FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_pmc.c
1 /*-
2 * Copyright (c) 2003-2005, Joseph Koshy
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include "opt_hwpmc_hooks.h"
30
31 #include <sys/types.h>
32 #include <sys/pmc.h>
33 #include <sys/pmckern.h>
34 #include <sys/smp.h>
35
36 #ifdef HWPMC_HOOKS
37 #define PMC_KERNEL_VERSION PMC_VERSION
38 #else
39 #define PMC_KERNEL_VERSION 0
40 #endif
41
42 const int pmc_kernel_version = PMC_KERNEL_VERSION;
43
44 /* Hook variable. */
45 int (*pmc_hook)(struct thread *td, int function, void *arg) = NULL;
46
47 /* Interrupt handler */
48 int (*pmc_intr)(int cpu, uintptr_t pc, int usermode) = NULL;
49
50 /* Bitmask of CPUs requiring servicing at hardclock time */
51 volatile cpumask_t pmc_cpumask;
52
53 /*
54 * A global count of SS mode PMCs. When non-zero, this means that
55 * we have processes that are sampling the system as a whole.
56 */
57 volatile int pmc_ss_count;
58
59 /*
60 * Since PMC(4) may not be loaded in the current kernel, the
61 * convention followed is that a non-NULL value of 'pmc_hook' implies
62 * the presence of this kernel module.
63 *
64 * This requires us to protect 'pmc_hook' with a
65 * shared (sx) lock -- thus making the process of calling into PMC(4)
66 * somewhat more expensive than a simple 'if' check and indirect call.
67 */
68 struct sx pmc_sx;
69 SX_SYSINIT(pmc, &pmc_sx, "pmc shared lock");
70
71 /*
72 * Helper functions
73 */
74
75 int
76 pmc_cpu_is_disabled(int cpu)
77 {
78 #ifdef SMP
79 return ((hlt_cpus_mask & (1 << cpu)) != 0);
80 #else
81 return 0;
82 #endif
83 }
84
85 int
86 pmc_cpu_is_logical(int cpu)
87 {
88 #ifdef SMP
89 return ((logical_cpus_mask & (1 << cpu)) != 0);
90 #else
91 return 0;
92 #endif
93 }
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