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
rb_free_rcu(struct rcu_head * rcu_head)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
rb_toggle_paused(struct ring_buffer * rb,bool pause)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
rb_has_aux(struct ring_buffer * rb)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
page_order(struct ring_buffer * rb)105 static inline int page_order(struct ring_buffer *rb)
106 {
107 return rb->page_order;
108 }
109
110 #else
111
page_order(struct ring_buffer * rb)112 static inline int page_order(struct ring_buffer *rb)
113 {
114 return 0;
115 }
116 #endif
117
perf_data_size(struct ring_buffer * rb)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
perf_aux_size(struct ring_buffer * rb)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
__output_custom(struct perf_output_handle * handle,perf_copy_f copy_func,const void * buf,unsigned long len)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
memcpy_common(void * dst,const void * src,unsigned long n)171 memcpy_common(void *dst, const void *src, unsigned long n)
172 {
173 memcpy(dst, src, n);
174 return 0;
175 }
176
DEFINE_OUTPUT_COPY(__output_copy,memcpy_common)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
DEFINE_OUTPUT_COPY(__output_skip,memcpy_skip)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
DEFINE_OUTPUT_COPY(__output_copy_user,arch_perf_out_copy_user)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
put_recursion_context(int * recursion,int rctx)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
arch_perf_have_user_stack_dump(void)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
arch_perf_have_user_stack_dump(void)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
