[PATCH v11 2/6] x86: Support Generic Initiator only proximity domains

Jonathan Cameron
2020-09-28T12:56:12Z

In common with memoryless domains we only register GI domains
if the proximity node is not online. If a domain is already
a memory containing domain, or a memoryless domain there is
nothing to do just because it also contains a Generic Initiator.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
v11: Improved description for init_gi_nodes()

arch/x86/include/asm/numa.h | 2 ++
arch/x86/kernel/setup.c | 1 +
arch/x86/mm/numa.c | 21 +++++++++++++++++++++
3 files changed, 24 insertions(+)

diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index bbfde3d2662f..f631467272a3 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -62,12 +62,14 @@ extern void numa_clear_node(int cpu);
extern void __init init_cpu_to_node(void);
extern void numa_add_cpu(int cpu);
extern void numa_remove_cpu(int cpu);
+extern void init_gi_nodes(void);
#else /* CONFIG_NUMA */
static inline void numa_set_node(int cpu, int node) { }
static inline void numa_clear_node(int cpu) { }
static inline void init_cpu_to_node(void) { }
static inline void numa_add_cpu(int cpu) { }
static inline void numa_remove_cpu(int cpu) { }
+static inline void init_gi_nodes(void) { }
#endif /* CONFIG_NUMA */

#ifdef CONFIG_DEBUG_PER_CPU_MAPS
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3511736fbc74..9062c146f03a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1218,6 +1218,7 @@ void __init setup_arch(char **cmdline_p)
prefill_possible_map();

init_cpu_to_node();
+ init_gi_nodes();

io_apic_init_mappings();

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index aa76ec2d359b..cab6f679941d 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -747,6 +747,27 @@ static void __init init_memory_less_node(int nid)
*/
}

+/*
+ * A node may exist which has one or more Generic Initiators but no CPUs and no
+ * memory.
+ *
+ * This function must be called after init_cpu_to_node() to ensure that we have
+ * already brought online any memoryless CPU nodes, and before the node_data[nid]
+ * needs to be available for zone list setup in build_all_zonelists().
+ *
+ * When this function is called, any nodes containing either memory and/or CPUs
+ * will already be online and there is no need to do anything extra, even if
+ * they also contain one or more Generic Initiators.
+ */
+void __init init_gi_nodes(void)
+{
+ int nid;
+
+ for_each_node_state(nid, N_GENERIC_INITIATOR)
+ if (!node_online(nid))
+ init_memory_less_node(nid);
+}
+
/*
* Setup early cpu_to_node.
*