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 perf_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         struct mutex                    aux_mutex;
  44         long                            aux_head;
  45         unsigned int                    aux_nest;
  46         long                            aux_wakeup;     /* last aux_watermark boundary crossed by aux_head */
  47         unsigned long                   aux_pgoff;
  48         int                             aux_nr_pages;
  49         int                             aux_overwrite;
  50         atomic_t                        aux_mmap_count;
  51         unsigned long                   aux_mmap_locked;
  52         void                            (*free_aux)(void *);
  53         refcount_t                      aux_refcount;
  54         int                             aux_in_sampling;
  55         int                             aux_in_pause_resume;
  56         void                            **aux_pages;
  57         void                            *aux_priv;
  58
  59         struct perf_event_mmap_page     *user_page;
  60         void                            *data_pages[];
  61 };
  62
  63 extern void rb_free(struct perf_buffer *rb);
  64
  65 static inline void rb_free_rcu(struct rcu_head *rcu_head)
  66 {
  67         struct perf_buffer *rb;
  68
  69         rb = container_of(rcu_head, struct perf_buffer, rcu_head);
  70         rb_free(rb);
  71 }
  72
  73 static inline void rb_toggle_paused(struct perf_buffer *rb, bool pause)
  74 {
  75         if (!pause && rb->nr_pages)
  76                 rb->paused = 0;
  77         else
  78                 rb->paused = 1;
  79 }
  80
  81 extern struct perf_buffer *
  82 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
  83 extern void perf_event_wakeup(struct perf_event *event);
  84 extern int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
  85                         pgoff_t pgoff, int nr_pages, long watermark, int flags);
  86 extern void rb_free_aux(struct perf_buffer *rb);
  87 extern struct perf_buffer *ring_buffer_get(struct perf_event *event);
  88 extern void ring_buffer_put(struct perf_buffer *rb);
  89
  90 static inline bool rb_has_aux(struct perf_buffer *rb)
  91 {
  92         return !!rb->aux_nr_pages;
  93 }
  94
  95 void perf_event_aux_event(struct perf_event *event, unsigned long head,
  96                           unsigned long size, u64 flags);
  97
  98 extern struct page *
  99 perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff);
 100
 101 #ifdef CONFIG_PERF_USE_VMALLOC
 102 /*
 103  * Back perf_mmap() with vmalloc memory.
 104  *
 105  * Required for architectures that have d-cache aliasing issues.
 106  */
 107
 108 static inline int page_order(struct perf_buffer *rb)
 109 {
 110         return rb->page_order;
 111 }
 112
 113 #else
 114
 115 static inline int page_order(struct perf_buffer *rb)
 116 {
 117         return 0;
 118 }
 119 #endif
 120
 121 static inline int data_page_nr(struct perf_buffer *rb)
 122 {
 123         return rb->nr_pages << page_order(rb);
 124 }
 125
 126 static inline unsigned long perf_data_size(struct perf_buffer *rb)
 127 {
 128         return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 129 }
 130
 131 static inline unsigned long perf_aux_size(struct perf_buffer *rb)
 132 {
 133         return (unsigned long)rb->aux_nr_pages << PAGE_SHIFT;
 134 }
 135
 136 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)        \
 137 {                                                                       \
 138         unsigned long size, written;                                    \
 139                                                                         \
 140         do {                                                            \
 141                 size    = min(handle->size, len);                       \
 142                 written = memcpy_func(__VA_ARGS__);                     \
 143                 written = size - written;                               \
 144                                                                         \
 145                 len -= written;                                         \
 146                 handle->addr += written;                                \
 147                 if (advance_buf)                                        \
 148                         buf += written;                                 \
 149                 handle->size -= written;                                \
 150                 if (!handle->size) {                                    \
 151                         struct perf_buffer *rb = handle->rb;    \
 152                                                                         \
 153                         handle->page++;                                 \
 154                         handle->page &= rb->nr_pages - 1;               \
 155                         handle->addr = rb->data_pages[handle->page];    \
 156                         handle->size = PAGE_SIZE << page_order(rb);     \
 157                 }                                                       \
 158         } while (len && written == size);                               \
 159                                                                         \
 160         return len;                                                     \
 161 }
 162
 163 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func)                      \
 164 static inline unsigned long                                             \
 165 func_name(struct perf_output_handle *handle,                            \
 166           const void *buf, unsigned long len)                           \
 167 __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)
 168
 169 static inline unsigned long
 170 __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
 171                 const void *buf, unsigned long len)
 172 {
 173         unsigned long orig_len = len;
 174         __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
 175                                   orig_len - len, size)
 176 }
 177
 178 static inline unsigned long
 179 memcpy_common(void *dst, const void *src, unsigned long n)
 180 {
 181         memcpy(dst, src, n);
 182         return 0;
 183 }
 184
 185 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
 186
 187 static inline unsigned long
 188 memcpy_skip(void *dst, const void *src, unsigned long n)
 189 {
 190         return 0;
 191 }
 192
 193 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
 194
 195 #ifndef arch_perf_out_copy_user
 196 #define arch_perf_out_copy_user arch_perf_out_copy_user
 197
 198 static inline unsigned long
 199 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
 200 {
 201         unsigned long ret;
 202
 203         pagefault_disable();
 204         ret = __copy_from_user_inatomic(dst, src, n);
 205         pagefault_enable();
 206
 207         return ret;
 208 }
 209 #endif
 210
 211 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
 212
 213 static inline int get_recursion_context(u8 *recursion)
 214 {
 215         unsigned char rctx = interrupt_context_level();
 216
 217         if (recursion[rctx])
 218                 return -1;
 219
 220         recursion[rctx]++;
 221         barrier();
 222
 223         return rctx;
 224 }
 225
 226 static inline void put_recursion_context(u8 *recursion, unsigned char rctx)
 227 {
 228         barrier();
 229         recursion[rctx]--;
 230 }
 231
 232 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
 233 static inline bool arch_perf_have_user_stack_dump(void)
 234 {
 235         return true;
 236 }
 237
 238 #define perf_user_stack_pointer(regs) user_stack_pointer(regs)
 239 #else
 240 static inline bool arch_perf_have_user_stack_dump(void)
 241 {
 242         return false;
 243 }
 244
 245 #define perf_user_stack_pointer(regs) 0
 246 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
 247
 248 #endif /* _KERNEL_EVENTS_INTERNAL_H */