Subject: [PATCH v3 19/26] mm: introduce numa_emulation

From: Mike Rapoport <[email-masked]>
Date: Thu, 1 Aug 2024 09:08:19 +0300

From: "Mike Rapoport (Microsoft)" <[email-masked]>

Move numa_emulation codfrom arch/x86 to mm/numa_emulation.c

This code will be later reused by arch_numa.

No functional changes.

Signed-off-by: Mike Rapoport (Microsoft) <[email-masked]>
Tested-by: Zi Yan <[email-masked]> # for x86_64 and arm64
---
 arch/x86/Kconfig                     |  8 --------
 arch/x86/include/asm/numa.h          | 12 ------------
 arch/x86/mm/Makefile                 |  1 -
 arch/x86/mm/numa_internal.h          | 11 -----------
 include/linux/numa_memblks.h         | 17 +++++++++++++++++
 mm/Kconfig                           |  8 ++++++++
 mm/Makefile                          |  1 +
 {arch/x86/mm => mm}/numa_emulation.c |  4 +---
 8 files changed, 27 insertions(+), 35 deletions(-)
 rename {arch/x86/mm => mm}/numa_emulation.c (99%)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 74afb59c6603..acd9745bf2ae 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1600,14 +1600,6 @@ config X86_64_ACPI_NUMA
 	help
 	  Enable ACPI SRAT based node topology detection.
 
-config NUMA_EMU
-	bool "NUMA emulation"
-	depends on NUMA
-	help
-	  Enable NUMA emulation. A flat machine will be split
-	  into virtual nodes when booted with "numa=fake=N", where N is the
-	  number of nodes. This is only useful for debugging.
-
 config NODES_SHIFT
 	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
 	range 1 10
diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index 203100500f24..5469d7a7c40f 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -65,16 +65,4 @@ static inline void init_gi_nodes(void)			{ }
 void debug_cpumask_set_cpu(unsigned int cpu, int node, bool enable);
 #endif
 
-#ifdef CONFIG_NUMA_EMU
-int numa_emu_cmdline(char *str);
-void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
-					unsigned int nr_emu_nids);
-u64 __init numa_emu_dma_end(void);
-#else /* CONFIG_NUMA_EMU */
-static inline int numa_emu_cmdline(char *str)
-{
-	return -EINVAL;
-}
-#endif /* CONFIG_NUMA_EMU */
-
 #endif	/* _ASM_X86_NUMA_H */
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 8d3a00e5c528..690fbf48e853 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -57,7 +57,6 @@ obj-$(CONFIG_MMIOTRACE_TEST)	+= testmmiotrace.o
 obj-$(CONFIG_NUMA)		+= numa.o numa_$(BITS).o
 obj-$(CONFIG_AMD_NUMA)		+= amdtopology.o
 obj-$(CONFIG_ACPI_NUMA)		+= srat.o
-obj-$(CONFIG_NUMA_EMU)		+= numa_emulation.o
 
 obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS)	+= pkeys.o
 obj-$(CONFIG_RANDOMIZE_MEMORY)			+= kaslr.o
diff --git a/arch/x86/mm/numa_internal.h b/arch/x86/mm/numa_internal.h
index 249e3aaeadce..11e1ff370c10 100644
--- a/arch/x86/mm/numa_internal.h
+++ b/arch/x86/mm/numa_internal.h
@@ -7,15 +7,4 @@
 
 void __init x86_numa_init(void);
 
-struct numa_meminfo;
-
-#ifdef CONFIG_NUMA_EMU
-void __init numa_emulation(struct numa_meminfo *numa_meminfo,
-			   int numa_dist_cnt);
-#else
-static inline void numa_emulation(struct numa_meminfo *numa_meminfo,
-				  int numa_dist_cnt)
-{ }
-#endif
-
 #endif	/* __X86_MM_NUMA_INTERNAL_H */
diff --git a/include/linux/numa_memblks.h b/include/linux/numa_memblks.h
index 968a590535ac..f81f98678074 100644
--- a/include/linux/numa_memblks.h
+++ b/include/linux/numa_memblks.h
@@ -34,6 +34,23 @@ int __init numa_register_meminfo(struct numa_meminfo *mi);
 void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
 				       const struct numa_meminfo *mi);
 
+#ifdef CONFIG_NUMA_EMU
+int numa_emu_cmdline(char *str);
+void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
+					unsigned int nr_emu_nids);
+u64 __init numa_emu_dma_end(void);
+void __init numa_emulation(struct numa_meminfo *numa_meminfo,
+			   int numa_dist_cnt);
+#else
+static inline void numa_emulation(struct numa_meminfo *numa_meminfo,
+				  int numa_dist_cnt)
+{ }
+static inline int numa_emu_cmdline(char *str)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_NUMA_EMU */
+
 #endif /* CONFIG_NUMA_MEMBLKS */
 
 #endif	/* __NUMA_MEMBLKS_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index dc5912d29ed5..3b466df1d9e2 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1266,6 +1266,14 @@ config EXECMEM
 config NUMA_MEMBLKS
 	bool
 
+config NUMA_EMU
+	bool "NUMA emulation"
+	depends on NUMA_MEMBLKS
+	help
+	  Enable NUMA emulation. A flat machine will be split
+	  into virtual nodes when booted with "numa=fake=N", where N is the
+	  number of nodes. This is only useful for debugging.
+
 source "mm/damon/Kconfig"
 
 endmenu
diff --git a/mm/Makefile b/mm/Makefile
index e3fac7efd880..75a189cc67ef 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -143,3 +143,4 @@ obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o
 obj-$(CONFIG_EXECMEM) += execmem.o
 obj-$(CONFIG_NUMA) += numa.o
 obj-$(CONFIG_NUMA_MEMBLKS) += numa_memblks.o
+obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
diff --git a/arch/x86/mm/numa_emulation.c b/mm/numa_emulation.c
similarity index 99%
rename from arch/x86/mm/numa_emulation.c
rename to mm/numa_emulation.c
index 33610026b7a3..031fb9961bf7 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/mm/numa_emulation.c
@@ -7,9 +7,7 @@
 #include <linux/topology.h>
 #include <linux/memblock.h>
 #include <linux/numa_memblks.h>
-#include <asm/dma.h>
-
-#include "numa_internal.h"
+#include <asm/numa.h>
 
 #define FAKE_NODE_MIN_SIZE	((u64)32 << 20)
 #define FAKE_NODE_MIN_HASH_MASK	(~(FAKE_NODE_MIN_SIZE - 1UL))
-- 
2.43.0