sparcv9_subr.s revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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
* 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]
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* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/asm_linkage.h>
#include <sys/privregs.h>
#if !defined(lint)
.seg ".text"
.align 4
#define PSR_PIL_BIT 0x8
/*
* Macro to raise processor priority level.
* Avoid dropping processor priority if already at high level.
* Also avoid going below CPU->cpu_base_spl, which could've just been set by
* a higher-level interrupt thread that just blocked.
* XXX4U: bring splr inline
*/
b splr; \
/*
* Macro to set the priority to a specified level.
* Avoid dropping the priority below CPU->cpu_base_spl.
* XXX4U: bring splx inline
*/
b splx; \
#endif /* lint */
/*
* Berkley 4.3 introduced symbolically named interrupt levels
* as a way deal with priority in a machine independent fashion.
* Numbered priorities are machine specific, and should be
* discouraged where possible.
*
* Note, for the machine specific priorities there are
* examples listed for devices that use a particular priority.
* It should not be construed that all devices of that
* type should be at that priority. It is currently were
* the current devices fit into the priority scheme based
* upon time criticalness.
*
* The underlying assumption of these assignments is that
* SPARC9 IPL 10 is the highest level from which a device
* routine can call wakeup. Devices that interrupt from higher
* levels are restricted in what they can do. If they need
* kernels services they should schedule a routine at a lower
* level (via software interrupt) to do the required
* processing.
*
* Examples of this higher usage:
* Level Usage
* 15 Asynchronous memory exceptions
* 14 Profiling clock (and PROM uart polling clock)
* 13 Audio device
* 12 Serial ports
* 11 Floppy controller
*
* The serial ports request lower level processing on level 6.
* Audio and floppy request lower level processing on level 4.
*
* Also, almost all splN routines (where N is a number or a
* mnemonic) will do a RAISE(), on the assumption that they are
* never used to lower our priority.
* The exceptions are:
* spl8() Because you can't be above 15 to begin with!
* splzs() Because this is used at boot time to lower our
* priority, to allow the PROM to poll the uart.
* spl0() Used to lower priority to 0.
* splsoftclock() Used by hardclock to lower priority.
*/
#if defined(lint)
int splimp(void) { return (0); }
int splnet(void) { return (0); }
#ifdef notdef
int spl6(void) { return (0); }
int spl5(void) { return (0); }
#endif notdef
#else /* lint */
/* locks out all interrupts, including memory errors */
SETPRI(15)
/* just below the level that profiling runs */
RAISE(13)
/* sun specific - highest priority onboard serial i/o zs ports */
/*
* should lock out clocks and all interrupts,
* as you can see, there are exceptions
*/
/* the standard clock interrupt priority */
/* highest priority for any tty handling */
/* highest priority required for protection of buffered io system */
/* machine specific */
RAISE(10)
/*
* machine specific
* for sun, some frame buffers must be at this priority
*/
RAISE(8)
/* highest level that any network device will use */
/*
* machine specific
* for sun, devices with limited buffering: tapes, ethernet
*/
RAISE(6)
/*
* machine specific - not as time critical as above
* for sun, disks
*/
RAISE(4)
RAISE(2)
/* highest level that any protocol handler will run */
RAISE(1)
/* softcall priority */
/* used by hardclock to LOWER priority */
SETPRI(1)
/* allow all interrupts */
SETPRI(0)
#endif /* lint */
/*
* splx - set PIL back to that indicated by the old %PSR passed as an argument,
* or to the CPU's base priority, whichever is higher.
* sys_rtt (in locore.s) relies on this not to use %g1 or %g2.
*/
#if defined(lint)
/* ARGSUSED */
void
{
}
#else /* lint */
#endif /* level */
/*
* splr()
*
* splr is like splx but will only raise the priority and never drop it
* Be careful not to set priority lower than CPU->cpu_base_pri,
* even though it seems we're raising the priority, it could be set higher
* at any time by an interrupt routine, so we must block interrupts and
* look at CPU->cpu_base_pri.
*
*/
#if defined(lint)
#ifdef notdef
/* ARGSUSED */
int
{ return (0); }
#endif notdef
#else /* lint */
/*
* splr(psr_pri_field)
* splr is like splx but will only raise the priority and never drop it
*/
ble 1f
1: retl
#endif /* lint */
/*
* get_ticks()
*/
#if defined(lint)
/* ARGSUSED */
get_ticks(void)
{ return (0); }
#else /* lint */
#endif /* lint */