[v7,06/11] cxl: Store the access coordinates for the generic ports

Commit Message

Dave Jiang June 16, 2023, 9:42 p.m. UTC

Each CXL host bridge is represented by an ACPI0016 device. A generic port
device handle that is an ACPI device is represented by a string of
ACPI0016 device HID and UID. Create a device handle from the ACPI device
and retrieve the access coordinates from the stored memory targets. The
access coordinates are stored under the cxl_dport that is associated with
the CXL host bridge.

The access coordinates struct is dynamically allocated under cxl_dport in
order for code later on to detect whether the data exists or not.

Reviewed-by: Jonathan Cameron <[e-mail]>
Signed-off-by: Dave Jiang <[e-mail]>
---
v7:
- Directly return from acpi_get_genport_coordinates(). (Jonathan)
v6:
- Change memcpy to strncpy. ACPI HID and UID are strings.
---
 drivers/cxl/acpi.c |   17 +++++++++++++++++
 drivers/cxl/cxl.h  |    2 ++
 2 files changed, 19 insertions(+)

Patch

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 8247df06d683..b54c325f9db3 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -557,8 +557,21 @@  static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
 	return 0;
 }
 
+static int get_genport_coordinates(struct device *dev, struct cxl_dport *dport)
+{
+	struct acpi_device *hb = to_cxl_host_bridge(NULL, dev);
+	u8 handle[ACPI_SRAT_DEVICE_HANDLE_SIZE] = { 0 };
+
+	/* ACPI spec 6.5 table 5.65 */
+	strncpy(handle, acpi_device_hid(hb), 8);
+	strncpy(&handle[8], acpi_device_uid(hb), 4);
+
+	return acpi_get_genport_coordinates(handle, &dport->hb_access);
+}
+
 static int add_host_bridge_dport(struct device *match, void *arg)
 {
+	int ret;
 	acpi_status rc;
 	struct device *bridge;
 	unsigned long long uid;
@@ -614,6 +627,10 @@  static int add_host_bridge_dport(struct device *match, void *arg)
 	if (IS_ERR(dport))
 		return PTR_ERR(dport);
 
+	ret = get_genport_coordinates(match, dport);
+	if (ret)
+		dev_dbg(match, "Failed to get generic port perf coordinates.\n");
+
 	return 0;
 }
 
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 208e98225abf..e55a62c461fd 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -636,6 +636,7 @@  cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev)
  * @rcrb: base address for the Root Complex Register Block
  * @rch: Indicate whether this dport was enumerated in RCH or VH mode
  * @port: reference to cxl_port that contains this downstream port
+ * @genport_coord: access coordinates (performance) from ACPI generic port
  * @coord: access coordinates (performance) for switch from CDAT
  * @link_latency: calculated PCIe downstream latency
  */
@@ -646,6 +647,7 @@  struct cxl_dport {
 	resource_size_t rcrb;
 	bool rch;
 	struct cxl_port *port;
+	struct access_coordinate hb_access;
 	struct access_coordinate coord;
 	long link_latency;
 };