Revert the critical section implementation to disable interrupts via

cli/sti now that we support many more than 32 interrupt sources.

2 files changed, 9 insertions, 145 deletions

diff --git a/sys/i386/i386/critical.c b/sys/i386/i386/critical.c
index 8c24387..325d97a 100644
--- a/sys/i386/i386/critical.c
+++ b/sys/i386/i386/critical.c
@@ -30,144 +30,17 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
-#include <sys/signalvar.h>
-#include <sys/kernel.h>
-#include <sys/lock.h>
-#include <sys/mutex.h>
-#include <sys/pcpu.h>
 #include <sys/proc.h>
-#include <sys/sysctl.h>
-#include <sys/ucontext.h>
-#include <machine/clock.h>
 #include <machine/critical.h>
 
-#ifdef SMP
-#include <machine/privatespace.h>
-#include <machine/smp.h>
-#else
-/*
- * XXX this mess to get sched_ithd() and call_fast_unpend()
- */
-#include <sys/bus.h>
-#include <machine/apic.h>
-#include <machine/frame.h>
-#include <i386/isa/icu.h>
-#include <i386/isa/intr_machdep.h>
-#endif
-
-void i386_unpend(void);		/* NOTE: not static, called from assembly */
-
-/*
- * cpu_unpend() -	called from critical_exit() inline after quick
- *			interrupt-pending check.
- */
-void
-cpu_unpend(void)
-{
-	register_t eflags;
-	struct thread *td;
-
-	td = curthread;
-	eflags = intr_disable();
-	if (PCPU_GET(int_pending)) {
-		++td->td_intr_nesting_level;
-		i386_unpend();
-		--td->td_intr_nesting_level;
-	}
-	intr_restore(eflags);
-}
-
 /*
  * cpu_critical_fork_exit() - cleanup after fork
- */
-void
-cpu_critical_fork_exit(void)
-{
-
-	enable_intr();
-}
-
-/*
- * Called from cpu_unpend or called from the assembly vector code
- * to process any interrupts which may have occured while we were in
- * a critical section.
- *
- * 	- interrupts must be disabled
- *	- td_critnest must be 0
- *	- td_intr_nesting_level must be incremented by the caller
  *
- * NOT STATIC (called from assembly)
+ *	Enable interrupts in the saved copy of eflags.
  */
 void
-i386_unpend(void)
+cpu_critical_fork_exit(void)
 {
-	struct clockframe frame;
-
-	frame.cf_cs = SEL_KPL;
-	frame.cf_eip = (register_t)i386_unpend;
-	frame.cf_eflags = PSL_KERNEL;
-	KASSERT(curthread->td_critnest == 0, ("unpend critnest != 0"));
-	KASSERT((read_eflags() & PSL_I) == 0, ("unpend interrupts enabled1"));
-	curthread->td_critnest = 1;
-	for (;;) {
-		u_int32_t mask;
-		int irq;
-
-		/*
-		 * Fast interrupts have priority
-		 */
-		if ((mask = PCPU_GET(fpending)) != 0) {
-			irq = bsfl(mask);
-			PCPU_SET(fpending, mask & ~(1 << irq));
-			call_fast_unpend(irq);
-			KASSERT((read_eflags() & PSL_I) == 0,
-			    ("unpend interrupts enabled2 %d", irq));
-			continue;
-		}
-
-		/*
-		 * Threaded interrupts come next
-		 */
-		if ((mask = PCPU_GET(ipending)) != 0) {
-			irq = bsfl(mask);
-			PCPU_SET(ipending, mask & ~(1 << irq));
-			sched_ithd((void *)irq);
-			KASSERT((read_eflags() & PSL_I) == 0,
-			    ("unpend interrupts enabled3 %d", irq));
-			continue;
-		}
 
-		/*
-		 * Software interrupts and delayed IPIs are last
-		 *
-		 * XXX give the bits #defined names.  see also
-		 * isa/xxx_vector.s
-		 */
-		if ((mask = PCPU_GET(spending)) != 0) {
-			irq = bsfl(mask);
-			PCPU_SET(spending, mask & ~(1 << irq));
-			switch(irq) {
-			case 0:		/* bit 0 - hardclock */
-				hardclock_process(&frame);
-				break;
-			case 1:		/* bit 1 - statclock */
-				if (profprocs != 0)
-					profclock(&frame);
-				if (pscnt == psdiv)
-					statclock(&frame);
-				break;
-			}
-			KASSERT((read_eflags() & PSL_I) == 0,
-			    ("unpend interrupts enabled4 %d", irq));
-			continue;
-		}
-		break;
-	}
-	/*
-	 * Interrupts are still disabled, we can safely clear int_pending 
-	 * and td_critnest.
-	 */
-	KASSERT((read_eflags() & PSL_I) == 0, ("unpend interrupts enabled5"));
-	PCPU_SET(int_pending, 0);
-	curthread->td_critnest = 0;
+	curthread->td_md.md_savecrit = read_eflags() | PSL_I;
 }
diff --git a/sys/i386/include/critical.h b/sys/i386/include/critical.h
index 689d039..5a14f70 100644
--- a/sys/i386/include/critical.h
+++ b/sys/i386/include/critical.h
@@ -44,7 +44,6 @@ __BEGIN_DECLS
 /*
  * Prototypes - see <arch>/<arch>/critical.c
  */
-void cpu_unpend(void);
 void cpu_critical_fork_exit(void);
 
 #ifdef	__GNUC__
@@ -59,7 +58,11 @@ void cpu_critical_fork_exit(void);
  *	However, as a side effect any interrupts occuring while td_critnest
  *	is non-zero will be deferred.
  */
-#define cpu_critical_enter()
+static __inline void
+cpu_critical_enter(void)
+{
+	curthread->td_md.md_savecrit = intr_disable();
+}
 
 /*
  *	cpu_critical_exit:
@@ -75,19 +78,7 @@ void cpu_critical_fork_exit(void);
 static __inline void
 cpu_critical_exit(void)
 {
-	/*
-	 * We may have to schedule pending interrupts.  Create
-	 * conditions similar to an interrupt context and call
-	 * unpend().
-	 *
-	 * note: we do this even if we are in an interrupt
-	 * nesting level.  Deep nesting is protected by
-	 * critical_*() and if we conditionalized it then we
-	 * would have to check int_pending again whenever
-	 * we decrement td_intr_nesting_level to 0.
-	 */
-	if (PCPU_GET(int_pending))
-		cpu_unpend();
+	intr_restore(curthread->td_md.md_savecrit);
 }
 
 #else /* !__GNUC__ */