[PATCH 20/20] X86_64, UV: Fix incorrect nodes and pnodes for cpuless and memoryless nodes

From: Mike Travis
Date: Tue May 03 2016 - 11:29:30 EST


From: Dimitri Sivanich <sivanich@xxxxxxx>

This patch fixes the problem of incorrect nodes and pnodes being returned
when referring to nodes that either have no cpus (AKA "headless") or no
memory.

Signed-off-by: Dimitri Sivanich <sivanich@xxxxxxx>
Signed-off-by: Mike Travis <travis@xxxxxxx>
Tested-by: John Estabrook <estabrook@xxxxxxx>
Tested-by: Gary Kroening <gfk@xxxxxxx>
Tested-by: Nathan Zimmer <nzimmer@xxxxxxx>
---
arch/x86/kernel/apic/x2apic_uv_x.c | 58 +++++++++++++++++--------------------
1 file changed, 28 insertions(+), 30 deletions(-)

--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c
+++ linux/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -1225,8 +1225,7 @@ static void __init decode_uv_systab(void
*/
static __init void boot_init_possible_blades(struct uv_hub_info_s *hub_info)
{
- size_t bytes;
- int blade, i, j, uv_pb = 0, num_nodes = num_possible_nodes();
+ int i, uv_pb = 0;

pr_info("UV: NODE_PRESENT_DEPTH = %d\n", UVH_NODE_PRESENT_TABLE_DEPTH);
for (i = 0; i < UVH_NODE_PRESENT_TABLE_DEPTH; i++) {
@@ -1240,28 +1239,6 @@ static __init void boot_init_possible_bl
}
if (uv_possible_blades != uv_pb)
uv_possible_blades = uv_pb;
-
- bytes = num_nodes * sizeof(_node_to_pnode[0]);
- _node_to_pnode = kmalloc(bytes, GFP_KERNEL);
- BUG_ON(!_node_to_pnode);
-
- for (blade = 0, i = 0; i < UVH_NODE_PRESENT_TABLE_DEPTH; i++) {
- unsigned short pnode;
- unsigned long present =
- uv_read_local_mmr(UVH_NODE_PRESENT_TABLE + i * 8);
-
- for (j = 0; j < 64; j++) {
- if (!test_bit(j, &present))
- continue;
- pnode = (i * 64 + j) & hub_info->pnode_mask;
- _node_to_pnode[blade++] = pnode;
- }
- if (blade > num_nodes) {
- pr_err("UV: blade count(%d) exceeds node count(%d)!\n",
- blade, num_nodes);
- BUG();
- }
- }
}

static void __init build_socket_tables(void)
@@ -1442,7 +1419,6 @@ void __init uv_system_init(void)
bytes = sizeof(struct uv_hub_info_s);
for_each_node(nodeid) {
struct uv_hub_info_s *new_hub;
- unsigned short pnode;

if (__uv_hub_info_list[nodeid]) {
pr_err("UV: Node %d UV HUB already initialized!?\n",
@@ -1460,10 +1436,11 @@ void __init uv_system_init(void)
BUG_ON(!new_hub);
*new_hub = hub_info;

- pnode = _node_to_pnode[nodeid];
- min_pnode = min(pnode, min_pnode);
- max_pnode = max(pnode, max_pnode);
- new_hub->pnode = pnode;
+ /* Use information from GAM table if available */
+ if (_node_to_pnode)
+ new_hub->pnode = _node_to_pnode[nodeid];
+ else /* Fill in during cpu loop */
+ new_hub->pnode = 0xffff;
new_hub->numa_blade_id = uv_node_to_blade_id(nodeid);
new_hub->memory_nid = -1;
new_hub->nr_possible_cpus = 0;
@@ -1473,18 +1450,39 @@ void __init uv_system_init(void)
/* Initialize per cpu info */
for_each_possible_cpu(cpu) {
int apicid = per_cpu(x86_cpu_to_apicid, cpu);
+ int numa_node_id;
+ unsigned short pnode;

nodeid = cpu_to_node(cpu);
+ numa_node_id = numa_cpu_node(cpu);
+ pnode = uv_apicid_to_pnode(apicid);
+
uv_cpu_info_per(cpu)->p_uv_hub_info = uv_hub_info_list(nodeid);
uv_cpu_info_per(cpu)->blade_cpu_id =
uv_cpu_hub_info(cpu)->nr_possible_cpus++;
if (uv_cpu_hub_info(cpu)->memory_nid == -1)
uv_cpu_hub_info(cpu)->memory_nid = cpu_to_node(cpu);
+ if (nodeid != numa_node_id && /* init memoryless node */
+ uv_hub_info_list(numa_node_id)->pnode == 0xffff)
+ uv_hub_info_list(numa_node_id)->pnode = pnode;
+ else if (uv_cpu_hub_info(cpu)->pnode == 0xffff)
+ uv_cpu_hub_info(cpu)->pnode = pnode;
uv_cpu_scir_info(cpu)->offset = uv_scir_offset(apicid);
}

- /* Display per node info */
for_each_node(nodeid) {
+ unsigned short pnode = uv_hub_info_list(nodeid)->pnode;
+
+ /* Add pnode info for pre-GAM list nodes without cpus */
+ if (pnode == 0xffff) {
+ unsigned long paddr;
+
+ paddr = node_start_pfn(nodeid) << PAGE_SHIFT;
+ pnode = uv_gpa_to_pnode(uv_soc_phys_ram_to_gpa(paddr));
+ uv_hub_info_list(nodeid)->pnode = pnode;
+ }
+ min_pnode = min(pnode, min_pnode);
+ max_pnode = max(pnode, max_pnode);
pr_info("UV: UVHUB node:%2d pn:%02x nrcpus:%d\n",
nodeid,
uv_hub_info_list(nodeid)->pnode,

--