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
13struct 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	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	int				aux_in_sampling;
54	void				**aux_pages;
55	void				*aux_priv;
56
57	struct perf_event_mmap_page	*user_page;
58	void				*data_pages[];
59};
60
61extern void rb_free(struct perf_buffer *rb);
62
63static inline void rb_free_rcu(struct rcu_head *rcu_head)
64{
65	struct perf_buffer *rb;
66
67	rb = container_of(rcu_head, struct perf_buffer, rcu_head);
68	rb_free(rb);
69}
70
71static inline void rb_toggle_paused(struct perf_buffer *rb, bool pause)
72{
73	if (!pause && rb->nr_pages)
74		rb->paused = 0;
75	else
76		rb->paused = 1;
77}
78
79extern struct perf_buffer *
80rb_alloc(int nr_pages, long watermark, int cpu, int flags);
81extern void perf_event_wakeup(struct perf_event *event);
82extern int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
83			pgoff_t pgoff, int nr_pages, long watermark, int flags);
84extern void rb_free_aux(struct perf_buffer *rb);
85extern struct perf_buffer *ring_buffer_get(struct perf_event *event);
86extern void ring_buffer_put(struct perf_buffer *rb);
87
88static inline bool rb_has_aux(struct perf_buffer *rb)
89{
90	return !!rb->aux_nr_pages;
91}
92
93void perf_event_aux_event(struct perf_event *event, unsigned long head,
94			  unsigned long size, u64 flags);
95
96extern struct page *
97perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff);
98
99#ifdef CONFIG_PERF_USE_VMALLOC
100/*
101 * Back perf_mmap() with vmalloc memory.
102 *
103 * Required for architectures that have d-cache aliasing issues.
104 */
105
106static inline int page_order(struct perf_buffer *rb)
107{
108	return rb->page_order;
109}
110
111#else
112
113static inline int page_order(struct perf_buffer *rb)
114{
115	return 0;
116}
117#endif
118
119static inline int data_page_nr(struct perf_buffer *rb)
120{
121	return rb->nr_pages << page_order(rb);
122}
123
124static inline unsigned long perf_data_size(struct perf_buffer *rb)
125{
126	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
127}
128
129static inline unsigned long perf_aux_size(struct perf_buffer *rb)
130{
131	return rb->aux_nr_pages << PAGE_SHIFT;
132}
133
134#define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)	\
135{									\
136	unsigned long size, written;					\
137									\
138	do {								\
139		size    = min(handle->size, len);			\
140		written = memcpy_func(__VA_ARGS__);			\
141		written = size - written;				\
142									\
143		len -= written;						\
144		handle->addr += written;				\
145		if (advance_buf)					\
146			buf += written;					\
147		handle->size -= written;				\
148		if (!handle->size) {					\
149			struct perf_buffer *rb = handle->rb;	\
150									\
151			handle->page++;					\
152			handle->page &= rb->nr_pages - 1;		\
153			handle->addr = rb->data_pages[handle->page];	\
154			handle->size = PAGE_SIZE << page_order(rb);	\
155		}							\
156	} while (len && written == size);				\
157									\
158	return len;							\
159}
160
161#define DEFINE_OUTPUT_COPY(func_name, memcpy_func)			\
162static inline unsigned long						\
163func_name(struct perf_output_handle *handle,				\
164	  const void *buf, unsigned long len)				\
165__DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size)
166
167static inline unsigned long
168__output_custom(struct perf_output_handle *handle, perf_copy_f copy_func,
169		const void *buf, unsigned long len)
170{
171	unsigned long orig_len = len;
172	__DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf,
173				  orig_len - len, size)
174}
175
176static inline unsigned long
177memcpy_common(void *dst, const void *src, unsigned long n)
178{
179	memcpy(dst, src, n);
180	return 0;
181}
182
183DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
184
185static inline unsigned long
186memcpy_skip(void *dst, const void *src, unsigned long n)
187{
188	return 0;
189}
190
191DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip)
192
193#ifndef arch_perf_out_copy_user
194#define arch_perf_out_copy_user arch_perf_out_copy_user
195
196static inline unsigned long
197arch_perf_out_copy_user(void *dst, const void *src, unsigned long n)
198{
199	unsigned long ret;
200
201	pagefault_disable();
202	ret = __copy_from_user_inatomic(dst, src, n);
203	pagefault_enable();
204
205	return ret;
206}
207#endif
208
209DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
210
211static inline int get_recursion_context(int *recursion)
212{
213	unsigned char rctx = interrupt_context_level();
214
215	if (recursion[rctx])
216		return -1;
217
218	recursion[rctx]++;
219	barrier();
220
221	return rctx;
222}
223
224static inline void put_recursion_context(int *recursion, int rctx)
225{
226	barrier();
227	recursion[rctx]--;
228}
229
230#ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
231static inline bool arch_perf_have_user_stack_dump(void)
232{
233	return true;
234}
235
236#define perf_user_stack_pointer(regs) user_stack_pointer(regs)
237#else
238static inline bool arch_perf_have_user_stack_dump(void)
239{
240	return false;
241}
242
243#define perf_user_stack_pointer(regs) 0
244#endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
245
246#endif /* _KERNEL_EVENTS_INTERNAL_H */
247