1/*
2 * Copyright (c) 2012 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <mach/mach_types.h>
30#include <kern/processor.h>
31#include <kern/thread.h>
32#include <kern/assert.h>
33#include <kern/locks.h>
34#include <sys/errno.h>
35
36#include <kern/kpc.h>
37
38
39/* global for whether to read PMCs on context switch */
40int kpc_threads_counting;
41
42/* current config and number of counters in that config */
43static uint32_t kpc_thread_classes = 0;
44static uint32_t kpc_thread_classes_count = 0;
45
46static lck_grp_attr_t *kpc_thread_lckgrp_attr = NULL;
47static lck_grp_t      *kpc_thread_lckgrp = NULL;
48static lck_mtx_t       kpc_thread_lock;
49
50void kpc_thread_init(void);
51
52void
53kpc_thread_init(void)
54{
55	kpc_thread_lckgrp_attr = lck_grp_attr_alloc_init();
56	kpc_thread_lckgrp = lck_grp_alloc_init("kpc", kpc_thread_lckgrp_attr);
57	lck_mtx_init(&kpc_thread_lock, kpc_thread_lckgrp, LCK_ATTR_NULL);
58}
59
60uint32_t
61kpc_get_thread_counting(void)
62{
63	uint32_t kpc_thread_classes_tmp;
64	int kpc_threads_counting_tmp;
65
66	/* Make sure we get a consistent snapshot of these values */
67	lck_mtx_lock(&kpc_thread_lock);
68
69	kpc_thread_classes_tmp = kpc_thread_classes;
70	kpc_threads_counting_tmp = kpc_threads_counting;
71
72	lck_mtx_unlock(&kpc_thread_lock);
73
74	if( kpc_threads_counting_tmp )
75		return kpc_thread_classes_tmp;
76	else
77		return 0;
78}
79
80int
81kpc_set_thread_counting(uint32_t classes)
82{
83	uint32_t count;
84
85	lck_mtx_lock(&kpc_thread_lock);
86
87	count = kpc_get_counter_count(classes);
88
89	if( (classes == 0)
90	    || (count == 0) )
91	{
92		/* shut down */
93		kpc_threads_counting = FALSE;
94	}
95	else
96	{
97		/* stash the config */
98		kpc_thread_classes = classes;
99
100		/* work out the size */
101		kpc_thread_classes_count = count;
102		assert(kpc_thread_classes_count <= KPC_MAX_COUNTERS);
103
104		/* enable switch */
105		kpc_threads_counting = TRUE;
106
107		/* and schedule an AST for this thread... */
108		if( !current_thread()->kpc_buf )
109		{
110			current_thread()->t_chud |= T_KPC_ALLOC;
111			act_set_kperf(current_thread());
112		}
113	}
114
115	lck_mtx_unlock(&kpc_thread_lock);
116
117	return 0;
118}
119
120/* snapshot current PMCs and update counters in the current thread */
121static void
122kpc_update_thread_counters( thread_t thread )
123{
124	uint32_t i;
125	uint64_t *tmp = NULL;
126	cpu_data_t *cpu = NULL;
127
128/* TODO: Fix this...*/
129#if defined (__x86_64__)
130	cpu = current_cpu_datap();
131#else
132#error architecture not yet supported
133#endif
134
135	/* 1. stash current PMCs into latest CPU block */
136	kpc_get_cpu_counters( FALSE, kpc_thread_classes,
137	                      NULL, cpu->cpu_kpc_buf[1] );
138
139	/* 2. apply delta to old thread */
140	if( thread->kpc_buf )
141		for( i = 0; i < kpc_thread_classes_count; i++ )
142			thread->kpc_buf[i] += cpu->cpu_kpc_buf[1][i] - cpu->cpu_kpc_buf[0][i];
143
144
145	/* schedule any necessary allocations */
146	if( !current_thread()->kpc_buf )
147	{
148		current_thread()->t_chud |= T_KPC_ALLOC;
149		act_set_kperf(current_thread());
150	}
151
152	/* 3. switch the PMC block pointers */
153	tmp = cpu->cpu_kpc_buf[1];
154	cpu->cpu_kpc_buf[1] = cpu->cpu_kpc_buf[0];
155	cpu->cpu_kpc_buf[0] = tmp;
156}
157
158void
159kpc_switch_context( thread_t old, thread_t new __unused )
160{
161	kpc_update_thread_counters( old );
162}
163
164/* get counter values for a thread */
165int
166kpc_get_curthread_counters(uint32_t *inoutcount, uint64_t *buf)
167{
168	thread_t thread = current_thread();
169	boolean_t enabled;
170
171	/* buffer too small :( */
172	if( *inoutcount < kpc_thread_classes_count )
173		return EINVAL;
174
175	/* copy data and actual size */
176	if( !thread->kpc_buf )
177		return EINVAL;
178
179	enabled = ml_set_interrupts_enabled(FALSE);
180
181	/* snap latest version of counters for this thread */
182	kpc_update_thread_counters( current_thread() );
183
184	/* copy out */
185	memcpy( buf, thread->kpc_buf,
186	        kpc_thread_classes_count * sizeof(*buf) );
187	*inoutcount = kpc_thread_classes_count;
188
189	ml_set_interrupts_enabled(enabled);
190
191	return 0;
192}
193
194
195void
196kpc_thread_create(thread_t thread)
197{
198	/* nothing to do if we're not counting */
199	if(!kpc_threads_counting)
200		return;
201
202	/* give the new thread a counterbuf */
203	thread->kpc_buf = kpc_counterbuf_alloc();
204}
205
206void
207kpc_thread_destroy(thread_t thread)
208{
209	uint64_t *buf = NULL;
210
211	/* usual case: no kpc buf, just return */
212	if( !thread->kpc_buf )
213		return;
214
215	/* otherwise, don't leak */
216	buf = thread->kpc_buf;
217	thread->kpc_buf = NULL;
218	kpc_counterbuf_free(buf);
219}
220
221/* ast callback on a thread */
222void
223kpc_thread_ast_handler( thread_t thread )
224{
225	/* see if we want an alloc */
226	if( thread->t_chud & T_KPC_ALLOC )
227		thread->kpc_buf = kpc_counterbuf_alloc();
228}
229