freebsd-dev/sys/i386/isa/ipl_funcs.c
Steve Passe c2d4a15648 Added a couple short-term debugs and a fix to the SPIN_MAX variable.
Debugs are an attempt to ferret out the PUSHDOWN_LEVEL_3 deadlock.
1997-09-28 19:34:48 +00:00

402 lines
9.7 KiB
C

/*-
* Copyright (c) 1997 Bruce Evans.
* 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.
*
* $Id: ipl_funcs.c,v 1.9 1997/09/21 21:41:16 gibbs Exp $
*/
#include <sys/types.h>
#include <sys/systm.h>
#include <machine/ipl.h>
#ifndef SMP
/*
* The volatile bitmap variables must be set atomically. This normally
* involves using a machine-dependent bit-set or `or' instruction.
*/
#define DO_SETBITS(name, var, bits) \
void name(void) \
{ \
setbits(var, bits); \
}
DO_SETBITS(setdelayed, &ipending, loadandclear((unsigned *)&idelayed))
DO_SETBITS(setsoftast, &ipending, SWI_AST_PENDING)
DO_SETBITS(setsoftclock, &ipending, SWI_CLOCK_PENDING)
DO_SETBITS(setsoftnet, &ipending, SWI_NET_PENDING)
DO_SETBITS(setsofttty, &ipending, SWI_TTY_PENDING)
DO_SETBITS(setsoftcamnet,&ipending, SWI_CAMNET_PENDING)
DO_SETBITS(setsoftcambio,&ipending, SWI_CAMBIO_PENDING)
DO_SETBITS(schedsoftnet, &idelayed, SWI_NET_PENDING)
DO_SETBITS(schedsofttty, &idelayed, SWI_TTY_PENDING)
DO_SETBITS(schedsoftcamnet, &idelayed, SWI_CAMNET_PENDING)
DO_SETBITS(schedsoftcambio, &idelayed, SWI_CAMBIO_PENDING)
unsigned
softclockpending(void)
{
return (ipending & SWI_CLOCK_PENDING);
}
#define GENSPL(name, set_cpl) \
unsigned name(void) \
{ \
unsigned x; \
\
x = cpl; \
set_cpl; \
return (x); \
}
GENSPL(splbio, cpl |= bio_imask)
GENSPL(splclock, cpl = HWI_MASK | SWI_MASK)
GENSPL(splhigh, cpl = HWI_MASK | SWI_MASK)
GENSPL(splimp, cpl |= net_imask)
GENSPL(splnet, cpl |= SWI_NET_MASK)
GENSPL(splcam, cpl |= cam_imask)
GENSPL(splsoftcam, cpl |= SWI_CAMBIO_MASK | SWI_CAMNET_MASK)
GENSPL(splsoftcambio, cpl |= SWI_CAMBIO_MASK)
GENSPL(splsoftcamnet, cpl |= SWI_CAMNET_MASK)
GENSPL(splsoftclock, cpl = SWI_CLOCK_MASK)
GENSPL(splsofttty, cpl |= SWI_TTY_MASK)
GENSPL(splstatclock, cpl |= stat_imask)
GENSPL(spltty, cpl |= tty_imask)
GENSPL(splvm, cpl |= net_imask | bio_imask)
void
spl0(void)
{
cpl = SWI_AST_MASK;
if (ipending & ~SWI_AST_MASK)
splz();
}
void
splx(unsigned ipl)
{
cpl = ipl;
if (ipending & ~ipl)
splz();
}
#else /* !SMP */
#include <machine/smp.h>
#include <machine/smptests.h>
#ifndef SPL_DEBUG_POSTCODE
#undef POSTCODE
#undef POSTCODE_LO
#undef POSTCODE_HI
#define POSTCODE(X)
#define POSTCODE_LO(X)
#define POSTCODE_HI(X)
#endif /* SPL_DEBUG_POSTCODE */
/*
* The volatile bitmap variables must be set atomically. This normally
* involves using a machine-dependent bit-set or `or' instruction.
*/
#define DO_SETBITS(name, var, bits) \
void name(void) \
{ \
IFCPL_LOCK(); \
setbits(var, bits); \
IFCPL_UNLOCK(); \
}
DO_SETBITS(setdelayed, &ipending, loadandclear((unsigned *)&idelayed))
DO_SETBITS(setsoftast, &ipending, SWI_AST_PENDING)
DO_SETBITS(setsoftclock, &ipending, SWI_CLOCK_PENDING)
DO_SETBITS(setsoftnet, &ipending, SWI_NET_PENDING)
DO_SETBITS(setsofttty, &ipending, SWI_TTY_PENDING)
DO_SETBITS(setsoftcamnet,&ipending, SWI_CAMNET_PENDING)
DO_SETBITS(setsoftcambio,&ipending, SWI_CAMBIO_PENDING)
DO_SETBITS(schedsoftnet, &idelayed, SWI_NET_PENDING)
DO_SETBITS(schedsofttty, &idelayed, SWI_TTY_PENDING)
DO_SETBITS(schedsoftcamnet, &idelayed, SWI_CAMNET_PENDING)
DO_SETBITS(schedsoftcambio, &idelayed, SWI_CAMBIO_PENDING)
unsigned
softclockpending(void)
{
unsigned x;
IFCPL_LOCK();
x = ipending & SWI_CLOCK_PENDING;
IFCPL_UNLOCK();
return (x);
}
/*
* This version has to check for bsp_apic_ready,
* as calling simple_lock() (ie ss_lock) before then deadlocks the system.
* A sample count of GENSPL calls before bsp_apic_ready was set: 2193
*/
#ifdef INTR_SPL
#ifdef SPL_DEBUG
#define MAXZ 100000000
#define SPIN_VAR unsigned z;
#define SPIN_RESET z = 0;
#if 0
#define SPIN_SPL \
if (++z >= MAXZ) { \
/* XXX allow lock-free panic */ \
bsp_apic_ready = 0; \
panic("\ncil: 0x%08x", cil); \
}
#else
#define SPIN_SPL \
if (++z >= MAXZ) { \
/* XXX allow lock-free panic */ \
bsp_apic_ready = 0; \
printf("\ncil: 0x%08x", cil); \
breakpoint(); \
}
#endif /* 0/1 */
#else /* SPL_DEBUG */
#define SPIN_VAR
#define SPIN_RESET
#define SPIN_SPL
#endif /* SPL_DEBUG */
#endif
#ifdef INTR_SPL
#define GENSPL(NAME, OP, MODIFIER, PC) \
unsigned NAME(void) \
{ \
unsigned x, y; \
SPIN_VAR; \
\
if (!bsp_apic_ready) { \
x = cpl; \
cpl OP MODIFIER; \
return (x); \
} \
\
for (;;) { \
IFCPL_LOCK(); /* MP-safe */ \
x = y = cpl; /* current value */ \
POSTCODE(0x20 | PC); \
if (inside_intr) \
break; /* XXX only 1 INT allowed */ \
y OP MODIFIER; /* desired value */ \
if (cil & y) { /* not now */ \
IFCPL_UNLOCK(); /* allow cil to change */ \
SPIN_RESET; \
while (cil & y) \
SPIN_SPL \
continue; /* try again */ \
} \
break; \
} \
cpl OP MODIFIER; /* make the change */ \
IFCPL_UNLOCK(); \
\
return (x); \
}
/* NAME: OP: MODIFIER: PC: */
GENSPL(splbio, |=, bio_imask, 2)
GENSPL(splclock, =, HWI_MASK | SWI_MASK, 3)
GENSPL(splhigh, =, HWI_MASK | SWI_MASK, 4)
GENSPL(splimp, |=, net_imask, 5)
GENSPL(splnet, |=, SWI_NET_MASK, 6)
GENSPL(splcam, |=, cam_imask, 7)
GENSPL(splsoftcam, |=, SWI_CAMBIO_MASK | SWI_CAMNET_MASK, 8)
GENSPL(splsoftcambio, |=, SWI_CAMBIO_MASK, 9)
GENSPL(splsoftcamnet, |=, SWI_CAMNET_MASK, 10)
GENSPL(splsoftclock, =, SWI_CLOCK_MASK, 11)
GENSPL(splsofttty, |=, SWI_TTY_MASK, 12)
GENSPL(splstatclock, |=, stat_imask, 13)
GENSPL(spltty, |=, tty_imask, 14)
GENSPL(splvm, |=, net_imask | bio_imask, 15)
#else /* INTR_SPL */
#define GENSPL(NAME, set_cpl) \
unsigned NAME(void) \
{ \
unsigned x; \
\
if (!bsp_apic_ready) { \
x = cpl; \
set_cpl; \
} \
else { \
IFCPL_LOCK(); \
x = cpl; \
set_cpl; \
IFCPL_UNLOCK(); \
} \
\
return (x); \
}
GENSPL(splbio, cpl |= bio_imask)
GENSPL(splclock, cpl = HWI_MASK | SWI_MASK)
GENSPL(splhigh, cpl = HWI_MASK | SWI_MASK)
GENSPL(splimp, cpl |= net_imask)
GENSPL(splnet, cpl |= SWI_NET_MASK)
GENSPL(splcam, cpl |= cam_imask)
GENSPL(splsoftcam, cpl |= SWI_CAMBIO_MASK | SWI_CAMNET_MASK)
GENSPL(splsoftcambio, cpl |= SWI_CAMBIO_MASK)
GENSPL(splsoftcamnet, cpl |= SWI_CAMNET_MASK)
GENSPL(splsoftclock, cpl = SWI_CLOCK_MASK)
GENSPL(splsofttty, cpl |= SWI_TTY_MASK)
GENSPL(splstatclock, cpl |= stat_imask)
GENSPL(spltty, cpl |= tty_imask)
GENSPL(splvm, cpl |= net_imask | bio_imask)
#endif /* INTR_SPL */
void
spl0(void)
{
int unpend;
#ifdef INTR_SPL
SPIN_VAR;
for (;;) {
IFCPL_LOCK();
POSTCODE_HI(0xc);
if (cil & SWI_AST_MASK) { /* not now */
IFCPL_UNLOCK(); /* allow cil to change */
SPIN_RESET;
while (cil & SWI_AST_MASK)
SPIN_SPL
continue; /* try again */
}
break;
}
#else /* INTR_SPL */
IFCPL_LOCK();
#endif /* INTR_SPL */
cpl = SWI_AST_MASK;
unpend = ipending & ~SWI_AST_MASK;
IFCPL_UNLOCK();
if (unpend && !inside_intr)
splz();
}
void
splx(unsigned ipl)
{
int unpend;
#ifdef INTR_SPL
SPIN_VAR;
#endif
if (!bsp_apic_ready) {
cpl = ipl;
if (ipending & ~ipl)
splz();
return;
}
#ifdef INTR_SPL
for (;;) {
IFCPL_LOCK();
POSTCODE_HI(0xe);
if (inside_intr)
break; /* XXX only 1 INT allowed */
POSTCODE_HI(0xf);
if (cil & ipl) { /* not now */
IFCPL_UNLOCK(); /* allow cil to change */
SPIN_RESET;
while (cil & ipl)
SPIN_SPL
continue; /* try again */
}
break;
}
#else /* INTR_SPL */
IFCPL_LOCK();
#endif /* INTR_SPL */
cpl = ipl;
unpend = ipending & ~ipl;
IFCPL_UNLOCK();
if (unpend && !inside_intr)
splz();
}
/*
* Replaces UP specific inline found in (?) pci/pci_support.c.
*
* Stefan said:
* You know, that splq() is used in the shared interrupt multiplexer, and that
* the SMP version should not have too much overhead. If it is significantly
* slower, then moving the splq() out of the loop in intr_mux() and passing in
* the logical OR of all mask values might be a better solution than the
* current code. (This logical OR could of course be pre-calculated whenever
* another shared interrupt is registered ...)
*/
intrmask_t
splq(intrmask_t mask)
{
intrmask_t tmp, tmp2;
#ifdef INTR_SPL
for (;;) {
IFCPL_LOCK();
tmp = tmp2 = cpl;
tmp2 |= mask;
if (cil & tmp2) { /* not now */
IFCPL_UNLOCK(); /* allow cil to change */
while (cil & tmp2)
/* spin */ ;
continue; /* try again */
}
break;
}
cpl = tmp2;
#else /* INTR_SPL */
IFCPL_LOCK();
tmp = cpl;
cpl |= mask;
#endif /* INTR_SPL */
IFCPL_UNLOCK();
return (tmp);
}
#endif /* !SMP */