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