- Remove the old smp cpu topology specification with a new, more flexible

   tree structure that encodes the level of cache sharing and other
   properties.
 - Provide several convenience functions for creating one and two level
   cpu trees as well as a default flat topology.  The system now always
   has some topology.
 - On i386 and amd64 create a seperate level in the hierarchy for HTT
   and multi-core cpus.  This will allow the scheduler to intelligently
   load balance non-uniform cores.  Presently we don't detect what level
   of the cache hierarchy is shared at each level in the topology.
 - Add a mechanism for testing common topologies that have more information
   than the MD code is able to provide via the kern.smp.topology tunable.
   This should be considered a debugging tool only and not a stable api.

Sponsored by:	Nokia

13 files changed, 330 insertions, 173 deletions

diff --git a/sys/amd64/amd64/identcpu.c b/sys/amd64/amd64/identcpu.c
index a51f02e..f0afb9f 100644
--- a/sys/amd64/amd64/identcpu.c
+++ b/sys/amd64/amd64/identcpu.c
@@ -97,6 +97,10 @@ static struct {
 	{ "Sledgehammer",	CPUCLASS_K8 },		/* CPU_SLEDGEHAMMER */
 };
 
+int cpu_cores;
+int cpu_logical;
+
+
 extern int pq_l2size;
 extern int pq_l2nways;
 
@@ -360,11 +364,13 @@ printcpuinfo(void)
 				if ((regs[0] & 0x1f) != 0)
 					cmp = ((regs[0] >> 26) & 0x3f) + 1;
 			}
+			cpu_cores = cmp;
+			cpu_logical = htt / cmp;
 			if (cmp > 1)
 				printf("\n  Cores per package: %d", cmp);
 			if ((htt / cmp) > 1)
 				printf("\n  Logical CPUs per core: %d",
-				    htt / cmp);
+				    cpu_logical);
 		}
 	}
 	/* Avoid ugly blank lines: only print newline when we have to. */
diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index a827137..83eab2e 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -83,12 +83,6 @@ extern	int nkpt;
 
 extern  struct pcpu __pcpu[];
 
-/*
- * CPU topology map datastructures for HTT.
- */
-static struct cpu_group mp_groups[MAXCPU];
-static struct cpu_top mp_top;
-
 /* AP uses this during bootstrap.  Do not staticize.  */
 char *bootSTK;
 static int bootAP;
@@ -182,40 +176,38 @@ mem_range_AP_init(void)
 		mem_range_softc.mr_op->initAP(&mem_range_softc);
 }
 
-void
-mp_topology(void)
+struct cpu_group *
+cpu_topo(void)
 {
-	struct cpu_group *group;
-	int apic_id;
-	int groups;
-	int cpu;
-
-	/* Build the smp_topology map. */
-	/* Nothing to do if there is no HTT support. */
-	if (hyperthreading_cpus <= 1)
-		return;
-	group = &mp_groups[0];
-	groups = 1;
-	for (cpu = 0, apic_id = 0; apic_id <= MAX_APIC_ID; apic_id++) {
-		if (!cpu_info[apic_id].cpu_present)
-			continue;
-		/*
-		 * If the current group has members and we're not a logical
-		 * cpu, create a new group.
-		 */
-		if (group->cg_count != 0 &&
-		    (apic_id % hyperthreading_cpus) == 0) {
-			group++;
-			groups++;
-		}
-		group->cg_count++;
-		group->cg_mask |= 1 << cpu;
-		cpu++;
+	if (cpu_cores == 0)
+		cpu_cores = 1;
+	if (cpu_logical == 0)
+		cpu_logical = 1;
+	if (mp_ncpus % (cpu_cores * cpu_logical) != 0) {
+		printf("WARNING: Non-uniform processors.\n");
+		printf("WARNING: Using suboptimal topology.\n");
+		return (smp_topo_none());
 	}
-
-	mp_top.ct_count = groups;
-	mp_top.ct_group = mp_groups;
-	smp_topology = &mp_top;
+	/*
+	 * No multi-core or hyper-threaded.
+	 */
+	if (cpu_logical * cpu_cores == 1)
+		return (smp_topo_none());
+	/*
+	 * Only HTT no multi-core.
+	 */
+	if (cpu_logical > 1 && cpu_cores == 1)
+		return (smp_topo_1level(CG_SHARE_L1, cpu_logical, CG_FLAG_HTT));
+	/*
+	 * Only multi-core no HTT.
+	 */
+	if (cpu_cores > 1 && cpu_logical == 1)
+		return (smp_topo_1level(CG_SHARE_NONE, cpu_cores, 0));
+	/*
+	 * Both HTT and multi-core.
+	 */
+	return (smp_topo_2level(CG_SHARE_NONE, cpu_cores,
+	    CG_SHARE_L1, cpu_logical, CG_FLAG_HTT));
 }
 
 /*
@@ -409,9 +401,6 @@ cpu_mp_start(void)
 	}
 
 	set_interrupt_apic_ids();
-
-	/* Last, setup the cpu topology now that we have probed CPUs */
-	mp_topology();
 }
 
 
diff --git a/sys/amd64/include/smp.h b/sys/amd64/include/smp.h
index d85c55e..f961d6b 100644
--- a/sys/amd64/include/smp.h
+++ b/sys/amd64/include/smp.h
@@ -36,6 +36,10 @@ extern int			boot_cpu_id;
 extern struct pcb		stoppcbs[];
 extern int			cpu_apic_ids[];
 
+/* global data in identcpu.c */
+extern int			cpu_cores;
+extern int			cpu_logical;
+
 /* IPI handlers */
 inthand_t
 	IDTVEC(invltlb),	/* TLB shootdowns - global */
@@ -57,7 +61,6 @@ void	ipi_self(u_int ipi);
 void 	ipi_bitmap_handler(struct trapframe frame);
 u_int	mp_bootaddress(u_int);
 int	mp_grab_cpu_hlt(void);
-void	mp_topology(void);
 void	smp_cache_flush(void);
 void	smp_invlpg(vm_offset_t addr);
 void	smp_masked_invlpg(u_int mask, vm_offset_t addr);
diff --git a/sys/i386/i386/identcpu.c b/sys/i386/i386/identcpu.c
index ccf6824..308b83b 100644
--- a/sys/i386/i386/identcpu.c
+++ b/sys/i386/i386/identcpu.c
@@ -142,6 +142,9 @@ static struct {
 	{ "Pentium 4",		CPUCLASS_686 },		/* CPU_P4 */
 };
 
+int cpu_cores;
+int cpu_logical;
+
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
 int has_f00f_bug = 0;		/* Initialized so that it can be patched. */
 #endif
@@ -857,11 +860,13 @@ printcpuinfo(void)
 				if ((regs[0] & 0x1f) != 0)
 					cmp = ((regs[0] >> 26) & 0x3f) + 1;
 			}
+			cpu_cores = cmp;
+			cpu_logical = htt / cmp;
 			if (cmp > 1)
 				printf("\n  Cores per package: %d", cmp);
 			if ((htt / cmp) > 1)
 				printf("\n  Logical CPUs per core: %d",
-				    htt / cmp);
+				    cpu_logical);
 		}
 	} else if (strcmp(cpu_vendor, "CyrixInstead") == 0) {
 		printf("  DIR=0x%04x", cyrix_did);
diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index c0a0b00..85d25a5 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -135,12 +135,6 @@ extern	int nkpt;
 
 extern	struct pcpu __pcpu[];
 
-/*
- * CPU topology map datastructures for HTT.
- */
-static struct cpu_group mp_groups[MAXCPU];
-static struct cpu_top mp_top;
-
 /* AP uses this during bootstrap.  Do not staticize.  */
 char *bootSTK;
 static int bootAP;
@@ -238,40 +232,38 @@ mem_range_AP_init(void)
 		mem_range_softc.mr_op->initAP(&mem_range_softc);
 }
 
-void
-mp_topology(void)
+struct cpu_group *
+cpu_topo(void)
 {
-	struct cpu_group *group;
-	int apic_id;
-	int groups;
-	int cpu;
-
-	/* Build the smp_topology map. */
-	/* Nothing to do if there is no HTT support. */
-	if (hyperthreading_cpus <= 1)
-		return;
-	group = &mp_groups[0];
-	groups = 1;
-	for (cpu = 0, apic_id = 0; apic_id <= MAX_APIC_ID; apic_id++) {
-		if (!cpu_info[apic_id].cpu_present)
-			continue;
-		/*
-		 * If the current group has members and we're not a logical
-		 * cpu, create a new group.
-		 */
-		if (group->cg_count != 0 &&
-		    (apic_id % hyperthreading_cpus) == 0) {
-			group++;
-			groups++;
-		}
-		group->cg_count++;
-		group->cg_mask |= 1 << cpu;
-		cpu++;
+	if (cpu_cores == 0)
+		cpu_cores = 1;
+	if (cpu_logical == 0)
+		cpu_logical = 1;
+	if (mp_ncpus % (cpu_cores * cpu_logical) != 0) {
+		printf("WARNING: Non-uniform processors.\n");
+		printf("WARNING: Using suboptimal topology.\n");
+		return (smp_topo_none());
 	}
-
-	mp_top.ct_count = groups;
-	mp_top.ct_group = mp_groups;
-	smp_topology = &mp_top;
+	/*
+	 * No multi-core or hyper-threaded.
+	 */
+	if (cpu_logical * cpu_cores == 1)
+		return (smp_topo_none());
+	/*
+	 * Only HTT no multi-core.
+	 */
+	if (cpu_logical > 1 && cpu_cores == 1)
+		return (smp_topo_1level(CG_SHARE_L1, cpu_logical, CG_FLAG_HTT));
+	/*
+	 * Only multi-core no HTT.
+	 */
+	if (cpu_cores > 1 && cpu_logical == 1)
+		return (smp_topo_1level(CG_SHARE_NONE, cpu_cores, 0));
+	/*
+	 * Both HTT and multi-core.
+	 */
+	return (smp_topo_2level(CG_SHARE_NONE, cpu_cores,
+	    CG_SHARE_L1, cpu_logical, CG_FLAG_HTT));
 }
 
 
@@ -459,9 +451,6 @@ cpu_mp_start(void)
 	}
 
 	set_interrupt_apic_ids();
-
-	/* Last, setup the cpu topology now that we have probed CPUs */
-	mp_topology();
 }
 
 
diff --git a/sys/i386/include/smp.h b/sys/i386/include/smp.h
index 264fb7f..acfd14a 100644
--- a/sys/i386/include/smp.h
+++ b/sys/i386/include/smp.h
@@ -45,6 +45,10 @@ extern u_long *ipi_rendezvous_counts[MAXCPU];
 extern u_long *ipi_lazypmap_counts[MAXCPU];
 #endif
 
+/* global data in identcpu.c */
+extern int			cpu_cores;
+extern int			cpu_logical;
+
 /* IPI handlers */
 inthand_t
 	IDTVEC(invltlb),	/* TLB shootdowns - global */
@@ -67,7 +71,6 @@ void	ipi_self(u_int ipi);
 void 	ipi_bitmap_handler(struct trapframe frame);
 u_int	mp_bootaddress(u_int);
 int	mp_grab_cpu_hlt(void);
-void	mp_topology(void);
 void	smp_cache_flush(void);
 void	smp_invlpg(vm_offset_t addr);
 void	smp_masked_invlpg(u_int mask, vm_offset_t addr);
diff --git a/sys/ia64/ia64/mp_machdep.c b/sys/ia64/ia64/mp_machdep.c
index 7886a0b..3589f89 100644
--- a/sys/ia64/ia64/mp_machdep.c
+++ b/sys/ia64/ia64/mp_machdep.c
@@ -84,6 +84,13 @@ volatile int ap_spin;
 
 static void cpu_mp_unleash(void *);
 
+struct cpu_group *
+cpu_topo(void)
+{
+
+	return smp_topo_none();
+}
+
 void
 ia64_ap_startup(void)
 {
diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c
index 4445b05..d17cd58 100644
--- a/sys/kern/sched_ule.c
+++ b/sys/kern/sched_ule.c
@@ -243,7 +243,6 @@ static int tryself = 1;
 static int steal_htt = 1;
 static int steal_idle = 1;
 static int steal_thresh = 2;
-static int topology = 0;
 
 /*
  * One thread queue per processor.
@@ -1212,43 +1211,6 @@ tdg_add(struct tdq_group *tdg, struct tdq *tdq)
 }
 
 static void
-sched_setup_topology(void)
-{
-	struct tdq_group *tdg;
-	struct cpu_group *cg;
-	int balance_groups;
-	struct tdq *tdq;
-	int i;
-	int j;
-
-	topology = 1;
-	balance_groups = 0;
-	for (i = 0; i < smp_topology->ct_count; i++) {
-		cg = &smp_topology->ct_group[i];
-		tdg = &tdq_groups[i];
-		/*
-		 * Initialize the group.
-		 */
-		tdg_setup(tdg);
-		/*
-		 * Find all of the group members and add them.
-		 */
-		for (j = 0; j < MAXCPU; j++) { 
-			if ((cg->cg_mask & (1 << j)) != 0) {
-				tdq = TDQ_CPU(j);
-				tdq_setup(tdq);
-				tdg_add(tdg, tdq);
-			}
-		}
-		if (tdg->tdg_cpus > 1)
-			balance_groups = 1;
-	}
-	tdg_maxid = smp_topology->ct_count - 1;
-	if (balance_groups)
-		sched_balance_groups();
-}
-
-static void
 sched_setup_smp(void)
 {
 	struct tdq_group *tdg;
@@ -1271,25 +1233,6 @@ sched_setup_smp(void)
 	}
 	tdg_maxid = cpus - 1;
 }
-
-/*
- * Fake a topology with one group containing all CPUs.
- */
-static void
-sched_fake_topo(void)
-{
-#ifdef SCHED_FAKE_TOPOLOGY
-	static struct cpu_top top;
-	static struct cpu_group group;
-
-	top.ct_count = 1;
-	top.ct_group = &group;
-	group.cg_mask = all_cpus;
-	group.cg_count = mp_ncpus;
-	group.cg_children = 0;
-	smp_topology = &top;
-#endif
-}
 #endif
 
 /*
@@ -1303,15 +1246,11 @@ sched_setup(void *dummy)
 
 	tdq = TDQ_SELF();
 #ifdef SMP
-	sched_fake_topo();
 	/*
 	 * Setup tdqs based on a topology configuration or vanilla SMP based
 	 * on mp_maxid.
 	 */
-	if (smp_topology == NULL)
-		sched_setup_smp();
-	else 
-		sched_setup_topology();
+	sched_setup_smp();
 	balance_tdq = tdq;
 	sched_balance();
 #else
@@ -2692,8 +2631,6 @@ SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0,
     "Attempts to steal work from other cores before idling");
 SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0,
     "Minimum load on remote cpu before we'll steal");
-SYSCTL_INT(_kern_sched, OID_AUTO, topology, CTLFLAG_RD, &topology, 0,
-    "True when a topology has been specified by the MD code.");
 #endif
 
 /* ps compat.  All cpu percentages from ULE are weighted. */
diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
index fa20e62..9c30a4a 100644
--- a/sys/kern/subr_smp.c
+++ b/sys/kern/subr_smp.c
@@ -68,7 +68,6 @@ int mp_ncpus;
 /* export this for libkvm consumers. */
 int mp_maxcpus = MAXCPU;
 
-struct cpu_top *smp_topology;
 volatile int smp_started;
 u_int mp_maxid;
 
@@ -90,6 +89,11 @@ int smp_cpus = 1;	/* how many cpu's running */
 SYSCTL_INT(_kern_smp, OID_AUTO, cpus, CTLFLAG_RD, &smp_cpus, 0,
     "Number of CPUs online");
 
+int smp_topology = 0;	/* Which topology we're using. */
+SYSCTL_INT(_kern_smp, OID_AUTO, topology, CTLFLAG_RD, &smp_topology, 0,
+    "Topology override setting; 0 is default provided by hardware.");
+TUNABLE_INT("kern.smp.topology", &smp_topology);
+
 #ifdef SMP
 /* Enable forwarding of a signal to a process running on a different CPU */
 static int forward_signal_enabled = 1;
@@ -385,22 +389,177 @@ smp_rendezvous(void (* setup_func)(void *),
 	/* release lock */
 	mtx_unlock_spin(&smp_ipi_mtx);
 }
-#else /* !SMP */
 
-/*
- * Provide dummy SMP support for UP kernels.  Modules that need to use SMP
- * APIs will still work using this dummy support.
- */
-static void
-mp_setvariables_for_up(void *dummy)
+static struct cpu_group group[MAXCPU];
+
+struct cpu_group *
+smp_topo(void)
 {
-	mp_ncpus = 1;
-	mp_maxid = PCPU_GET(cpuid);
-	all_cpus = PCPU_GET(cpumask);
-	KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
+	struct cpu_group *top;
+
+	/*
+	 * Check for a fake topology request for debugging purposes.
+	 */
+	switch (smp_topology) {
+	case 1:
+		/* Dual core with no sharing.  */
+		top = smp_topo_1level(CG_SHARE_NONE, 2, 0);
+		break;
+	case 3:
+		/* Dual core with shared L2.  */
+		top = smp_topo_1level(CG_SHARE_L2, 2, 0);
+		break;
+	case 4:
+		/* quad core, shared l3 among each package, private l2.  */
+		top = smp_topo_1level(CG_SHARE_L3, 4, 0);
+		break;
+	case 5:
+		/* quad core,  2 dualcore parts on each package share l2.  */
+		top = smp_topo_2level(CG_SHARE_NONE, 2, CG_SHARE_L2, 2, 0);
+		break;
+	case 6:
+		/* Single-core 2xHTT */
+		top = smp_topo_1level(CG_SHARE_L1, 2, CG_FLAG_HTT);
+		break;
+	case 7:
+		/* quad core with a shared l3, 8 threads sharing L2.  */
+		top = smp_topo_2level(CG_SHARE_L3, 4, CG_SHARE_L2, 8,
+		    CG_FLAG_THREAD);
+		break;
+	default:
+		/* Default, ask the system what it wants. */
+		top = cpu_topo();
+		break;
+	}
+	/*
+	 * Verify the returned topology.
+	 */
+	if (top->cg_count != mp_ncpus)
+		panic("Built bad topology at %p.  CPU count %d != %d",
+		    top, top->cg_count, mp_ncpus);
+	if (top->cg_mask != all_cpus)
+		panic("Built bad topology at %p.  CPU mask 0x%X != 0x%X",
+		    top, top->cg_mask, all_cpus);
+	return (top);
 }
-SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
-    mp_setvariables_for_up, NULL)
+
+struct cpu_group *
+smp_topo_none(void)
+{
+	struct cpu_group *top;
+
+	top = &group[0];
+	top->cg_parent = NULL;
+	top->cg_child = NULL;
+	top->cg_mask = (1 << mp_ncpus) - 1;
+	top->cg_count = mp_ncpus;
+	top->cg_children = 0;
+	top->cg_level = CG_SHARE_NONE;
+	top->cg_flags = 0;
+	
+	return (top);
+}
+
+static int
+smp_topo_addleaf(struct cpu_group *parent, struct cpu_group *child, int share,
+    int count, int flags, int start)
+{
+	cpumask_t mask;
+	int i;
+
+	for (mask = 0, i = 0; i < count; i++, start++)
+		mask |= (1 << start);
+	child->cg_parent = parent;
+	child->cg_child = NULL;
+	child->cg_children = 0;
+	child->cg_level = share;
+	child->cg_count = count;
+	child->cg_flags = flags;
+	child->cg_mask = mask;
+	parent->cg_children++;
+	for (; parent != NULL; parent = parent->cg_parent) {
+		if ((parent->cg_mask & child->cg_mask) != 0)
+			panic("Duplicate children in %p.  mask 0x%X child 0x%X",
+			    parent, parent->cg_mask, child->cg_mask);
+		parent->cg_mask |= child->cg_mask;
+		parent->cg_count += child->cg_count;
+	}
+
+	return (start);
+}
+
+struct cpu_group *
+smp_topo_1level(int share, int count, int flags)
+{
+	struct cpu_group *child;
+	struct cpu_group *top;
+	int packages;
+	int cpu;
+	int i;
+
+	cpu = 0;
+	top = &group[0];
+	packages = mp_ncpus / count;
+	top->cg_child = child = &group[1];
+	top->cg_level = CG_SHARE_NONE;
+	for (i = 0; i < packages; i++, child++)
+		cpu = smp_topo_addleaf(top, child, share, count, flags, cpu);
+	return (top);
+}
+
+struct cpu_group *
+smp_topo_2level(int l2share, int l2count, int l1share, int l1count,
+    int l1flags)
+{
+	struct cpu_group *top;
+	struct cpu_group *l1g;
+	struct cpu_group *l2g;
+	int cpu;
+	int i;
+	int j;
+
+	cpu = 0;
+	top = &group[0];
+	l2g = &group[1];
+	top->cg_child = l2g;
+	top->cg_level = CG_SHARE_NONE;
+	top->cg_children = mp_ncpus / (l2count * l1count);
+	l1g = l2g + top->cg_children;
+	for (i = 0; i < top->cg_children; i++, l2g++) {
+		l2g->cg_parent = top;
+		l2g->cg_child = l1g;
+		l2g->cg_level = l2share;
+		for (j = 0; j < l2count; j++, l1g++)
+			cpu = smp_topo_addleaf(l2g, l1g, l1share, l1count,
+			    l1flags, cpu);
+	}
+	return (top);
+}
+
+
+struct cpu_group *
+smp_topo_find(struct cpu_group *top, int cpu)
+{
+	struct cpu_group *cg;
+	cpumask_t mask;
+	int children;
+	int i;
+
+	mask = (1 << cpu);
+	cg = top;
+	for (;;) {
+		if ((cg->cg_mask & mask) == 0)
+			return (NULL);
+		if (cg->cg_children == 0)
+			return (cg);
+		children = cg->cg_children;
+		for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
+			if ((cg->cg_mask & mask) != 0)
+				break;
+	}
+	return (NULL);
+}
+#else /* !SMP */
 
 void
 smp_rendezvous(void (*setup_func)(void *), 
@@ -416,4 +575,19 @@ smp_rendezvous(void (*setup_func)(void *),
 	if (teardown_func != NULL)
 		teardown_func(arg);
 }
+
+/*
+ * Provide dummy SMP support for UP kernels.  Modules that need to use SMP
+ * APIs will still work using this dummy support.
+ */
+static void
+mp_setvariables_for_up(void *dummy)
+{
+	mp_ncpus = 1;
+	mp_maxid = PCPU_GET(cpuid);
+	all_cpus = PCPU_GET(cpumask);
+	KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
+}
+SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
+    mp_setvariables_for_up, NULL)
 #endif /* SMP */
diff --git a/sys/powerpc/powerpc/mp_machdep.c b/sys/powerpc/powerpc/mp_machdep.c
index f76eedf..0c9dbe0 100644
--- a/sys/powerpc/powerpc/mp_machdep.c
+++ b/sys/powerpc/powerpc/mp_machdep.c
@@ -45,6 +45,13 @@
 
 int			boot_cpu_id;
 
+struct cpu_group *
+cpu_topo(void)
+{
+
+        return smp_topo_none();
+}
+
 void
 cpu_mp_setmaxid(void)
 {
diff --git a/sys/sparc64/sparc64/mp_machdep.c b/sys/sparc64/sparc64/mp_machdep.c
index d005f8a..1eef281 100644
--- a/sys/sparc64/sparc64/mp_machdep.c
+++ b/sys/sparc64/sparc64/mp_machdep.c
@@ -189,6 +189,13 @@ cpu_mp_probe(void)
 	return (mp_maxid > 0);
 }
 
+struct cpu_group *
+cpu_topo(void)
+{
+
+	return smp_topo_none();
+}
+
 static void
 sun4u_startcpu(phandle_t cpu, void *func, u_long arg)
 {
diff --git a/sys/sun4v/sun4v/mp_machdep.c b/sys/sun4v/sun4v/mp_machdep.c
index 5c13b32..e59679a 100644
--- a/sys/sun4v/sun4v/mp_machdep.c
+++ b/sys/sun4v/sun4v/mp_machdep.c
@@ -241,6 +241,13 @@ cpu_mp_probe(void)
 	return (mp_maxid > 0);
 }
 
+struct cpu_group *
+cpu_topo(void)
+{
+
+	return smp_topo_none();
+}
+
 static int
 start_ap_bycpuid(int cpuid, void *func, u_long arg)
 {
diff --git a/sys/sys/smp.h b/sys/sys/smp.h
index 7c79bb9..1f0010a 100644
--- a/sys/sys/smp.h
+++ b/sys/sys/smp.h
@@ -32,18 +32,40 @@
  */
 
 struct cpu_group {
-	cpumask_t cg_mask;		/* Mask of cpus in this group. */
-	int	cg_count;		/* Count of cpus in this group. */
-	int	cg_children;		/* Number of children groups. */
-	struct cpu_group *cg_child;	/* Optional child group. */
+	struct cpu_group *cg_parent;	/* Our parent group. */
+	struct cpu_group *cg_child;	/* Optional children groups. */
+	cpumask_t	cg_mask;	/* Mask of cpus in this group. */
+	int8_t		cg_count;	/* Count of cpus in this group. */
+	int8_t		cg_children;	/* Number of children groups. */
+	int8_t		cg_level;	/* Shared cache level. */
+	int8_t		cg_flags;	/* Traversal modifiers. */
 };
 
-struct cpu_top {
-	int	ct_count;		/* Count of groups. */
-	struct cpu_group *ct_group;	/* Array of pointers to cpu groups. */
-};
+/*
+ * Defines common resources for CPUs in the group.  The highest level
+ * resource should be used when multiple are shared.
+ */
+#define	CG_SHARE_NONE	0
+#define	CG_SHARE_L1	1
+#define	CG_SHARE_L2	2
+#define	CG_SHARE_L3	3
+
+/*
+ * Behavior modifiers for load balancing and affinity.
+ */
+#define	CG_FLAG_HTT	0x01		/* Schedule the alternate core last. */
+#define	CG_FLAG_THREAD	0x02		/* New age htt, less crippled. */
+
+/*
+ * Convenience routines for building topologies.
+ */
+struct cpu_group *smp_topo(void);
+struct cpu_group *smp_topo_none(void);
+struct cpu_group *smp_topo_1level(int l1share, int l1count, int l1flags);
+struct cpu_group *smp_topo_2level(int l2share, int l2count, int l1share,
+    int l1count, int l1flags);
+struct cpu_group *smp_topo_find(struct cpu_group *top, int cpu);
 
-extern struct cpu_top *smp_topology;
 extern void (*cpustop_restartfunc)(void);
 extern int smp_active;
 extern int smp_cpus;
@@ -90,6 +112,7 @@ extern cpumask_t all_cpus;
  */
 struct thread;
 
+struct cpu_group *cpu_topo(void);
 void	cpu_mp_announce(void);
 int	cpu_mp_probe(void);
 void	cpu_mp_setmaxid(void);