OpenSolaris_b135/uts/sun4v/sys/machclock.h
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_MACHCLOCK_H
#define _SYS_MACHCLOCK_H
#include <sys/intreg.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* Tick/Stick Register Access
*
* The following assembly language macros are defined for reading
* the %tick and %stick registers as well as reading and writing
* the stick compare register. With the exception of trapstat, reads
* and writes of these registers all take into account an offset
* value which is added to the hardware counter. By default, this
* offset is zero. The offsets can only be modified when CPUs are
* paused and are only intended to be modified during an OS suspend
* operation.
*
* Since the read of the %tick or %stick is not an atomic operation,
* it is possible for a suspend operation to occur between the read
* of the hardware register and its offset variable. The default
* macros here take this into account by comparing the value of the
* offset variable before and after reading the hardware register.
* Callers that need to read the %tick register and can guarantee
* they will not be preempted can use the RD_TICK_NO_SUSPEND_CHECK
* which does not check for native_tick_offset changing.
*/
#define RD_STICK(out, scr1, scr2, label) \
.rd_stick.label: \
sethi %hi(native_stick_offset), scr1; \
ldx [scr1 + %lo(native_stick_offset)], scr2; \
rd STICK, out; \
ldx [scr1 + %lo(native_stick_offset)], scr1; \
sub scr1, scr2, scr2; \
/* CSTYLED */ \
brnz,pn scr2, .rd_stick.label; \
sllx out, 1, out; \
srlx out, 1, out; \
add out, scr1, out
#define RD_TICK(out, scr1, scr2, label) \
.rd_tick.label: \
sethi %hi(native_tick_offset), scr1; \
ldx [scr1 + %lo(native_tick_offset)], scr2; \
rd %tick, out; \
ldx [scr1 + %lo(native_tick_offset)], scr1; \
sub scr1, scr2, scr2; \
/* CSTYLED */ \
brnz,pn scr2, .rd_tick.label; \
sllx out, 1, out; \
srlx out, 1, out; \
add out, scr1, out
#define RD_TICK_NO_SUSPEND_CHECK(out, scr1) \
sethi %hi(native_tick_offset), scr1; \
ldx [scr1 + %lo(native_tick_offset)], scr1; \
rd %tick, out; \
sllx out, 1, out; \
srlx out, 1, out; \
add out, scr1, out
/*
* Read the %stick register without taking the native_stick_offset
* into account.
*/
#define RD_STICK_PHYSICAL(out) \
rd %stick, out
/*
* Read the %tick register without taking the native_tick_offset
* into account. Required to be a single instruction, usable in a
* delay slot.
*/
#define RD_TICK_PHYSICAL(out) \
rd %tick, out
/*
* For traptrace, which requires either the %tick or %stick
* counter depending on the value of a global variable.
* If the kernel variable passed in as 'use_stick' is non-zero,
* read the %stick counter into the 'out' register, otherwise,
* read the %tick counter. Note the label-less branches.
* We do not check for the tick or stick offset variables changing
* during the course of the macro's execution and as a result
* if a suspend operation occurs between the time the offset
* variable is read and the hardware register is read, we will
* use an inaccurate traptrace timestamp.
*/
#define RD_TICKSTICK_FLAG(out, scr1, use_stick) \
sethi %hi(use_stick), scr1; \
lduw [scr1 + %lo(use_stick)], scr1; \
/* CSTYLED */ \
brz,a scr1, .+24; \
rd %tick, out; \
sethi %hi(native_stick_offset), scr1; \
ldx [scr1 + %lo(native_stick_offset)], scr1; \
ba .+16; \
rd STICK, out; \
sethi %hi(native_tick_offset), scr1; \
ldx [scr1 + %lo(native_tick_offset)], scr1; \
sllx out, 1, out; \
srlx out, 1, out; \
add out, scr1, out;
#define RD_TICKCMPR(out, scr1, scr2, label) \
.rd_stickcmpr.label: \
sethi %hi(native_stick_offset), scr1; \
ldx [scr1 + %lo(native_stick_offset)], scr2; \
rd STICK_COMPARE, out; \
ldx [scr1 + %lo(native_stick_offset)], scr1; \
sub scr1, scr2, scr2; \
/* CSTYLED */ \
brnz,pn scr2, .rd_stickcmpr.label; \
add out, scr1, out
#define WR_TICKCMPR(in, scr1, scr2, label) \
sethi %hi(native_stick_offset), scr1; \
ldx [scr1 + %lo(native_stick_offset)], scr1; \
sub in, scr1, scr1; \
wr scr1, STICK_COMPARE
#define GET_NATIVE_TIME(out, scr1, scr2, label) \
/* CSTYLED */ \
RD_STICK(out,scr1,scr2,label)
/*
* Sun4v processors come up with NPT cleared and there is no need to
* clear it again. Also, clearing of the NPT cannot be done atomically
* on a CMT processor.
*/
#define CLEARTICKNPT
#if defined(CPU_MODULE)
/*
* Constants used to convert hi-res timestamps into nanoseconds
* (see <sys/clock.h> file for more information)
*/
/*
* At least 62.5 MHz, for faster %tick-based systems.
*/
#define NSEC_SHIFT 4
/*
* NOTE: the macros below assume that the various time-related variables
* (hrestime, hrestime_adj, hres_last_tick, timedelta, nsec_scale, etc)
* are all stored together on a 64-byte boundary. The primary motivation
* is cache performance, but we also take advantage of a convenient side
* effect: these variables all have the same high 22 address bits, so only
* one sethi is needed to access them all.
*/
/*
* GET_HRESTIME() returns the value of hrestime, hrestime_adj and the
* number of nanoseconds since the last clock tick ('nslt'). It also
* sets 'nano' to the value NANOSEC (one billion).
*
* This macro assumes that all registers are globals or outs so they can
* safely contain 64-bit data, and that it's safe to use the label "5:".
* Further, this macro calls the NATIVE_TIME_TO_NSEC_SCALE which in turn
* uses the labels "6:" and "7:"; labels "5:", "6:" and "7:" must not
* be used across invocations of this macro.
*/
#define GET_HRESTIME(hrestsec, hrestnsec, adj, nslt, nano, scr, hrlock, \
gnt1, gnt2, label) \
5: sethi %hi(hres_lock), scr; \
lduw [scr + %lo(hres_lock)], hrlock; /* load clock lock */ \
lduw [scr + %lo(nsec_scale)], nano; /* tick-to-ns factor */ \
andn hrlock, 1, hrlock; /* see comments above! */ \
ldx [scr + %lo(hres_last_tick)], nslt; \
ldn [scr + %lo(hrestime)], hrestsec; /* load hrestime.sec */\
add scr, %lo(hrestime), hrestnsec; \
ldn [hrestnsec + CLONGSIZE], hrestnsec; \
/* CSTYLED */ \
GET_NATIVE_TIME(adj,gnt1,gnt2,label); /* get current %stick */ \
subcc adj, nslt, nslt; /* nslt = ticks since last clockint */ \
movneg %xcc, %g0, nslt; /* ignore neg delta from tick skew */ \
ldx [scr + %lo(hrestime_adj)], adj; /* load hrestime_adj */ \
/* membar #LoadLoad; (see comment (2) above) */ \
lduw [scr + %lo(hres_lock)], scr; /* load clock lock */ \
NATIVE_TIME_TO_NSEC_SCALE(nslt, nano, gnt1, NSEC_SHIFT); \
sethi %hi(NANOSEC), nano; \
xor hrlock, scr, scr; \
/* CSTYLED */ \
brnz,pn scr, 5b; \
or nano, %lo(NANOSEC), nano;
/*
* Similar to above, but returns current gethrtime() value in 'base'.
*/
#define GET_HRTIME(base, now, nslt, scale, scr, hrlock, gnt1, gnt2, label) \
5: sethi %hi(hres_lock), scr; \
lduw [scr + %lo(hres_lock)], hrlock; /* load clock lock */ \
lduw [scr + %lo(nsec_scale)], scale; /* tick-to-ns factor */ \
andn hrlock, 1, hrlock; /* see comments above! */ \
ldx [scr + %lo(hres_last_tick)], nslt; \
ldx [scr + %lo(hrtime_base)], base; /* load hrtime_base */ \
/* CSTYLED */ \
GET_NATIVE_TIME(now,gnt1,gnt2,label); /* get current %stick */ \
subcc now, nslt, nslt; /* nslt = ticks since last clockint */ \
movneg %xcc, %g0, nslt; /* ignore neg delta from tick skew */ \
/* membar #LoadLoad; (see comment (2) above) */ \
ld [scr + %lo(hres_lock)], scr; /* load clock lock */ \
NATIVE_TIME_TO_NSEC_SCALE(nslt, scale, gnt1, NSEC_SHIFT); \
xor hrlock, scr, scr; \
/* CSTYLED */ \
brnz,pn scr, 5b; \
add base, nslt, base;
#endif /* CPU_MODULE */
#ifdef __cplusplus
}
#endif
#endif /* !_SYS_MACHCLOCK_H */