include/linux/oprofile.h

   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 super_block;
  46 struct dentry;
  47 struct file_operations;
  48 struct pt_regs;
  49
  50 /* Operations structure to be filled in */
  51 struct oprofile_operations {
  52         /* create any necessary configuration files in the oprofile fs.
  53          * Optional. */
  54         int (*create_files)(struct super_block * sb, struct dentry * root);
  55         /* Do any necessary interrupt setup. Optional. */
  56         int (*setup)(void);
  57         /* Do any necessary interrupt shutdown. Optional. */
  58         void (*shutdown)(void);
  59         /* Start delivering interrupts. */
  60         int (*start)(void);
  61         /* Stop delivering interrupts. */
  62         void (*stop)(void);
  63         /* Arch-specific buffer sync functions.
  64          * Return value = 0:  Success
  65          * Return value = -1: Failure
  66          * Return value = 1:  Run generic sync function
  67          */
  68         int (*sync_start)(void);
  69         int (*sync_stop)(void);
  70
  71         /* Initiate a stack backtrace. Optional. */
  72         void (*backtrace)(struct pt_regs * const regs, unsigned int depth);
  73
  74         /* Multiplex between different events. Optional. */
  75         int (*switch_events)(void);
  76         /* CPU identification string. */
  77         char * cpu_type;
  78 };
  79
  80 /**
  81  * One-time initialisation. *ops must be set to a filled-in
  82  * operations structure. This is called even in timer interrupt
  83  * mode so an arch can set a backtrace callback.
  84  *
  85  * If an error occurs, the fields should be left untouched.
  86  */
  87 int oprofile_arch_init(struct oprofile_operations * ops);
  88
  89 /**
  90  * One-time exit/cleanup for the arch.
  91  */
  92 void oprofile_arch_exit(void);
  93
  94 /**
  95  * Add a sample. This may be called from any context.
  96  */
  97 void oprofile_add_sample(struct pt_regs * const regs, unsigned long event);
  98
  99 /**
 100  * Add an extended sample.  Use this when the PC is not from the regs, and
 101  * we cannot determine if we're in kernel mode from the regs.
 102  *
 103  * This function does perform a backtrace.
 104  *
 105  */
 106 void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
 107                                 unsigned long event, int is_kernel);
 108
 109 /**
 110  * Add an hardware sample.
 111  */
 112 void oprofile_add_ext_hw_sample(unsigned long pc, struct pt_regs * const regs,
 113         unsigned long event, int is_kernel,
 114         struct task_struct *task);
 115
 116 /* Use this instead when the PC value is not from the regs. Doesn't
 117  * backtrace. */
 118 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event);
 119
 120 /* add a backtrace entry, to be called from the ->backtrace callback */
 121 void oprofile_add_trace(unsigned long eip);
 122
 123
 124 /**
 125  * Create a file of the given name as a child of the given root, with
 126  * the specified file operations.
 127  */
 128 int oprofilefs_create_file(struct super_block * sb, struct dentry * root,
 129         char const * name, const struct file_operations * fops);
 130
 131 int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root,
 132         char const * name, const struct file_operations * fops, int perm);
 133
 134 /** Create a file for read/write access to an unsigned long. */
 135 int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root,
 136         char const * name, ulong * val);
 137
 138 /** Create a file for read-only access to an unsigned long. */
 139 int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root,
 140         char const * name, ulong * val);
 141
 142 /** Create a file for read-only access to an atomic_t. */
 143 int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root,
 144         char const * name, atomic_t * val);
 145
 146 /** create a directory */
 147 struct dentry * oprofilefs_mkdir(struct super_block * sb, struct dentry * root,
 148         char const * name);
 149
 150 /**
 151  * Write the given asciz string to the given user buffer @buf, updating *offset
 152  * appropriately. Returns bytes written or -EFAULT.
 153  */
 154 ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset);
 155
 156 /**
 157  * Convert an unsigned long value into ASCII and copy it to the user buffer @buf,
 158  * updating *offset appropriately. Returns bytes written or -EFAULT.
 159  */
 160 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset);
 161
 162 /**
 163  * Read an ASCII string for a number from a userspace buffer and fill *val on success.
 164  * Returns 0 on success, < 0 on error.
 165  */
 166 int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count);
 167
 168 /** lock for read/write safety */
 169 extern spinlock_t oprofilefs_lock;
 170
 171 /**
 172  * Add the contents of a circular buffer to the event buffer.
 173  */
 174 void oprofile_put_buff(unsigned long *buf, unsigned int start,
 175                         unsigned int stop, unsigned int max);
 176
 177 unsigned long oprofile_get_cpu_buffer_size(void);
 178 void oprofile_cpu_buffer_inc_smpl_lost(void);
 179
 180 /* cpu buffer functions */
 181
 182 struct op_sample;
 183
 184 struct op_entry {
 185         struct ring_buffer_event *event;
 186         struct op_sample *sample;
 187         unsigned long size;
 188         unsigned long *data;
 189 };
 190
 191 void oprofile_write_reserve(struct op_entry *entry,
 192                             struct pt_regs * const regs,
 193                             unsigned long pc, int code, int size);
 194 int oprofile_add_data(struct op_entry *entry, unsigned long val);
 195 int oprofile_add_data64(struct op_entry *entry, u64 val);
 196 int oprofile_write_commit(struct op_entry *entry);
 197
 198 #ifdef CONFIG_HW_PERF_EVENTS
 199 int __init oprofile_perf_init(struct oprofile_operations *ops);
 200 void oprofile_perf_exit(void);
 201 char *op_name_from_perf_id(void);
 202 #else
 203 static inline int __init oprofile_perf_init(struct oprofile_operations *ops)
 204 {
 205         pr_info("oprofile: hardware counters not available\n");
 206         return -ENODEV;
 207 }
 208 static inline void oprofile_perf_exit(void) { }
 209 #endif /* CONFIG_HW_PERF_EVENTS */
 210
 211 #endif /* OPROFILE_H */