[PATCH v4 1/4] memblock tests: add simulation of physical memory with multiple NUMA nodes

[Rebecca Mckeever <remckee0@gmail.com>]

Add function setup_numa_memblock() for setting up a memory layout with
multiple NUMA nodes in a previously allocated dummy physical memory.
This function can be used in place of setup_memblock() in tests that need
to simulate a NUMA system.

setup_numa_memblock():
- allows for setting up a memory layout by specifying the fraction of
  MEM_SIZE in each node

Set CONFIG_NODES_SHIFT to 4 when building with NUMA=1 to allow for up to
16 NUMA nodes.

Signed-off-by: Rebecca Mckeever <remckee0@gmail.com>
---
 .../testing/memblock/scripts/Makefile.include |  2 +-
 tools/testing/memblock/tests/common.c         | 29 +++++++++++++++++++
 tools/testing/memblock/tests/common.h         |  4 ++-
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/tools/testing/memblock/scripts/Makefile.include b/tools/testing/memblock/scripts/Makefile.include
index aa6d82d56a23..998281723590 100644
--- a/tools/testing/memblock/scripts/Makefile.include
+++ b/tools/testing/memblock/scripts/Makefile.include
@@ -3,7 +3,7 @@
 
 # Simulate CONFIG_NUMA=y
 ifeq ($(NUMA), 1)
-	CFLAGS += -D CONFIG_NUMA
+	CFLAGS += -D CONFIG_NUMA -D CONFIG_NODES_SHIFT=4
 endif
 
 # Use 32 bit physical addresses.
diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
index eec6901081af..b6110df21b2a 100644
--- a/tools/testing/memblock/tests/common.c
+++ b/tools/testing/memblock/tests/common.c
@@ -72,6 +72,35 @@ void setup_memblock(void)
 	fill_memblock();
 }
 
+/**
+ * setup_numa_memblock:
+ * Set up a memory layout with multiple NUMA nodes in a previously allocated
+ * dummy physical memory.
+ * @nodes: an array containing the denominators of the fractions of MEM_SIZE
+ *         contained in each node (e.g., if nodes[0] = SZ_8, node 0 will
+ *         contain 1/8th of MEM_SIZE)
+ *
+ * The nids will be set to 0 through NUMA_NODES - 1.
+ */
+void setup_numa_memblock(const phys_addr_t nodes[])
+{
+	phys_addr_t base;
+	int flags;
+
+	reset_memblock_regions();
+	base = (phys_addr_t)memory_block.base;
+	flags = (movable_node_is_enabled()) ? MEMBLOCK_NONE : MEMBLOCK_HOTPLUG;
+
+	for (int i = 0; i < NUMA_NODES; i++) {
+		assert(nodes[i] <= MEM_SIZE && nodes[i] > 0);
+		phys_addr_t size = MEM_SIZE / nodes[i];
+
+		memblock_add_node(base, size, i, flags);
+		base += size;
+	}
+	fill_memblock();
+}
+
 void dummy_physical_memory_init(void)
 {
 	memory_block.base = malloc(MEM_SIZE);
diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
index 78128e109a95..caf01543a315 100644
--- a/tools/testing/memblock/tests/common.h
+++ b/tools/testing/memblock/tests/common.h
@@ -10,7 +10,8 @@
 #include <linux/printk.h>
 #include <../selftests/kselftest.h>
 
-#define MEM_SIZE SZ_16K
+#define MEM_SIZE		SZ_16K
+#define NUMA_NODES		8
 
 enum test_flags {
 	/* No special request. */
@@ -102,6 +103,7 @@ struct region {
 void reset_memblock_regions(void);
 void reset_memblock_attributes(void);
 void setup_memblock(void);
+void setup_numa_memblock(const phys_addr_t nodes[]);
 void dummy_physical_memory_init(void);
 void dummy_physical_memory_cleanup(void);
 void parse_args(int argc, char **argv);
-- 
2.25.1