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freebsd/stand/libsa/tslog.c
Colin Percival e6caac717b libsa: Add tslog support for arm64
The original code only supported x86 and used rdtsc(); we now also
support arm64 and use the CNTVCT_EL0 special register.
2021-06-23 22:21:23 -07:00

85 lines
2.5 KiB
C

/*-
* Copyright (c) 2021 Colin Percival
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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 <sys/types.h>
#if defined(__amd64__) || defined(__i386__)
#include <machine/cpufunc.h>
#elif defined(__aarch64__)
#include <machine/armreg.h>
#endif
#include <stand.h>
/* Buffer for holding tslog data in string format. */
static char * tslog_buf = NULL;
static size_t tslog_buflen = 0;
static size_t tslog_bufpos = 0;
void
tslog_setbuf(void * buf, size_t len)
{
tslog_buf = (char *)buf;
tslog_buflen = len;
tslog_bufpos = 0;
}
void
tslog_getbuf(void ** buf, size_t * len)
{
*buf = (void *)tslog_buf;
*len = tslog_bufpos;
}
void
tslog(const char * type, const char * f, const char * s)
{
#if defined(__amd64__) || defined(__i386__)
uint64_t tsc = rdtsc();
#elif defined(__aarch64__)
uint64_t tsc = READ_SPECIALREG(cntvct_el0);
#else
uint64_t tsc = 0;
#endif
int len;
/* If we have no buffer, do nothing. */
if (tslog_buf == NULL)
return;
/* Append to existing buffer, if we have enough space. */
len = snprintf(&tslog_buf[tslog_bufpos],
tslog_buflen - tslog_bufpos, "0x0 %llu %s %s%s%s\n",
(unsigned long long)tsc, type, f, s ? " " : "", s ? s : "");
if ((len > 0) && (tslog_bufpos + len <= tslog_buflen))
tslog_bufpos += len;
}