1 /*
2 * Copyright (C) 2002-2003 Hewlett-Packard Co
3 * Stephane Eranian <eranian@hpl.hp.com>
4 *
5 * This file implements the default sampling buffer format
6 * for the Linux/ia64 perfmon-2 subsystem.
7 */
8 #include <linux/kernel.h>
9 #include <linux/types.h>
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <asm/delay.h>
13 #include <linux/smp.h>
14
15 #include <asm/perfmon.h>
16 #include <asm/perfmon_default_smpl.h>
17
18 MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>");
19 MODULE_DESCRIPTION("perfmon default sampling format");
20 MODULE_LICENSE("GPL");
21
22 #define DEFAULT_DEBUG 1
23
24 #ifdef DEFAULT_DEBUG
25 #define DPRINT(a) \
26 do { \
27 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d ", __func__, __LINE__, smp_processor_id()); printk a; } \
28 } while (0)
29
30 #define DPRINT_ovfl(a) \
31 do { \
32 if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d ", __func__, __LINE__, smp_processor_id()); printk a; } \
33 } while (0)
34
35 #else
36 #define DPRINT(a)
37 #define DPRINT_ovfl(a)
38 #endif
39
40 static int
default_validate(struct task_struct * task,unsigned int flags,int cpu,void * data)41 default_validate(struct task_struct *task, unsigned int flags, int cpu, void *data)
42 {
43 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t*)data;
44 int ret = 0;
45
46 if (data == NULL) {
47 DPRINT(("[%d] no argument passed\n", task_pid_nr(task)));
48 return -EINVAL;
49 }
50
51 DPRINT(("[%d] validate flags=0x%x CPU%d\n", task_pid_nr(task), flags, cpu));
52
53 /*
54 * must hold at least the buffer header + one minimally sized entry
55 */
56 if (arg->buf_size < PFM_DEFAULT_SMPL_MIN_BUF_SIZE) return -EINVAL;
57
58 DPRINT(("buf_size=%lu\n", arg->buf_size));
59
60 return ret;
61 }
62
63 static int
default_get_size(struct task_struct * task,unsigned int flags,int cpu,void * data,unsigned long * size)64 default_get_size(struct task_struct *task, unsigned int flags, int cpu, void *data, unsigned long *size)
65 {
66 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
67
68 /*
69 * size has been validated in default_validate
70 */
71 *size = arg->buf_size;
72
73 return 0;
74 }
75
76 static int
default_init(struct task_struct * task,void * buf,unsigned int flags,int cpu,void * data)77 default_init(struct task_struct *task, void *buf, unsigned int flags, int cpu, void *data)
78 {
79 pfm_default_smpl_hdr_t *hdr;
80 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
81
82 hdr = (pfm_default_smpl_hdr_t *)buf;
83
84 hdr->hdr_version = PFM_DEFAULT_SMPL_VERSION;
85 hdr->hdr_buf_size = arg->buf_size;
86 hdr->hdr_cur_offs = sizeof(*hdr);
87 hdr->hdr_overflows = 0UL;
88 hdr->hdr_count = 0UL;
89
90 DPRINT(("[%d] buffer=%p buf_size=%lu hdr_size=%lu hdr_version=%u cur_offs=%lu\n",
91 task_pid_nr(task),
92 buf,
93 hdr->hdr_buf_size,
94 sizeof(*hdr),
95 hdr->hdr_version,
96 hdr->hdr_cur_offs));
97
98 return 0;
99 }
100
101 static int
default_handler(struct task_struct * task,void * buf,pfm_ovfl_arg_t * arg,struct pt_regs * regs,unsigned long stamp)102 default_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg, struct pt_regs *regs, unsigned long stamp)
103 {
104 pfm_default_smpl_hdr_t *hdr;
105 pfm_default_smpl_entry_t *ent;
106 void *cur, *last;
107 unsigned long *e, entry_size;
108 unsigned int npmds, i;
109 unsigned char ovfl_pmd;
110 unsigned char ovfl_notify;
111
112 if (unlikely(buf == NULL || arg == NULL|| regs == NULL || task == NULL)) {
113 DPRINT(("[%d] invalid arguments buf=%p arg=%p\n", task->pid, buf, arg));
114 return -EINVAL;
115 }
116
117 hdr = (pfm_default_smpl_hdr_t *)buf;
118 cur = buf+hdr->hdr_cur_offs;
119 last = buf+hdr->hdr_buf_size;
120 ovfl_pmd = arg->ovfl_pmd;
121 ovfl_notify = arg->ovfl_notify;
122
123 /*
124 * precheck for sanity
125 */
126 if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
127
128 npmds = hweight64(arg->smpl_pmds[0]);
129
130 ent = (pfm_default_smpl_entry_t *)cur;
131
132 prefetch(arg->smpl_pmds_values);
133
134 entry_size = sizeof(*ent) + (npmds << 3);
135
136 /* position for first pmd */
137 e = (unsigned long *)(ent+1);
138
139 hdr->hdr_count++;
140
141 DPRINT_ovfl(("[%d] count=%lu cur=%p last=%p free_bytes=%lu ovfl_pmd=%d ovfl_notify=%d npmds=%u\n",
142 task->pid,
143 hdr->hdr_count,
144 cur, last,
145 last-cur,
146 ovfl_pmd,
147 ovfl_notify, npmds));
148
149 /*
150 * current = task running at the time of the overflow.
151 *
152 * per-task mode:
153 * - this is usually the task being monitored.
154 * Under certain conditions, it might be a different task
155 *
156 * system-wide:
157 * - this is not necessarily the task controlling the session
158 */
159 ent->pid = current->pid;
160 ent->ovfl_pmd = ovfl_pmd;
161 ent->last_reset_val = arg->pmd_last_reset; //pmd[0].reg_last_reset_val;
162
163 /*
164 * where did the fault happen (includes slot number)
165 */
166 ent->ip = regs->cr_iip | ((regs->cr_ipsr >> 41) & 0x3);
167
168 ent->tstamp = stamp;
169 ent->cpu = smp_processor_id();
170 ent->set = arg->active_set;
171 ent->tgid = current->tgid;
172
173 /*
174 * selectively store PMDs in increasing index number
175 */
176 if (npmds) {
177 unsigned long *val = arg->smpl_pmds_values;
178 for(i=0; i < npmds; i++) {
179 *e++ = *val++;
180 }
181 }
182
183 /*
184 * update position for next entry
185 */
186 hdr->hdr_cur_offs += entry_size;
187 cur += entry_size;
188
189 /*
190 * post check to avoid losing the last sample
191 */
192 if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
193
194 /*
195 * keep same ovfl_pmds, ovfl_notify
196 */
197 arg->ovfl_ctrl.bits.notify_user = 0;
198 arg->ovfl_ctrl.bits.block_task = 0;
199 arg->ovfl_ctrl.bits.mask_monitoring = 0;
200 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1; /* reset before returning from interrupt handler */
201
202 return 0;
203 full:
204 DPRINT_ovfl(("sampling buffer full free=%lu, count=%lu, ovfl_notify=%d\n", last-cur, hdr->hdr_count, ovfl_notify));
205
206 /*
207 * increment number of buffer overflow.
208 * important to detect duplicate set of samples.
209 */
210 hdr->hdr_overflows++;
211
212 /*
213 * if no notification requested, then we saturate the buffer
214 */
215 if (ovfl_notify == 0) {
216 arg->ovfl_ctrl.bits.notify_user = 0;
217 arg->ovfl_ctrl.bits.block_task = 0;
218 arg->ovfl_ctrl.bits.mask_monitoring = 1;
219 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0;
220 } else {
221 arg->ovfl_ctrl.bits.notify_user = 1;
222 arg->ovfl_ctrl.bits.block_task = 1; /* ignored for non-blocking context */
223 arg->ovfl_ctrl.bits.mask_monitoring = 1;
224 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0; /* no reset now */
225 }
226 return -1; /* we are full, sorry */
227 }
228
229 static int
default_restart(struct task_struct * task,pfm_ovfl_ctrl_t * ctrl,void * buf,struct pt_regs * regs)230 default_restart(struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
231 {
232 pfm_default_smpl_hdr_t *hdr;
233
234 hdr = (pfm_default_smpl_hdr_t *)buf;
235
236 hdr->hdr_count = 0UL;
237 hdr->hdr_cur_offs = sizeof(*hdr);
238
239 ctrl->bits.mask_monitoring = 0;
240 ctrl->bits.reset_ovfl_pmds = 1; /* uses long-reset values */
241
242 return 0;
243 }
244
245 static int
default_exit(struct task_struct * task,void * buf,struct pt_regs * regs)246 default_exit(struct task_struct *task, void *buf, struct pt_regs *regs)
247 {
248 DPRINT(("[%d] exit(%p)\n", task_pid_nr(task), buf));
249 return 0;
250 }
251
252 static pfm_buffer_fmt_t default_fmt={
253 .fmt_name = "default_format",
254 .fmt_uuid = PFM_DEFAULT_SMPL_UUID,
255 .fmt_arg_size = sizeof(pfm_default_smpl_arg_t),
256 .fmt_validate = default_validate,
257 .fmt_getsize = default_get_size,
258 .fmt_init = default_init,
259 .fmt_handler = default_handler,
260 .fmt_restart = default_restart,
261 .fmt_restart_active = default_restart,
262 .fmt_exit = default_exit,
263 };
264
265 static int __init
pfm_default_smpl_init_module(void)266 pfm_default_smpl_init_module(void)
267 {
268 int ret;
269
270 ret = pfm_register_buffer_fmt(&default_fmt);
271 if (ret == 0) {
272 printk("perfmon_default_smpl: %s v%u.%u registered\n",
273 default_fmt.fmt_name,
274 PFM_DEFAULT_SMPL_VERSION_MAJ,
275 PFM_DEFAULT_SMPL_VERSION_MIN);
276 } else {
277 printk("perfmon_default_smpl: %s cannot register ret=%d\n",
278 default_fmt.fmt_name,
279 ret);
280 }
281
282 return ret;
283 }
284
285 static void __exit
pfm_default_smpl_cleanup_module(void)286 pfm_default_smpl_cleanup_module(void)
287 {
288 int ret;
289 ret = pfm_unregister_buffer_fmt(default_fmt.fmt_uuid);
290
291 printk("perfmon_default_smpl: unregister %s=%d\n", default_fmt.fmt_name, ret);
292 }
293
294 module_init(pfm_default_smpl_init_module);
295 module_exit(pfm_default_smpl_cleanup_module);
296
297