Re: [PATCH V12 22/24] LoongArch: Add Non-Uniform Memory Access (NUMA) support

[WANG Xuerui]

On 6/1/22 18:00, Huacai Chen wrote:
> Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch
> has 48-bit physical address, but the HyperTransport I/O bus only support
> 40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to
> extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical
> address space and embed it into 40-bit. In the 40-bit dma address, node
> id offset can be read from the LS7A_DMA_CFG register.
>
> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> ---
>   arch/loongarch/Kconfig                  |  21 ++
>   arch/loongarch/include/asm/bootinfo.h   |   2 +
>   arch/loongarch/include/asm/dma-direct.h |  11 +
>   arch/loongarch/include/asm/mmzone.h     |  18 +
>   arch/loongarch/include/asm/numa.h       |  69 ++++
>   arch/loongarch/include/asm/pgtable.h    |  12 +
>   arch/loongarch/include/asm/topology.h   |  21 ++
>   arch/loongarch/kernel/Makefile          |   2 +
>   arch/loongarch/kernel/acpi.c            |  95 +++++
>   arch/loongarch/kernel/dma.c             |  40 ++
>   arch/loongarch/kernel/module.c          |   1 +
>   arch/loongarch/kernel/numa.c            | 466 ++++++++++++++++++++++++
>   arch/loongarch/kernel/setup.c           |  11 +-
>   arch/loongarch/kernel/smp.c             |  52 ++-
>   arch/loongarch/kernel/traps.c           |   4 +-
>   arch/loongarch/mm/init.c                |  13 +
>   arch/loongarch/mm/tlb.c                 |  37 +-
>   17 files changed, 846 insertions(+), 29 deletions(-)
>   create mode 100644 arch/loongarch/include/asm/dma-direct.h
>   create mode 100644 arch/loongarch/include/asm/mmzone.h
>   create mode 100644 arch/loongarch/include/asm/numa.h
>   create mode 100644 arch/loongarch/kernel/dma.c
>   create mode 100644 arch/loongarch/kernel/numa.c
>
> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> index b252a51946e3..71496e170bd1 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -7,6 +7,7 @@ config LOONGARCH
>   	select ARCH_ENABLE_MEMORY_HOTPLUG
>   	select ARCH_ENABLE_MEMORY_HOTREMOVE
>   	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
> +	select ARCH_HAS_PHYS_TO_DMA
>   	select ARCH_HAS_PTE_SPECIAL
>   	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>   	select ARCH_INLINE_READ_LOCK if !PREEMPTION
> @@ -41,6 +42,7 @@ config LOONGARCH
>   	select ARCH_SUPPORTS_ACPI
>   	select ARCH_SUPPORTS_ATOMIC_RMW
>   	select ARCH_SUPPORTS_HUGETLBFS
> +	select ARCH_SUPPORTS_NUMA_BALANCING
>   	select ARCH_USE_BUILTIN_BSWAP
>   	select ARCH_USE_CMPXCHG_LOCKREF
>   	select ARCH_USE_QUEUED_RWLOCKS
> @@ -91,12 +93,15 @@ config LOONGARCH
>   	select HAVE_PERF_EVENTS
>   	select HAVE_REGS_AND_STACK_ACCESS_API
>   	select HAVE_RSEQ
> +	select HAVE_SETUP_PER_CPU_AREA if NUMA
>   	select HAVE_SYSCALL_TRACEPOINTS
>   	select HAVE_TIF_NOHZ
>   	select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP
>   	select IRQ_FORCED_THREADING
>   	select IRQ_LOONGARCH_CPU
>   	select MODULES_USE_ELF_RELA if MODULES
> +	select NEED_PER_CPU_EMBED_FIRST_CHUNK
> +	select NEED_PER_CPU_PAGE_FIRST_CHUNK
>   	select OF
>   	select OF_EARLY_FLATTREE
>   	select PERF_USE_VMALLOC
> @@ -105,6 +110,7 @@ config LOONGARCH
>   	select SYSCTL_EXCEPTION_TRACE
>   	select SWIOTLB
>   	select TRACE_IRQFLAGS_SUPPORT
> +	select USE_PERCPU_NUMA_NODE_ID
>   	select ZONE_DMA32
>   
>   config 32BIT
> @@ -344,6 +350,20 @@ config NR_CPUS
>   	  This allows you to specify the maximum number of CPUs which this
>   	  kernel will support.
>   
> +config NUMA
> +	bool "NUMA Support"
> +	select ACPI_NUMA if ACPI
> +	help
> +	  Say Y to compile the kernel with NUMA (Non-Uniform Memory Access)
> +	  support.  This option improves performance on systems with more
> +	  than one NUMA node; on single node systems it is generally better
> +	  to leave it disabled.
> +
> +config NODES_SHIFT
> +	int
> +	default "6"
> +	depends on NUMA
> +
>   config FORCE_MAX_ZONEORDER
>   	int "Maximum zone order"
>   	range 14 64 if PAGE_SIZE_64KB
> @@ -390,6 +410,7 @@ config ARCH_SELECT_MEMORY_MODEL
>   
>   config ARCH_FLATMEM_ENABLE
>   	def_bool y
> +	depends on !NUMA
>   
>   config ARCH_SPARSEMEM_ENABLE
>   	def_bool y
> diff --git a/arch/loongarch/include/asm/bootinfo.h b/arch/loongarch/include/asm/bootinfo.h
> index 7b60f202faaf..9b8d49d9e61b 100644
> --- a/arch/loongarch/include/asm/bootinfo.h
> +++ b/arch/loongarch/include/asm/bootinfo.h
> @@ -13,6 +13,8 @@ const char *get_system_type(void);
>   extern void init_environ(void);
>   extern void memblock_init(void);
>   extern void platform_init(void);
> +extern void plat_swiotlb_setup(void);
> +extern int __init init_numa_memory(void);
>   
>   struct loongson_board_info {
>   	int bios_size;
> diff --git a/arch/loongarch/include/asm/dma-direct.h b/arch/loongarch/include/asm/dma-direct.h
> new file mode 100644
> index 000000000000..75ccd808a2af
> --- /dev/null
> +++ b/arch/loongarch/include/asm/dma-direct.h
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _LOONGARCH_DMA_DIRECT_H
> +#define _LOONGARCH_DMA_DIRECT_H
> +
> +dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
> +
> +#endif /* _LOONGARCH_DMA_DIRECT_H */
> diff --git a/arch/loongarch/include/asm/mmzone.h b/arch/loongarch/include/asm/mmzone.h
> new file mode 100644
> index 000000000000..fe67d0b4b33d
> --- /dev/null
> +++ b/arch/loongarch/include/asm/mmzone.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Author: Huacai Chen (chenhuacai@xxxxxxxxxxx)
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_MMZONE_H_
> +#define _ASM_MMZONE_H_
> +
> +#include <asm/page.h>
> +#include <asm/numa.h>
> +
> +extern struct pglist_data *node_data[];
> +
> +#define NODE_DATA(nid)	(node_data[(nid)])
> +
> +extern void setup_zero_pages(void);
> +
> +#endif /* _ASM_MMZONE_H_ */
> diff --git a/arch/loongarch/include/asm/numa.h b/arch/loongarch/include/asm/numa.h
> new file mode 100644
> index 000000000000..8f9c81af7930
> --- /dev/null
> +++ b/arch/loongarch/include/asm/numa.h
> @@ -0,0 +1,69 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * LoongArch specific ACPICA environments and implementation
> + *
> + * Author: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
> + *         Huacai Chen <chenhuacai@xxxxxxxxxxx>
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef _ASM_LOONGARCH_NUMA_H
> +#define _ASM_LOONGARCH_NUMA_H
> +
> +#include <linux/nodemask.h>
> +
> +#define NODE_ADDRSPACE_SHIFT 44
> +
> +#define pa_to_nid(addr)		(((addr) & 0xf00000000000) >> NODE_ADDRSPACE_SHIFT)
> +#define nid_to_addrbase(nid)	(_ULCAST_(nid) << NODE_ADDRSPACE_SHIFT)
> +
> +#ifdef CONFIG_NUMA
> +
> +extern int numa_off;
> +extern s16 __cpuid_to_node[CONFIG_NR_CPUS];
> +extern nodemask_t numa_nodes_parsed __initdata;
> +
> +struct numa_memblk {
> +	u64			start;
> +	u64			end;
> +	int			nid;
> +};
> +
> +#define NR_NODE_MEMBLKS		(MAX_NUMNODES*2)
> +struct numa_meminfo {
> +	int			nr_blks;
> +	struct numa_memblk	blk[NR_NODE_MEMBLKS];
> +};
> +
> +extern int __init numa_add_memblk(int nodeid, u64 start, u64 end);
> +
> +extern void __init early_numa_add_cpu(int cpuid, s16 node);
> +extern void numa_add_cpu(unsigned int cpu);
> +extern void numa_remove_cpu(unsigned int cpu);
> +
> +static inline void numa_clear_node(int cpu)
> +{
> +}
> +
> +static inline void set_cpuid_to_node(int cpuid, s16 node)
> +{
> +	__cpuid_to_node[cpuid] = node;
> +}
> +
> +extern int early_cpu_to_node(int cpu);
> +
> +#else
> +
> +static inline void early_numa_add_cpu(int cpuid, s16 node)	{ }
> +static inline void numa_add_cpu(unsigned int cpu)		{ }
> +static inline void numa_remove_cpu(unsigned int cpu)		{ }
> +
> +static inline int early_cpu_to_node(int cpu)
> +{
> +	return 0;
> +}
> +
> +#endif	/* CONFIG_NUMA */
> +
> +#endif	/* _ASM_LOONGARCH_NUMA_H */
> diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
> index 5e33987d0a13..5dc84d8f18d6 100644
> --- a/arch/loongarch/include/asm/pgtable.h
> +++ b/arch/loongarch/include/asm/pgtable.h
> @@ -541,6 +541,18 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
>   
>   #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>   
> +#ifdef CONFIG_NUMA_BALANCING
> +static inline long pte_protnone(pte_t pte)
> +{
> +	return (pte_val(pte) & _PAGE_PROTNONE);
> +}
> +
> +static inline long pmd_protnone(pmd_t pmd)
> +{
> +	return (pmd_val(pmd) & _PAGE_PROTNONE);
> +}
> +#endif /* CONFIG_NUMA_BALANCING */
> +
>   /*
>    * We provide our own get_unmapped area to cope with the virtual aliasing
>    * constraints placed on us by the cache architecture.
> diff --git a/arch/loongarch/include/asm/topology.h b/arch/loongarch/include/asm/topology.h
> index da135841e5b1..66128dec0bf6 100644
> --- a/arch/loongarch/include/asm/topology.h
> +++ b/arch/loongarch/include/asm/topology.h
> @@ -7,6 +7,27 @@
>   
>   #include <linux/smp.h>
>   
> +#ifdef CONFIG_NUMA
> +
> +extern cpumask_t cpus_on_node[];
> +
> +#define cpumask_of_node(node)  (&cpus_on_node[node])
> +
> +struct pci_bus;
> +extern int pcibus_to_node(struct pci_bus *);
> +
> +#define cpumask_of_pcibus(bus)	(cpu_online_mask)
> +
> +extern unsigned char node_distances[MAX_NUMNODES][MAX_NUMNODES];
> +
> +void numa_set_distance(int from, int to, int distance);
> +
> +#define node_distance(from, to)	(node_distances[(from)][(to)])
> +
> +#else
> +#define pcibus_to_node(bus)	0
> +#endif
> +
>   #ifdef CONFIG_SMP
>   #define topology_physical_package_id(cpu)	(cpu_data[cpu].package)
>   #define topology_core_id(cpu)			(cpu_data[cpu].core)
> diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile
> index 2cb6f698716a..940de9173542 100644
> --- a/arch/loongarch/kernel/Makefile
> +++ b/arch/loongarch/kernel/Makefile
> @@ -20,4 +20,6 @@ obj-$(CONFIG_PROC_FS)		+= proc.o
>   
>   obj-$(CONFIG_SMP)		+= smp.o
>   
> +obj-$(CONFIG_NUMA)		+= numa.o
> +
>   CPPFLAGS_vmlinux.lds		:= $(KBUILD_CFLAGS)
> diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c
> index 181c59493b63..b16c3dea5eeb 100644
> --- a/arch/loongarch/kernel/acpi.c
> +++ b/arch/loongarch/kernel/acpi.c
> @@ -14,6 +14,7 @@
>   #include <linux/memblock.h>
>   #include <linux/serial_core.h>
>   #include <asm/io.h>
> +#include <asm/numa.h>
>   #include <asm/loongson.h>
>   
>   int acpi_disabled;
> @@ -199,6 +200,79 @@ int __init acpi_boot_init(void)
>   	return 0;
>   }
>   
> +#ifdef CONFIG_ACPI_NUMA
> +
> +static __init int setup_node(int pxm)
> +{
> +	return acpi_map_pxm_to_node(pxm);
> +}
> +
> +/*
> + * Callback for SLIT parsing.  pxm_to_node() returns NUMA_NO_NODE for
> + * I/O localities since SRAT does not list them.  I/O localities are
> + * not supported at this point.
> + */
> +unsigned int numa_distance_cnt;
> +
> +static inline unsigned int get_numa_distances_cnt(struct acpi_table_slit *slit)
> +{
> +	return slit->locality_count;
> +}
> +
> +void __init numa_set_distance(int from, int to, int distance)
> +{
> +	if ((u8)distance != distance || (from == to && distance != LOCAL_DISTANCE)) {
> +		pr_warn_once("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
> +				from, to, distance);
> +		return;
> +	}
> +
> +	node_distances[from][to] = distance;
> +}
> +
> +/* Callback for Proximity Domain -> CPUID mapping */
> +void __init
> +acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa)
> +{
> +	int pxm, node;
> +
> +	if (srat_disabled())
> +		return;
> +	if (pa->header.length != sizeof(struct acpi_srat_cpu_affinity)) {
> +		bad_srat();
> +		return;
> +	}
> +	if ((pa->flags & ACPI_SRAT_CPU_ENABLED) == 0)
> +		return;
> +	pxm = pa->proximity_domain_lo;
> +	if (acpi_srat_revision >= 2) {
> +		pxm |= (pa->proximity_domain_hi[0] << 8);
> +		pxm |= (pa->proximity_domain_hi[1] << 16);
> +		pxm |= (pa->proximity_domain_hi[2] << 24);
> +	}
> +	node = setup_node(pxm);
> +	if (node < 0) {
> +		pr_err("SRAT: Too many proximity domains %x\n", pxm);
> +		bad_srat();
> +		return;
> +	}
> +
> +	if (pa->apic_id >= CONFIG_NR_CPUS) {
> +		pr_info("SRAT: PXM %u -> CPU 0x%02x -> Node %u skipped apicid that is too big\n",
> +				pxm, pa->apic_id, node);
> +		return;
> +	}
> +
> +	early_numa_add_cpu(pa->apic_id, node);
> +
> +	set_cpuid_to_node(pa->apic_id, node);
> +	node_set(node, numa_nodes_parsed);
> +	pr_info("SRAT: PXM %u -> CPU 0x%02x -> Node %u\n", pxm, pa->apic_id, node);
> +}
> +
> +void __init acpi_numa_arch_fixup(void) {}
> +#endif
> +
>   void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
>   {
>   	memblock_reserve(addr, size);
> @@ -208,6 +282,22 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
>   
>   #include <acpi/processor.h>
>   
> +static int __ref acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> +{
> +#ifdef CONFIG_ACPI_NUMA
> +	int nid;
> +
> +	nid = acpi_get_node(handle);
> +	if (nid != NUMA_NO_NODE) {
> +		set_cpuid_to_node(physid, nid);
> +		node_set(nid, numa_nodes_parsed);
> +		set_cpu_numa_node(cpu, nid);
> +		cpumask_set_cpu(cpu, cpumask_of_node(nid));
> +	}
> +#endif
> +	return 0;
> +}
> +
>   int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id, int *pcpu)
>   {
>   	int cpu;
> @@ -218,6 +308,8 @@ int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id, int *pcpu
>   		return cpu;
>   	}
>   
> +	acpi_map_cpu2node(handle, cpu, physid);
> +
>   	*pcpu = cpu;
>   
>   	return 0;
> @@ -226,6 +318,9 @@ EXPORT_SYMBOL(acpi_map_cpu);
>   
>   int acpi_unmap_cpu(int cpu)
>   {
> +#ifdef CONFIG_ACPI_NUMA
> +	set_cpuid_to_node(cpu_logical_map(cpu), NUMA_NO_NODE);
> +#endif
>   	set_cpu_present(cpu, false);
>   	num_processors--;
>   
> diff --git a/arch/loongarch/kernel/dma.c b/arch/loongarch/kernel/dma.c
> new file mode 100644
> index 000000000000..8c9b5314a13e
> --- /dev/null
> +++ b/arch/loongarch/kernel/dma.c
> @@ -0,0 +1,40 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#include <linux/init.h>
> +#include <linux/dma-direct.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma-map-ops.h>
> +#include <linux/swiotlb.h>
> +
> +#include <asm/bootinfo.h>
> +#include <asm/dma.h>
> +#include <asm/loongson.h>
> +
> +/*
> + * We extract 4bit node id (bit 44~47) from Loongson-3's
> + * 48bit physical address space and embed it into 40bit.
> + */
> +
> +static int node_id_offset;
> +
> +dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
> +{
> +	long nid = (paddr >> 44) & 0xf;
> +
> +	return ((nid << 44) ^ paddr) | (nid << node_id_offset);
> +}
> +
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
> +{
> +	long nid = (daddr >> node_id_offset) & 0xf;
> +
> +	return ((nid << node_id_offset) ^ daddr) | (nid << 44);
> +}
> +
> +void __init plat_swiotlb_setup(void)
> +{
> +	swiotlb_init(true, SWIOTLB_VERBOSE);
> +	node_id_offset = ((readl(LS7A_DMA_CFG) & LS7A_DMA_NODE_MASK) >> LS7A_DMA_NODE_SHF) + 36;
> +}
> diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c
> index 87b3768f1eef..638427ff0d51 100644
> --- a/arch/loongarch/kernel/module.c
> +++ b/arch/loongarch/kernel/module.c
> @@ -11,6 +11,7 @@
>   #include <linux/moduleloader.h>
>   #include <linux/elf.h>
>   #include <linux/mm.h>
> +#include <linux/numa.h>
>   #include <linux/vmalloc.h>
>   #include <linux/slab.h>
>   #include <linux/fs.h>
> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
> new file mode 100644
> index 000000000000..a76f547a5aa3
> --- /dev/null
> +++ b/arch/loongarch/kernel/numa.c
> @@ -0,0 +1,466 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Author:  Xiang Gao <gaoxiang@xxxxxxxxxxx>
> + *          Huacai Chen <chenhuacai@xxxxxxxxxxx>
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/mmzone.h>
> +#include <linux/export.h>
> +#include <linux/nodemask.h>
> +#include <linux/swap.h>
> +#include <linux/memblock.h>
> +#include <linux/pfn.h>
> +#include <linux/acpi.h>
> +#include <linux/efi.h>
> +#include <linux/irq.h>
> +#include <linux/pci.h>
> +#include <asm/bootinfo.h>
> +#include <asm/loongson.h>
> +#include <asm/numa.h>
> +#include <asm/page.h>
> +#include <asm/pgalloc.h>
> +#include <asm/sections.h>
> +#include <asm/time.h>
> +
> +int numa_off;
> +struct pglist_data *node_data[MAX_NUMNODES];
> +unsigned char node_distances[MAX_NUMNODES][MAX_NUMNODES];
> +
> +EXPORT_SYMBOL(node_data);
> +EXPORT_SYMBOL(node_distances);
> +
> +static struct numa_meminfo numa_meminfo;
> +cpumask_t cpus_on_node[MAX_NUMNODES];
> +cpumask_t phys_cpus_on_node[MAX_NUMNODES];
> +EXPORT_SYMBOL(cpus_on_node);
> +
> +/*
> + * apicid, cpu, node mappings
> + */
> +s16 __cpuid_to_node[CONFIG_NR_CPUS] = {
> +	[0 ... CONFIG_NR_CPUS - 1] = NUMA_NO_NODE
> +};
> +EXPORT_SYMBOL(__cpuid_to_node);
> +
> +nodemask_t numa_nodes_parsed __initdata;
> +
> +#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
> +unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
> +EXPORT_SYMBOL(__per_cpu_offset);
> +
> +static int __init pcpu_cpu_to_node(int cpu)
> +{
> +	return early_cpu_to_node(cpu);
> +}
> +
> +static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
> +{
> +	if (early_cpu_to_node(from) == early_cpu_to_node(to))
> +		return LOCAL_DISTANCE;
> +	else
> +		return REMOTE_DISTANCE;
> +}
> +
> +void __init pcpu_populate_pte(unsigned long addr)
> +{
> +	pgd_t *pgd = pgd_offset_k(addr);
> +	p4d_t *p4d = p4d_offset(pgd, addr);
> +	pud_t *pud;
> +	pmd_t *pmd;
> +
> +	if (p4d_none(*p4d)) {
> +		pud_t *new;
> +
> +		new = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> +		pgd_populate(&init_mm, pgd, new);
> +#ifndef __PAGETABLE_PUD_FOLDED
> +		pud_init((unsigned long)new, (unsigned long)invalid_pmd_table);
> +#endif
> +	}
> +
> +	pud = pud_offset(p4d, addr);
> +	if (pud_none(*pud)) {
> +		pmd_t *new;
> +
> +		new = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> +		pud_populate(&init_mm, pud, new);
> +#ifndef __PAGETABLE_PMD_FOLDED
> +		pmd_init((unsigned long)new, (unsigned long)invalid_pte_table);
> +#endif
> +	}
> +
> +	pmd = pmd_offset(pud, addr);
> +	if (!pmd_present(*pmd)) {
> +		pte_t *new;
> +
> +		new = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> +		pmd_populate_kernel(&init_mm, pmd, new);
> +	}
> +}
> +
> +void __init setup_per_cpu_areas(void)
> +{
> +	unsigned long delta;
> +	unsigned int cpu;
> +	int rc = -EINVAL;
> +
> +	if (pcpu_chosen_fc == PCPU_FC_AUTO) {
> +		if (nr_node_ids >= 8)
> +			pcpu_chosen_fc = PCPU_FC_PAGE;
> +		else
> +			pcpu_chosen_fc = PCPU_FC_EMBED;
> +	}
> +
> +	/*
> +	 * Always reserve area for module percpu variables.  That's
> +	 * what the legacy allocator did.
> +	 */
> +	if (pcpu_chosen_fc != PCPU_FC_PAGE) {
> +		rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
> +					    PERCPU_DYNAMIC_RESERVE, PMD_SIZE,
> +					    pcpu_cpu_distance, pcpu_cpu_to_node);
> +		if (rc < 0)
> +			pr_warn("%s allocator failed (%d), falling back to page size\n",
> +				pcpu_fc_names[pcpu_chosen_fc], rc);
> +	}
> +	if (rc < 0)
> +		rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, pcpu_cpu_to_node);
> +	if (rc < 0)
> +		panic("cannot initialize percpu area (err=%d)", rc);
> +
> +	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
> +	for_each_possible_cpu(cpu)
> +		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
> +}
> +#endif
> +
> +/*
> + * Get nodeid by logical cpu number.
> + * __cpuid_to_node maps phyical cpu id to node, so we
> + * should use cpu_logical_map(cpu) to index it.
> + *
> + * This routine is only used in early phase during
> + * booting, after setup_per_cpu_areas calling and numa_node
> + * initialization, cpu_to_node will be used instead.
> + */
> +int early_cpu_to_node(int cpu)
> +{
> +	int physid = cpu_logical_map(cpu);
> +
> +	if (physid < 0)
> +		return NUMA_NO_NODE;
> +
> +	return __cpuid_to_node[physid];
> +}
> +
> +void __init early_numa_add_cpu(int cpuid, s16 node)
> +{
> +	int cpu = __cpu_number_map[cpuid];
> +
> +	if (cpu < 0)
> +		return;
> +
> +	cpumask_set_cpu(cpu, &cpus_on_node[node]);
> +	cpumask_set_cpu(cpuid, &phys_cpus_on_node[node]);
> +}
> +
> +void numa_add_cpu(unsigned int cpu)
> +{
> +	int nid = cpu_to_node(cpu);
> +	cpumask_set_cpu(cpu, &cpus_on_node[nid]);
> +}
> +
> +void numa_remove_cpu(unsigned int cpu)
> +{
> +	int nid = cpu_to_node(cpu);
> +	cpumask_clear_cpu(cpu, &cpus_on_node[nid]);
> +}
> +
> +static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
> +				     struct numa_meminfo *mi)
> +{
> +	/* ignore zero length blks */
> +	if (start == end)
> +		return 0;
> +
> +	/* whine about and ignore invalid blks */
> +	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
> +		pr_warn("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
> +			   nid, start, end - 1);
> +		return 0;
> +	}
> +
> +	if (mi->nr_blks >= NR_NODE_MEMBLKS) {
> +		pr_err("NUMA: too many memblk ranges\n");
> +		return -EINVAL;
> +	}
> +
> +	mi->blk[mi->nr_blks].start = PFN_ALIGN(start);
> +	mi->blk[mi->nr_blks].end = PFN_ALIGN(end - PAGE_SIZE + 1);
> +	mi->blk[mi->nr_blks].nid = nid;
> +	mi->nr_blks++;
> +	return 0;
> +}
> +
> +/**
> + * numa_add_memblk - Add one numa_memblk to numa_meminfo
> + * @nid: NUMA node ID of the new memblk
> + * @start: Start address of the new memblk
> + * @end: End address of the new memblk
> + *
> + * Add a new memblk to the default numa_meminfo.
> + *
> + * RETURNS:
> + * 0 on success, -errno on failure.
> + */
> +int __init numa_add_memblk(int nid, u64 start, u64 end)
> +{
> +	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
> +}
> +
> +static void __init alloc_node_data(int nid)
> +{
> +	void *nd;
> +	unsigned long nd_pa;
> +	size_t nd_sz = roundup(sizeof(pg_data_t), PAGE_SIZE);
> +
> +	nd_pa = memblock_phys_alloc_try_nid(nd_sz, SMP_CACHE_BYTES, nid);
> +	if (!nd_pa) {
> +		pr_err("Cannot find %zu Byte for node_data (initial node: %d)\n", nd_sz, nid);
> +		return;
> +	}
> +
> +	nd = __va(nd_pa);
> +
> +	node_data[nid] = nd;
> +	memset(nd, 0, sizeof(pg_data_t));
> +}
> +
> +static void __init node_mem_init(unsigned int node)
> +{
> +	unsigned long start_pfn, end_pfn;
> +	unsigned long node_addrspace_offset;
> +
> +	node_addrspace_offset = nid_to_addrbase(node);
> +	pr_info("Node%d's addrspace_offset is 0x%lx\n",
> +			node, node_addrspace_offset);
> +
> +	get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
> +	pr_info("Node%d: start_pfn=0x%lx, end_pfn=0x%lx\n",
> +		node, start_pfn, end_pfn);
> +
> +	alloc_node_data(node);
> +}
> +
> +#ifdef CONFIG_ACPI_NUMA
> +
> +/*
> + * Sanity check to catch more bad NUMA configurations (they are amazingly
> + * common).  Make sure the nodes cover all memory.
> + */
> +static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
> +{
> +	int i;
> +	u64 numaram, biosram;
> +
> +	numaram = 0;
> +	for (i = 0; i < mi->nr_blks; i++) {
> +		u64 s = mi->blk[i].start >> PAGE_SHIFT;
> +		u64 e = mi->blk[i].end >> PAGE_SHIFT;
> +
> +		numaram += e - s;
> +		numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
> +		if ((s64)numaram < 0)
> +			numaram = 0;
> +	}
> +	max_pfn = max_low_pfn;
> +	biosram = max_pfn - absent_pages_in_range(0, max_pfn);
> +
> +	BUG_ON((s64)(biosram - numaram) >= (1 << (20 - PAGE_SHIFT)));
> +	return true;
> +}
> +
> +static void __init add_node_intersection(u32 node, u64 start, u64 size, u32 type)
> +{
> +	static unsigned long num_physpages;
> +
> +	num_physpages += (size >> PAGE_SHIFT);
> +	pr_info("Node%d: mem_type:%d, mem_start:0x%llx, mem_size:0x%llx Bytes\n",
> +		node, type, start, size);
> +	pr_info("       start_pfn:0x%llx, end_pfn:0x%llx, num_physpages:0x%lx\n",
> +		start >> PAGE_SHIFT, (start + size) >> PAGE_SHIFT, num_physpages);
> +	memblock_set_node(start, size, &memblock.memory, node);
> +}
> +
> +/*
> + * add_numamem_region
> + *
> + * Add a uasable memory region described by BIOS. The
> + * routine gets each intersection between BIOS's region
> + * and node's region, and adds them into node's memblock
> + * pool.
> + *
> + */
> +static void __init add_numamem_region(u64 start, u64 end, u32 type)
> +{
> +	u32 i;
> +	u64 ofs = start;
> +
> +	if (start >= end) {
> +		pr_debug("Invalid region: %016llx-%016llx\n", start, end);
> +		return;
> +	}
> +
> +	for (i = 0; i < numa_meminfo.nr_blks; i++) {
> +		struct numa_memblk *mb = &numa_meminfo.blk[i];
> +
> +		if (ofs > mb->end)
> +			continue;
> +
> +		if (end > mb->end) {
> +			add_node_intersection(mb->nid, ofs, mb->end - ofs, type);
> +			ofs = mb->end;
> +		} else {
> +			add_node_intersection(mb->nid, ofs, end - ofs, type);
> +			break;
> +		}
> +	}
> +}
> +
> +static void __init init_node_memblock(void)
> +{
> +	u32 mem_type;
> +	u64 mem_end, mem_start, mem_size;
> +	efi_memory_desc_t *md;
> +
> +	/* Parse memory information and activate */
> +	for_each_efi_memory_desc(md) {
> +		mem_type = md->type;
> +		mem_start = md->phys_addr;
> +		mem_size = md->num_pages << EFI_PAGE_SHIFT;
> +		mem_end = mem_start + mem_size;
> +
> +		switch (mem_type) {
> +		case EFI_LOADER_CODE:
> +		case EFI_LOADER_DATA:
> +		case EFI_BOOT_SERVICES_CODE:
> +		case EFI_BOOT_SERVICES_DATA:
> +		case EFI_PERSISTENT_MEMORY:
> +		case EFI_CONVENTIONAL_MEMORY:
> +			add_numamem_region(mem_start, mem_end, mem_type);
> +			break;
> +		case EFI_PAL_CODE:
> +		case EFI_UNUSABLE_MEMORY:
> +		case EFI_ACPI_RECLAIM_MEMORY:
> +			add_numamem_region(mem_start, mem_end, mem_type);
> +			fallthrough;
> +		case EFI_RESERVED_TYPE:
> +		case EFI_RUNTIME_SERVICES_CODE:
> +		case EFI_RUNTIME_SERVICES_DATA:
> +		case EFI_MEMORY_MAPPED_IO:
> +		case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
> +			pr_info("Resvd: mem_type:%d, mem_start:0x%llx, mem_size:0x%llx Bytes\n",
> +					mem_type, mem_start, mem_size);
> +			break;
> +		}
> +	}
> +}
> +
> +static void __init numa_default_distance(void)
> +{
> +	int row, col;
> +
> +	for (row = 0; row < MAX_NUMNODES; row++)
> +		for (col = 0; col < MAX_NUMNODES; col++) {
> +			if (col == row)
> +				node_distances[row][col] = LOCAL_DISTANCE;
> +			else
> +				/* We assume that one node per package here!
> +				 *
> +				 * A SLIT should be used for multiple nodes
> +				 * per package to override default setting.
> +				 */
> +				node_distances[row][col] = REMOTE_DISTANCE;
> +	}
> +}
> +
> +int __init init_numa_memory(void)
> +{
> +	int i;
> +	int ret;
> +	int node;
> +
> +	for (i = 0; i < NR_CPUS; i++)
> +		set_cpuid_to_node(i, NUMA_NO_NODE);
> +
> +	numa_default_distance();
> +	nodes_clear(numa_nodes_parsed);
> +	nodes_clear(node_possible_map);
> +	nodes_clear(node_online_map);
> +	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
> +
> +	/* Parse SRAT and SLIT if provided by firmware. */
> +	ret = acpi_numa_init();
> +	if (ret < 0)
> +		return ret;
> +
> +	node_possible_map = numa_nodes_parsed;
> +	if (WARN_ON(nodes_empty(node_possible_map)))
> +		return -EINVAL;
> +
> +	init_node_memblock();
> +	if (numa_meminfo_cover_memory(&numa_meminfo) == false)
> +		return -EINVAL;
> +
> +	for_each_node_mask(node, node_possible_map) {
> +		node_mem_init(node);
> +		node_set_online(node);
> +	}
> +	max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
> +
> +	setup_nr_node_ids();
> +	loongson_sysconf.nr_nodes = nr_node_ids;
> +	loongson_sysconf.cores_per_node = cpumask_weight(&phys_cpus_on_node[0]);
> +
> +	return 0;
> +}
> +
> +EXPORT_SYMBOL(init_numa_memory);
> +#endif
> +
> +void __init paging_init(void)
> +{
> +	unsigned int node;
> +	unsigned long zones_size[MAX_NR_ZONES] = {0, };
> +
> +	for_each_online_node(node) {
> +		unsigned long start_pfn, end_pfn;
> +
> +		get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
> +
> +		if (end_pfn > max_low_pfn)
> +			max_low_pfn = end_pfn;
> +	}
> +#ifdef CONFIG_ZONE_DMA32
> +	zones_size[ZONE_DMA32] = MAX_DMA32_PFN;
> +#endif
> +	zones_size[ZONE_NORMAL] = max_low_pfn;
> +	free_area_init(zones_size);
> +}
> +
> +void __init mem_init(void)
> +{
> +	high_memory = (void *) __va(get_num_physpages() << PAGE_SHIFT);
> +	memblock_free_all();
> +	setup_zero_pages();	/* This comes from node 0 */
> +}
> +
> +int pcibus_to_node(struct pci_bus *bus)
> +{
> +	return dev_to_node(&bus->dev);
> +}
> +EXPORT_SYMBOL(pcibus_to_node);
> diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
> index 34a3011f679e..185e4035811a 100644
> --- a/arch/loongarch/kernel/setup.c
> +++ b/arch/loongarch/kernel/setup.c
> @@ -35,6 +35,7 @@
>   #include <asm/dma.h>
>   #include <asm/efi.h>
>   #include <asm/loongson.h>
> +#include <asm/numa.h>
>   #include <asm/pgalloc.h>
>   #include <asm/sections.h>
>   #include <asm/setup.h>
> @@ -185,7 +186,10 @@ static int __init early_parse_mem(char *p)
>   		return -EINVAL;
>   	}
>   
> -	memblock_add(start, size);
> +	if (!IS_ENABLED(CONFIG_NUMA))
> +		memblock_add(start, size);
> +	else
> +		memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);
>   
>   	return 0;
>   }
> @@ -203,6 +207,9 @@ void __init platform_init(void)
>   	acpi_boot_init();
>   #endif
>   
> +#ifdef CONFIG_NUMA
> +	init_numa_memory();
> +#endif
>   	dmi_setup();
>   	smbios_parse();
>   	pr_info("The BIOS Version: %s\n", b_info.bios_version);
> @@ -241,7 +248,7 @@ static void __init arch_mem_init(char **cmdline_p)
>   	sparse_init();
>   	memblock_set_bottom_up(true);
>   
> -	swiotlb_init(true, SWIOTLB_VERBOSE);
> +	plat_swiotlb_setup();
>   
>   	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
>   
> diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
> index 99ba7a56edf9..b8c53b755a25 100644
> --- a/arch/loongarch/kernel/smp.c
> +++ b/arch/loongarch/kernel/smp.c
> @@ -25,6 +25,7 @@
>   #include <asm/idle.h>
>   #include <asm/loongson.h>
>   #include <asm/mmu_context.h>
> +#include <asm/numa.h>
>   #include <asm/processor.h>
>   #include <asm/setup.h>
>   #include <asm/time.h>
> @@ -222,6 +223,9 @@ void loongson3_init_secondary(void)
>   
>   	iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
>   
> +#ifdef CONFIG_NUMA
> +	numa_add_cpu(cpu);
> +#endif
>   	per_cpu(cpu_state, cpu) = CPU_ONLINE;
>   	cpu_data[cpu].core =
>   		     cpu_logical_map(cpu) % loongson_sysconf.cores_per_package;
> @@ -254,6 +258,9 @@ int loongson3_cpu_disable(void)
>   	if (io_master(cpu))
>   		return -EBUSY;
>   
> +#ifdef CONFIG_NUMA
> +	numa_remove_cpu(cpu);
> +#endif
>   	set_cpu_online(cpu, false);
>   	calculate_cpu_foreign_map();
>   	local_irq_save(flags);
> @@ -478,14 +485,36 @@ void calculate_cpu_foreign_map(void)
>   /* Preload SMP state for boot cpu */
>   void smp_prepare_boot_cpu(void)
>   {
> -	unsigned int cpu;
> +	unsigned int cpu, node, rr_node;
>   
>   	set_cpu_possible(0, true);
>   	set_cpu_online(0, true);
>   	set_my_cpu_offset(per_cpu_offset(0));
>   
> -	for_each_possible_cpu(cpu)
> -		set_cpu_numa_node(cpu, 0);
> +	rr_node = first_node(node_online_map);
> +	for_each_possible_cpu(cpu) {
> +		node = early_cpu_to_node(cpu);
> +
> +		/*
> +		 * The mapping between present cpus and nodes has been
> +		 * built during MADT and SRAT parsing.
> +		 *
> +		 * If possible cpus = present cpus here, early_cpu_to_node
> +		 * will return valid node.
> +		 *
> +		 * If possible cpus > present cpus here (e.g. some possible
> +		 * cpus will be added by cpu-hotplug later), for possible but
> +		 * not present cpus, early_cpu_to_node will return NUMA_NO_NODE,
> +		 * and we just map them to online nodes in round-robin way.
> +		 * Once hotplugged, new correct mapping will be built for them.
> +		 */
> +		if (node != NUMA_NO_NODE)
> +			set_cpu_numa_node(cpu, node);
> +		else {
> +			set_cpu_numa_node(cpu, rr_node);
> +			rr_node = next_node_in(rr_node, node_online_map);
> +		}
> +	}
>   }
>   
>   /* called from main before smp_init() */
> @@ -651,17 +680,10 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned l
>   		on_each_cpu_mask(mm_cpumask(mm), flush_tlb_range_ipi, &fd, 1);
>   	} else {
>   		unsigned int cpu;
> -		int exec = vma->vm_flags & VM_EXEC;
>   
>   		for_each_online_cpu(cpu) {
> -			/*
> -			 * flush_cache_range() will only fully flush icache if
> -			 * the VMA is executable, otherwise we must invalidate
> -			 * ASID without it appearing to has_valid_asid() as if
> -			 * mm has been completely unused by that CPU.
> -			 */
>   			if (cpu != smp_processor_id() && cpu_context(cpu, mm))
> -				cpu_context(cpu, mm) = !exec;
> +				cpu_context(cpu, mm) = 0;
>   		}
>   		local_flush_tlb_range(vma, start, end);
>   	}
> @@ -706,14 +728,8 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
>   		unsigned int cpu;
>   
>   		for_each_online_cpu(cpu) {
> -			/*
> -			 * flush_cache_page() only does partial flushes, so
> -			 * invalidate ASID without it appearing to
> -			 * has_valid_asid() as if mm has been completely unused
> -			 * by that CPU.
> -			 */
>   			if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
> -				cpu_context(cpu, vma->vm_mm) = 1;
> +				cpu_context(cpu, vma->vm_mm) = 0;
>   		}
>   		local_flush_tlb_page(vma, page);
>   	}
> diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
> index 8be071b265b3..e4060f84a221 100644
> --- a/arch/loongarch/kernel/traps.c
> +++ b/arch/loongarch/kernel/traps.c
> @@ -630,7 +630,7 @@ asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp)
>   	irqentry_exit(regs, state);
>   }
>   
> -extern void tlb_init(void);
> +extern void tlb_init(int cpu);
>   extern void cache_error_setup(void);
>   
>   unsigned long eentry;
> @@ -669,7 +669,7 @@ void per_cpu_trap_init(int cpu)
>   		for (i = 0; i < 64; i++)
>   			set_handler(i * VECSIZE, handle_reserved, VECSIZE);
>   
> -	tlb_init();
> +	tlb_init(cpu);
>   	cpu_cache_init();
>   }
>   
> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
> index afd6634ce171..7094a68c9b83 100644
> --- a/arch/loongarch/mm/init.c
> +++ b/arch/loongarch/mm/init.c
> @@ -84,6 +84,7 @@ int __ref page_is_ram(unsigned long pfn)
>   	return memblock_is_memory(addr) && !memblock_is_reserved(addr);
>   }
>   
> +#ifndef CONFIG_NUMA
>   void __init paging_init(void)
>   {
>   	unsigned long max_zone_pfns[MAX_NR_ZONES];
> @@ -107,6 +108,7 @@ void __init mem_init(void)
>   	memblock_free_all();
>   	setup_zero_pages();	/* Setup zeroed pages.  */
>   }
> +#endif /* !CONFIG_NUMA */
>   
>   void __ref free_initmem(void)
>   {
> @@ -129,6 +131,17 @@ int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
>   	return ret;
>   }
>   
> +#ifdef CONFIG_NUMA
> +int memory_add_physaddr_to_nid(u64 start)
> +{
> +	int nid;
> +
> +	nid = pa_to_nid(start);
> +	return nid;
> +}
> +EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
> +#endif
> +
>   #ifdef CONFIG_MEMORY_HOTREMOVE
>   void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
>   {
> diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
> index 78dd328cec77..e272f8ac57d1 100644
> --- a/arch/loongarch/mm/tlb.c
> +++ b/arch/loongarch/mm/tlb.c
> @@ -250,15 +250,18 @@ static void output_pgtable_bits_defines(void)
>   	pr_debug("\n");
>   }
>   
> -void setup_tlb_handler(void)
> -{
> -	static int run_once = 0;
> +#ifdef CONFIG_NUMA
> +static unsigned long pcpu_handlers[NR_CPUS];
> +#endif
> +extern long exception_handlers[VECSIZE * 128 / sizeof(long)];
>   
> +void setup_tlb_handler(int cpu)
> +{
>   	setup_ptwalker();
>   	output_pgtable_bits_defines();
>   
>   	/* The tlb handlers are generated only once */
> -	if (!run_once) {
> +	if (cpu == 0) {
>   		memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
>   		local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
>   		set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
> @@ -268,15 +271,35 @@ void setup_tlb_handler(void)
>   		set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE);
>   		set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE);
>   		set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
> -		run_once++;
>   	}
> +#ifdef CONFIG_NUMA
> +	else {
> +		void *addr;
> +		struct page *page;
> +		const int vec_sz = sizeof(exception_handlers);
> +
> +		if (pcpu_handlers[cpu])
> +			return;
> +
> +		page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, get_order(vec_sz));
> +		if (!page)
> +			return;
> +
> +		addr = page_address(page);
> +		pcpu_handlers[cpu] = virt_to_phys(addr);
> +		memcpy((void *)addr, (void *)eentry, vec_sz);
> +		local_flush_icache_range((unsigned long)addr, (unsigned long)addr + vec_sz);
> +		csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_TLBRENTRY);
> +		csr_write64(pcpu_handlers[cpu] + 80*VECSIZE, LOONGARCH_CSR_TLBRENTRY);
> +	}
> +#endif
>   }
>   
> -void tlb_init(void)
> +void tlb_init(int cpu)
>   {
>   	write_csr_pagesize(PS_DEFAULT_SIZE);
>   	write_csr_stlbpgsize(PS_DEFAULT_SIZE);
>   	write_csr_tlbrefill_pagesize(PS_DEFAULT_SIZE);
> -	setup_tlb_handler();
> +	setup_tlb_handler(cpu);
>   	local_flush_tlb_all();
>   }

As I said in v11, I still don't have the hardware to test on, but 
recently in making a compatibility layer for the legacy boot protocol 
(the "struct bootparamsinterface" or BPI thing; semi-working draft at 
[1]) I had to go through some of this NUMA logic, and they looked 
reasonable too. I mainly checked the memory map and node initialization 
parts but the others also looked okay at a quick glance.

Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>


[1]: https://github.com/xen0n/linux/tree/loongarch-port-v12-with-bpi