- Split cpu_mp_probe() into two parts. cpu_mp_setmaxid() is still called

  very early (SI_SUB_TUNABLES - 1) and is responsible for setting mp_maxid.
  cpu_mp_probe() is now called at SI_SUB_CPU and determines if SMP is
  actually present and sets mp_ncpus and all_cpus.  Splitting these up
  allows an architecture to probe CPUs later than SI_SUB_TUNABLES by just
  setting mp_maxid to MAXCPU in cpu_mp_setmaxid().  This could allow the
  CPU probing code to live in a module, for example, since modules
  sysinit's in modules cannot be invoked prior to SI_SUB_KLD.  This is
  needed to re-enable the ACPI module on i386.
- For the alpha SMP probing code, use LOCATE_PCS() instead of duplicating
  its contents in a few places.  Also, add a smp_cpu_enabled() function
  to avoid duplicating some code.  There is room for further code
  reduction later since much of this code is also present in cpu_mp_start().
- All archs besides i386 still set mp_maxid to the same values they set it
  to before this change.  i386 now sets mp_maxid to MAXCPU.

Tested on:	alpha, amd64, i386, ia64, sparc64
Approved by:	re (scottl)

1 files changed, 45 insertions, 22 deletions

diff --git a/sys/alpha/alpha/mp_machdep.c b/sys/alpha/alpha/mp_machdep.c
index 914410c..d3a6460 100644
--- a/sys/alpha/alpha/mp_machdep.c
+++ b/sys/alpha/alpha/mp_machdep.c
@@ -64,6 +64,7 @@ static struct mtx ap_boot_mtx;
 u_int boot_cpu_id;
 
 static void	release_aps(void *dummy);
+static int	smp_cpu_enabled(struct pcs *pcsp);
 extern void	smp_init_secondary_glue(void);
 static int	smp_send_secondary_command(const char *command, int cpuid);
 static int	smp_start_secondary(int cpuid);
@@ -301,10 +302,50 @@ smp_start_secondary(int cpuid)
 
 /* Other stuff */
 
+static int
+smp_cpu_enabled(struct pcs *pcsp)
+{
+
+	/* Is this CPU present? */
+	if ((pcsp->pcs_flags & PCS_PP) == 0)
+		return (0);
+
+	/* Is this CPU available? */
+	if ((pcsp->pcs_flags & PCS_PA) == 0)
+		/*
+		 * The TurboLaser PCS_PA bit doesn't seem to be set
+		 * correctly.
+		 */
+		if (hwrpb->rpb_type != ST_DEC_21000) 
+			return (0);
+
+	/* Is this CPU's PALcode valid? */
+	if ((pcsp->pcs_flags & PCS_PV) == 0)
+		return (0);
+
+	return (1);
+}
+
+void
+cpu_mp_setmaxid(void)
+{
+	int i;
+
+	mp_maxid = 0;
+	for (i = 0; i < hwrpb->rpb_pcs_cnt; i++) {
+		if (i == PCPU_GET(cpuid))
+			continue;
+		if (!smp_cpu_enabled(LOCATE_PCS(hwrpb, i)))
+			continue;
+		if (i > MAXCPU)
+			continue;
+		mp_maxid = i;
+	}
+}
+
 int
 cpu_mp_probe(void)
 {
-	struct pcs *pcsp;
 	int i, cpus;
 
 	/* XXX: Need to check for valid platforms here. */
@@ -315,33 +356,16 @@ cpu_mp_probe(void)
 	all_cpus = 1 << boot_cpu_id;
 
 	mp_ncpus = 1;
-	mp_maxid = 0;
 
 	/* Make sure we have at least one secondary CPU. */
 	cpus = 0;
 	for (i = 0; i < hwrpb->rpb_pcs_cnt; i++) {
 		if (i == PCPU_GET(cpuid))
 			continue;
-		pcsp = (struct pcs *)((char *)hwrpb + hwrpb->rpb_pcs_off +
-		    (i * hwrpb->rpb_pcs_size));
-		if ((pcsp->pcs_flags & PCS_PP) == 0) {
+		if (!smp_cpu_enabled(LOCATE_PCS(hwrpb, i)))
 			continue;
-		}
-		if ((pcsp->pcs_flags & PCS_PA) == 0) {
-			/*
-			 * The TurboLaser PCS_PA bit doesn't seem to be set
-			 * correctly.
-			 */
-			if (hwrpb->rpb_type != ST_DEC_21000) 
-				continue;
-		}
-		if ((pcsp->pcs_flags & PCS_PV) == 0) {
-			continue;
-		}
-		if (i > MAXCPU) {
+		if (i > MAXCPU)
 			continue;
-		}
-		mp_maxid = i;
 		cpus++;
 	}
 	return (cpus);
@@ -359,8 +383,7 @@ cpu_mp_start(void)
 
 		if (i == boot_cpu_id)
 			continue;
-		pcsp = (struct pcs *)((char *)hwrpb + hwrpb->rpb_pcs_off +
-		    (i * hwrpb->rpb_pcs_size));
+		pcsp = LOCATE_PCS(hwrpb, i);
 		if ((pcsp->pcs_flags & PCS_PP) == 0)
 			continue;
 		if ((pcsp->pcs_flags & PCS_PA) == 0) {