path: root/drivers/acpi/numa/hmat.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2019, Intel Corporation.
 *
 * Heterogeneous Memory Attributes Table (HMAT) representation
 *
 * This program parses and reports the platform's HMAT tables, and registers
 * the applicable attributes with the node's interfaces.
 */

#define pr_fmt(fmt) "acpi/hmat: " fmt

#include <linux/acpi.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/list_sort.h>
#include <linux/memregion.h>
#include <linux/memory.h>
#include <linux/mutex.h>
#include <linux/node.h>
#include <linux/sysfs.h>
#include <linux/dax.h>
#include <linux/memory-tiers.h>

static u8 hmat_revision;
static int hmat_disable __initdata;

void __init disable_hmat(void)
{
	hmat_disable = 1;
}

static LIST_HEAD(targets);
static LIST_HEAD(initiators);
static LIST_HEAD(localities);

static DEFINE_MUTEX(target_lock);

/*
 * The defined enum order is used to prioritize attributes to break ties when
 * selecting the best performing node.
 */
enum locality_types {
	WRITE_LATENCY,
	READ_LATENCY,
	WRITE_BANDWIDTH,
	READ_BANDWIDTH,
};

static struct memory_locality *localities_types[4];

struct target_cache {
	struct list_head node;
	struct node_cache_attrs cache_attrs;
};

enum {
	NODE_ACCESS_CLASS_GENPORT_SINK_LOCAL = ACCESS_COORDINATE_MAX,
	NODE_ACCESS_CLASS_GENPORT_SINK_CPU,
	NODE_ACCESS_CLASS_MAX,
};

struct memory_target {
	struct list_head node;
	unsigned int memory_pxm;
	unsigned int processor_pxm;
	struct resource memregions;
	struct access_coordinate coord[NODE_ACCESS_CLASS_MAX];
	struct list_head caches;
	struct node_cache_attrs cache_attrs;
	u8 gen_port_device_handle[ACPI_SRAT_DEVICE_HANDLE_SIZE];
	bool registered;
	bool ext_updated;	/* externally updated */
};

struct memory_initiator {
	struct list_head node;
	unsigned int processor_pxm;
	bool has_cpu;
};

struct memory_locality {
	struct list_head node;
	struct acpi_hmat_locality *hmat_loc;
};

static struct memory_initiator *find_mem_initiator(unsigned int cpu_pxm)
{
	struct memory_initiator *initiator;

	list_for_each_entry(initiator, &initiators, node)
		if (initiator->processor_pxm == cpu_pxm)
			return initiator;
	return NULL;
}

static struct memory_target *find_mem_target(unsigned int mem_pxm)
{
	struct memory_target *target;

	list_for_each_entry(target, &targets, node)
		if (target->memory_pxm == mem_pxm)
			return target;
	return NULL;
}

static struct memory_target *acpi_find_genport_target(u32 uid)
{
	struct memory_target *target;
	u32 target_uid;
	u8 *uid_ptr;

	list_for_each_entry(target, &targets, node) {
		uid_ptr = target->gen_port_device_handle + 8;
		target_uid = *(u32 *)uid_ptr;
		if (uid == target_uid)
			return target;
	}

	return NULL;
}

/**
 * acpi_get_genport_coordinates - Retrieve the access coordinates for a generic port
 * @uid: ACPI unique id
 * @coord: The access coordinates written back out for the generic port.
 *	   Expect 2 levels array.
 *
 * Return: 0 on success. Errno on failure.
 *
 * Only supports device handles that are ACPI. Assume ACPI0016 HID for CXL.
 */
int acpi_get_genport_coordinates(u32 uid,
				 struct access_coordinate *coord)
{
	struct memory_target *target;

	guard(mutex)(&target_lock);
	target = acpi_find_genport_target(uid);
	if (!target)
		return -ENOENT;

	coord[ACCESS_COORDINATE_LOCAL] =
		target->coord[NODE_ACCESS_CLASS_GENPORT_SINK_LOCAL];
	coord[ACCESS_COORDINATE_CPU] =
		target->coord[NODE_ACCESS_CLASS_GENPORT_SINK_CPU];

	return 0;
}
EXPORT_SYMBOL_NS_GPL(acpi_get_genport_coordinates, "CXL");

static __init void alloc_memory_initiator(unsigned int cpu_pxm)
{
	struct memory_initiator *initiator;

	if (pxm_to_node(cpu_pxm) == NUMA_NO_NODE)
		return;

	initiator = find_mem_initiator(cpu_pxm);
	if (initiator)
		return;

	initiator = kzalloc(sizeof(*initiator), GFP_KERNEL);
	if (!initiator)
		return;

	initiator->processor_pxm = cpu_pxm;
	initiator->has_cpu = node_state(pxm_to_node(cpu_pxm), N_CPU);
	list_add_tail(&initiator->node, &initiators);
}

static __init struct memory_target *alloc_target(unsigned int mem_pxm)
{
	struct memory_target *target;

	target = find_mem_target(mem_pxm);
	if (!target) {
		target = kzalloc(sizeof(*target), GFP_KERNEL);
		if (!target)
			return NULL;
		target->memory_pxm = mem_pxm;
		target->processor_pxm = PXM_INVAL;
		target->memregions = (struct resource) {
			.name	= "ACPI mem",
			.start	= 0,
			.end	= -1,
			.flags	= IORESOURCE_MEM,
		};
		list_add_tail(&target->node, &targets);
		INIT_LIST_HEAD(&target->caches);
	}

	return target;
}

static