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 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[0]; 59 }; 60 61 extern void rb_free(struct ring_buffer *rb); 62 63 static inline void rb_free_rcu(struct rcu_head *rcu_head) 64 { 65 struct ring_buffer *rb; 66 67 rb = container_of(rcu_head, struct ring_buffer, rcu_head); 68 rb_free(rb); 69 } 70 71 static inline void rb_toggle_paused(struct ring_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 ring_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 ring_buffer *rb, struct perf_event *event, 83 pgoff_t pgoff, int nr_pages, long watermark, int flags); 84 extern void rb_free_aux(struct ring_buffer *rb); 85 extern struct ring_buffer *ring_buffer_get(struct perf_event *event); 86 extern void ring_buffer_put(struct ring_buffer *rb); 87 88 static inline bool rb_has_aux(struct ring_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 ring_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 ring_buffer *rb) 107 { 108 return rb->page_order; 109 } 110 111 #else 112 113 static inline int page_order(struct ring_buffer *rb) 114 { 115 return 0; 116 } 117 #endif 118 119 static inline unsigned long perf_data_size(struct ring_buffer *rb) 120 { 121 return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); 122 } 123 124 static inline unsigned long perf_aux_size(struct ring_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 ring_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 int rctx; 209 210 if (unlikely(in_nmi())) 211 rctx = 3; 212 else if (in_irq()) 213 rctx = 2; 214 else if (in_softirq()) 215 rctx = 1; 216 else 217 rctx = 0; 218 219 if (recursion[rctx]) 220 return -1; 221 222 recursion[rctx]++; 223 barrier(); 224 225 return rctx; 226 } 227 228 static inline void put_recursion_context(int *recursion, int rctx) 229 { 230 barrier(); 231 recursion[rctx]--; 232 } 233 234 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP 235 static inline bool arch_perf_have_user_stack_dump(void) 236 { 237 return true; 238 } 239 240 #define perf_user_stack_pointer(regs) user_stack_pointer(regs) 241 #else 242 static inline bool arch_perf_have_user_stack_dump(void) 243 { 244 return false; 245 } 246 247 #define perf_user_stack_pointer(regs) 0 248 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */ 249 250 #endif /* _KERNEL_EVENTS_INTERNAL_H */ 251