1 /**
2  * @file oprofile.h
3  *
4  * API for machine-specific interrupts to interface
5  * to oprofile.
6  *
7  * @remark Copyright 2002 OProfile authors
8  * @remark Read the file COPYING
9  *
10  * @author John Levon <levon@movementarian.org>
11  */
12 
13 #ifndef OPROFILE_H
14 #define OPROFILE_H
15 
16 #include <linux/types.h>
17 #include <linux/spinlock.h>
18 #include <linux/init.h>
19 #include <linux/errno.h>
20 #include <linux/printk.h>
21 #include <linux/atomic.h>
22 
23 /* Each escaped entry is prefixed by ESCAPE_CODE
24  * then one of the following codes, then the
25  * relevant data.
26  * These #defines live in this file so that arch-specific
27  * buffer sync'ing code can access them.
28  */
29 #define ESCAPE_CODE			~0UL
30 #define CTX_SWITCH_CODE			1
31 #define CPU_SWITCH_CODE			2
32 #define COOKIE_SWITCH_CODE		3
33 #define KERNEL_ENTER_SWITCH_CODE	4
34 #define KERNEL_EXIT_SWITCH_CODE		5
35 #define MODULE_LOADED_CODE		6
36 #define CTX_TGID_CODE			7
37 #define TRACE_BEGIN_CODE		8
38 #define TRACE_END_CODE			9
39 #define XEN_ENTER_SWITCH_CODE		10
40 #define SPU_PROFILING_CODE		11
41 #define SPU_CTX_SWITCH_CODE		12
42 #define IBS_FETCH_CODE			13
43 #define IBS_OP_CODE			14
44 
45 struct dentry;
46 struct file_operations;
47 struct pt_regs;
48 
49 /* Operations structure to be filled in */
50 struct oprofile_operations {
51 	/* create any necessary configuration files in the oprofile fs.
52 	 * Optional. */
53 	int (*create_files)(struct dentry * root);
54 	/* Do any necessary interrupt setup. Optional. */
55 	int (*setup)(void);
56 	/* Do any necessary interrupt shutdown. Optional. */
57 	void (*shutdown)(void);
58 	/* Start delivering interrupts. */
59 	int (*start)(void);
60 	/* Stop delivering interrupts. */
61 	void (*stop)(void);
62 	/* Arch-specific buffer sync functions.
63 	 * Return value = 0:  Success
64 	 * Return value = -1: Failure
65 	 * Return value = 1:  Run generic sync function
66 	 */
67 	int (*sync_start)(void);
68 	int (*sync_stop)(void);
69 
70 	/* Initiate a stack backtrace. Optional. */
71 	void (*backtrace)(struct pt_regs * const regs, unsigned int depth);
72 
73 	/* Multiplex between different events. Optional. */
74 	int (*switch_events)(void);
75 	/* CPU identification string. */
76 	char * cpu_type;
77 };
78 
79 /**
80  * One-time initialisation. *ops must be set to a filled-in
81  * operations structure. This is called even in timer interrupt
82  * mode so an arch can set a backtrace callback.
83  *
84  * If an error occurs, the fields should be left untouched.
85  */
86 int oprofile_arch_init(struct oprofile_operations * ops);
87 
88 /**
89  * One-time exit/cleanup for the arch.
90  */
91 void oprofile_arch_exit(void);
92 
93 /**
94  * Add a sample. This may be called from any context.
95  */
96 void oprofile_add_sample(struct pt_regs * const regs, unsigned long event);
97 
98 /**
99  * Add an extended sample.  Use this when the PC is not from the regs, and
100  * we cannot determine if we're in kernel mode from the regs.
101  *
102  * This function does perform a backtrace.
103  *
104  */
105 void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
106 				unsigned long event, int is_kernel);
107 
108 /**
109  * Add an hardware sample.
110  */
111 void oprofile_add_ext_hw_sample(unsigned long pc, struct pt_regs * const regs,
112 	unsigned long event, int is_kernel,
113 	struct task_struct *task);
114 
115 /* Use this instead when the PC value is not from the regs. Doesn't
116  * backtrace. */
117 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event);
118 
119 /* add a backtrace entry, to be called from the ->backtrace callback */
120 void oprofile_add_trace(unsigned long eip);
121 
122 
123 /**
124  * Create a file of the given name as a child of the given root, with
125  * the specified file operations.
126  */
127 int oprofilefs_create_file(struct dentry * root,
128 	char const * name, const struct file_operations * fops);
129 
130 int oprofilefs_create_file_perm(struct dentry * root,
131 	char const * name, const struct file_operations * fops, int perm);
132 
133 /** Create a file for read/write access to an unsigned long. */
134 int oprofilefs_create_ulong(struct dentry * root,
135 	char const * name, ulong * val);
136 
137 /** Create a file for read-only access to an unsigned long. */
138 int oprofilefs_create_ro_ulong(struct dentry * root,
139 	char const * name, ulong * val);
140 
141 /** Create a file for read-only access to an atomic_t. */
142 int oprofilefs_create_ro_atomic(struct dentry * root,
143 	char const * name, atomic_t * val);
144 
145 /** create a directory */
146 struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name);
147 
148 /**
149  * Write the given asciz string to the given user buffer @buf, updating *offset
150  * appropriately. Returns bytes written or -EFAULT.
151  */
152 ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset);
153 
154 /**
155  * Convert an unsigned long value into ASCII and copy it to the user buffer @buf,
156  * updating *offset appropriately. Returns bytes written or -EFAULT.
157  */
158 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset);
159 
160 /**
161  * Read an ASCII string for a number from a userspace buffer and fill *val on success.
162  * Returns 0 on success, < 0 on error.
163  */
164 int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count);
165 
166 /** lock for read/write safety */
167 extern raw_spinlock_t oprofilefs_lock;
168 
169 /**
170  * Add the contents of a circular buffer to the event buffer.
171  */
172 void oprofile_put_buff(unsigned long *buf, unsigned int start,
173 			unsigned int stop, unsigned int max);
174 
175 unsigned long oprofile_get_cpu_buffer_size(void);
176 void oprofile_cpu_buffer_inc_smpl_lost(void);
177 
178 /* cpu buffer functions */
179 
180 struct op_sample;
181 
182 struct op_entry {
183 	struct ring_buffer_event *event;
184 	struct op_sample *sample;
185 	unsigned long size;
186 	unsigned long *data;
187 };
188 
189 void oprofile_write_reserve(struct op_entry *entry,
190 			    struct pt_regs * const regs,
191 			    unsigned long pc, int code, int size);
192 int oprofile_add_data(struct op_entry *entry, unsigned long val);
193 int oprofile_add_data64(struct op_entry *entry, u64 val);
194 int oprofile_write_commit(struct op_entry *entry);
195 
196 #ifdef CONFIG_HW_PERF_EVENTS
197 int __init oprofile_perf_init(struct oprofile_operations *ops);
198 void oprofile_perf_exit(void);
199 char *op_name_from_perf_id(void);
200 #else
oprofile_perf_init(struct oprofile_operations * ops)201 static inline int __init oprofile_perf_init(struct oprofile_operations *ops)
202 {
203 	pr_info("oprofile: hardware counters not available\n");
204 	return -ENODEV;
205 }
oprofile_perf_exit(void)206 static inline void oprofile_perf_exit(void) { }
207 #endif /* CONFIG_HW_PERF_EVENTS */
208 
209 #endif /* OPROFILE_H */
210