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