Re: [PATCHv8 07/10] acpi/hmat: Register processor domain to its memory

If the HMAT Subsystem Address Range provides a valid processor proximity
domain for a memory domain, or a processor domain matches the performance
access of the valid processor proximity domain, register the memory
target with that initiator so this relationship will be visible under
the node's sysfs directory.

Since HMAT requires valid address ranges have an equivalent SRAT entry,
verify each memory target satisfies this requirement.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Keith Busch <redacted>
---
 drivers/acpi/hmat/Kconfig |   3 +-
 drivers/acpi/hmat/hmat.c  | 392 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 393 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/hmat/Kconfig b/drivers/acpi/hmat/Kconfig
index 2f7111b7af62..13cddd612a52 100644
--- a/drivers/acpi/hmat/Kconfig
+++ b/drivers/acpi/hmat/Kconfig

@@ -4,4 +4,5 @@ config ACPI_HMAT
        depends on ACPI_NUMA
        help
         If set, this option has the kernel parse and report the
-        platform's ACPI HMAT (Heterogeneous Memory Attributes Table).
+        platform's ACPI HMAT (Heterogeneous Memory Attributes Table),
+        and register memory initiators with their targets.

diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
index 4758beb3b2c1..01a6eddac6f7 100644
--- a/drivers/acpi/hmat/hmat.c
+++ b/drivers/acpi/hmat/hmat.c

@@ -13,11 +13,105 @@
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/list.h>
+#include <linux/list_sort.h>
 #include <linux/node.h>
 #include <linux/sysfs.h>

 static __initdata u8 hmat_revision;

+static __initdata LIST_HEAD(targets);
+static __initdata LIST_HEAD(initiators);
+static __initdata LIST_HEAD(localities);
+
+/*
+ * 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 memory_target {
+       struct list_head node;
+       unsigned int memory_pxm;
+       unsigned int processor_pxm;
+       struct node_hmem_attrs hmem_attrs;
+};
+
+struct memory_initiator {
+       struct list_head node;
+       unsigned int processor_pxm;
+};
+
+struct memory_locality {
+       struct list_head node;
+       struct acpi_hmat_locality *hmat_loc;
+};
+
+static __init 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 __init 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;