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[PowerPC] Implement VDSO timebase access on powerpc*

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Implement the remaining pieces needed to allow userland timestamp reading.

Rewritten based on an intial essay into the problem by Justin Hibbits.
(Copyright changed to my own on his request.)

Tested on ppc64 (POWER9 Talos II), powerpcspe (e500v2 RB800), and
powerpc (g4 PowerBook).

Reviewed by:	jhibbits (in irc)
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D26347
This commit is contained in:
Brandon Bergren 2020-09-08 03:00:31 +00:00
parent a5c869c1f6
commit 328b5f2570
11 changed files with 177 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/libc/powerpc/Makefile.inc
View File

@ -1,7 +1,5 @@
# $FreeBSD$
SRCS+= trivial-vdso_tc.c
# Long double is 64-bits
SRCS+=machdep_ldisd.c
SYM_MAPS+=${LIBC_SRCTOP}/powerpc/Symbol.map

1
lib/libc/powerpc/sys/Makefile.inc
View File

@ -1,3 +1,4 @@
# $FreeBSD$
SRCS+= __vdso_gettc.c
MDASM+= cerror.S

68
lib/libc/powerpc/sys/__vdso_gettc.c Normal file
View File

@ -0,0 +1,68 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Brandon Bergren <bdragon@FreeBSD.org>
*
* This software was developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* 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>
#include <sys/elf.h>
#include <sys/time.h>
#include <sys/vdso.h>
#include <machine/cpufunc.h>
#include <machine/spr.h>
#include <errno.h>
#include "libc_private.h"
#pragma weak __vdso_gettc
int
__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
{
if (__predict_false(th->th_algo != VDSO_TH_ALGO_PPC_TB))
return (ENOSYS);
/*
* While the timebase is a 64 bit quantity, we are only interested
* in the lower 32 bits of it.
*/
*tc = mfspr(TBR_TBL);
return (0);
}
#pragma weak __vdso_gettimekeep
int
__vdso_gettimekeep(struct vdso_timekeep **tk)
{
return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
}

2
lib/libc/powerpc64/Makefile.inc
View File

@ -1,7 +1,5 @@
# $FreeBSD$
SRCS+= trivial-vdso_tc.c
# Long double is 64-bits
SRCS+=machdep_ldisd.c
SYM_MAPS+=${LIBC_SRCTOP}/powerpc64/Symbol.map

1
lib/libc/powerpc64/sys/Makefile.inc
View File

@ -1,3 +1,4 @@
# $FreeBSD$
SRCS+= __vdso_gettc.c
MDASM+= cerror.S

65
lib/libc/powerpc64/sys/__vdso_gettc.c Normal file
View File

@ -0,0 +1,65 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Brandon Bergren <bdragon@FreeBSD.org>
*
* This software was developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* 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>
#include <sys/elf.h>
#include <sys/time.h>
#include <sys/vdso.h>
#include <machine/cpufunc.h>
#include <errno.h>
#include "libc_private.h"
#pragma weak __vdso_gettc
int
__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
{
u_quad_t tb;
if (__predict_false(th->th_algo != VDSO_TH_ALGO_PPC_TB))
return (ENOSYS);
__asm __volatile ("mftb %0" : "=r"(tb));
*tc = tb;
return (0);
}
#pragma weak __vdso_gettimekeep
int
__vdso_gettimekeep(struct vdso_timekeep **tk)
{
return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
}

1
lib/libc/powerpcspe/Makefile.inc
View File

@ -1,7 +1,6 @@
# $FreeBSD$
CFLAGS+= -I${LIBC_SRCTOP}/powerpc
SRCS+= trivial-vdso_tc.c
# Long double is 64-bits
SRCS+=machdep_ldisd.c

2
sys/powerpc/include/vdso.h
View File

@ -33,6 +33,8 @@
#define VDSO_TIMEHANDS_MD \
uint32_t th_res[8];
#define VDSO_TH_ALGO_PPC_TB VDSO_TH_ALGO_1
#ifdef _KERNEL
#ifdef COMPAT_FREEBSD32

39
sys/powerpc/powerpc/clock.c
View File

@ -69,6 +69,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/vdso.h>
#include <dev/ofw/openfirm.h>
@ -90,6 +91,12 @@ static int decr_et_start(struct eventtimer *et,
sbintime_t first, sbintime_t period);
static int decr_et_stop(struct eventtimer *et);
static timecounter_get_t decr_get_timecount;
static uint32_t decr_vdso_timehands(struct vdso_timehands *vdso_th,
struct timecounter *tc);
#ifdef COMPAT_FREEBSD32
static uint32_t decr_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
struct timecounter *tc);
#endif
struct decr_state {
int mode; /* 0 - off, 1 - periodic, 2 - one-shot. */
@ -99,11 +106,14 @@ DPCPU_DEFINE_STATIC(struct decr_state, decr_state);
static struct eventtimer decr_et;
static struct timecounter decr_tc = {
decr_get_timecount, /* get_timecount */
0, /* no poll_pps */
~0u, /* counter_mask */
0, /* frequency */
"timebase" /* name */
.tc_get_timecount = decr_get_timecount,
.tc_counter_mask = ~0u,
.tc_name = "timebase",
.tc_quality = 1000,
.tc_fill_vdso_timehands = decr_vdso_timehands,
#ifdef COMPAT_FREEBSD32
.tc_fill_vdso_timehands32 = decr_vdso_timehands32,
#endif
};
/*
@ -224,6 +234,25 @@ decr_tc_init(void)
et_register(&decr_et);
}
uint32_t
decr_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
{
vdso_th->th_algo = VDSO_TH_ALGO_PPC_TB;
bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
return (initialized == 1);
}
#ifdef COMPAT_FREEBSD32
uint32_t
decr_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
struct timecounter *tc)
{
vdso_th32->th_algo = VDSO_TH_ALGO_PPC_TB;
bzero(vdso_th32->th_res, sizeof(vdso_th32->th_res));
return (initialized == 1);
}
#endif
/*
* Event timer start method.
*/

3
sys/powerpc/powerpc/elf32_machdep.c
View File

@ -122,7 +122,8 @@ struct sysentvec elf32_freebsd_sysvec = {
.sv_fixlimit = NULL,
#endif
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_ASLR,
.sv_flags = SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_ASLR |
SV_TIMEKEEP,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_shared_page_base = FREEBSD32_SHAREDPAGE,

6
sys/powerpc/powerpc/elf64_machdep.c
View File

@ -83,7 +83,8 @@ struct sysentvec elf64_freebsd_sysvec_v1 = {
.sv_setregs = exec_setregs_funcdesc,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR,
.sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR |
SV_TIMEKEEP,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,
@ -120,7 +121,8 @@ struct sysentvec elf64_freebsd_sysvec_v2 = {
.sv_setregs = exec_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP,
.sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP |
SV_TIMEKEEP,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,