summaryrefslogtreecommitdiffstats
path: root/kernel/events/internal.h
blob: 3aef4191798c3468fa28e4daadade29cde44373a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _KERNEL_EVENTS_INTERNAL_H
#define _KERNEL_EVENTS_INTERNAL_H

#include <linux/hardirq.h>
#include <linux/uaccess.h>
#include <linux/refcount.h>

/* Buffer handling */

#define RING_BUFFER_WRITABLE		0x01

struct ring_buffer {
	refcount_t			refcount;
	struct rcu_head			rcu_head;
#ifdef CONFIG_PERF_USE_VMALLOC
	struct work_struct		work;
	int				page_order;	/* allocation order  */
#endif
	int				nr_pages;	/* nr of data pages  */
	int				overwrite;	/* can overwrite itself */
	int				paused;		/* can write into ring buffer */

	atomic_t			poll;		/* POLL_ for wakeups */

	local_t				head;		/* write position    */
	unsigned int			nest;		/* nested writers    */
	local_t				events;		/* event limit       */
	local_t				wakeup;		/* wakeup stamp      */
	local_t				lost;		/* nr records lost   */

	long				watermark;	/* wakeup watermark  */
	long				aux_watermark;
	/* poll crap */
	spinlock_t			event_lock;
	struct list_head		event_list;

	atomic_t			mmap_count;
	unsigned long			mmap_locked;
	struct user_struct		*mmap_user;

	/* AUX area */
	long				aux_head;
	unsigned int			aux_nest;
	long				aux_wakeup;	/* last aux_watermark boundary crossed by aux_head */
	unsigned long			aux_pgoff;
	int				aux_nr_pages;
	int				aux_overwrite;
	atomic_t			aux_mmap_count;
	unsigned long			aux_mmap_locked;
	void				(*free_aux)(void *);
	refcount_t			aux_refcount;
	void				**aux_pages;
	void				*aux_priv;

	struct perf_event_mmap_page	*user_page;
	void				*data_pages[0];
};

extern void rb_free(struct ring_buffer *rb);

static inline void rb_free_rcu(struct rcu_head *rcu_head)
{
	struct ring_buffer *rb;

	rb = container_of(rcu_head, struct ring_buffer, rcu_head);
	rb_free(rb);
}

static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
{
	if (!pause && rb->nr_pages)
		rb->paused = 0;
	else
		rb->paused = 1;
}

extern struct ring_buffer *
rb_alloc(int nr_pages, long watermark, int cpu, int flags);
extern void perf_event_wakeup(struct perf_event *event);
extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
			pgoff_t pgoff, int nr_pages, long watermark, int flags);
extern void rb_free_aux(struct ring_buffer *rb);
extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
extern void ring_buffer_put(struct ring_buffer *rb);

static inline bool rb_has_aux(struct ring_buffer *rb)
{
	return !!rb->aux_nr_pages;
}

void perf_event_aux_event(struct perf_event *event, unsigned long head,
			  unsigned long size, u64 flags);

extern struct page *
perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);

#ifdef CONFIG_PERF_USE_VMALLOC
/*
 * Back perf_mmap() with vmalloc memory.
 *
 * Required for architectures that have d-cache aliasing issues.
 */

static inline int page_order(struct ring_buffer *rb)
{
	return rb->page_order;
}

#else

static inline int page_order(struct ring_buffer *rb)
{
	return 0;
}
#endif

static inline unsigned long perf_data_size(struct ring_buffer *rb)
{
	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
}

static inline unsigned long perf_aux_size(struct ring_buffer *rb)
{
	return rb->aux_nr_pages << PAGE_SHIFT;
}

#define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)	\
{									\
	unsigned long size, written;					\
									\
	do {								\
		size    = min(handle->size, len);			\
		written = memcpy_func(__VA_ARGS__);			\
		written = size - written;				\
									\
		len -= written;						\
		handle->addr += written;				\
		if (advance_buf)					\
			buf += written;					\
		handle->size -= written;				\
		if (!handle->size) {					\
			struct ring_buffer *rb = handle->rb;		\
									\
			handle->page++;					\
			handle->page &= rb->nr_pages - 1;		\
			handle->addr = rb->data_pages[handle->page];	\
			handle->size = PAGE_SIZE << page_order(rb);	\
		}							\
	} while (len && written == size);				\
									\
	return len;							\
}

#define DEFINE_OUTPUT_COPY(func_name, memcpy_func)			\
static inline unsigned long						\
func_name(struct perf_output_handle *handle,				\
	  const void *buf, unsigned long len)				\
__DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)

static inline unsigned long
__output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
		const void *buf, unsigned long len)
{
	unsigned long orig_len = len;
	__DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
				  orig_len - len, size)
}

static inline unsigned long
memcpy_common(void *dst, const void *src, unsigned long n)
{
	memcpy(dst, src, n);
	return 0;
}

DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)

static inline unsigned long
memcpy_skip(void *dst, const void *src, unsigned long n)
{
	return 0;
}

DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)

#ifndef arch_perf_out_copy_user
#define arch_perf_out_copy_user arch_perf_out_copy_user

static inline unsigned long
arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
{
	unsigned long ret;

	pagefault_disable();
	ret = __copy_from_user_inatomic(dst, src, n);
	pagefault_enable();

	return ret;
}
#endif

DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)

static inline int get_recursion_context(int *recursion)
{
	int rctx;

	if (unlikely(in_nmi()))
		rctx = 3;
	else if (in_irq())
		rctx = 2;
	else if (in_softirq())
		rctx = 1;
	else
		rctx = 0;

	if (recursion[rctx])
		return -1;

	recursion[rctx]++;
	barrier();

	return rctx;
}

static inline void put_recursion_context(int *recursion, int rctx)
{
	barrier();
	recursion[rctx]--;
}

#ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
static inline bool arch_perf_have_user_stack_dump(void)
{
	return true;
}

#define perf_user_stack_pointer(regs) user_stack_pointer(regs)
#else
static inline bool arch_perf_have_user_stack_dump(void)
{
	return false;
}

#define perf_user_stack_pointer(regs) 0
#endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */

#endif /* _KERNEL_EVENTS_INTERNAL_H */