1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2002-2003 Hewlett-Packard Co
4 * Stephane Eranian <eranian@hpl.hp.com>
5 *
6 * This file implements the default sampling buffer format
7 * for the Linux/ia64 perfmon-2 subsystem.
8 */
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <asm/delay.h>
14 #include <linux/smp.h>
15
16 #include <asm/perfmon.h>
17 #include <asm/perfmon_default_smpl.h>
18
19 MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>");
20 MODULE_DESCRIPTION("perfmon default sampling format");
21 MODULE_LICENSE("GPL");
22
23 #define DEFAULT_DEBUG 1
24
25 #ifdef DEFAULT_DEBUG
26 #define DPRINT(a) \
27 do { \
28 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d ", __func__, __LINE__, smp_processor_id()); printk a; } \
29 } while (0)
30
31 #define DPRINT_ovfl(a) \
32 do { \
33 if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d ", __func__, __LINE__, smp_processor_id()); printk a; } \
34 } while (0)
35
36 #else
37 #define DPRINT(a)
38 #define DPRINT_ovfl(a)
39 #endif
40
41 static int
default_validate(struct task_struct * task,unsigned int flags,int cpu,void * data)42 default_validate(struct task_struct *task, unsigned int flags, int cpu, void *data)
43 {
44 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t*)data;
45 int ret = 0;
46
47 if (data == NULL) {
48 DPRINT(("[%d] no argument passed\n", task_pid_nr(task)));
49 return -EINVAL;
50 }
51
52 DPRINT(("[%d] validate flags=0x%x CPU%d\n", task_pid_nr(task), flags, cpu));
53
54 /*
55 * must hold at least the buffer header + one minimally sized entry
56 */
57 if (arg->buf_size < PFM_DEFAULT_SMPL_MIN_BUF_SIZE) return -EINVAL;
58
59 DPRINT(("buf_size=%lu\n", arg->buf_size));
60
61 return ret;
62 }
63
64 static int
default_get_size(struct task_struct * task,unsigned int flags,int cpu,void * data,unsigned long * size)65 default_get_size(struct task_struct *task, unsigned int flags, int cpu, void *data, unsigned long *size)
66 {
67 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
68
69 /*
70 * size has been validated in default_validate
71 */
72 *size = arg->buf_size;
73
74 return 0;
75 }
76
77 static int
default_init(struct task_struct * task,void * buf,unsigned int flags,int cpu,void * data)78 default_init(struct task_struct *task, void *buf, unsigned int flags, int cpu, void *data)
79 {
80 pfm_default_smpl_hdr_t *hdr;
81 pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
82
83 hdr = (pfm_default_smpl_hdr_t *)buf;
84
85 hdr->hdr_version = PFM_DEFAULT_SMPL_VERSION;
86 hdr->hdr_buf_size = arg->buf_size;
87 hdr->hdr_cur_offs = sizeof(*hdr);
88 hdr->hdr_overflows = 0UL;
89 hdr->hdr_count = 0UL;
90
91 DPRINT(("[%d] buffer=%p buf_size=%lu hdr_size=%lu hdr_version=%u cur_offs=%lu\n",
92 task_pid_nr(task),
93 buf,
94 hdr->hdr_buf_size,
95 sizeof(*hdr),
96 hdr->hdr_version,
97 hdr->hdr_cur_offs));
98
99 return 0;
100 }
101
102 static int
default_handler(struct task_struct * task,void * buf,pfm_ovfl_arg_t * arg,struct pt_regs * regs,unsigned long stamp)103 default_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg, struct pt_regs *regs, unsigned long stamp)
104 {
105 pfm_default_smpl_hdr_t *hdr;
106 pfm_default_smpl_entry_t *ent;
107 void *cur, *last;
108 unsigned long *e, entry_size;
109 unsigned int npmds, i;
110 unsigned char ovfl_pmd;
111 unsigned char ovfl_notify;
112
113 if (unlikely(buf == NULL || arg == NULL|| regs == NULL || task == NULL)) {
114 DPRINT(("[%d] invalid arguments buf=%p arg=%p\n", task->pid, buf, arg));
115 return -EINVAL;
116 }
117
118 hdr = (pfm_default_smpl_hdr_t *)buf;
119 cur = buf+hdr->hdr_cur_offs;
120 last = buf+hdr->hdr_buf_size;
121 ovfl_pmd = arg->ovfl_pmd;
122 ovfl_notify = arg->ovfl_notify;
123
124 /*
125 * precheck for sanity
126 */
127 if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
128
129 npmds = hweight64(arg->smpl_pmds[0]);
130
131 ent = (pfm_default_smpl_entry_t *)cur;
132
133 prefetch(arg->smpl_pmds_values);
134
135 entry_size = sizeof(*ent) + (npmds << 3);
136
137 /* position for first pmd */
138 e = (unsigned long *)(ent+1);
139
140 hdr->hdr_count++;
141
142 DPRINT_ovfl(("[%d] count=%lu cur=%p last=%p free_bytes=%lu ovfl_pmd=%d ovfl_notify=%d npmds=%u\n",
143 task->pid,
144 hdr->hdr_count,
145 cur, last,
146 last-cur,
147 ovfl_pmd,
148 ovfl_notify, npmds));
149
150 /*
151 * current = task running at the time of the overflow.
152 *
153 * per-task mode:
154 * - this is usually the task being monitored.
155 * Under certain conditions, it might be a different task
156 *
157 * system-wide:
158 * - this is not necessarily the task controlling the session
159 */
160 ent->pid = current->pid;
161 ent->ovfl_pmd = ovfl_pmd;
162 ent->last_reset_val = arg->pmd_last_reset; //pmd[0].reg_last_reset_val;
163
164 /*
165 * where did the fault happen (includes slot number)
166 */
167 ent->ip = regs->cr_iip | ((regs->cr_ipsr >> 41) & 0x3);
168
169 ent->tstamp = stamp;
170 ent->cpu = smp_processor_id();
171 ent->set = arg->active_set;
172 ent->tgid = current->tgid;
173
174 /*
175 * selectively store PMDs in increasing index number
176 */
177 if (npmds) {
178 unsigned long *val = arg->smpl_pmds_values;
179 for(i=0; i < npmds; i++) {
180 *e++ = *val++;
181 }
182 }
183
184 /*
185 * update position for next entry
186 */
187 hdr->hdr_cur_offs += entry_size;
188 cur += entry_size;
189
190 /*
191 * post check to avoid losing the last sample
192 */
193 if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
194
195 /*
196 * keep same ovfl_pmds, ovfl_notify
197 */
198 arg->ovfl_ctrl.bits.notify_user = 0;
199 arg->ovfl_ctrl.bits.block_task = 0;
200 arg->ovfl_ctrl.bits.mask_monitoring = 0;
201 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1; /* reset before returning from interrupt handler */
202
203 return 0;
204 full:
205 DPRINT_ovfl(("sampling buffer full free=%lu, count=%lu, ovfl_notify=%d\n", last-cur, hdr->hdr_count, ovfl_notify));
206
207 /*
208 * increment number of buffer overflow.
209 * important to detect duplicate set of samples.
210 */
211 hdr->hdr_overflows++;
212
213 /*
214 * if no notification requested, then we saturate the buffer
215 */
216 if (ovfl_notify == 0) {
217 arg->ovfl_ctrl.bits.notify_user = 0;
218 arg->ovfl_ctrl.bits.block_task = 0;
219 arg->ovfl_ctrl.bits.mask_monitoring = 1;
220 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0;
221 } else {
222 arg->ovfl_ctrl.bits.notify_user = 1;
223 arg->ovfl_ctrl.bits.block_task = 1; /* ignored for non-blocking context */
224 arg->ovfl_ctrl.bits.mask_monitoring = 1;
225 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0; /* no reset now */
226 }
227 return -1; /* we are full, sorry */
228 }
229
230 static int
default_restart(struct task_struct * task,pfm_ovfl_ctrl_t * ctrl,void * buf,struct pt_regs * regs)231 default_restart(struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
232 {
233 pfm_default_smpl_hdr_t *hdr;
234
235 hdr = (pfm_default_smpl_hdr_t *)buf;
236
237 hdr->hdr_count = 0UL;
238 hdr->hdr_cur_offs = sizeof(*hdr);
239
240 ctrl->bits.mask_monitoring = 0;
241 ctrl->bits.reset_ovfl_pmds = 1; /* uses long-reset values */
242
243 return 0;
244 }
245
246 static int
default_exit(struct task_struct * task,void * buf,struct pt_regs * regs)247 default_exit(struct task_struct *task, void *buf, struct pt_regs *regs)
248 {
249 DPRINT(("[%d] exit(%p)\n", task_pid_nr(task), buf));
250 return 0;
251 }
252
253 static pfm_buffer_fmt_t default_fmt={
254 .fmt_name = "default_format",
255 .fmt_uuid = PFM_DEFAULT_SMPL_UUID,
256 .fmt_arg_size = sizeof(pfm_default_smpl_arg_t),
257 .fmt_validate = default_validate,
258 .fmt_getsize = default_get_size,
259 .fmt_init = default_init,
260 .fmt_handler = default_handler,
261 .fmt_restart = default_restart,
262 .fmt_restart_active = default_restart,
263 .fmt_exit = default_exit,
264 };
265
266 static int __init
pfm_default_smpl_init_module(void)267 pfm_default_smpl_init_module(void)
268 {
269 int ret;
270
271 ret = pfm_register_buffer_fmt(&default_fmt);
272 if (ret == 0) {
273 printk("perfmon_default_smpl: %s v%u.%u registered\n",
274 default_fmt.fmt_name,
275 PFM_DEFAULT_SMPL_VERSION_MAJ,
276 PFM_DEFAULT_SMPL_VERSION_MIN);
277 } else {
278 printk("perfmon_default_smpl: %s cannot register ret=%d\n",
279 default_fmt.fmt_name,
280 ret);
281 }
282
283 return ret;
284 }
285
286 static void __exit
pfm_default_smpl_cleanup_module(void)287 pfm_default_smpl_cleanup_module(void)
288 {
289 int ret;
290 ret = pfm_unregister_buffer_fmt(default_fmt.fmt_uuid);
291
292 printk("perfmon_default_smpl: unregister %s=%d\n", default_fmt.fmt_name, ret);
293 }
294
295 module_init(pfm_default_smpl_init_module);
296 module_exit(pfm_default_smpl_cleanup_module);
297
298
