freebsd-skq/sys/kern/kern_pmc.c
jkoshy 05d42812ac Fail the module loading process if the currently executing kernel
was not compiled with 'options HWPMC_HOOKS' or if the compiled-in
version numbers of the kernel and module are out of sync.

Reported by:	cracauer
MFC after:	3 days
2005-07-30 09:02:42 +00:00

94 lines
2.7 KiB
C

/*-
* Copyright (c) 2003-2005, Joseph Koshy
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_hwpmc_hooks.h"
#include <sys/types.h>
#include <sys/pmc.h>
#include <sys/pmckern.h>
#include <sys/smp.h>
#if HWPMC_HOOKS
#define PMC_KERNEL_VERSION PMC_VERSION
#else
#define PMC_KERNEL_VERSION 0
#endif
const int pmc_kernel_version = PMC_KERNEL_VERSION;
/* Hook variable. */
int (*pmc_hook)(struct thread *td, int function, void *arg) = NULL;
/* Interrupt handler */
int (*pmc_intr)(int cpu, uintptr_t pc, int usermode) = NULL;
/* Bitmask of CPUs requiring servicing at hardclock time */
volatile cpumask_t pmc_cpumask;
/*
* A global count of SS mode PMCs. When non-zero, this means that
* we have processes that are sampling the system as a whole.
*/
volatile int pmc_ss_count;
/*
* Since PMC(4) may not be loaded in the current kernel, the
* convention followed is that a non-NULL value of 'pmc_hook' implies
* the presence of this kernel module.
*
* This requires us to protect 'pmc_hook' with a
* shared (sx) lock -- thus making the process of calling into PMC(4)
* somewhat more expensive than a simple 'if' check and indirect call.
*/
struct sx pmc_sx;
SX_SYSINIT(pmc, &pmc_sx, "pmc shared lock");
/*
* Helper functions
*/
int
pmc_cpu_is_disabled(int cpu)
{
#ifdef SMP
return ((hlt_cpus_mask & (1 << cpu)) != 0);
#else
return 0;
#endif
}
int
pmc_cpu_is_logical(int cpu)
{
#ifdef SMP
return ((logical_cpus_mask & (1 << cpu)) != 0);
#else
return 0;
#endif
}