1 files changed, 877 insertions, 0 deletions

diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
new file mode 100644
index 000000000..6cceca64a
--- /dev/null
+++ b/drivers/acpi/numa/hmat.c
@@ -0,0 +1,877 @@
+// 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>
+
+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;
+};
+
+struct memory_target {
+	struct list_head node;
+	unsigned int memory_pxm;
+	unsigned int processor_pxm;
+	struct resource memregions;
+	struct node_hmem_attrs hmem_attrs[2];
+	struct list_head caches;
+	struct node_cache_attrs cache_attrs;
+	bool registered;
+};
+
+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 __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 void alloc_memory_target(unsigned int mem_pxm,
+		resource_size_t start, resource_size_t len)
+{
+	struct memory_target *target;
+
+	target = find_mem_target(mem_pxm);
+	if (!target) {
+		target = kzalloc(sizeof(*target), GFP_KERNEL);
+		if (!target)
+			return;
+		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);
+	}
+
+	/*
+	 * There are potentially multiple ranges per PXM, so record each
+	 * in the per-target memregions resource tree.
+	 */
+	if (!__request_region(&target->memregions, start, len, "memory target",
+				IORESOURCE_MEM))
+		pr_warn("failed to reserve %#llx - %#llx in pxm: %d\n",
+				start, start + len, mem_pxm);
+}
+
+static __init const char *hmat_data_type(u8 type)
+{
+	switch (type) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+		return "Access Latency";
+	case ACPI_HMAT_READ_LATENCY:
+		return "Read Latency";
+	case ACPI_HMAT_WRITE_LATENCY:
+		return "Write Latency";
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+		return "Access Bandwidth";
+	case ACPI_HMAT_READ_BANDWIDTH:
+		return "Read Bandwidth";
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		return "Write Bandwidth";
+	default:
+		return "Reserved";
+	}
+}
+
+static __init const char *hmat_data_type_suffix(u8 type)
+{
+	switch (type) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+	case ACPI_HMAT_READ_LATENCY:
+	case ACPI_HMAT_WRITE_LATENCY:
+		return " nsec";
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+	case ACPI_HMAT_READ_BANDWIDTH:
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		return " MB/s";
+	default:
+		return "";
+	}
+}
+
+static u32 hmat_normalize(u16 entry, u64 base, u8 type)
+{
+	u32 value;
+
+	/*
+	 * Check for invalid and overflow values
+	 */
+	if (entry == 0xffff || !entry)
+		return 0;
+	else if (base > (UINT_MAX / (entry)))
+		return 0;
+
+	/*
+	 * Divide by the base unit for version 1, convert latency from
+	 * picosenonds to nanoseconds if revision 2.
+	 */
+	value = entry * base;
+	if (hmat_revision == 1) {
+		if (value < 10)
+			return 0;
+		value = DIV_ROUND_UP(value, 10);
+	} else if (hmat_revision == 2) {
+		switch (type) {
+		case ACPI_HMAT_ACCESS_LATENCY:
+		case ACPI_HMAT_READ_LATENCY:
+		case ACPI_HMAT_WRITE_LATENCY:
+			value = DIV_ROUND_UP(value, 1000);
+			break;
+		default:
+			break;
+		}
+	}
+	return value;
+}
+
+static void hmat_update_target_access(struct memory_target *target,
+				      u8 type, u32 value, int access)
+{
+	switch (type) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+		target->hmem_attrs[access].read_latency = value;
+		target->hmem_attrs[access].write_latency = value;
+		break;
+	case ACPI_HMAT_READ_LATENCY:
+		target->hmem_attrs[access].read_latency = value;
+		break;
+	case ACPI_HMAT_WRITE_LATENCY:
+		target->hmem_attrs[access].write_latency = value;
+		break;
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+		target->hmem_attrs[access].read_bandwidth = value;
+		target->hmem_attrs[access].write_bandwidth = value;
+		break;
+	case ACPI_HMAT_READ_BANDWIDTH:
+		target->hmem_attrs[access].read_bandwidth = value;
+		break;
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		target->hmem_attrs[access].write_bandwidth = value;
+		break;
+	default:
+		break;
+	}
+}
+
+static __init void hmat_add_locality(struct acpi_hmat_locality *hmat_loc)
+{
+	struct memory_locality *loc;
+
+	loc = kzalloc(sizeof(*loc), GFP_KERNEL);
+	if (!loc) {
+		pr_notice_once("Failed to allocate HMAT locality\n");
+		return;
+	}
+
+	loc->hmat_loc = hmat_loc;
+	list_add_tail(&loc->node, &localities);
+
+	switch (hmat_loc->data_type) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+		localities_types[READ_LATENCY] = loc;
+		localities_types[WRITE_LATENCY] = loc;
+		break;
+	case ACPI_HMAT_READ_LATENCY:
+		localities_types[READ_LATENCY] = loc;
+		break;
+	case ACPI_HMAT_WRITE_LATENCY:
+		localities_types[WRITE_LATENCY] = loc;
+		break;
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+		localities_types[READ_BANDWIDTH] = loc;
+		localities_types[WRITE_BANDWIDTH] = loc;
+		break;
+	case ACPI_HMAT_READ_BANDWIDTH:
+		localities_types[READ_BANDWIDTH] = loc;
+		break;
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		localities_types[WRITE_BANDWIDTH] = loc;
+		break;
+	default:
+		break;
+	}
+}
+
+static __init int hmat_parse_locality(union acpi_subtable_headers *header,
+				      const unsigned long end)
+{
+	struct acpi_hmat_locality *hmat_loc = (void *)header;
+	struct memory_target *target;
+	unsigned int init, targ, total_size, ipds, tpds;
+	u32 *inits, *targs, value;
+	u16 *entries;
+	u8 type, mem_hier;
+
+	if (hmat_loc->header.length < sizeof(*hmat_loc)) {
+		pr_notice("Unexpected locality header length: %u\n",
+			 hmat_loc->header.length);
+		return -EINVAL;
+	}
+
+	type = hmat_loc->data_type;
+	mem_hier = hmat_loc->flags & ACPI_HMAT_MEMORY_HIERARCHY;
+	ipds = hmat_loc->number_of_initiator_Pds;
+	tpds = hmat_loc->number_of_target_Pds;
+	total_size = sizeof(*hmat_loc) + sizeof(*entries) * ipds * tpds +
+		     sizeof(*inits) * ipds + sizeof(*targs) * tpds;
+	if (hmat_loc->header.length < total_size) {
+		pr_notice("Unexpected locality header length:%u, minimum required:%u\n",
+			 hmat_loc->header.length, total_size);
+		return -EINVAL;
+	}
+
+	pr_info("Locality: Flags:%02x Type:%s Initiator Domains:%u Target Domains:%u Base:%lld\n",
+		hmat_loc->flags, hmat_data_type(type), ipds, tpds,
+		hmat_loc->entry_base_unit);
+
+	inits = (u32 *)(hmat_loc + 1);
+	targs = inits + ipds;
+	entries = (u16 *)(targs + tpds);
+	for (init = 0; init < ipds; init++) {
+		alloc_memory_initiator(inits[init]);
+		for (targ = 0; targ < tpds; targ++) {
+			value = hmat_normalize(entries[init * tpds + targ],
+					       hmat_loc->entry_base_unit,
+					       type);
+			pr_info("  Initiator-Target[%u-%u]:%u%s\n",
+				inits[init], targs[targ], value,
+				hmat_data_type_suffix(type));
+
+			if (mem_hier == ACPI_HMAT_MEMORY) {
+				target = find_mem_target(targs[targ]);
+				if (target && target->processor_pxm == inits[init]) {
+					hmat_update_target_access(target, type, value, 0);
+					/* If the node has a CPU, update access 1 */
+					if (node_state(pxm_to_node(inits[init]), N_CPU))
+						hmat_update_target_access(target, type, value, 1);
+				}
+			}
+		}
+	}
+
+	if (mem_hier == ACPI_HMAT_MEMORY)
+		hmat_add_locality(hmat_loc);
+
+	return 0;
+}
+
+static __init int hmat_parse_cache(union acpi_subtable_headers *header,
+				   const unsigned long end)
+{
+	struct acpi_hmat_cache *cache = (void *)header;
+	struct memory_target *target;
+	struct target_cache *tcache;
+	u32 attrs;
+
+	if (cache->header.length < sizeof(*cache)) {
+		pr_notice("Unexpected cache header length: %u\n",
+			 cache->header.length);
+		return -EINVAL;
+	}
+
+	attrs = cache->cache_attributes;
+	pr_info("Cache: Domain:%u Size:%llu Attrs:%08x SMBIOS Handles:%d\n",
+		cache->memory_PD, cache->cache_size, attrs,
+		cache->number_of_SMBIOShandles);
+
+	target = find_mem_target(cache->memory_PD);
+	if (!target)
+		return 0;
+
+	tcache = kzalloc(sizeof(*tcache), GFP_KERNEL);
+	if (!tcache) {
+		pr_notice_once("Failed to allocate HMAT cache info\n");
+		return 0;
+	}
+
+	tcache->cache_attrs.size = cache->cache_size;
+	tcache->cache_attrs.level = (attrs & ACPI_HMAT_CACHE_LEVEL) >> 4;
+	tcache->cache_attrs.line_size = (attrs & ACPI_HMAT_CACHE_LINE_SIZE) >> 16;
+
+	switch ((attrs & ACPI_HMAT_CACHE_ASSOCIATIVITY) >> 8) {
+	case ACPI_HMAT_CA_DIRECT_MAPPED:
+		tcache->cache_attrs.indexing = NODE_CACHE_DIRECT_MAP;
+		break;
+	case ACPI_HMAT_CA_COMPLEX_CACHE_INDEXING:
+		tcache->cache_attrs.indexing = NODE_CACHE_INDEXED;
+		break;
+	case ACPI_HMAT_CA_NONE:
+	default:
+		tcache->cache_attrs.indexing = NODE_CACHE_OTHER;
+		break;
+	}
+
+	switch ((attrs & ACPI_HMAT_WRITE_POLICY) >> 12) {
+	case ACPI_HMAT_CP_WB:
+		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_BACK;
+		break;
+	case ACPI_HMAT_CP_WT:
+		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_THROUGH;
+		break;
+	case ACPI_HMAT_CP_NONE:
+	default:
+		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_OTHER;
+		break;
+	}
+	list_add_tail(&tcache->node, &target->caches);
+
+	return 0;
+}
+
+static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *header,
+					      const unsigned long end)
+{
+	struct acpi_hmat_proximity_domain *p = (void *)header;
+	struct memory_target *target = NULL;
+
+	if (p->header.length != sizeof(*p)) {
+		pr_notice("Unexpected address range header length: %u\n",
+			 p->header.length);
+		return -EINVAL;
+	}
+
+	if (hmat_revision == 1)
+		pr_info("Memory (%#llx length %#llx) Flags:%04x Processor Domain:%u Memory Domain:%u\n",
+			p->reserved3, p->reserved4, p->flags, p->processor_PD,
+			p->memory_PD);
+	else
+		pr_info("Memory Flags:%04x Processor Domain:%u Memory Domain:%u\n",
+			p->flags, p->processor_PD, p->memory_PD);
+
+	if ((hmat_revision == 1 && p->flags & ACPI_HMAT_MEMORY_PD_VALID) ||
+	    hmat_revision > 1) {
+		target = find_mem_target(p->memory_PD);
+		if (!target) {
+			pr_debug("Memory Domain missing from SRAT\n");
+			return -EINVAL;
+		}
+	}
+	if (target && p->flags & ACPI_HMAT_PROCESSOR_PD_VALID) {
+		int p_node = pxm_to_node(p->processor_PD);
+
+		if (p_node == NUMA_NO_NODE) {
+			pr_debug("Invalid Processor Domain\n");
+			return -EINVAL;
+		}
+		target->processor_pxm = p->processor_PD;
+	}
+
+	return 0;
+}
+
+static int __init hmat_parse_subtable(union acpi_subtable_headers *header,
+				      const unsigned long end)
+{
+	struct acpi_hmat_structure *hdr = (void *)header;
+
+	if (!hdr)
+		return -EINVAL;
+
+	switch (hdr->type) {
+	case ACPI_HMAT_TYPE_PROXIMITY:
+		return hmat_parse_proximity_domain(header, end);
+	case ACPI_HMAT_TYPE_LOCALITY:
+		return hmat_parse_locality(header, end);
+	case ACPI_HMAT_TYPE_CACHE:
+		return hmat_parse_cache(header, end);
+	default:
+		return -EINVAL;
+	}
+}
+
+static __init int srat_parse_mem_affinity(union acpi_subtable_headers *header,
+					  const unsigned long end)
+{
+	struct acpi_srat_mem_affinity *ma = (void *)header;
+
+	if (!ma)
+		return -EINVAL;
+	if (!(ma->flags & ACPI_SRAT_MEM_ENABLED))
+		return 0;
+	alloc_memory_target(ma->proximity_domain, ma->base_address, ma->length);
+	return 0;
+}
+
+static u32 hmat_initiator_perf(struct memory_target *target,
+			       struct memory_initiator *initiator,
+			       struct acpi_hmat_locality *hmat_loc)
+{
+	unsigned int ipds, tpds, i, idx = 0, tdx = 0;
+	u32 *inits, *targs;
+	u16 *entries;
+
+	ipds = hmat_loc->number_of_initiator_Pds;
+	tpds = hmat_loc->number_of_target_Pds;
+	inits = (u32 *)(hmat_loc + 1);
+	targs = inits + ipds;
+	entries = (u16 *)(targs + tpds);
+
+	for (i = 0; i < ipds; i++) {
+		if (inits[i] == initiator->processor_pxm) {
+			idx = i;
+			break;
+		}
+	}
+
+	if (i == ipds)
+		return 0;
+
+	for (i = 0; i < tpds; i++) {
+		if (targs[i] == target->memory_pxm) {
+			tdx = i;
+			break;
+		}
+	}
+	if (i == tpds)
+		return 0;
+
+	return hmat_normalize(entries[idx * tpds + tdx],
+			      hmat_loc->entry_base_unit,
+			      hmat_loc->data_type);
+}
+
+static bool hmat_update_best(u8 type, u32 value, u32 *best)
+{
+	bool updated = false;
+
+	if (!value)
+		return false;
+
+	switch (type) {
+	case ACPI_HMAT_ACCESS_LATENCY:
+	case ACPI_HMAT_READ_LATENCY:
+	case ACPI_HMAT_WRITE_LATENCY:
+		if (!*best || *best > value) {
+			*best = value;
+			updated = true;
+		}
+		break;
+	case ACPI_HMAT_ACCESS_BANDWIDTH:
+	case ACPI_HMAT_READ_BANDWIDTH:
+	case ACPI_HMAT_WRITE_BANDWIDTH:
+		if (!*best || *best < value) {
+			*best = value;
+			updated = true;
+		}
+		break;
+	}
+
+	return updated;
+}
+
+static int initiator_cmp(void *priv, const struct list_head *a,
+			 const struct list_head *b)
+{
+	struct memory_initiator *ia;
+	struct memory_initiator *ib;
+
+	ia = list_entry(a, struct memory_initiator, node);
+	ib = list_entry(b, struct memory_initiator, node);
+
+	return ia->processor_pxm - ib->processor_pxm;
+}
+
+static int initiators_to_nodemask(unsigned long *p_nodes)
+{
+	struct memory_initiator *initiator;
+
+	if (list_empty(&initiators))
+		return -ENXIO;
+
+	list_for_each_entry(initiator, &initiators, node)
+		set_bit(initiator->processor_pxm, p_nodes);
+
+	return 0;
+}
+
+static void hmat_register_target_initiators(struct memory_target *target)
+{
+	static DECLARE_BITMAP(p_nodes, MAX_NUMNODES);
+	struct memory_initiator *initiator;
+	unsigned int mem_nid, cpu_nid;
+	struct memory_locality *loc = NULL;
+	u32 best = 0;
+	bool access0done = false;
+	int i;
+
+	mem_nid = pxm_to_node(target->memory_pxm);
+	/*
+	 * If the Address Range Structure provides a local processor pxm, link
+	 * only that one. Otherwise, find the best performance attributes and
+	 * register all initiators that match.
+	 */
+	if (target->processor_pxm != PXM_INVAL) {
+		cpu_nid = pxm_to_node(target->processor_pxm);
+		register_memory_node_under_compute_node(mem_nid, cpu_nid, 0);
+		access0done = true;
+		if (node_state(cpu_nid, N_CPU)) {
+			register_memory_node_under_compute_node(mem_nid, cpu_nid, 1);
+			return;
+		}
+	}
+
+	if (list_empty(&localities))
+		return;
+
+	/*
+	 * We need the initiator list sorted so we can use bitmap_clear for
+	 * previously set initiators when we find a better memory accessor.
+	 * We'll also use the sorting to prime the candidate nodes with known
+	 * initiators.
+	 */
+	bitmap_zero(p_nodes, MAX_NUMNODES);
+	list_sort(NULL, &initiators, initiator_cmp);
+	if (initiators_to_nodemask(p_nodes) < 0)
+		return;
+
+	if (!access0done) {
+		for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
+			loc = localities_types[i];
+			if (!loc)
+				continue;
+
+			best = 0;
+			list_for_each_entry(initiator, &initiators, node) {
+				u32 value;
+
+				if (!test_bit(initiator->processor_pxm, p_nodes))
+					continue;
+
+				value = hmat_initiator_perf(target, initiator,
+							    loc->hmat_loc);
+				if (hmat_update_best(loc->hmat_loc->data_type, value, &best))
+					bitmap_clear(p_nodes, 0, initiator->processor_pxm);
+				if (value != best)
+					clear_bit(initiator->processor_pxm, p_nodes);
+			}
+			if (best)
+				hmat_update_target_access(target, loc->hmat_loc->data_type,
+							  best, 0);
+		}
+
+		for_each_set_bit(i, p_nodes, MAX_NUMNODES) {
+			cpu_nid = pxm_to_node(i);
+			register_memory_node_under_compute_node(mem_nid, cpu_nid, 0);
+		}
+	}
+
+	/* Access 1 ignores Generic Initiators */
+	bitmap_zero(p_nodes, MAX_NUMNODES);
+	if (initiators_to_nodemask(p_nodes) < 0)
+		return;
+
+	for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
+		loc = localities_types[i];
+		if (!loc)
+			continue;
+
+		best = 0;
+		list_for_each_entry(initiator, &initiators, node) {
+			u32 value;
+
+			if (!initiator->has_cpu) {
+				clear_bit(initiator->processor_pxm, p_nodes);
+				continue;
+			}
+			if (!test_bit(initiator->processor_pxm, p_nodes))
+				continue;
+
+			value = hmat_initiator_perf(target, initiator, loc->hmat_loc);
+			if (hmat_update_best(loc->hmat_loc->data_type, value, &best))
+				bitmap_clear(p_nodes, 0, initiator->processor_pxm);
+			if (value != best)
+				clear_bit(initiator->processor_pxm, p_nodes);
+		}
+		if (best)
+			hmat_update_target_access(target, loc->hmat_loc->data_type, best, 1);
+	}
+	for_each_set_bit(i, p_nodes, MAX_NUMNODES) {
+		cpu_nid = pxm_to_node(i);
+		register_memory_node_under_compute_node(mem_nid, cpu_nid, 1);
+	}
+}
+
+static void hmat_register_target_cache(struct memory_target *target)
+{
+	unsigned mem_nid = pxm_to_node(target->memory_pxm);
+	struct target_cache *tcache;
+
+	list_for_each_entry(tcache, &target->caches, node)
+		node_add_cache(mem_nid, &tcache->cache_attrs);
+}
+
+static void hmat_register_target_perf(struct memory_target *target, int access)
+{
+	unsigned mem_nid = pxm_to_node(target->memory_pxm);
+	node_set_perf_attrs(mem_nid, &target->hmem_attrs[access], access);
+}
+
+static void hmat_register_target_devices(struct memory_target *target)
+{
+	struct resource *res;
+
+	/*
+	 * Do not bother creating devices if no driver is available to
+	 * consume them.
+	 */
+	if (!IS_ENABLED(CONFIG_DEV_DAX_HMEM))
+		return;
+
+	for (res = target->memregions.child; res; res = res->sibling) {
+		int target_nid = pxm_to_node(target->memory_pxm);
+
+		hmem_register_device(target_nid, res);
+	}
+}
+
+static void hmat_register_target(struct memory_target *target)
+{
+	int nid = pxm_to_node(target->memory_pxm);
+
+	/*
+	 * Devices may belong to either an offline or online
+	 * node, so unconditionally add them.
+	 */
+	hmat_register_target_devices(target);
+
+	/*
+	 * Skip offline nodes. This can happen when memory
+	 * marked EFI_MEMORY_SP, "specific purpose", is applied
+	 * to all the memory in a proximity domain leading to
+	 * the node being marked offline / unplugged, or if
+	 * memory-only "hotplug" node is offline.
+	 */
+	if (nid == NUMA_NO_NODE || !node_online(nid))
+		return;
+
+	mutex_lock(&target_lock);
+	if (!target->registered) {
+		hmat_register_target_initiators(target);
+		hmat_register_target_cache(target);
+		hmat_register_target_perf(target, 0);
+		hmat_register_target_perf(target, 1);
+		target->registered = true;
+	}
+	mutex_unlock(&target_lock);
+}
+
+static void hmat_register_targets(void)
+{
+	struct memory_target *target;
+
+	list_for_each_entry(target, &targets, node)
+		hmat_register_target(target);
+}
+
+static int hmat_callback(struct notifier_block *self,
+			 unsigned long action, void *arg)
+{
+	struct memory_target *target;
+	struct memory_notify *mnb = arg;
+	int pxm, nid = mnb->status_change_nid;
+
+	if (nid == NUMA_NO_NODE || action != MEM_ONLINE)
+		return NOTIFY_OK;
+
+	pxm = node_to_pxm(nid);
+	target = find_mem_target(pxm);
+	if (!target)
+		return NOTIFY_OK;
+
+	hmat_register_target(target);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block hmat_callback_nb = {
+	.notifier_call = hmat_callback,
+	.priority = 2,
+};
+
+static __init void hmat_free_structures(void)
+{
+	struct memory_target *target, *tnext;
+	struct memory_locality *loc, *lnext;
+	struct memory_initiator *initiator, *inext;
+	struct target_cache *tcache, *cnext;
+
+	list_for_each_entry_safe(target, tnext, &targets, node) {
+		struct resource *res, *res_next;
+
+		list_for_each_entry_safe(tcache, cnext, &target->caches, node) {
+			list_del(&tcache->node);
+			kfree(tcache);
+		}
+
+		list_del(&target->node);
+		res = target->memregions.child;
+		while (res) {
+			res_next = res->sibling;
+			__release_region(&target->memregions, res->start,
+					resource_size(res));
+			res = res_next;
+		}
+		kfree(target);
+	}
+
+	list_for_each_entry_safe(initiator, inext, &initiators, node) {
+		list_del(&initiator->node);
+		kfree(initiator);
+	}
+
+	list_for_each_entry_safe(loc, lnext, &localities, node) {
+		list_del(&loc->node);
+		kfree(loc);
+	}
+}
+
+static __init int hmat_init(void)
+{
+	struct acpi_table_header *tbl;
+	enum acpi_hmat_type i;
+	acpi_status status;
+
+	if (srat_disabled() || hmat_disable)
+		return 0;
+
+	status = acpi_get_table(ACPI_SIG_SRAT, 0, &tbl);
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	if (acpi_table_parse_entries(ACPI_SIG_SRAT,
+				sizeof(struct acpi_table_srat),
+				ACPI_SRAT_TYPE_MEMORY_AFFINITY,
+				srat_parse_mem_affinity, 0) < 0)
+		goto out_put;
+	acpi_put_table(tbl);
+
+	status = acpi_get_table(ACPI_SIG_HMAT, 0, &tbl);
+	if (ACPI_FAILURE(status))
+		goto out_put;
+
+	hmat_revision = tbl->revision;
+	switch (hmat_revision) {
+	case 1:
+	case 2:
+		break;
+	default:
+		pr_notice("Ignoring: Unknown revision:%d\n", hmat_revision);
+		goto out_put;
+	}
+
+	for (i = ACPI_HMAT_TYPE_PROXIMITY; i < ACPI_HMAT_TYPE_RESERVED; i++) {
+		if (acpi_table_parse_entries(ACPI_SIG_HMAT,
+					     sizeof(struct acpi_table_hmat), i,
+					     hmat_parse_subtable, 0) < 0) {
+			pr_notice("Ignoring: Invalid table");
+			goto out_put;
+		}
+	}
+	hmat_register_targets();
+
+	/* Keep the table and structures if the notifier may use them */
+	if (!register_hotmemory_notifier(&hmat_callback_nb))
+		return 0;
+out_put:
+	hmat_free_structures();
+	acpi_put_table(tbl);
+	return 0;
+}
+device_initcall(hmat_init);