Re: [PATCH v4 1/4] ACPI: RISCV: Add NUMA support based on SRAT and SLIT

[Andrew Jones]

On Thu, Jun 13, 2024 at 04:54:33PM GMT, Haibo Xu wrote:
> Add acpi_numa.c file to enable parse NUMA information from
> ACPI SRAT and SLIT tables. SRAT table provide CPUs(Hart) and
> memory nodes to proximity domain mapping, while SLIT table
> provide the distance metrics between proximity domains.
> 
> Signed-off-by: Haibo Xu <haibo1.xu@xxxxxxxxx>
> Reviewed-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/acpi.h |  15 +++-
>  arch/riscv/kernel/Makefile    |   1 +
>  arch/riscv/kernel/acpi.c      |   5 --
>  arch/riscv/kernel/acpi_numa.c | 131 ++++++++++++++++++++++++++++++++++
>  arch/riscv/kernel/setup.c     |   4 +-
>  arch/riscv/kernel/smpboot.c   |   2 -
>  include/linux/acpi.h          |   6 ++
>  7 files changed, 154 insertions(+), 10 deletions(-)
>  create mode 100644 arch/riscv/kernel/acpi_numa.c
> 
> diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
> index 7dad0cf9d701..e0a1f84404f3 100644
> --- a/arch/riscv/include/asm/acpi.h
> +++ b/arch/riscv/include/asm/acpi.h
> @@ -61,11 +61,14 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { }
>  
>  void acpi_init_rintc_map(void);
>  struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu);
> -u32 get_acpi_id_for_cpu(int cpu);
> +static inline u32 get_acpi_id_for_cpu(int cpu)
> +{
> +	return acpi_cpu_get_madt_rintc(cpu)->uid;
> +}
> +
>  int acpi_get_riscv_isa(struct acpi_table_header *table,
>  		       unsigned int cpu, const char **isa);
>  
> -static inline int acpi_numa_get_nid(unsigned int cpu) { return NUMA_NO_NODE; }
>  void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
>  			     u32 *cboz_size, u32 *cbop_size);
>  #else
> @@ -87,4 +90,12 @@ static inline void acpi_get_cbo_block_size(struct acpi_table_header *table,
>  
>  #endif /* CONFIG_ACPI */
>  
> +#ifdef CONFIG_ACPI_NUMA
> +int acpi_numa_get_nid(unsigned int cpu);
> +void acpi_map_cpus_to_nodes(void);
> +#else
> +static inline int acpi_numa_get_nid(unsigned int cpu) { return NUMA_NO_NODE; }
> +static inline void acpi_map_cpus_to_nodes(void) { }
> +#endif /* CONFIG_ACPI_NUMA */
> +
>  #endif /*_ASM_ACPI_H*/
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 5b243d46f4b1..1e2afec141b5 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -110,3 +110,4 @@ obj-$(CONFIG_COMPAT)		+= compat_vdso/
>  
>  obj-$(CONFIG_64BIT)		+= pi/
>  obj-$(CONFIG_ACPI)		+= acpi.o
> +obj-$(CONFIG_ACPI_NUMA)	+= acpi_numa.o
> diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c
> index e619edc8b0cc..040bdbfea2b4 100644
> --- a/arch/riscv/kernel/acpi.c
> +++ b/arch/riscv/kernel/acpi.c
> @@ -191,11 +191,6 @@ struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
>  	return &cpu_madt_rintc[cpu];
>  }
>  
> -u32 get_acpi_id_for_cpu(int cpu)
> -{
> -	return acpi_cpu_get_madt_rintc(cpu)->uid;
> -}
> -
>  /*
>   * __acpi_map_table() will be called before paging_init(), so early_ioremap()
>   * or early_memremap() should be called here to for ACPI table mapping.
> diff --git a/arch/riscv/kernel/acpi_numa.c b/arch/riscv/kernel/acpi_numa.c
> new file mode 100644
> index 000000000000..0231482d6946
> --- /dev/null
> +++ b/arch/riscv/kernel/acpi_numa.c
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ACPI 6.6 based NUMA setup for RISCV
> + * Lots of code was borrowed from arch/arm64/kernel/acpi_numa.c
> + *
> + * Copyright 2004 Andi Kleen, SuSE Labs.
> + * Copyright (C) 2013-2016, Linaro Ltd.
> + *		Author: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> + * Copyright (C) 2024 Intel Corporation.
> + *
> + * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
> + *
> + * Called from acpi_numa_init while reading the SRAT and SLIT tables.
> + * Assumes all memory regions belonging to a single proximity domain
> + * are in one chunk. Holes between them will be included in the node.
> + */
> +
> +#define pr_fmt(fmt) "ACPI: NUMA: " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/bitmap.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/memblock.h>
> +#include <linux/mmzone.h>
> +#include <linux/module.h>
> +#include <linux/topology.h>
> +
> +#include <asm/numa.h>
> +
> +static int acpi_early_node_map[NR_CPUS] __initdata = { NUMA_NO_NODE };

This only sets acpi_early_node_map[0] to NUMA_NO_NODE. Assuming we want
to ensure all of them are initialized to NUMA_NO_NODE, then we need

static int acpi_early_node_map[NR_CPUS] __initdata = { [0 ... NR_CPUS - 1] = NUMA_NO_NODE };

Thanks,
drew