Change simple lock handling to not depend upon having a local apic

available.  The per-cpu variable ss_tpr has been replaced by ss_eflags.
This reduced the number of interrupts sent to the wrong CPU, due to
the cpu having the global lock being inside a critical region.

Remove some unneeded manipulation of tpr register in mplock.s.

Adjust code in mplock.s to be aware of variables on the stack being
destroyed by MPgetlock if GRAB_LOPRIO is defined.

sys/amd64/amd64/genassym.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)genassym.c	5.11 (Berkeley) 5/10/91
- *	$Id: genassym.c,v 1.55 1998/05/17 18:53:11 tegge Exp $
+ *	$Id: genassym.c,v 1.56 1998/05/17 22:12:07 tegge Exp $
  */
 
 #include "opt_vm86.h"
@@ -218,7 +218,7 @@ main()
 	printf("#define\tGD_CPU_LOCKID %d\n", &globaldata->cpu_lockid);
 	printf("#define\tGD_OTHER_CPUS %d\n", &globaldata->other_cpus);
 	printf("#define\tGD_MY_IDLEPTD %d\n", &globaldata->my_idlePTD);
-	printf("#define\tGD_SS_TPR %d\n", &globaldata->ss_tpr);
+	printf("#define\tGD_SS_EFLAGS %d\n", &globaldata->ss_eflags);
 	printf("#define\tGD_PRV_CMAP1 %d\n", &globaldata->prv_CMAP1);
 	printf("#define\tGD_PRV_CMAP2 %d\n", &globaldata->prv_CMAP2);
 	printf("#define\tGD_PRV_CMAP3 %d\n", &globaldata->prv_CMAP3);

sys/amd64/include/pcpu.h

@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globaldata.h,v 1.2 1998/04/06 18:59:15 peter Exp $
+ * $Id: globaldata.h,v 1.3 1998/05/17 18:53:07 tegge Exp $
  */
 
 /*
@@ -53,7 +53,7 @@ struct globaldata {
 	u_int		cpu_lockid;
 	u_int		other_cpus;
 	pd_entry_t	*my_idlePTD;
-	u_int		ss_tpr;
+	u_int		ss_eflags;
 	pt_entry_t	*prv_CMAP1;
 	pt_entry_t	*prv_CMAP2;
 	pt_entry_t	*prv_CMAP3;

sys/i386/i386/genassym.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)genassym.c	5.11 (Berkeley) 5/10/91
- *	$Id: genassym.c,v 1.55 1998/05/17 18:53:11 tegge Exp $
+ *	$Id: genassym.c,v 1.56 1998/05/17 22:12:07 tegge Exp $
  */
 
 #include "opt_vm86.h"
@@ -218,7 +218,7 @@ main()
 	printf("#define\tGD_CPU_LOCKID %d\n", &globaldata->cpu_lockid);
 	printf("#define\tGD_OTHER_CPUS %d\n", &globaldata->other_cpus);
 	printf("#define\tGD_MY_IDLEPTD %d\n", &globaldata->my_idlePTD);
-	printf("#define\tGD_SS_TPR %d\n", &globaldata->ss_tpr);
+	printf("#define\tGD_SS_EFLAGS %d\n", &globaldata->ss_eflags);
 	printf("#define\tGD_PRV_CMAP1 %d\n", &globaldata->prv_CMAP1);
 	printf("#define\tGD_PRV_CMAP2 %d\n", &globaldata->prv_CMAP2);
 	printf("#define\tGD_PRV_CMAP3 %d\n", &globaldata->prv_CMAP3);

sys/i386/i386/globals.s

@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globals.s,v 1.2 1998/04/06 18:59:14 peter Exp $
+ * $Id: globals.s,v 1.3 1998/05/17 18:53:19 tegge Exp $
  */
 
 #include "opt_vm86.h"
@@ -86,7 +86,7 @@ globaldata:
 	 * The BSP version of these get setup in locore.s and pmap.c, while
 	 * the AP versions are setup in mp_machdep.c.
 	 */
-	.globl	_cpuid,_cpu_lockid,_other_cpus,_my_idlePTD,_ss_tpr
+	.globl	_cpuid,_cpu_lockid,_other_cpus,_my_idlePTD,_ss_eflags
 	.globl	_prv_CMAP1,_prv_CMAP2,_prv_CMAP3,_prv_PMAP1
 	.globl	_inside_intr
 
@@ -94,7 +94,7 @@ globaldata:
 	.set	_cpu_lockid,globaldata + GD_CPU_LOCKID
 	.set	_other_cpus,globaldata + GD_OTHER_CPUS
 	.set	_my_idlePTD,globaldata + GD_MY_IDLEPTD
-	.set	_ss_tpr,globaldata + GD_SS_TPR
+	.set	_ss_eflags,globaldata + GD_SS_EFLAGS
 	.set	_prv_CMAP1,globaldata + GD_PRV_CMAP1
 	.set	_prv_CMAP2,globaldata + GD_PRV_CMAP2
 	.set	_prv_CMAP3,globaldata + GD_PRV_CMAP3

sys/i386/i386/mplock.s

@@ -6,7 +6,7 @@
  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  * ----------------------------------------------------------------------------
  *
- * $Id: mplock.s,v 1.22 1997/08/29 18:16:17 fsmp Exp $
+ * $Id: mplock.s,v 1.23 1997/08/30 08:08:10 fsmp Exp $
  *
  * Functions for locking between CPUs in a SMP system.
  *
@@ -77,7 +77,7 @@
 /***********************************************************************
  *  void MPgetlock(unsigned int *lock)
  *  ----------------------------------
- *  Destroys	%eax, %ecx and %edx.
+ *  Destroys	%eax, %ecx, %edx and 12(%esp).
  */
 
 NON_GPROF_ENTRY(MPgetlock)
@@ -213,7 +213,6 @@ NON_GPROF_ENTRY(get_mplock)
 	pushfl				/* save current EFLAGS */
 	testl	$(1<<9), (%esp)		/* test EI bit */
 	jnz	1f			/* INTs currently enabled */
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti				/* allow IPI and FAST INTs */
 1:
 	pushl	$_mp_lock
@@ -238,10 +237,20 @@ NON_GPROF_ENTRY(boot_get_mplock)
 	pushl	%ecx
 	pushl	%edx
 
+#ifdef GRAB_LOPRIO	
+	pushl	$0
+	pushfl
+#endif
+	
 	pushl	$_mp_lock
 	call	_MPgetlock
 	add	$4, %esp
 
+#ifdef GRAB_LOPRIO	
+	popfl
+	addl	$4, %esp
+#endif
+
 	popl	%edx
 	popl	%ecx
 	popl	%eax
@@ -298,7 +307,6 @@ NON_GPROF_ENTRY(get_isrlock)
 	/* block all HW INTs via Task Priority Register */
 	pushl	lapic_tpr		/* save current TPR */
 	pushfl				/* save current EFLAGS */
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti				/* allow IPI and FAST INTs */
 
 	pushl	$_mp_lock
@@ -344,7 +352,6 @@ NON_GPROF_ENTRY(rel_isrlock)
 NON_GPROF_ENTRY(get_fpu_lock)
 	pushl	lapic_tpr
 	pushfl
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti
 	pushl	$_mp_lock
 	call	_MPgetlock
@@ -375,7 +382,6 @@ NON_GPROF_ENTRY(rel_fpu_lock)
 NON_GPROF_ENTRY(get_align_lock)
 	pushl	lapic_tpr
 	pushfl
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti
 	pushl	$_mp_lock
 	call	_MPgetlock
@@ -406,7 +412,6 @@ NON_GPROF_ENTRY(rel_align_lock)
 NON_GPROF_ENTRY(get_syscall_lock)
 	pushl	lapic_tpr
 	pushfl
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti
 	pushl	$_mp_lock
 	call	_MPgetlock
@@ -437,7 +442,6 @@ NON_GPROF_ENTRY(rel_syscall_lock)
 NON_GPROF_ENTRY(get_altsyscall_lock)
 	pushl	lapic_tpr
 	pushfl
-	movl	$TPR_IGNORE_HWI, lapic_tpr	/* CHEAP_TPR */
 	sti
 	pushl	$_mp_lock
 	call	_MPgetlock
@@ -473,10 +477,20 @@ NON_GPROF_ENTRY(get_mpintrlock)
 	pushl	%ecx
 	pushl	%edx
 
+#ifdef GRAB_LOPRIO
+	pushl	lapic_tpr
+	pushfl
+#endif
+
 	pushl	$_mpintr_lock
 	call	_MPgetlock
 	add	$4, %esp
 
+#ifdef GRAB_LOPRIO	
+	popfl
+	popl	lapic_tpr
+#endif
+
 	popl	%edx
 	popl	%ecx
 	popl	%eax

sys/i386/i386/simplelock.s

@@ -22,7 +22,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: simplelock.s,v 1.7 1997/12/15 02:18:22 tegge Exp $
+ *	$Id: simplelock.s,v 1.8 1998/01/19 17:33:08 tegge Exp $
  */
 
 /*
@@ -31,6 +31,7 @@
 
 #include <machine/asmacros.h>			/* miscellaneous macros */
 #include <i386/isa/intr_machdep.h>
+#include <machine/psl.h>
 	
 #include <machine/smptests.h>			/** FAST_HI */
 
@@ -102,9 +103,6 @@ gotit:
 #else /* SL_DEBUG */
 
 ENTRY(s_lock)
-	cmpl	$0, _smp_active
-	je	gotit
-
 	movl	4(%esp), %edx		/* get the address of the lock */
 setlock:
 	movl	_cpu_lockid, %ecx	/* add cpu id portion */
@@ -190,16 +188,17 @@ ENTRY(test_and_set)
 
 
 /*
- * These versions of simple_lock block hardware INTS,
+ * These versions of simple_lock block interrupts,
  * making it suitable for regions accessed by both top and bottom levels.
- * This is done by saving the current value of the TPR in a per-cpu global,
- * then taking the lock.  On the way out the lock is released, then the
- * original value of the TPR is restored.
+ * This is done by saving the current value of the cpu flags in a per-cpu
+ * global, and disabling interrupts when the lock is taken.  When the
+ * lock is released, interrupts might be enabled, depending upon the saved
+ * cpu flags.
  * Because of this, it must ONLY be used for SHORT, deterministic paths!
  *
  * Note:
  * It would appear to be "bad behaviour" to blindly store a value in
- * ss_tpr, as this could destroy the previous contents.  But since ss_tpr
+ * ss_eflags, as this could destroy the previous contents.  But since ss_eflags
  * is a per-cpu variable, and its fatal to attempt to acquire a simplelock
  * that you already hold, we get away with it.  This needs to be cleaned
  * up someday...
@@ -214,40 +213,29 @@ ENTRY(ss_lock)
 	movl	4(%esp), %eax		/* get the address of the lock */
 	movl	$1, %ecx		/* value for a held lock */
 ssetlock:
-	pushl	lapic_tpr		/* save current task priority */
-#ifdef FAST_HI
-	movl	$TPR_BLOCK_FHWI, lapic_tpr	/* block FAST hw INTs */
-#else
-	movl	$TPR_BLOCK_HWI, lapic_tpr	/* block hw INTs */
-#endif
+	pushfl
+	cli
 	xchgl	%ecx, (%eax)		/* compete */
 	testl	%ecx, %ecx
 	jz	sgotit			/* it was clear, return */
-	popl	lapic_tpr		/* previous value while waiting */
+	popfl				/* previous value while waiting */
 swait:
 	cmpl	$0, (%eax)		/* wait to empty */
 	jne	swait			/* still set... */
 	jmp	ssetlock		/* empty again, try once more */
 sgotit:
-	popl	_ss_tpr			/* save the old task priority */
+	popl	_ss_eflags		/* save the old eflags */
 	ret
 
 #else /* SL_DEBUG */
 
 ENTRY(ss_lock)
-	cmpl	$0, _smp_active
-	je	sgotit2
-
 	movl	4(%esp), %edx		/* get the address of the lock */
 ssetlock:
 	movl	_cpu_lockid, %ecx	/* add cpu id portion */
 	incl	%ecx			/* add lock portion */
-	pushl	lapic_tpr		/* save current task priority */
-#ifdef FAST_HI
-	movl	$TPR_BLOCK_FHWI, lapic_tpr	/* block FAST hw INTs */
-#else
-	movl	$TPR_BLOCK_HWI, lapic_tpr	/* block hw INTs */
-#endif
+	pushfl
+	cli
 	movl	$0, %eax
 	lock
 	cmpxchgl %ecx, (%edx)		/* compete */
@@ -257,13 +245,13 @@ ssetlock:
 	cmpl	_cpu_lockid, %eax	/* do we hold it? */
 	je	sbad_slock		/* yes, thats not good... */
 	addl	$4, %esp		/* clear the stack */
-	popl	lapic_tpr		/* previous value while waiting */
+	popfl
 swait:
 	cmpl	$0, (%edx)		/* wait to empty */
 	jne	swait			/* still set... */
 	jmp	ssetlock		/* empty again, try once more */
 sgotit:
-	popl	_ss_tpr			/* save the old task priority */
+	popl	_ss_eflags		/* save the old task priority */
 sgotit2:
 	ret
 
@@ -285,8 +273,10 @@ sbsl1:	.asciz	"rsslock: cpu: %d, addr: 0x%08x, lock: 0x%08x"
 ENTRY(ss_unlock)
 	movl	4(%esp), %eax		/* get the address of the lock */
 	movl	$0, (%eax)		/* clear the simple lock */
-	movl	_ss_tpr, %eax
-	movl	%eax, lapic_tpr		/* restore the old task priority */
+	testl	$PSL_I, _ss_eflags
+	jz	ss_unlock2
+	sti
+ss_unlock2:	
 	ret
 
 /* 

sys/i386/include/globaldata.h

@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globaldata.h,v 1.2 1998/04/06 18:59:15 peter Exp $
+ * $Id: globaldata.h,v 1.3 1998/05/17 18:53:07 tegge Exp $
  */
 
 /*
@@ -53,7 +53,7 @@ struct globaldata {
 	u_int		cpu_lockid;
 	u_int		other_cpus;
 	pd_entry_t	*my_idlePTD;
-	u_int		ss_tpr;
+	u_int		ss_eflags;
 	pt_entry_t	*prv_CMAP1;
 	pt_entry_t	*prv_CMAP2;
 	pt_entry_t	*prv_CMAP3;

sys/i386/include/pcpu.h

@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globaldata.h,v 1.2 1998/04/06 18:59:15 peter Exp $
+ * $Id: globaldata.h,v 1.3 1998/05/17 18:53:07 tegge Exp $
  */
 
 /*
@@ -53,7 +53,7 @@ struct globaldata {
 	u_int		cpu_lockid;
 	u_int		other_cpus;
 	pd_entry_t	*my_idlePTD;
-	u_int		ss_tpr;
+	u_int		ss_eflags;
 	pt_entry_t	*prv_CMAP1;
 	pt_entry_t	*prv_CMAP2;
 	pt_entry_t	*prv_CMAP3;