           /* POLL_ for wakeups */
  25
  26         local_t                         head;           /* write position    */
  27         unsigned int                    nest;           /* nested writers    */
  28         local_t                         events;         /* event limit       */
  29         local_t                         wakeup;         /* wakeup stamp      */
  30         local_t                         lost;           /* nr records lost   */
  31
  32         long                            watermark;      /* wakeup watermark  */
  33         long                            aux_watermark;
  34         /* poll crap */
  35         spinlock_t                      event_lock;
  36         struct list_head                event_list;
  37
  38         atomic_t                        mmap_count;
  39         unsigned long                   mmap_locked;
  40         struct user_struct              *mmap_user;
  41
  42         /* AUX area */
  43         long                            aux_head;
  44         unsigned int                    aux_nest;
  45         long                            aux_wakeup;     /* last aux_watermark boundary crossed by aux_head */
  46         unsigned long                   aux_pgoff;
  47         int                             aux_nr_pages;
  48         int                             aux_overwrite;
  49         atomic_t                        aux_mmap_count;
  50         unsigned long                   aux_mmap_locked;
  51         void                            (*free_aux)(void *);
  52         refcount_t                      aux_refcount;
  53         void                            **aux_pages;
  54         void                            *aux_priv;
  55
  56         struct perf_event_mmap_page     *user_page;
  57         void                            *data_pages[0];
  58 };
  59
  60 extern void rb_free(struct ring_buffer *rb);
  61
  62 static inline void rb_free_rcu(struct rcu_head *rcu_head)
  63 {
  64         struct ring_buffer *rb;
  65
  66         rb = container_of(rcu_head, struct ring_buffer, rcu_head);
  67         rb_free(rb);
  68 }
  69
  70 static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
  71 {
  72         if (!pause && rb->nr_pages)
  73                 rb->paused = 0;
  74         else
  75                 rb->paused = 1;
  76 }
  77
  78 extern struct ring_buffer *
  79 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  80 extern void perf_event_wakeup(struct perf_event *event);
  81 extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
  82                         pgoff_t pgoff, int nr_pages, long watermark, int flags);
  83 extern void rb_free_aux(struct ring_buffer *rb);
  84 extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
  85 extern void ring_buffer_put(struct ring_buffer *rb);
  86
  87 static inline bool rb_has_aux(struct ring_buffer *rb)
  88 {
  89         return !!rb->aux_nr_pages;
  90 }
  91
  92 void perf_event_aux_event(struct perf_event *event, unsigned long head,
  93                           unsigned long size, u64 flags);
  94
  95 extern struct page *
  96 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  97
  98 #ifdef CONFIG_PERF_USE_VMALLOC
  99 /*
 100  * Back perf_mmap() with vmalloc memory.
 101  *
 102  * Required for architectures that have d-cache aliasing issues.
 103  */
 104
 105 static inline int page_order(struct ring_buffer *rb)
 106 {
 107         return rb->page_order;
 108 }
 109
 110 #else
 111
 112 static inline int page_order(struct ring_buffer *rb)
 113 {
 114         return 0;
 115 }
 116 #endif
 117
 118 static inline unsigned long perf_data_size(struct ring_buffer *rb)
 119 {
 120         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 121 }
 122
 123 static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 124 {
 125         return rb->aux_nr_pages << PAGE_SHIFT;
 126 }
 127
 128 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)        \
 129 {                                                                       \
 130         unsigned long size, written;                                    \
 131                                                                         \
 132         do {                                                            \
 133                 size    = min(handle->size, len);                       \
 134                 written = memcpy_func(__VA_ARGS__);                     \
 135                 written = size - written;                               \
 136                                                                         \
 137                 len -= written;                                         \
 138                 handle->addr += written;                                \
 139                 if (advance_buf)                                        \
 140                         buf += written;                                 \
 141                 handle->size -= written;                                \
 142                 if (!handle->size) {                                    \
 143                         struct ring_buffer *rb = handle->rb;            \
 144                                                                         \
 145                         handle->page++;                                 \
 146                         handle->page &= rb->nr_pages - 1;               \
 147                         handle->addr = rb->data_pages[handle->page];    \
 148                         handle->size = PAGE_SIZE << page_order(rb);     \
 149                 }                                                       \
 150         } while (len && written == size);                               \
 151                                                                         \
 152         return len;                                                     \
 153 }
 154
 155 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
 156 static inline unsigned long                                             \
 157 func_name(struct perf_output_handle *handle,                            \
 158           const void *buf, unsigned long len)                           \
 159 __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)
 160
 161 static inline unsigned long
 162 __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
 163                 const void *buf, unsigned long len)
 164 {
 165         unsigned long orig_len = len;
 166         __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
 167                                   orig_len - len, size)
 168 }
 169
 170 static inline unsigned long
 171 memcpy_common(void *dst, const void *src, unsigned long n)
 172 {
 173         memcpy(dst, src, n);
 174         return 0;
 175 }
 176
 177 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 178
 179 static inline unsigned long
 180 memcpy_skip(void *dst, const void *src, unsigned long n)
 181 {
 182         return 0;
 183 }
 184
 185 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 186
 187 #ifndef arch_perf_out_copy_user
 188 #define arch_perf_out_copy_user arch_perf_out_copy_user
 189
 190 static inline unsigned long
 191 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 192 {
 193         unsigned long ret;
 194
 195         pagefault_disable();
 196         ret = __copy_from_user_inatomic(dst, src, n);
 197         pagefault_enable();
 198
 199         return ret;
 200 }
 201 #endif
 202
 203 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 204
 205 static inline int get_recursion_context(int *recursion)
 206 {
 207         int rctx;
 208
 209         if (unlikely(in_nmi()))
 210                 rctx = 3;
 211         else if (in_irq())
 212                 rctx = 2;
 213         else if (in_softirq())
 214                 rctx = 1;
 215         else
 216                 rctx = 0;
 217
 218         if (recursion[rctx])
 219                 return -1;
 220
 221         recursion[rctx]++;
 222         barrier();
 223
 224         return rctx;
 225 }
 226
 227 static inline void put_recursion_context(int *recursion, int rctx)
 228 {
 229         barrier();
 230         recursion[rctx]--;
 231 }
 232
 233 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 234 static inline bool arch_perf_have_user_stack_dump(void)
 235 {
 236         return true;
 237 }
 238
 239 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 240 #else
 241 static inline bool arch_perf_have_user_stack_dump(void)
 242 {
 243         return false;
 244 }
 245
 246 #define perf_user_stack_pointer(regs) 0
 247 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 248
 249 #endif /* _KERNEL_EVENTS_INTERNAL_H */