Major update to the way synchronization is done in the kernel. Highlights

include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh

1 files changed, 44 insertions, 223 deletions

diff --git a/sys/i386/isa/ipl_funcs.c b/sys/i386/isa/ipl_funcs.c
index d27d97f..14eb240 100644
--- a/sys/i386/isa/ipl_funcs.c
+++ b/sys/i386/isa/ipl_funcs.c
@@ -27,11 +27,13 @@
  */
 
 #include <sys/param.h>
+#include <sys/bus.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/sysctl.h>
 #include <machine/ipl.h>
-#include <machine/globals.h>
+#include <sys/proc.h>
+#include <i386/isa/icu.h>
 #include <i386/isa/intr_machdep.h>
 
 /*
@@ -45,236 +47,55 @@
 void name(void)					\
 {						\
 	atomic_set_int(var, bits);		\
+	sched_ithd((void *) SOFTINTR);		\
 }
 
-DO_SETBITS(setdelayed,   &ipending, loadandclear(&idelayed))
+DO_SETBITS(setdelayed,   &spending, loadandclear(&idelayed))
+DO_SETBITS(setsoftcamnet,&spending, SWI_CAMNET_PENDING)
+DO_SETBITS(setsoftcambio,&spending, SWI_CAMBIO_PENDING)
+DO_SETBITS(setsoftclock, &spending, SWI_CLOCK_PENDING)
+DO_SETBITS(setsoftnet,   &spending, SWI_NET_PENDING)
+DO_SETBITS(setsofttty,   &spending, SWI_TTY_PENDING)
+DO_SETBITS(setsoftvm,	 &spending, SWI_VM_PENDING)
+DO_SETBITS(setsofttq,	 &spending, SWI_TQ_PENDING)
 
-DO_SETBITS(setsoftcamnet,&ipending, SWI_CAMNET_PENDING)
-DO_SETBITS(setsoftcambio,&ipending, SWI_CAMBIO_PENDING)
-DO_SETBITS(setsoftclock, &ipending, SWI_CLOCK_PENDING)
-DO_SETBITS(setsoftnet,   &ipending, SWI_NET_PENDING)
-DO_SETBITS(setsofttty,   &ipending, SWI_TTY_PENDING)
-DO_SETBITS(setsoftvm,	 &ipending, SWI_VM_PENDING)
-DO_SETBITS(setsofttq,	 &ipending, SWI_TQ_PENDING)
-
-DO_SETBITS(schedsoftcamnet, &idelayed, SWI_CAMNET_PENDING)
-DO_SETBITS(schedsoftcambio, &idelayed, SWI_CAMBIO_PENDING)
-DO_SETBITS(schedsoftnet, &idelayed, SWI_NET_PENDING)
-DO_SETBITS(schedsofttty, &idelayed, SWI_TTY_PENDING)
-DO_SETBITS(schedsoftvm,	&idelayed, SWI_VM_PENDING)
-DO_SETBITS(schedsofttq,	&idelayed, SWI_TQ_PENDING)
+/*
+ * We don't need to schedule soft interrupts any more, it happens
+ * automatically.
+ */ 
+#define	schedsoftcamnet
+#define	schedsoftcambio
+#define	schedsoftnet
+#define	schedsofttty
+#define	schedsoftvm
+#define	schedsofttq
 
 unsigned
 softclockpending(void)
 {
-	return (ipending & SWI_CLOCK_PENDING);
+	return (spending & SWI_CLOCK_PENDING);
 }
 
 /*
- * Support for SPL assertions.
- */
-
-#ifdef INVARIANT_SUPPORT
-
-#define	SPLASSERT_IGNORE	0
-#define	SPLASSERT_LOG		1
-#define	SPLASSERT_PANIC		2
-
-static int splassertmode = SPLASSERT_LOG;
-SYSCTL_INT(_kern, OID_AUTO, splassertmode, CTLFLAG_RW,
-	&splassertmode, 0, "Set the mode of SPLASSERT");
-
-static void
-init_splassertmode(void *ignored)
-{
-	TUNABLE_INT_FETCH("kern.splassertmode", 0, splassertmode);
-}
-SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_splassertmode, NULL);
-
-static void
-splassertfail(char *str, const char *msg, char *name, int level)
-{
-	switch (splassertmode) {
-	case SPLASSERT_IGNORE:
-		break;
-	case SPLASSERT_LOG:
-		printf(str, msg, name, level);
-		printf("\n");
-		break;
-	case SPLASSERT_PANIC:
-		panic(str, msg, name, level);
-		break;
-	}
-}
-
-#define	GENSPLASSERT(NAME, MODIFIER)			\
-void							\
-NAME##assert(const char *msg)				\
-{							\
-	if ((cpl & (MODIFIER)) != (MODIFIER))		\
-		splassertfail("%s: not %s, cpl == %#x",	\
-		    msg, __XSTRING(NAME) + 3, cpl);	\
-}
-#else
-#define	GENSPLASSERT(NAME, MODIFIER)
-#endif
-
-/************************************************************************
- *			GENERAL SPL CODE				*
- ************************************************************************
- *
- *  Implement splXXX(), spl0(), splx(), and splq().  splXXX() disables a
- *  set of interrupts (e.g. splbio() disables interrupts relating to 
- *  device I/O) and returns the previous interrupt mask.  splx() restores
- *  the previous interrupt mask, spl0() is a special case which enables
- *  all interrupts and is typically used inside i386/i386 swtch.s and
- *  fork_trampoline.  splq() is a generic version of splXXX().
- *
- *  The SPL routines mess around with the 'cpl' global, which masks 
- *  interrupts.  Interrupts are not *actually* masked.  What happens is 
- *  that if an interrupt masked by the cpl occurs, the appropriate bit
- *  in 'ipending' is set and the interrupt is defered.  When we clear
- *  bits in the cpl we must check to see if any ipending interrupts have
- *  been unmasked and issue the synchronously, which is what the splz()
- *  call does.
- *
- *  Because the cpl is often saved and restored in a nested fashion, cpl
- *  modifications are only allowed in the SMP case when the MP lock is held
- *  to prevent multiple processes from tripping over each other's masks.
- *  The cpl is saved when you do a context switch (mi_switch()) and restored
- *  when your process gets cpu again.
- *
- *  An interrupt routine is allowed to modify the cpl as long as it restores
- *  it prior to returning (thus the interrupted mainline code doesn't notice
- *  anything amiss).  For the SMP case, the interrupt routine must hold 
- *  the MP lock for any cpl manipulation.
- *
- *  Likewise, due to the deterministic nature of cpl modifications, we do
- *  NOT need to use locked instructions to modify it.
+ * Dummy spl calls.  The only reason for these is to not break
+ * all the code which expects to call them.
  */
-
-#ifndef SMP
-
-#define	GENSPL(NAME, OP, MODIFIER, PC)		\
-GENSPLASSERT(NAME, MODIFIER)			\
-unsigned NAME(void)				\
-{						\
-	unsigned x;				\
-						\
-	x = cpl;				\
-	cpl OP MODIFIER;			\
-	return (x);				\
-}
-
-void
-spl0(void)
-{
-	cpl = 0;
-	if (ipending)
-		splz();
-}
-
-void
-splx(unsigned ipl)
-{
-	cpl = ipl;
-	if (ipending & ~ipl)
-		splz();
-}
-
-intrmask_t
-splq(intrmask_t mask)
-{ 
-	intrmask_t tmp = cpl;
-	cpl |= mask;
-	return (tmp);
-}       
-
-#else /* !SMP */
-
-#include <machine/smp.h>
-#include <machine/smptests.h>
-
-/*
- *	SMP CASE
- *
- *	Mostly the same as the non-SMP case now, but it didn't used to be
- *	this clean.
- */
-
-#define	GENSPL(NAME, OP, MODIFIER, PC)		\
-GENSPLASSERT(NAME, MODIFIER)			\
-unsigned NAME(void)				\
-{						\
-	unsigned x;				\
-						\
-	x = cpl;				\
-	cpl OP MODIFIER;			\
-						\
-	return (x);				\
-}
-
-/*
- * spl0() -	unmask all interrupts
- *
- *	The MP lock must be held on entry
- *	This routine may only be called from mainline code.
- */
-void
-spl0(void)
-{
-	KASSERT(inside_intr == 0, ("spl0: called from interrupt"));
-	cpl = 0;
-	if (ipending)
-		splz();
-}
-
-/*
- * splx() -	restore previous interrupt mask
- *
- *	The MP lock must be held on entry
- */
-
-void
-splx(unsigned ipl)
-{
-	cpl = ipl;
-	if (inside_intr == 0 && (ipending & ~cpl) != 0)
-		splz();
-}
-
-
-/*
- * splq() -	blocks specified interrupts
- *
- *	The MP lock must be held on entry
- */
-intrmask_t
-splq(intrmask_t mask)
-{
-	intrmask_t tmp = cpl;
-	cpl |= mask;
-	return (tmp);
-}
-
-#endif /* !SMP */
-
-/* Finally, generate the actual spl*() functions */
-
-/*    NAME:            OP:     MODIFIER:				PC: */
-GENSPL(splbio,		|=,	bio_imask,				2)
-GENSPL(splcam,		|=,	cam_imask,				7)
-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(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(splsoftvm,	|=,	SWI_VM_MASK,				16)
-GENSPL(splsofttq,	|=,	SWI_TQ_MASK,				17)
-GENSPL(splstatclock,	|=,	stat_imask,				13)
-GENSPL(spltty,		|=,	tty_imask,				14)
-GENSPL(splvm,		|=,	net_imask | bio_imask | cam_imask,	15)
+void spl0 (void) {}
+void splx (intrmask_t x) {}
+intrmask_t  splq(intrmask_t mask) {return 0; }
+intrmask_t  splbio(void) {return 0; }
+intrmask_t  splcam(void) {return 0; }
+intrmask_t  splclock(void) {return 0; }
+intrmask_t  splhigh(void) {return 0; }
+intrmask_t  splimp(void) {return 0; }
+intrmask_t  splnet(void) {return 0; }
+intrmask_t  splsoftcam(void) {return 0; }
+intrmask_t  splsoftcambio(void) {return 0; }
+intrmask_t  splsoftcamnet(void) {return 0; }
+intrmask_t  splsoftclock(void) {return 0; }
+intrmask_t  splsofttty(void) {return 0; }
+intrmask_t  splsoftvm(void) {return 0; }
+intrmask_t  splsofttq(void) {return 0; }
+intrmask_t  splstatclock(void) {return 0; }
+intrmask_t  spltty(void) {return 0; }
+intrmask_t  splvm(void) {return 0; }