acpi: numa: Add support to enumerate and store extended linear address mode

Store the address mode as part of the cache attriutes. Export the mode
attribute to sysfs as all other cache attributes.

Link: https://lore.kernel.org/linux-cxl/668333b17e4b2_5639294fd@dwillia2-xfh.jf.intel.com.notmuch/
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20250226162224.3633792-2-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node
index 402af4b2b905f3e273ec9be14218ba8350d31295..a02707cb7cbc8a77a21c55a04e1d11130fa64b7b 100644 (file)
--- a/Documentation/ABI/stable/sysfs-devices-node
+++ b/Documentation/ABI/stable/sysfs-devices-node
@@ -177,6 +177,12 @@ Description:
                The cache write policy: 0 for write-back, 1 for write-through,
                other or unknown.
 
+What:          /sys/devices/system/node/nodeX/memory_side_cache/indexY/address_mode
+Date:          March 2025
+Contact:       Dave Jiang <dave.jiang@intel.com>
+Description:
+               The address mode: 0 for reserved, 1 for extended-linear.
+
 What:          /sys/devices/system/node/nodeX/x86/sgx_total_bytes
 Date:          November 2021
 Contact:       Jarkko Sakkinen <jarkko@kernel.org>

diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index bfbb08b1e6af64bac3338bb9f3df27f19cd49f5d..2630511937f523f1cb37e96927020ddad0ae886b 100644 (file)
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -506,6 +506,11 @@ static __init int hmat_parse_cache(union acpi_subtable_headers *header,
        switch ((attrs & ACPI_HMAT_CACHE_ASSOCIATIVITY) >> 8) {
        case ACPI_HMAT_CA_DIRECT_MAPPED:
                tcache->cache_attrs.indexing = NODE_CACHE_DIRECT_MAP;
+               /* Extended Linear mode is only valid if cache is direct mapped */
+               if (cache->address_mode == ACPI_HMAT_CACHE_MODE_EXTENDED_LINEAR) {
+                       tcache->cache_attrs.address_mode =
+                               NODE_CACHE_ADDR_MODE_EXTENDED_LINEAR;
+               }
                break;
        case ACPI_HMAT_CA_COMPLEX_CACHE_INDEXING:
                tcache->cache_attrs.indexing = NODE_CACHE_INDEXED;

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 0ea653fa34330eb2d89daae455b4b9f101b79f4e..cd13ef2870119fd2d9f6b6d3f84ad7797ce76732 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -244,12 +244,14 @@ CACHE_ATTR(size, "%llu")
 CACHE_ATTR(line_size, "%u")
 CACHE_ATTR(indexing, "%u")
 CACHE_ATTR(write_policy, "%u")
+CACHE_ATTR(address_mode, "%#x")
 
 static struct attribute *cache_attrs[] = {
        &dev_attr_indexing.attr,
        &dev_attr_size.attr,
        &dev_attr_line_size.attr,
        &dev_attr_write_policy.attr,
+       &dev_attr_address_mode.attr,
        NULL,
 };
 ATTRIBUTE_GROUPS(cache);

diff --git a/include/linux/node.h b/include/linux/node.h
index 9a881c2208b3bdaa44b6afb9c23450261b3e622b..2b751789223019bb4909b75d3105d91c319e0a68 100644 (file)
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -57,6 +57,11 @@ enum cache_write_policy {
        NODE_CACHE_WRITE_OTHER,
 };
 
+enum cache_mode {
+       NODE_CACHE_ADDR_MODE_RESERVED,
+       NODE_CACHE_ADDR_MODE_EXTENDED_LINEAR,
+};
+
 /**
  * struct node_cache_attrs - system memory caching attributes
  *
@@ -65,6 +70,7 @@ enum cache_write_policy {
  * @size:              Total size of cache in bytes
  * @line_size:         Number of bytes fetched on a cache miss
  * @level:             The cache hierarchy level
+ * @address_mode:              The address mode
  */
 struct node_cache_attrs {
        enum cache_indexing indexing;
@@ -72,6 +78,7 @@ struct node_cache_attrs {
        u64 size;
        u16 line_size;
        u8 level;
+       u16 address_mode;
 };
 
 #ifdef CONFIG_HMEM_REPORTING