- 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, 6 insertions, 6 deletions

diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
index 5bb0289..b6fd97f 100644
--- a/sys/kern/subr_smp.c
+++ b/sys/kern/subr_smp.c
@@ -92,17 +92,16 @@ static void (*smp_rv_teardown_func)(void *arg);
 static void *smp_rv_func_arg;
 static volatile int smp_rv_waiters[2];
 static struct mtx smp_rv_mtx;
-static int mp_probe_status;
 
 /*
- * Initialize MI SMP variables.
+ * Let the MD SMP code initialize mp_maxid very early if it can.
  */
 static void
-mp_probe(void *dummy)
+mp_setmaxid(void *dummy)
 {
-	mp_probe_status = cpu_mp_probe();
+	cpu_mp_setmaxid();
 }
-SYSINIT(cpu_mp_probe, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_probe, NULL)
+SYSINIT(cpu_mp_setmaxid, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_setmaxid, NULL)
 
 /*
  * Call the MD SMP initialization code.
@@ -112,8 +111,9 @@ mp_start(void *dummy)
 {
 
 	/* Probe for MP hardware. */
-	if (mp_probe_status == 0 || smp_disabled != 0) {
+	if (smp_disabled != 0 || cpu_mp_probe() == 0) {
 		mp_ncpus = 1;
+		all_cpus = PCPU_GET(cpumask);
 		return;
 	}