[PATCH 1/3] ACPI: Support Generic Initator only domains

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

Generic Initiators are a new ACPI concept that allows for
the description of proximity domains that contain a
device which performs memory access (such as a network card)
but neither host CPU nor memory.

This first patch has the parsing code and provides the
infrastructure for an architecture to associate these
new domains with their nearest memory possessing node.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/acpi/numa.c            | 62 +++++++++++++++++++++++++++++++++-
 drivers/base/node.c            |  3 ++
 include/acpi/actbl3.h          | 37 +++++++++++++++++++-
 include/asm-generic/topology.h |  3 ++
 include/linux/nodemask.h       |  1 +
 include/linux/topology.h       |  7 ++++
 6 files changed, 111 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 7bbbf8256a41..890095794695 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -183,6 +183,38 @@ acpi_table_print_srat_entry(struct acpi_subtable_header *header)
 		}
 		break;
 
+	case ACPI_SRAT_TYPE_GENERIC_INITIATOR_AFFINITY:
+	{
+		struct acpi_srat_gi_affinity *p =
+			(struct acpi_srat_gi_affinity *)header;
+		char name[9] = {};
+
+		if (p->flags & ACPI_SRAT_GI_PCI_HANDLE) {
+			/*
+			 * For pci devices this may be the only place they
+			 * are assigned a proximity domain
+			 */
+			pr_debug("SRAT Generic Initiator(Seg:%u BDF:%u) in proximity domain %d %s\n",
+				p->pci_handle.segment,
+				p->pci_handle.bdf,
+				p->proximity_domain,
+				(p->flags & ACPI_SRAT_GI_ENABLED) ?
+				"enabled" : "disabled");
+		} else {
+			/*
+			 * In this case we can rely on the device having a
+			 * proximity domain reference
+			 */
+			memcpy(name, p->acpi_handle.hid, 8);
+			pr_info("SRAT Generic Initiator(HID=%s UID=%u) in proximity domain %d %s\n",
+				name,
+				p->acpi_handle.uid,
+				p->proximity_domain,
+				(p->flags & ACPI_SRAT_GI_ENABLED) ?
+				"enabled" : "disabled");
+		}
+	}
+	break;
 	default:
 		pr_warn("Found unsupported SRAT entry (type = 0x%x)\n",
 			header->type);
@@ -391,6 +423,32 @@ acpi_parse_gicc_affinity(struct acpi_subtable_header *header,
 	return 0;
 }
 
+static int __init
+acpi_parse_gi_affinity(struct acpi_subtable_header *header,
+		       const unsigned long end)
+{
+	struct acpi_srat_gi_affinity *gi_affinity;
+	int node;
+
+	gi_affinity = (struct acpi_srat_gi_affinity *)header;
+	if (!gi_affinity)
+		return -EINVAL;
+	acpi_table_print_srat_entry(header);
+
+	if (!(gi_affinity->flags & ACPI_SRAT_GI_ENABLED))
+		return EINVAL;
+
+	node = acpi_map_pxm_to_node(gi_affinity->proximity_domain);
+	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
+		pr_err("SRAT: Too many proximity domains.\n");
+		return -EINVAL;
+	}
+	node_set(node, numa_nodes_parsed);
+	node_set_state(node, N_GENERIC_INITIATOR);
+
+	return 0;
+}
+
 static int __initdata parsed_numa_memblks;
 
 static int __init
@@ -446,7 +504,7 @@ int __init acpi_numa_init(void)
 
 	/* SRAT: System Resource Affinity Table */
 	if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
-		struct acpi_subtable_proc srat_proc[3];
+		struct acpi_subtable_proc srat_proc[4];
 
 		memset(srat_proc, 0, sizeof(srat_proc));
 		srat_proc[0].id = ACPI_SRAT_TYPE_CPU_AFFINITY;
@@ -455,6 +513,8 @@ int __init acpi_numa_init(void)
 		srat_proc[1].handler = acpi_parse_x2apic_affinity;
 		srat_proc[2].id = ACPI_SRAT_TYPE_GICC_AFFINITY;
 		srat_proc[2].handler = acpi_parse_gicc_affinity;
+		srat_proc[3].id = ACPI_SRAT_TYPE_GENERIC_INITIATOR_AFFINITY;
+		srat_proc[3].handler = acpi_parse_gi_affinity;
 
 		acpi_table_parse_entries_array(ACPI_SIG_SRAT,
 					sizeof(struct acpi_table_srat),
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 86d6cd92ce3d..f59b9d4ca5d5 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -634,6 +634,8 @@ static struct node_attr node_state_attr[] = {
 #endif
 	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
+	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
+					   N_GENERIC_INITIATOR),
 };
 
 static struct attribute *node_state_attrs[] = {
@@ -645,6 +647,7 @@ static struct attribute *node_state_attrs[] = {
 #endif
 	&node_state_attr[N_MEMORY].attr.attr,
 	&node_state_attr[N_CPU].attr.attr,
+	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
 	NULL
 };
 
diff --git a/include/acpi/actbl3.h b/include/acpi/actbl3.h
index ea1ca49c9c1b..35ea3f736697 100644
--- a/include/acpi/actbl3.h
+++ b/include/acpi/actbl3.h
@@ -190,7 +190,8 @@ enum acpi_srat_type {
 	ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY = 2,
 	ACPI_SRAT_TYPE_GICC_AFFINITY = 3,
 	ACPI_SRAT_TYPE_GIC_ITS_AFFINITY = 4,	/* ACPI 6.2 */
-	ACPI_SRAT_TYPE_RESERVED = 5	/* 5 and greater are reserved */
+	ACPI_SRAT_TYPE_GENERIC_INITIATOR_AFFINITY = 5, /* ACPI 6.3 */
+	ACPI_SRAT_TYPE_RESERVED = 6	/* 6 and greater are reserved */
 };
 
 /*
@@ -271,6 +272,40 @@ struct acpi_srat_gic_its_affinity {
 	u32 its_id;
 };
 
+/* Flags for struct acpi_srat_gi_affinity */
+
+#define ACPI_SRAT_GI_ENABLED     (1)		/* 00: Use affinity structure */
+#define ACPI_SRAT_GI_ACPI_HANDLE (0)		/* 01: */
+#define ACPI_SRAT_GI_PCI_HANDLE  (1 << 1)	/* 01: */
+
+/* Handles to associate the generic initiator with types of ACPI device */
+
+struct acpi_srat_gi_acpi_handle {
+	char hid[8];
+	u32 uid;
+	u32 reserved;
+};
+
+struct acpi_srat_gi_pci_handle {
+	u16 segment;
+	u16 bdf;
+	u8 reserved[12];
+};
+
+/* 5 : Generic Initiator Affinity (ACPI 6.3) */
+
+struct acpi_srat_gi_affinity {
+	struct acpi_subtable_header header;
+	u8 reserved;
+	u8 device_handl_type;
+	u32 proximity_domain;
+	union {
+		struct acpi_srat_gi_acpi_handle acpi_handle;
+		struct acpi_srat_gi_pci_handle pci_handle;
+	};
+	u32 flags;
+	u32 reserved2;
+};
 /*******************************************************************************
  *
  * STAO - Status Override Table (_STA override) - ACPI 6.0
diff --git a/include/asm-generic/topology.h b/include/asm-generic/topology.h
index 238873739550..54d0b4176a45 100644
--- a/include/asm-generic/topology.h
+++ b/include/asm-generic/topology.h
@@ -71,6 +71,9 @@
 #ifndef set_cpu_numa_mem
 #define set_cpu_numa_mem(cpu, node)
 #endif
+#ifndef set_gi_numa_mem
+#define set_gi_numa_mem(gi, node)
+#endif
 
 #endif	/* !CONFIG_NUMA || !CONFIG_HAVE_MEMORYLESS_NODES */
 
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 5a30ad594ccc..501b1d32b323 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -399,6 +399,7 @@ enum node_states {
 #endif
 	N_MEMORY,		/* The node has memory(regular, high, movable) */
 	N_CPU,		/* The node has one or more cpus */
+	N_GENERIC_INITIATOR,	/* The node is a GI only node */
 	NR_NODE_STATES
 };
 
diff --git a/include/linux/topology.h b/include/linux/topology.h
index cb0775e1ee4b..9d5f8501efcf 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -125,6 +125,13 @@ static inline void set_numa_mem(int node)
 }
 #endif
 
+#ifndef set_gi_numa_mem
+static inline void set_gi_numa_mem(int gi, int node)
+{
+	_node_numa_mem_[gi] = node;
+}
+#endif
+
 #ifndef node_to_mem_node
 static inline int node_to_mem_node(int node)
 {
-- 
2.18.0