[PATCH 06/18] cxl: Add callback to parse the DSMAS subtables from CDAT

[Dave Jiang <dave.jiang@xxxxxxxxx>]

Provide a callback function to the CDAT parser in order to parse the Device
Scoped Memory Affinity Structure (DSMAS). Each DSMAS structure contains the
DPA range and its associated attributes in each entry. See the CDAT
specification for details.

Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
 drivers/cxl/core/cdat.c |   25 +++++++++++++++++++++++++
 drivers/cxl/core/port.c |    2 ++
 drivers/cxl/cxl.h       |   11 +++++++++++
 drivers/cxl/port.c      |    8 ++++++++
 4 files changed, 46 insertions(+)

diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
index be09c8a690f5..f9a64a0f1ee4 100644
--- a/drivers/cxl/core/cdat.c
+++ b/drivers/cxl/core/cdat.c
@@ -96,3 +96,28 @@ int cdat_table_parse_dslbis(void *table, cdat_tbl_entry_handler handler, void *a
 	return cdat_table_parse_entries(ACPI_CDAT_TYPE_DSLBIS, header, &proc, 0);
 }
 EXPORT_SYMBOL_NS_GPL(cdat_table_parse_dslbis, CXL);
+
+int cxl_dsmas_parse_entry(struct acpi_cdat_header *header, void *arg)
+{
+	struct cxl_port *port = (struct cxl_port *)arg;
+	struct dsmas_entry *dent;
+	struct acpi_cdat_dsmas *dsmas;
+
+	if (header->type != ACPI_CDAT_TYPE_DSMAS)
+		return -EINVAL;
+
+	dent = devm_kzalloc(&port->dev, sizeof(*dent), GFP_KERNEL);
+	if (!dent)
+		return -ENOMEM;
+
+	dsmas = (struct acpi_cdat_dsmas *)((unsigned long)header + sizeof(*header));
+	dent->handle = dsmas->dsmad_handle;
+	dent->dpa_range.start = dsmas->dpa_base_address;
+	dent->dpa_range.end = dsmas->dpa_base_address + dsmas->dpa_length - 1;
+
+	mutex_lock(&port->cdat.dsmas_lock);
+	list_add_tail(&dent->list, &port->cdat.dsmas_list);
+	mutex_unlock(&port->cdat.dsmas_lock);
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dsmas_parse_entry, CXL);
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index fe78daf7e7c8..2b27319cfd42 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -660,6 +660,8 @@ static struct cxl_port *cxl_port_alloc(struct device *uport,
 	device_set_pm_not_required(dev);
 	dev->bus = &cxl_bus_type;
 	dev->type = &cxl_port_type;
+	INIT_LIST_HEAD(&port->cdat.dsmas_list);
+	mutex_init(&port->cdat.dsmas_lock);
 
 	return port;
 
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 839a121c1997..1e5e69f08480 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -8,6 +8,7 @@
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/log2.h>
+#include <linux/list.h>
 #include <linux/io.h>
 #include <linux/acpi.h>
 
@@ -520,6 +521,8 @@ struct cxl_port {
 	struct cxl_cdat {
 		void *table;
 		size_t length;
+		struct list_head dsmas_list;
+		struct mutex dsmas_lock; /* lock for dsmas_list */
 	} cdat;
 	bool cdat_available;
 };
@@ -698,6 +701,12 @@ static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
 }
 #endif
 
+struct dsmas_entry {
+	struct list_head list;
+	struct range dpa_range;
+	u16 handle;
+};
+
 typedef int (*cdat_tbl_entry_handler)(struct acpi_cdat_header *header, void *arg);
 
 u8 cdat_table_checksum(u8 *buffer, u32 length);
@@ -706,6 +715,8 @@ int cdat_table_parse_dsmas(void *table, cdat_tbl_entry_handler handler,
 int cdat_table_parse_dslbis(void *table, cdat_tbl_entry_handler handler,
 			    void *arg);
 
+int cxl_dsmas_parse_entry(struct acpi_cdat_header *header, void *arg);
+
 /*
  * Unit test builds overrides this to __weak, find the 'strong' version
  * of these symbols in tools/testing/cxl/.
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 5453771bf330..b1da73e99bab 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -61,6 +61,14 @@ static int cxl_port_probe(struct device *dev)
 		if (rc)
 			return rc;
 
+		if (port->cdat.table) {
+			rc = cdat_table_parse_dsmas(port->cdat.table,
+						    cxl_dsmas_parse_entry,
+						    (void *)port);
+			if (rc < 0)
+				dev_dbg(dev, "Failed to parse DSMAS: %d\n", rc);
+		}
+
 		rc = cxl_hdm_decode_init(cxlds, cxlhdm);
 		if (rc)
 			return rc;