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
 18MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>");
 19MODULE_DESCRIPTION("perfmon default sampling format");
 20MODULE_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
 40static int
 41default_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
 63static int
 64default_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
 76static int
 77default_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
101static int
102default_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;
203full:
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
229static int
230default_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
245static int
246default_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
252static 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
265static int __init
266pfm_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
285static void __exit
286pfm_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
294module_init(pfm_default_smpl_init_module);
295module_exit(pfm_default_smpl_cleanup_module);
296