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 int aux_in_pause_resume;
56 void **aux_pages;
57 void *aux_priv;
58
59 struct perf_event_mmap_page *user_page;
60 void *data_pages[];
61 };
62
63 extern void rb_free(struct perf_buffer *rb);
64
rb_free_rcu(struct rcu_head * rcu_head)65 static inline void rb_free_rcu(struct rcu_head *rcu_head)
66 {
67 struct perf_buffer *rb;
68
69 rb = container_of(rcu_head, struct perf_buffer, rcu_head);
70 rb_free(rb);
71 }
72
rb_toggle_paused(struct perf_buffer * rb,bool pause)73 static inline void rb_toggle_paused(struct perf_buffer *rb, bool pause)
74 {
75 if (!pause && rb->nr_pages)
76 rb->paused = 0;
77 else
78 rb->paused = 1;
79 }
80
81 extern struct perf_buffer *
82 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
83 extern void perf_event_wakeup(struct perf_event *event);
84 extern int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
85 pgoff_t pgoff, int nr_pages, long watermark, int flags);
86 extern void rb_free_aux(struct perf_buffer *rb);
87 extern struct perf_buffer *ring_buffer_get(struct perf_event *event);
88 extern void ring_buffer_put(struct perf_buffer *rb);
89
rb_has_aux(struct perf_buffer * rb)90 static inline bool rb_has_aux(struct perf_buffer *rb)
91 {
92 return !!rb->aux_nr_pages;
93 }
94
95 void perf_event_aux_event(struct perf_event *event, unsigned long head,
96 unsigned long size, u64 flags);
97
98 extern struct page *
99 perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff);
100
101 #ifdef CONFIG_PERF_USE_VMALLOC
102 /*
103 * Back perf_mmap() with vmalloc memory.
104 *
105 * Required for architectures that have d-cache aliasing issues.
106 */
107
page_order(struct perf_buffer * rb)108 static inline int page_order(struct perf_buffer *rb)
109 {
110 return rb->page_order;
111 }
112
113 #else
114
page_order(struct perf_buffer * rb)115 static inline int page_order(struct perf_buffer *rb)
116 {
117 return 0;
118 }
119 #endif
120
data_page_nr(struct perf_buffer * rb)121 static inline int data_page_nr(struct perf_buffer *rb)
122 {
123 return rb->nr_pages << page_order(rb);
124 }
125
perf_data_size(struct perf_buffer * rb)126 static inline unsigned long perf_data_size(struct perf_buffer *rb)
127 {
128 return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
129 }
130
perf_aux_size(struct perf_buffer * rb)131 static inline unsigned long perf_aux_size(struct perf_buffer *rb)
132 {
133 return (unsigned long)rb->aux_nr_pages << PAGE_SHIFT;
134 }
135
136 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...) \
137 { \
138 unsigned long size, written; \
139 \
140 do { \
141 size = min(handle->size, len); \
142 written = memcpy_func(__VA_ARGS__); \
143 written = size - written; \
144 \
145 len -= written; \
146 handle->addr += written; \
147 if (advance_buf) \
148 buf += written; \
149 handle->size -= written; \
150 if (!handle->size) { \
151 struct perf_buffer *rb = handle->rb; \
152 \
153 handle->page++; \
154 handle->page &= rb->nr_pages - 1; \
155 handle->addr = rb->data_pages[handle->page]; \
156 handle->size = PAGE_SIZE << page_order(rb); \
157 } \
158 } while (len && written == size); \
159 \
160 return len; \
161 }
162
163 #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
164 static inline unsigned long \
165 func_name(struct perf_output_handle *handle, \
166 const void *buf, unsigned long len) \
167 __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)
168
169 static inline unsigned long
__output_custom(struct perf_output_handle * handle,perf_copy_f copy_func,const void * buf,unsigned long len)170 __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
171 const void *buf, unsigned long len)
172 {
173 unsigned long orig_len = len;
174 __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
175 orig_len - len, size)
176 }
177
178 static inline unsigned long
memcpy_common(void * dst,const void * src,unsigned long n)179 memcpy_common(void *dst, const void *src, unsigned long n)
180 {
181 memcpy(dst, src, n);
182 return 0;
183 }
184
DEFINE_OUTPUT_COPY(__output_copy,memcpy_common)185 DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
186
187 static inline unsigned long
188 memcpy_skip(void *dst, const void *src, unsigned long n)
189 {
190 return 0;
191 }
192
DEFINE_OUTPUT_COPY(__output_skip,memcpy_skip)193 DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
194
195 #ifndef arch_perf_out_copy_user
196 #define arch_perf_out_copy_user arch_perf_out_copy_user
197
198 static inline unsigned long
199 arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
200 {
201 unsigned long ret;
202
203 pagefault_disable();
204 ret = __copy_from_user_inatomic(dst, src, n);
205 pagefault_enable();
206
207 return ret;
208 }
209 #endif
210
DEFINE_OUTPUT_COPY(__output_copy_user,arch_perf_out_copy_user)211 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
212
213 static inline int get_recursion_context(u8 *recursion)
214 {
215 unsigned char rctx = interrupt_context_level();
216
217 if (recursion[rctx])
218 return -1;
219
220 recursion[rctx]++;
221 barrier();
222
223 return rctx;
224 }
225
put_recursion_context(u8 * recursion,unsigned char rctx)226 static inline void put_recursion_context(u8 *recursion, unsigned char rctx)
227 {
228 barrier();
229 recursion[rctx]--;
230 }
231
232 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
arch_perf_have_user_stack_dump(void)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
arch_perf_have_user_stack_dump(void)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 */
249