On 08/15/2020 03:17 AM, Atish Patra wrote:
> ARM64 numa implementation is generic enough that RISC-V can reuse that
> implementation with very minor cosmetic changes. This will help both
> ARM64 and RISC-V in terms of maintanace and feature improvement
>
> Move the numa implementation code to common directory so that both ISAs
> can reuse this. This doesn't introduce any function changes for ARM64.
>
> Signed-off-by: Atish Patra <[email protected]>
> ---
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/numa.h | 45 +---------------
> arch/arm64/mm/Makefile | 1 -
> drivers/base/Kconfig | 6 +++
> drivers/base/Makefile | 1 +
> .../mm/numa.c => drivers/base/arch_numa.c | 0
> include/asm-generic/numa.h | 51 +++++++++++++++++++
> 7 files changed, 60 insertions(+), 45 deletions(-)
> rename arch/arm64/mm/numa.c => drivers/base/arch_numa.c (100%)
> create mode 100644 include/asm-generic/numa.h
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 6d232837cbee..955a0cf75b16 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -960,6 +960,7 @@ config HOTPLUG_CPU
> # Common NUMA Features
> config NUMA
> bool "NUMA Memory Allocation and Scheduler Support"
> + select GENERIC_ARCH_NUMA
So this introduces a generic NUMA framework selectable with GENERIC_ARCH_NUMA.
> select ACPI_NUMA if ACPI
> select OF_NUMA
> help
> diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
> index 626ad01e83bf..8c8cf4297cc3 100644
> --- a/arch/arm64/include/asm/numa.h
> +++ b/arch/arm64/include/asm/numa.h
> @@ -3,49 +3,6 @@
> #define __ASM_NUMA_H
>
> #include <asm/topology.h>
> -
> -#ifdef CONFIG_NUMA
> -
> -#define NR_NODE_MEMBLKS (MAX_NUMNODES * 2)
> -
> -int __node_distance(int from, int to);
> -#define node_distance(a, b) __node_distance(a, b)
> -
> -extern nodemask_t numa_nodes_parsed __initdata;
> -
> -extern bool numa_off;
> -
> -/* Mappings between node number and cpus on that node. */
> -extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
> -void numa_clear_node(unsigned int cpu);
> -
> -#ifdef CONFIG_DEBUG_PER_CPU_MAPS
> -const struct cpumask *cpumask_of_node(int node);
> -#else
> -/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
> -static inline const struct cpumask *cpumask_of_node(int node)
> -{
> - return node_to_cpumask_map[node];
> -}
> -#endif
> -
> -void __init arm64_numa_init(void);
> -int __init numa_add_memblk(int nodeid, u64 start, u64 end);
> -void __init numa_set_distance(int from, int to, int distance);
> -void __init numa_free_distance(void);
> -void __init early_map_cpu_to_node(unsigned int cpu, int nid);
> -void numa_store_cpu_info(unsigned int cpu);
> -void numa_add_cpu(unsigned int cpu);
> -void numa_remove_cpu(unsigned int cpu);
> -
> -#else /* CONFIG_NUMA */
> -
> -static inline void numa_store_cpu_info(unsigned int cpu) { }
> -static inline void numa_add_cpu(unsigned int cpu) { }
> -static inline void numa_remove_cpu(unsigned int cpu) { }
> -static inline void arm64_numa_init(void) { }
> -static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
> -
> -#endif /* CONFIG_NUMA */
> +#include <asm-generic/numa.h>
>
> #endif /* __ASM_NUMA_H */
> diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
> index d91030f0ffee..928c308b044b 100644
> --- a/arch/arm64/mm/Makefile
> +++ b/arch/arm64/mm/Makefile
> @@ -6,7 +6,6 @@ obj-y := dma-mapping.o extable.o
> fault.o init.o \
> obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
> obj-$(CONFIG_PTDUMP_CORE) += dump.o
> obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
> -obj-$(CONFIG_NUMA) += numa.o
> obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
> KASAN_SANITIZE_physaddr.o += n
>
> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> index 8d7001712062..73c2151de194 100644
> --- a/drivers/base/Kconfig
> +++ b/drivers/base/Kconfig
> @@ -210,4 +210,10 @@ config GENERIC_ARCH_TOPOLOGY
> appropriate scaling, sysfs interface for reading capacity values at
> runtime.
>
> +config GENERIC_ARCH_NUMA
> + bool
> + help
> + Enable support for generic numa implementation. Currently, RISC-V
> + and ARM64 uses it.
> +
> endmenu
> diff --git a/drivers/base/Makefile b/drivers/base/Makefile
> index 157452080f3d..c3d02c644222 100644
> --- a/drivers/base/Makefile
> +++ b/drivers/base/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o
> obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
> obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o
> obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
> +obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
>
> obj-y += test/
>
> diff --git a/arch/arm64/mm/numa.c b/drivers/base/arch_numa.c
> similarity index 100%
> rename from arch/arm64/mm/numa.c
> rename to drivers/base/arch_numa.c
drivers/base/ does not seem right place to host generic NUMA code.
Probably it should be either mm/ or kernel/. The other question here
would be if existing arm64 NUMA implementation is sufficient enough
for generic NUMA. I would expect any platform selecting this config
should get some NUMA enabled, will be that be true with present code ?
Otherwise it will be difficult to name it as GENERIC_ARCH_NUMA.
