Re: [PATCH v4 5/5] riscv: Add numa support for riscv64 platform

[Anup Patel <anup@brainfault.org>]

On Tue, Oct 6, 2020 at 5:48 AM Atish Patra <atish.patra@wdc.com> wrote:
>
> Use the generic numa implementation to add NUMA support for RISC-V.
> This is based on Greentime's patch[1] but modified to use generic NUMA
> implementation and few more fixes.
>
> [1] https://lkml.org/lkml/2020/1/10/233
>
> Co-developed-by: Greentime Hu <greentime.hu@sifive.com>
> Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
>  arch/riscv/Kconfig              | 31 ++++++++++++++++++++++++++++++-
>  arch/riscv/include/asm/mmzone.h | 13 +++++++++++++
>  arch/riscv/include/asm/numa.h   |  8 ++++++++
>  arch/riscv/include/asm/pci.h    | 14 ++++++++++++++
>  arch/riscv/kernel/setup.c       | 10 ++++++++--
>  arch/riscv/kernel/smpboot.c     | 12 +++++++++++-
>  arch/riscv/mm/init.c            |  4 +++-
>  7 files changed, 87 insertions(+), 5 deletions(-)
>  create mode 100644 arch/riscv/include/asm/mmzone.h
>  create mode 100644 arch/riscv/include/asm/numa.h
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index df18372861d8..7beb6ddb6eb1 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -137,7 +137,7 @@ config PAGE_OFFSET
>         default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
>
>  config ARCH_FLATMEM_ENABLE
> -       def_bool y
> +       def_bool !NUMA
>
>  config ARCH_SPARSEMEM_ENABLE
>         def_bool y
> @@ -295,6 +295,35 @@ config TUNE_GENERIC
>
>  endchoice
>
> +# Common NUMA Features
> +config NUMA
> +       bool "NUMA Memory Allocation and Scheduler Support"
> +       select GENERIC_ARCH_NUMA
> +       select OF_NUMA
> +       select ARCH_SUPPORTS_NUMA_BALANCING
> +       help
> +         Enable NUMA (Non-Uniform Memory Access) support.
> +
> +         The kernel will try to allocate memory used by a CPU on the
> +         local memory of the CPU and add some more NUMA awareness to the kernel.
> +
> +config NODES_SHIFT
> +       int "Maximum NUMA Nodes (as a power of 2)"
> +       range 1 10
> +       default "2"
> +       depends on NEED_MULTIPLE_NODES
> +       help
> +         Specify the maximum number of NUMA Nodes available on the target
> +         system.  Increases memory reserved to accommodate various tables.
> +
> +config USE_PERCPU_NUMA_NODE_ID
> +       def_bool y
> +       depends on NUMA
> +
> +config NEED_PER_CPU_EMBED_FIRST_CHUNK
> +       def_bool y
> +       depends on NUMA
> +
>  config RISCV_ISA_C
>         bool "Emit compressed instructions when building Linux"
>         default y
> diff --git a/arch/riscv/include/asm/mmzone.h b/arch/riscv/include/asm/mmzone.h
> new file mode 100644
> index 000000000000..fa17e01d9ab2
> --- /dev/null
> +++ b/arch/riscv/include/asm/mmzone.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_MMZONE_H
> +#define __ASM_MMZONE_H
> +
> +#ifdef CONFIG_NUMA
> +
> +#include <asm/numa.h>
> +
> +extern struct pglist_data *node_data[];
> +#define NODE_DATA(nid)         (node_data[(nid)])
> +
> +#endif /* CONFIG_NUMA */
> +#endif /* __ASM_MMZONE_H */
> diff --git a/arch/riscv/include/asm/numa.h b/arch/riscv/include/asm/numa.h
> new file mode 100644
> index 000000000000..8c8cf4297cc3
> --- /dev/null
> +++ b/arch/riscv/include/asm/numa.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_NUMA_H
> +#define __ASM_NUMA_H
> +
> +#include <asm/topology.h>
> +#include <asm-generic/numa.h>
> +
> +#endif /* __ASM_NUMA_H */
> diff --git a/arch/riscv/include/asm/pci.h b/arch/riscv/include/asm/pci.h
> index 1c473a1bd986..658e112c3ce7 100644
> --- a/arch/riscv/include/asm/pci.h
> +++ b/arch/riscv/include/asm/pci.h
> @@ -32,6 +32,20 @@ static inline int pci_proc_domain(struct pci_bus *bus)
>         /* always show the domain in /proc */
>         return 1;
>  }
> +
> +#ifdef CONFIG_NUMA
> +
> +static inline int pcibus_to_node(struct pci_bus *bus)
> +{
> +       return dev_to_node(&bus->dev);
> +}
> +#ifndef cpumask_of_pcibus
> +#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ?            \
> +                                cpu_all_mask :                         \
> +                                cpumask_of_node(pcibus_to_node(bus)))
> +#endif
> +#endif /* CONFIG_NUMA */
> +
>  #endif  /* CONFIG_PCI */
>
>  #endif  /* _ASM_RISCV_PCI_H */
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 07fa6d13367e..53a806a9cbaf 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -101,13 +101,19 @@ void __init setup_arch(char **cmdline_p)
>
>  static int __init topology_init(void)
>  {
> -       int i;
> +       int i, ret;
> +
> +       for_each_online_node(i)
> +               register_one_node(i);
>
>         for_each_possible_cpu(i) {
>                 struct cpu *cpu = &per_cpu(cpu_devices, i);
>
>                 cpu->hotpluggable = cpu_has_hotplug(i);
> -               register_cpu(cpu, i);
> +               ret = register_cpu(cpu, i);
> +               if (unlikely(ret))
> +                       pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
> +                              __func__, i, ret);
>         }
>
>         return 0;
> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
> index 96167d55ed98..5e276c25646f 100644
> --- a/arch/riscv/kernel/smpboot.c
> +++ b/arch/riscv/kernel/smpboot.c
> @@ -27,6 +27,7 @@
>  #include <asm/cpu_ops.h>
>  #include <asm/irq.h>
>  #include <asm/mmu_context.h>
> +#include <asm/numa.h>
>  #include <asm/tlbflush.h>
>  #include <asm/sections.h>
>  #include <asm/sbi.h>
> @@ -45,13 +46,18 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
>  {
>         int cpuid;
>         int ret;
> +       unsigned int curr_cpuid;
> +
> +       curr_cpuid = smp_processor_id();
> +       numa_store_cpu_info(curr_cpuid);
> +       numa_add_cpu(curr_cpuid);
>
>         /* This covers non-smp usecase mandated by "nosmp" option */
>         if (max_cpus == 0)
>                 return;
>
>         for_each_possible_cpu(cpuid) {
> -               if (cpuid == smp_processor_id())
> +               if (cpuid == curr_cpuid)
>                         continue;
>                 if (cpu_ops[cpuid]->cpu_prepare) {
>                         ret = cpu_ops[cpuid]->cpu_prepare(cpuid);
> @@ -59,6 +65,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
>                                 continue;
>                 }
>                 set_cpu_present(cpuid, true);
> +               numa_store_cpu_info(cpuid);
>         }
>  }
>
> @@ -79,6 +86,7 @@ void __init setup_smp(void)
>                 if (hart == cpuid_to_hartid_map(0)) {
>                         BUG_ON(found_boot_cpu);
>                         found_boot_cpu = 1;
> +                       early_map_cpu_to_node(0, of_node_to_nid(dn));
>                         continue;
>                 }
>                 if (cpuid >= NR_CPUS) {
> @@ -88,6 +96,7 @@ void __init setup_smp(void)
>                 }
>
>                 cpuid_to_hartid_map(cpuid) = hart;
> +               early_map_cpu_to_node(cpuid, of_node_to_nid(dn));
>                 cpuid++;
>         }
>
> @@ -153,6 +162,7 @@ asmlinkage __visible void smp_callin(void)
>         current->active_mm = mm;
>
>         notify_cpu_starting(curr_cpuid);
> +       numa_add_cpu(curr_cpuid);
>         update_siblings_masks(curr_cpuid);
>         set_cpu_online(curr_cpuid, 1);
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 114c3966aadb..c4046e11d264 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -20,6 +20,7 @@
>  #include <asm/soc.h>
>  #include <asm/io.h>
>  #include <asm/ptdump.h>
> +#include <asm/numa.h>
>
>  #include "../kernel/head.h"
>
> @@ -185,7 +186,6 @@ void __init setup_bootmem(void)
>
>         early_init_fdt_scan_reserved_mem();
>         memblock_allow_resize();
> -       memblock_dump_all();
>
>         for_each_memblock(memory, reg) {
>                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
> @@ -570,9 +570,11 @@ void __init paging_init(void)
>
>  void __init misc_mem_init(void)
>  {
> +       arch_numa_init();
>         sparse_init();
>         zone_sizes_init();
>         resource_init();
> +       memblock_dump_all();
>  }
>
>  #ifdef CONFIG_SPARSEMEM_VMEMMAP
> --
> 2.25.1
>

Looks good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup