Implement userspace gettimeofday(2) with HPET timecounter.

Right now, userspace (fast) gettimeofday(2) on x86 only works for
RDTSC.  For older machines, like Core2, where RDTSC is not C2/C3
invariant, and which fall to HPET hardware, this means that the call
has both the penalty of the syscall and of the uncached hw behind the
QPI or PCIe connection to the sought bridge.  Nothing can me done
against the access latency, but the syscall overhead can be removed.
System already provides mappable /dev/hpetX devices, which gives
straight access to the HPET registers page.

Add yet another algorithm to the x86 'vdso' timehands. Libc is updated
to handle both RDTSC and HPET.  For HPET, the index of the hpet device
to mmap is passed from kernel to userspace, index might be changed and
libc invalidates its mapping as needed.

Remove cpu_fill_vdso_timehands() KPI, instead require that
timecounters which can be used from userspace, to provide
tc_fill_vdso_timehands{,32}() methods.  Merge i386 and amd64
libc/<arch>/sys/__vdso_gettc.c into one source file in the new
libc/x86/sys location.  __vdso_gettc() internal interface is changed
to move timecounter algorithm detection into the MD code.

Measurements show that RDTSC even with the syscall overhead is faster
than userspace HPET access.  But still, userspace HPET is three-four
times faster than syscall HPET on several Core2 and SandyBridge
machines.

Tested by:	Howard Su <howard0su@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D7473

lib/libc/Makefile

@@ -110,6 +110,9 @@ NOASM=
      ${LIBC_ARCH} == "mips"
 .include "${LIBC_SRCTOP}/softfloat/Makefile.inc"
 .endif
+.if ${LIBC_ARCH} == "i386" || ${LIBC_ARCH} == "amd64"
+.include "${LIBC_SRCTOP}/x86/sys/Makefile.inc"
+.endif
 .if ${MK_NIS} != "no"
 CFLAGS+= -DYP
 .include "${LIBC_SRCTOP}/yp/Makefile.inc"

lib/libc/aarch64/sys/__vdso_gettc.c

@@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/time.h>
 #include <sys/vdso.h>
 #include <machine/cpufunc.h>
+#include <errno.h>
 #include "libc_private.h"
 
 static inline uint64_t
@@ -55,14 +56,15 @@ cp15_cntpct_get(void)
 }
 
 #pragma weak __vdso_gettc
-u_int
-__vdso_gettc(const struct vdso_timehands *th)
+int
+__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
 {
-	uint64_t val;
 
+	if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM)
+		return (ENOSYS);
 	__asm __volatile("isb" : : : "memory");
-	val = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
-	return (val);
+	*tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
+	return (0);
 }
 
 #pragma weak __vdso_gettimekeep

lib/libc/amd64/sys/Makefile.inc

@@ -2,7 +2,7 @@
 # $FreeBSD$
 
 SRCS+=	amd64_get_fsbase.c amd64_get_gsbase.c amd64_set_fsbase.c \
-	amd64_set_gsbase.c __vdso_gettc.c
+	amd64_set_gsbase.c
 
 MDASM=	vfork.S brk.S cerror.S exect.S getcontext.S ptrace.S \
 	sbrk.S setlogin.S sigreturn.S

lib/libc/amd64/sys/__vdso_gettc.c

@@ -1,70 +0,0 @@
-/*-
- * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
- *
- * 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 "libc_private.h"
-
-static u_int
-__vdso_gettc_low(const struct vdso_timehands *th)
-{
-	u_int rv;
-
-	__asm __volatile("lfence; rdtsc; shrd %%cl, %%edx, %0"
-	    : "=a" (rv) : "c" (th->th_x86_shift) : "edx");
-	return (rv);
-}
-
-static u_int
-__vdso_rdtsc32(void)
-{
-	u_int rv;
-
-	__asm __volatile("lfence;rdtsc" : "=a" (rv) : : "edx");
-	return (rv);
-}
-
-#pragma weak __vdso_gettc
-u_int
-__vdso_gettc(const struct vdso_timehands *th)
-{
-
-	return (th->th_x86_shift > 0 ? __vdso_gettc_low(th) :
-	    __vdso_rdtsc32());
-}
-
-#pragma weak __vdso_gettimekeep
-int
-__vdso_gettimekeep(struct vdso_timekeep **tk)
-{
-
-	return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
-}

lib/libc/arm/sys/__vdso_gettc.c

@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/vdso.h>
 #include <machine/cpufunc.h>
 #include <machine/acle-compat.h>
+#include <errno.h>
 #include "libc_private.h"
 
 #if __ARM_ARCH >= 6
@@ -58,11 +59,12 @@ cp15_cntpct_get(void)
 #endif
 
 #pragma weak __vdso_gettc
-u_int
-__vdso_gettc(const struct vdso_timehands *th)
+int
+__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
 {
-	uint64_t val;
 
+	if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM)
+		return (ENOSYS);
 #if __ARM_ARCH >= 6
 	/*
 	 * Userspace gettimeofday() is only enabled on ARMv7 CPUs, but
@@ -70,11 +72,12 @@ __vdso_gettc(const struct vdso_timehands *th)
 	 * armv7-a directive does not work.
 	 */
 	__asm __volatile(".word\t0xf57ff06f" : : : "memory"); /* isb */
-	val = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
+	*tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
+	return (0);
 #else
-	val = 0;
+	*tc = 0;
+	return (ENOSYS);
 #endif
-	return (val);
 }
 
 #pragma weak __vdso_gettimekeep

lib/libc/i386/sys/Makefile.inc

@@ -5,8 +5,7 @@
 SRCS+=	i386_clr_watch.c i386_set_watch.c i386_vm86.c
 .endif
 SRCS+=	i386_get_fsbase.c i386_get_gsbase.c i386_get_ioperm.c i386_get_ldt.c \
-	i386_set_fsbase.c i386_set_gsbase.c i386_set_ioperm.c i386_set_ldt.c \
-	__vdso_gettc.c
+	i386_set_fsbase.c i386_set_gsbase.c i386_set_ioperm.c i386_set_ldt.c
 
 MDASM=	Ovfork.S brk.S cerror.S exect.S getcontext.S ptrace.S \
 	sbrk.S setlogin.S sigreturn.S syscall.S

lib/libc/sys/__vdso_gettimeofday.c

@@ -34,12 +34,16 @@ __FBSDID("$FreeBSD$");
 #include <machine/atomic.h>
 #include "libc_private.h"
 
-static u_int
-tc_delta(const struct vdso_timehands *th)
+static int
+tc_delta(const struct vdso_timehands *th, u_int *delta)
 {
+	int error;
+	u_int tc;
 
-	return ((__vdso_gettc(th) - th->th_offset_count) &
-	    th->th_counter_mask);
+	error = __vdso_gettc(th, &tc);
+	if (error == 0)
+		*delta = (tc - th->th_offset_count) & th->th_counter_mask;
+	return (error);
 }
 
 /*
@@ -56,6 +60,8 @@ binuptime(struct bintime *bt, struct vdso_timekeep *tk, int abs)
 {
 	struct vdso_timehands *th;
 	uint32_t curr, gen;
+	u_int delta;
+	int error;
 
 	do {
 		if (!tk->tk_enabled)
@@ -63,11 +69,14 @@ binuptime(struct bintime *bt, struct vdso_timekeep *tk, int abs)
 
 		curr = atomic_load_acq_32(&tk->tk_current);
 		th = &tk->tk_th[curr];
-		if (th->th_algo != VDSO_TH_ALGO_1)
-			return (ENOSYS);
 		gen = atomic_load_acq_32(&th->th_gen);
 		*bt = th->th_offset;
-		bintime_addx(bt, th->th_scale * tc_delta(th));
+		error = tc_delta(th, &delta);
+		if (error == EAGAIN)
+			continue;
+		if (error != 0)
+			return (error);
+		bintime_addx(bt, th->th_scale * delta);
 		if (abs)
 			bintime_add(bt, &th->th_boottime);
 

lib/libc/sys/trivial-vdso_tc.c

@@ -32,11 +32,11 @@ __FBSDID("$FreeBSD$");
 #include <errno.h>
 
 #pragma weak __vdso_gettc
-u_int
-__vdso_gettc(const struct vdso_timehands *th)
+int
+__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
 {
 
-	return (0);
+	return (ENOSYS);
 }
 
 #pragma weak __vdso_gettimekeep

lib/libc/x86/sys/Makefile.inc

@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+.PATH:	${LIBC_SRCTOP}/x86/sys
+
+SRCS+= \
+	__vdso_gettc.c

lib/libc/x86/sys/__vdso_gettc.c

@@ -1,5 +1,10 @@
 /*-
  * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
+ * Copyright (c) 2016 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were 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
@@ -26,19 +31,27 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <sys/types.h>
+#include <sys/param.h>
+#include "namespace.h"
 #include <sys/elf.h>
+#include <sys/fcntl.h>
+#include <sys/mman.h>
 #include <sys/time.h>
 #include <sys/vdso.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include "un-namespace.h"
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
+#include <dev/acpica/acpi_hpet.h>
 #include "libc_private.h"
 
-static int lfence_works = -1;
-
-static int
-get_lfence_usage(void)
+static void
+lfence_mb(void)
 {
+#if defined(__i386__)
+	static int lfence_works = -1;
 	u_int cpuid_supported, p[4];
 
 	if (lfence_works == -1) {
@@ -57,7 +70,7 @@ get_lfence_usage(void)
 		    "	jmp	2f\n"
 		    "1:	movl	$0,%0\n"
 		    "2:\n"
-		    : "=r" (cpuid_supported) : : "eax", "ecx");
+		    : "=r" (cpuid_supported) : : "eax", "ecx", "cc");
 		if (cpuid_supported) {
 			__asm __volatile(
 			    "	pushl	%%ebx\n"
@@ -70,16 +83,21 @@ get_lfence_usage(void)
 		} else
 			lfence_works = 0;
 	}
-	return (lfence_works);
+	if (lfence_works == 1)
+		lfence();
+#elif defined(__amd64__)
+	lfence();
+#else
+#error "arch"
+#endif
 }
 
 static u_int
-__vdso_gettc_low(const struct vdso_timehands *th)
+__vdso_gettc_rdtsc_low(const struct vdso_timehands *th)
 {
 	u_int rv;
 
-	if (get_lfence_usage() == 1)
-		lfence();
+	lfence_mb();
 	__asm __volatile("rdtsc; shrd %%cl, %%edx, %0"
 	    : "=a" (rv) : "c" (th->th_x86_shift) : "edx");
 	return (rv);
@@ -88,21 +106,68 @@ __vdso_gettc_low(const struct vdso_timehands *th)
 static u_int
 __vdso_rdtsc32(void)
 {
-	u_int rv;
 
-	if (get_lfence_usage() == 1)
-		lfence();
-	rv = rdtsc32();
-	return (rv);
+	lfence_mb();
+	return (rdtsc32());
+}
+
+static char *hpet_dev_map = NULL;
+static uint32_t hpet_idx = 0xffffffff;
+
+static void
+__vdso_init_hpet(uint32_t u)
+{
+	static const char devprefix[] = "/dev/hpet";
+	char devname[64], *c, *c1, t;
+	int fd;
+
+	c1 = c = stpcpy(devname, devprefix);
+	u = hpet_idx;
+	do {
+		*c++ = u % 10 + '0';
+		u /= 10;
+	} while (u != 0);
+	*c = '\0';
+	for (c--; c1 != c; c1++, c--) {
+		t = *c1;
+		*c1 = *c;
+		*c = t;
+	}
+	fd = _open(devname, O_RDONLY);
+	if (fd == -1) {
+		hpet_dev_map = MAP_FAILED;
+		return;
+	}
+	if (hpet_dev_map != NULL && hpet_dev_map != MAP_FAILED)
+		munmap(hpet_dev_map, PAGE_SIZE);
+	hpet_dev_map = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
+	_close(fd);
 }
 
 #pragma weak __vdso_gettc
-u_int
-__vdso_gettc(const struct vdso_timehands *th)
+int
+__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
 {
+	uint32_t tmp;
 
-	return (th->th_x86_shift > 0 ? __vdso_gettc_low(th) :
-	    __vdso_rdtsc32());
+	switch (th->th_algo) {
+	case VDSO_TH_ALGO_X86_TSC:
+		*tc = th->th_x86_shift > 0 ? __vdso_gettc_rdtsc_low(th) :
+		    __vdso_rdtsc32();
+		return (0);
+	case VDSO_TH_ALGO_X86_HPET:
+		tmp = th->th_x86_hpet_idx;
+		if (hpet_dev_map == NULL || tmp != hpet_idx) {
+			hpet_idx = tmp;
+			__vdso_init_hpet(hpet_idx);
+		}
+		if (hpet_dev_map == MAP_FAILED)
+			return (ENOSYS);
+		*tc = *(volatile uint32_t *)(hpet_dev_map + HPET_MAIN_COUNTER);
+		return (0);
+	default:
+		return (ENOSYS);
+	}
 }
 
 #pragma weak __vdso_gettimekeep

sys/arm/arm/generic_timer.c

@@ -105,6 +105,10 @@ static struct resource_spec timer_spec[] = {
 	{ -1, 0 }
 };
 
+static uint32_t arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
+    struct timecounter *tc);
+static void arm_tmr_do_delay(int usec, void *);
+
 static timecounter_get_t arm_tmr_get_timecount;
 
 static struct timecounter arm_tmr_timecount = {
@@ -114,6 +118,7 @@ static struct timecounter arm_tmr_timecount = {
 	.tc_counter_mask   = ~0u,
 	.tc_frequency      = 0,
 	.tc_quality        = 1000,
+	.tc_fill_vdso_timehands = arm_tmr_fill_vdso_timehands,
 };
 
 #ifdef __arm__
@@ -128,10 +133,6 @@ static struct timecounter arm_tmr_timecount = {
 #define	set_el1(x, val)	WRITE_SPECIALREG(x ##_el1, val)
 #endif
 
-static uint32_t arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
-    struct timecounter *tc);
-static void arm_tmr_do_delay(int usec, void *);
-
 static int
 get_freq(void)
 {
@@ -412,8 +413,6 @@ arm_tmr_attach(device_t dev)
 		}
 	}
 
-	arm_cpu_fill_vdso_timehands = arm_tmr_fill_vdso_timehands;
-
 	arm_tmr_timecount.tc_frequency = sc->clkfreq;
 	tc_init(&arm_tmr_timecount);
 
@@ -535,7 +534,8 @@ arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
     struct timecounter *tc)
 {
 
+	vdso_th->th_algo = VDSO_TH_ALGO_ARM_GENTIM;
 	vdso_th->th_physical = arm_tmr_sc->physical;
 	bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
-	return (tc == &arm_tmr_timecount);
+	return (1);
 }

sys/arm/arm/machdep.c

@@ -2003,14 +2003,3 @@ initarm(struct arm_boot_params *abp)
 
 #endif /* __ARM_ARCH < 6 */
 #endif /* FDT */
-
-uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
-    struct timecounter *);
-
-uint32_t
-cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
-{
-
-	return (arm_cpu_fill_vdso_timehands != NULL ?
-	    arm_cpu_fill_vdso_timehands(vdso_th, tc) : 0);
-}

sys/arm/include/md_var.h

@@ -45,11 +45,6 @@ extern int (*_arm_bzero)(void *, int, int);
 extern int _min_memcpy_size;
 extern int _min_bzero_size;
 
-struct vdso_timehands;
-struct timecounter;
-extern uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
-    struct timecounter *);
-
 #define DST_IS_USER	0x1
 #define SRC_IS_USER	0x2
 #define IS_PHYSICAL	0x4

sys/arm/include/vdso.h

@@ -32,4 +32,6 @@
 	uint32_t	th_physical;		\
 	uint32_t	th_res[7];
 
+#define	VDSO_TH_ALGO_ARM_GENTIM	VDSO_TH_ALGO_1
+
 #endif

sys/arm64/arm64/machdep.c

@@ -1005,17 +1005,6 @@ initarm(struct arm64_bootparams *abp)
 	early_boot = 0;
 }
 
-uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
-    struct timecounter *);
-
-uint32_t
-cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
-{
-
-	return (arm_cpu_fill_vdso_timehands != NULL ?
-	    arm_cpu_fill_vdso_timehands(vdso_th, tc) : 0);
-}
-
 #ifdef DDB
 #include <ddb/ddb.h>
 

sys/arm64/include/md_var.h

@@ -47,9 +47,4 @@ void dump_add_page(vm_paddr_t);
 void dump_drop_page(vm_paddr_t);
 int minidumpsys(struct dumperinfo *);
 
-struct vdso_timehands;
-struct timecounter;
-extern uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
-    struct timecounter *);
-
 #endif /* !_MACHINE_MD_VAR_H_ */

sys/arm64/include/vdso.h

@@ -32,4 +32,6 @@
 	uint32_t	th_physical;		\
 	uint32_t	th_res[7];
 
+#define	VDSO_TH_ALGO_ARM_GENTIM	VDSO_TH_ALGO_1
+
 #endif /* !_MACHINE_VDSO_H_ */

sys/dev/acpica/acpi_hpet.c

@@ -29,6 +29,8 @@
 __FBSDID("$FreeBSD$");
 
 #include "opt_acpi.h"
+#include "opt_compat.h"
+
 #if defined(__amd64__)
 #define	DEV_APIC
 #else
@@ -47,6 +49,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/sysctl.h>
 #include <sys/timeet.h>
 #include <sys/timetc.h>
+#include <sys/vdso.h>
 
 #include <contrib/dev/acpica/include/acpi.h>
 #include <contrib/dev/acpica/include/accommon.h>
@@ -141,6 +144,35 @@ hpet_get_timecount(struct timecounter *tc)
 	return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
 }
 
+uint32_t
+hpet_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
+{
+	struct hpet_softc *sc;
+
+	sc = tc->tc_priv;
+	vdso_th->th_algo = VDSO_TH_ALGO_X86_HPET;
+	vdso_th->th_x86_shift = 0;
+	vdso_th->th_x86_hpet_idx = device_get_unit(sc->dev);
+	bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
+	return (sc->mmap_allow != 0);
+}
+
+#ifdef COMPAT_FREEBSD32
+uint32_t
+hpet_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
+    struct timecounter *tc)
+{
+	struct hpet_softc *sc;
+
+	sc = tc->tc_priv;
+	vdso_th32->th_algo = VDSO_TH_ALGO_X86_HPET;
+	vdso_th32->th_x86_shift = 0;
+	vdso_th32->th_x86_hpet_idx = device_get_unit(sc->dev);
+	bzero(vdso_th32->th_res, sizeof(vdso_th32->th_res));
+	return (sc->mmap_allow != 0);
+}
+#endif
+
 static void
 hpet_enable(struct hpet_softc *sc)
 {
@@ -537,6 +569,10 @@ hpet_attach(device_t dev)
 		sc->tc.tc_quality = 950,
 		sc->tc.tc_frequency = sc->freq;
 		sc->tc.tc_priv = sc;
+		sc->tc.tc_fill_vdso_timehands = hpet_vdso_timehands;
+#ifdef COMPAT_FREEBSD32
+		sc->tc.tc_fill_vdso_timehands32 = hpet_vdso_timehands32;
+#endif
 		tc_init(&sc->tc);
 	}
 	/* If not disabled - setup and announce event timers. */

sys/dev/acpica/acpi_hpet.h

@@ -64,4 +64,15 @@
 
 #define	HPET_MIN_CYCLES		128	/* Period considered reliable. */
 
+#ifdef _KERNEL
+struct timecounter;
+struct vdso_timehands;
+struct vdso_timehands32;
+
+uint32_t hpet_vdso_timehands(struct vdso_timehands *vdso_th,
+    struct timecounter *tc);
+uint32_t hpet_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
+    struct timecounter *tc);
+#endif
+
 #endif /* !__ACPI_HPET_H__ */

sys/kern/kern_tc.c

@@ -6,11 +6,14 @@
  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  * ----------------------------------------------------------------------------
  *
- * Copyright (c) 2011 The FreeBSD Foundation
+ * Copyright (c) 2011, 2015, 2016 The FreeBSD Foundation
  * All rights reserved.
  *
  * Portions of this software were developed by Julien Ridoux at the University
  * of Melbourne under sponsorship from the FreeBSD Foundation.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
  */
 
 #include <sys/cdefs.h>
@@ -2130,13 +2133,16 @@ tc_fill_vdso_timehands(struct vdso_timehands *vdso_th)
 	uint32_t enabled;
 
 	th = timehands;
-	vdso_th->th_algo = VDSO_TH_ALGO_1;
 	vdso_th->th_scale = th->th_scale;
 	vdso_th->th_offset_count = th->th_offset_count;
 	vdso_th->th_counter_mask = th->th_counter->tc_counter_mask;
 	vdso_th->th_offset = th->th_offset;
 	vdso_th->th_boottime = th->th_boottime;
-	enabled = cpu_fill_vdso_timehands(vdso_th, th->th_counter);
+	if (th->th_counter->tc_fill_vdso_timehands != NULL) {
+		enabled = th->th_counter->tc_fill_vdso_timehands(vdso_th,
+		    th->th_counter);
+	} else
+		enabled = 0;
 	if (!vdso_th_enable)
 		enabled = 0;
 	return (enabled);
@@ -2150,7 +2156,6 @@ tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32)
 	uint32_t enabled;
 
 	th = timehands;
-	vdso_th32->th_algo = VDSO_TH_ALGO_1;
 	*(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale;
 	vdso_th32->th_offset_count = th->th_offset_count;
 	vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask;
@@ -2158,7 +2163,11 @@ tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32)
 	*(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac;
 	vdso_th32->th_boottime.sec = th->th_boottime.sec;
 	*(uint64_t *)&vdso_th32->th_boottime.frac[0] = th->th_boottime.frac;
-	enabled = cpu_fill_vdso_timehands32(vdso_th32, th->th_counter);
+	if (th->th_counter->tc_fill_vdso_timehands32 != NULL) {
+		enabled = th->th_counter->tc_fill_vdso_timehands32(vdso_th32,
+		    th->th_counter);
+	} else
+		enabled = 0;
 	if (!vdso_th_enable)
 		enabled = 0;
 	return (enabled);

sys/sys/timetc.h

@@ -28,8 +28,14 @@
  */
 
 struct timecounter;
+struct vdso_timehands;
+struct vdso_timehands32;
 typedef u_int timecounter_get_t(struct timecounter *);
 typedef void timecounter_pps_t(struct timecounter *);
+typedef uint32_t timecounter_fill_vdso_timehands_t(struct vdso_timehands *,
+    struct timecounter *);
+typedef uint32_t timecounter_fill_vdso_timehands32_t(struct vdso_timehands32 *,
+    struct timecounter *);
 
 struct timecounter {
 	timecounter_get_t	*tc_get_timecount;
@@ -68,6 +74,8 @@ struct timecounter {
 		/* Pointer to the timecounter's private parts. */
 	struct timecounter	*tc_next;
 		/* Pointer to the next timecounter. */
+	timecounter_fill_vdso_timehands_t *tc_fill_vdso_timehands;
+	timecounter_fill_vdso_timehands32_t *tc_fill_vdso_timehands32;
 };
 
 extern struct timecounter *timecounter;

sys/sys/vdso.h

@@ -53,6 +53,7 @@ struct vdso_timekeep {
 #define	VDSO_TK_VER_1		0x1
 #define	VDSO_TK_VER_CURR	VDSO_TK_VER_1
 #define	VDSO_TH_ALGO_1		0x1
+#define	VDSO_TH_ALGO_2		0x2
 
 #ifndef _KERNEL
 
@@ -62,7 +63,7 @@ struct timezone;
 
 int __vdso_clock_gettime(clockid_t clock_id, struct timespec *ts);
 int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
-u_int __vdso_gettc(const struct vdso_timehands *vdso_th);
+int __vdso_gettc(const struct vdso_timehands *vdso_th, u_int *tc);
 int __vdso_gettimekeep(struct vdso_timekeep **tk);
 
 #endif

sys/x86/include/vdso.h

@@ -1,7 +1,11 @@
 /*-
  * Copyright 2012 Konstantin Belousov <kib@FreeBSD.ORG>.
+ * Copyright 2016 The FreeBSD Foundation.
  * All rights reserved.
  *
+ * Portions of this software were 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:
@@ -30,7 +34,11 @@
 
 #define	VDSO_TIMEHANDS_MD			\
 	uint32_t	th_x86_shift;		\
-	uint32_t	th_res[7];
+	uint32_t	th_x86_hpet_idx;	\
+	uint32_t	th_res[6];
+
+#define	VDSO_TH_ALGO_X86_TSC	VDSO_TH_ALGO_1
+#define	VDSO_TH_ALGO_X86_HPET	VDSO_TH_ALGO_2
 
 #ifdef _KERNEL
 #ifdef COMPAT_FREEBSD32

sys/x86/x86/tsc.c

@@ -48,6 +48,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/md_var.h>
 #include <machine/specialreg.h>
 #include <x86/vmware.h>
+#include <dev/acpica/acpi_hpet.h>
 
 #include "cpufreq_if.h"
 
@@ -93,14 +94,22 @@ static unsigned tsc_get_timecount_low_lfence(struct timecounter *tc);
 static unsigned tsc_get_timecount_mfence(struct timecounter *tc);
 static unsigned tsc_get_timecount_low_mfence(struct timecounter *tc);
 static void tsc_levels_changed(void *arg, int unit);
+static uint32_t x86_tsc_vdso_timehands(struct vdso_timehands *vdso_th,
+    struct timecounter *tc);
+#ifdef COMPAT_FREEBSD32
+static uint32_t x86_tsc_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
+    struct timecounter *tc);
+#endif
 
 static struct timecounter tsc_timecounter = {
-	tsc_get_timecount,	/* get_timecount */
-	0,			/* no poll_pps */
-	~0u,			/* counter_mask */
-	0,			/* frequency */
-	"TSC",			/* name */
-	800,			/* quality (adjusted in code) */
+	.tc_get_timecount =		tsc_get_timecount,
+	.tc_counter_mask =		~0u,
+	.tc_name =			"TSC",
+	.tc_quality =			800,	/* adjusted in code */
+	.tc_fill_vdso_timehands = 	x86_tsc_vdso_timehands,
+#ifdef COMPAT_FREEBSD32
+	.tc_fill_vdso_timehands32 = 	x86_tsc_vdso_timehands32,
+#endif
 };
 
 static void
@@ -724,23 +733,27 @@ tsc_get_timecount_low_mfence(struct timecounter *tc)
 	return (tsc_get_timecount_low(tc));
 }
 
-uint32_t
-cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
+static uint32_t
+x86_tsc_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
 {
 
+	vdso_th->th_algo = VDSO_TH_ALGO_X86_TSC;
 	vdso_th->th_x86_shift = (int)(intptr_t)tc->tc_priv;
+	vdso_th->th_x86_hpet_idx = 0xffffffff;
 	bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
-	return (tc == &tsc_timecounter);
+	return (1);
 }
 
 #ifdef COMPAT_FREEBSD32
-uint32_t
-cpu_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
+static uint32_t
+x86_tsc_vdso_timehands32(struct vdso_timehands32 *vdso_th32,
     struct timecounter *tc)
 {
 
+	vdso_th32->th_algo = VDSO_TH_ALGO_X86_TSC;
 	vdso_th32->th_x86_shift = (int)(intptr_t)tc->tc_priv;
+	vdso_th32->th_x86_hpet_idx = 0xffffffff;
 	bzero(vdso_th32->th_res, sizeof(vdso_th32->th_res));
-	return (tc == &tsc_timecounter);
+	return (1);
 }
 #endif