xref: /openbmc/linux/kernel/events/internal.h (revision c4b69bee)
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 
rb_free_rcu(struct rcu_head * rcu_head)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 
rb_toggle_paused(struct perf_buffer * rb,bool pause)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 
rb_has_aux(struct perf_buffer * rb)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 
page_order(struct perf_buffer * rb)107 static inline int page_order(struct perf_buffer *rb)
108 {
109 	return rb->page_order;
110 }
111 
112 #else
113 
page_order(struct perf_buffer * rb)114 static inline int page_order(struct perf_buffer *rb)
115 {
116 	return 0;
117 }
118 #endif
119 
data_page_nr(struct perf_buffer * rb)120 static inline int data_page_nr(struct perf_buffer *rb)
121 {
122 	return rb->nr_pages << page_order(rb);
123 }
124 
perf_data_size(struct perf_buffer * rb)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 
perf_aux_size(struct perf_buffer * rb)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
__output_custom(struct perf_output_handle * handle,perf_copy_f copy_func,const void * buf,unsigned long len)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
memcpy_common(void * dst,const void * src,unsigned long n)178 memcpy_common(void *dst, const void *src, unsigned long n)
179 {
180 	memcpy(dst, src, n);
181 	return 0;
182 }
183 
DEFINE_OUTPUT_COPY(__output_copy,memcpy_common)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 
DEFINE_OUTPUT_COPY(__output_skip,memcpy_skip)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 
DEFINE_OUTPUT_COPY(__output_copy_user,arch_perf_out_copy_user)210 DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
211 
212 static inline int get_recursion_context(int *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 
put_recursion_context(int * recursion,int rctx)225 static inline void put_recursion_context(int *recursion, int rctx)
226 {
227 	barrier();
228 	recursion[rctx]--;
229 }
230 
231 #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
arch_perf_have_user_stack_dump(void)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
arch_perf_have_user_stack_dump(void)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 */
248