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