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 void **aux_pages; 54 void *aux_priv; 55 56 struct perf_event_mmap_page *user_page; 57 void *data_pages[0]; 58 }; 59 60 extern void rb_free(struct ring_buffer *rb); 61 62 static inline void rb_free_rcu(struct rcu_head *rcu_head) 63 { 64 struct ring_buffer *rb; 65 66 rb = container_of(rcu_head, struct ring_buffer, rcu_head); 67 rb_free(rb); 68 } 69 70 static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause) 71 { 72 if (!pause && rb->nr_pages) 73 rb->paused = 0; 74 else 75 rb->paused = 1; 76 } 77 78 extern struct ring_buffer * 79 rb_alloc(int nr_pages, long watermark, int cpu, int flags); 80 extern void perf_event_wakeup(struct perf_event *event); 81 extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event, 82 pgoff_t pgoff, int nr_pages, long watermark, int flags); 83 extern void rb_free_aux(struct ring_buffer *rb); 84 extern struct ring_buffer *ring_buffer_get(struct perf_event *event); 85 extern void ring_buffer_put(struct ring_buffer *rb); 86 87 static inline bool rb_has_aux(struct ring_buffer *rb) 88 { 89 return !!rb->aux_nr_pages; 90 } 91 92 void perf_event_aux_event(struct perf_event *event, unsigned long head, 93 unsigned long size, u64 flags); 94 95 extern struct page * 96 perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff); 97 98 #ifdef CONFIG_PERF_USE_VMALLOC 99 /* 100 * Back perf_mmap() with vmalloc memory. 101 * 102 * Required for architectures that have d-cache aliasing issues. 103 */ 104 105 static inline int page_order(struct ring_buffer *rb) 106 { 107 return rb->page_order; 108 } 109 110 #else 111 112 static inline int page_order(struct ring_buffer *rb) 113 { 114 return 0; 115 } 116 #endif 117 118 static inline unsigned long perf_data_size(struct ring_buffer *rb) 119 { 120 return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); 121 } 122 123 static inline unsigned long perf_aux_size(struct ring_buffer *rb) 124 { 125 return rb->aux_nr_pages << PAGE_SHIFT; 126 } 127 128 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...) \ 129 { \ 130 unsigned long size, written; \ 131 \ 132 do { \ 133 size = min(handle->size, len); \ 134 written = memcpy_func(__VA_ARGS__); \ 135 written = size - written; \ 136 \ 137 len -= written; \ 138 handle->addr += written; \ 139 if (advance_buf) \ 140 buf += written; \ 141 handle->size -= written; \ 142 if (!handle->size) { \ 143 struct ring_buffer *rb = handle->rb; \ 144 \ 145 handle->page++; \ 146 handle->page &= rb->nr_pages - 1; \ 147 handle->addr = rb->data_pages[handle->page]; \ 148 handle->size = PAGE_SIZE << page_order(rb); \ 149 } \ 150 } while (len && written == size); \ 151 \ 152 return len; \ 153 } 154 155 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \ 156 static inline unsigned long \ 157 func_name(struct perf_output_handle *handle, \ 158 const void *buf, unsigned long len) \ 159 __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size) 160 161 static inline unsigned long 162 __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func, 163 const void *buf, unsigned long len) 164 { 165 unsigned long orig_len = len; 166 __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf, 167 orig_len - len, size) 168 } 169 170 static inline unsigned long 171 memcpy_common(void *dst, const void *src, unsigned long n) 172 { 173 memcpy(dst, src, n); 174 return 0; 175 } 176 177 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common) 178 179 static inline unsigned long 180 memcpy_skip(void *dst, const void *src, unsigned long n) 181 { 182 return 0; 183 } 184 185 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip) 186 187 #ifndef arch_perf_out_copy_user 188 #define arch_perf_out_copy_user arch_perf_out_copy_user 189 190 static inline unsigned long 191 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n) 192 { 193 unsigned long ret; 194 195 pagefault_disable(); 196 ret = __copy_from_user_inatomic(dst, src, n); 197 pagefault_enable(); 198 199 return ret; 200 } 201 #endif 202 203 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user) 204 205 static inline int get_recursion_context(int *recursion) 206 { 207 int rctx; 208 209 if (unlikely(in_nmi())) 210 rctx = 3; 211 else if (in_irq()) 212 rctx = 2; 213 else if (in_softirq()) 214 rctx = 1; 215 else 216 rctx = 0; 217 218 if (recursion[rctx]) 219 return -1; 220 221 recursion[rctx]++; 222 barrier(); 223 224 return rctx; 225 } 226 227 static inline void put_recursion_context(int *recursion, int rctx) 228 { 229 barrier(); 230 recursion[rctx]--; 231 } 232 233 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP 234 static inline bool arch_perf_have_user_stack_dump(void) 235 { 236 return true; 237 } 238 239 #define perf_user_stack_pointer(regs) user_stack_pointer(regs) 240 #else 241 static inline bool arch_perf_have_user_stack_dump(void) 242 { 243 return false; 244 } 245 246 #define perf_user_stack_pointer(regs) 0 247 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */ 248 249 #endif /* _KERNEL_EVENTS_INTERNAL_H */ 250