Commit 9559d580 authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: Increase max supported CPUs up to 2048 



Increase max supported CPUs up to 2048, including:
1. Increase CSR.CPUID register's effective width;
2. Define MAX_CORE_PIC (a.k.a. max physical ID) to 2048;
3. Allow NR_CPUS (a.k.a. max logical ID) to be as large as 2048;
4. Introduce acpi_numa_x2apic_affinity_init() to handle ACPI SRAT
   for CPUID >= 256.

Note: The reason of increasing to 2048 rather than 4096/8192 is because
      the IPI hardware can only support 2048 as a maximum.

Reviewed-by: default avatarYanteng Si <si.yanteng@linux.dev>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent a45728fd

arch/loongarch/Kconfig

+3 −3
Original line number Diff line number Diff line
@@ -496,10 +496,10 @@ config HOTPLUG_CPU 
	  Say N if you want to disable CPU hotplug.



config NR_CPUS

	int "Maximum number of CPUs (2-256)"

	range 2 256

	int "Maximum number of CPUs (2-2048)"

	range 2 2048

	default "2048"

	depends on SMP

	default "64"

	help

	  This allows you to specify the maximum number of CPUs which this

	  kernel will support.

arch/loongarch/include/asm/acpi.h

+1 −1
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ static inline bool acpi_has_cpu_in_madt(void) 
	return true;

}



#define MAX_CORE_PIC 256

#define MAX_CORE_PIC 2048



extern struct list_head acpi_wakeup_device_list;

extern struct acpi_madt_core_pic acpi_core_pic[MAX_CORE_PIC];

arch/loongarch/include/asm/loongarch.h

+2 −2
Original line number Diff line number Diff line
@@ -411,8 +411,8 @@ 


/* Config CSR registers */

#define LOONGARCH_CSR_CPUID		0x20	/* CPU core id */

#define  CSR_CPUID_COREID_WIDTH		9

#define  CSR_CPUID_COREID		_ULCAST_(0x1ff)

#define  CSR_CPUID_COREID_WIDTH		11

#define  CSR_CPUID_COREID		_ULCAST_(0x7ff)



#define LOONGARCH_CSR_PRCFG1		0x21	/* Config1 */

#define  CSR_CONF1_VSMAX_SHIFT		12

arch/loongarch/kernel/acpi.c

+35 −6
Original line number Diff line number Diff line
@@ -244,11 +244,6 @@ void __init acpi_boot_table_init(void) 


#ifdef CONFIG_ACPI_NUMA



static __init int setup_node(int pxm)

{

	return acpi_map_pxm_to_node(pxm);

}



void __init numa_set_distance(int from, int to, int distance)

{

	if ((u8)distance != distance || (from == to && distance != LOCAL_DISTANCE)) {
@@ -280,7 +275,41 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa) 
		pxm |= (pa->proximity_domain_hi[1] << 16);

		pxm |= (pa->proximity_domain_hi[2] << 24);

	}

	node = setup_node(pxm);

	node = acpi_map_pxm_to_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_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)

{

	int pxm, node;



	if (srat_disabled())

		return;

	if (pa->header.length < sizeof(struct acpi_srat_x2apic_cpu_affinity)) {

		bad_srat();

		return;

	}

	if ((pa->flags & ACPI_SRAT_CPU_ENABLED) == 0)

		return;

	pxm = pa->proximity_domain;

	node = acpi_map_pxm_to_node(pxm);

	if (node < 0) {

		pr_err("SRAT: Too many proximity domains %x\n", pxm);

		bad_srat();