powerpc/nodes: Ensure enough nodes avail for operations.
On systems like PowerPC which allow 'hot-add' of CPU or memory
resources, it may occur that the new resources are to be inserted
into nodes that were not used for these resources at bootup. In
the kernel, any node that is used must be defined and initialized
at boot. This patch extracts the value of the lowest domain level
(number of allocable resources) from the "rtas" device tree property
"ibm,current-associativity-domains" or the device tree property
"ibm,max-associativity-domains" to use as the maximum number of nodes
to setup as possibly available in the system.
powerpc/hotplug: Fix CPU-only node bringup bug
On systems like PowerPC which allow 'hot-add' of CPU, it may occur
that the new resources are to be inserted into nodes that were not
used for memory resources at bootup. Many different configurations
of PowerPC resources may need to be supported depending upon the
environment. This patch fixes some problems encountered at runtime
with configurations that support memory-less nodes, but which allow
CPUs to be added at and after boot.
Signed-off-by: Michael Bringmann <[email protected]>
Michael Bringmann (2):
powerpc/vphn: Ensure enough nodes avail for operations
powerpc/hotplug: Fix CPU-only node bringup bug
powerpc/nodes: On systems like PowerPC which allow 'hot-add' of CPU
or memory resources, it may occur that the new resources are to be
inserted into nodes that were not used for these resources at bootup.
In the kernel, any node that is used must be defined and initialized
at boot.
This patch extracts the value of the lowest domain level (number of
allocable resources) from the "rtas" device tree property
"ibm,current-associativity-domains" or the device tree property
"ibm,max-associativity-domains" to use as the maximum number of nodes
to setup as possibly available in the system. This new setting will
override the instruction,
nodes_and(node_possible_map, node_possible_map, node_online_map);
presently seen in the function arch/powerpc/mm/numa.c:initmem_init().
If the property is not present at boot, no operation will be performed
to define or enable additional nodes.
Signed-off-by: Michael Bringmann <[email protected]>
---
arch/powerpc/mm/numa.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index ec098b3..b385cd0 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -892,6 +892,51 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
NODE_DATA(nid)->node_spanned_pages = spanned_pages;
}
+static void __init node_associativity_setup(void)
+{
+ struct device_node *rtas;
+
+ rtas = of_find_node_by_path("/rtas");
+ if (rtas) {
+ const __be32 *prop;
+ u32 len, entries, numnodes, i;
+
+ prop = of_get_property(rtas,
+ "ibm,current-associativity-domains", &len);
+ if (!prop || len < sizeof(unsigned int)) {
+ prop = of_get_property(rtas,
+ "ibm,max-associativity-domains", &len);
+ goto endit;
+ }
+
+ entries = of_read_number(prop++, 1);
+
+ if (len < (entries * sizeof(unsigned int)))
+ goto endit;
+
+ if ((0 <= min_common_depth) && (min_common_depth <= (entries-1)))
+ entries = min_common_depth;
+ else
+ entries -= 1;
+
+ numnodes = of_read_number(&prop[entries], 1);
+
+ printk(KERN_INFO "numa: Nodes = %d (mcd = %d)\n", numnodes,
+ min_common_depth);
+
+ for (i = 0; i < numnodes; i++) {
+ if (!node_possible(i)) {
+ setup_node_data(i, 0, 0);
+ node_set(i, node_possible_map);
+ }
+ }
+ }
+
+endit:
+ if (rtas)
+ of_node_put(rtas);
+}
+
void __init initmem_init(void)
{
int nid, cpu;
@@ -911,6 +956,8 @@ void __init initmem_init(void)
*/
nodes_and(node_possible_map, node_possible_map, node_online_map);
+ node_associativity_setup();
+
for_each_online_node(nid) {
unsigned long start_pfn, end_pfn;
powerpc/hotplug: On systems like PowerPC which allow 'hot-add' of CPU,
it may occur that the new resources are to be inserted into nodes
that were not used for memory resources at bootup. Many different
configurations of PowerPC resources may need to be supported depending
upon the environment. This patch fixes some problems encountered at
runtime with configurations that support memory-less nodes, but which
allow CPUs to be added at and after boot.
Signed-off-by: Michael Bringmann <[email protected]>
---
arch/powerpc/mm/numa.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b385cd0..e811dd1 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -551,7 +551,7 @@ static int numa_setup_cpu(unsigned long lcpu)
nid = of_node_to_nid_single(cpu);
out_present:
- if (nid < 0 || !node_online(nid))
+ if (nid < 0 || !node_possible(nid))
nid = first_online_node;
map_cpu_to_node(lcpu, nid);
@@ -1325,6 +1325,17 @@ static long vphn_get_associativity(unsigned long cpu,
return rc;
}
+static int verify_node_preparation(int nid)
+{
+ if ((NODE_DATA(nid) == NULL) ||
+ (NODE_DATA(nid)->node_spanned_pages == 0)) {
+ if (try_online_node(nid))
+ return first_online_node;
+ }
+
+ return nid;
+}
+
/*
* Update the CPU maps and sysfs entries for a single CPU when its NUMA
* characteristics change. This function doesn't perform any locking and is
@@ -1433,9 +1444,11 @@ int numa_update_cpu_topology(bool cpus_locked)
/* Use associativity from first thread for all siblings */
vphn_get_associativity(cpu, associativity);
new_nid = associativity_to_nid(associativity);
- if (new_nid < 0 || !node_online(new_nid))
+ if (new_nid < 0 || !node_possible(new_nid))
new_nid = first_online_node;
+ new_nid = verify_node_preparation(new_nid);
+
if (new_nid == numa_cpu_lookup_table[cpu]) {
cpumask_andnot(&cpu_associativity_changes_mask,
&cpu_associativity_changes_mask,