drm/xe/xe_late_bind_fw: Initialize late binding firmware

Search for late binding firmware binaries and populate the meta data of
firmware structures.

v2 (Daniele):
 - drm_err if firmware size is more than max pay load size
 - s/request_firmware/firmware_request_nowarn/ as firmware will
   not be available for all possible cards
v3 (Daniele):
 - init firmware from within xe_late_bind_init, propagate error
 - switch late_bind_fw to array to handle multiple firmware types
v4 (Daniele):
 - Alloc payload dynamically, fix nits
v6 (Daniele)
 - %s/MAX_PAYLOAD_SIZE/XE_LB_MAX_PAYLOAD_SIZE/

Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/20250905154953.3974335-5-badal.nilawar@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

drivers/gpu/drm/xe/xe_late_bind_fw.c

@@ -5,6 +5,7 @@
 
 #include <linux/component.h>
 #include <linux/delay.h>
+#include <linux/firmware.h>
 
 #include <drm/drm_managed.h>
 #include <drm/intel/i915_component.h>
@@ -13,6 +14,16 @@
 
 #include "xe_device.h"
 #include "xe_late_bind_fw.h"
+#include "xe_pcode.h"
+#include "xe_pcode_api.h"
+
+static const u32 fw_id_to_type[] = {
+		[XE_LB_FW_FAN_CONTROL] = INTEL_LB_TYPE_FAN_CONTROL,
+	};
+
+static const char * const fw_id_to_name[] = {
+		[XE_LB_FW_FAN_CONTROL] = "fan_control",
+	};
 
 static struct xe_device *
 late_bind_to_xe(struct xe_late_bind *late_bind)
@@ -20,6 +31,89 @@ late_bind_to_xe(struct xe_late_bind *late_bind)
 	return container_of(late_bind, struct xe_device, late_bind);
 }
 
+static int xe_late_bind_fw_num_fans(struct xe_late_bind *late_bind)
+{
+	struct xe_device *xe = late_bind_to_xe(late_bind);
+	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
+	u32 uval;
+
+	if (!xe_pcode_read(root_tile,
+			   PCODE_MBOX(FAN_SPEED_CONTROL, FSC_READ_NUM_FANS, 0), &uval, NULL))
+		return uval;
+	else
+		return 0;
+}
+
+static int __xe_late_bind_fw_init(struct xe_late_bind *late_bind, u32 fw_id)
+{
+	struct xe_device *xe = late_bind_to_xe(late_bind);
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	struct xe_late_bind_fw *lb_fw;
+	const struct firmware *fw;
+	u32 num_fans;
+	int ret;
+
+	if (fw_id >= XE_LB_FW_MAX_ID)
+		return -EINVAL;
+
+	lb_fw = &late_bind->late_bind_fw[fw_id];
+
+	lb_fw->id = fw_id;
+	lb_fw->type = fw_id_to_type[lb_fw->id];
+	lb_fw->flags &= ~INTEL_LB_FLAG_IS_PERSISTENT;
+
+	if (lb_fw->type == INTEL_LB_TYPE_FAN_CONTROL) {
+		num_fans = xe_late_bind_fw_num_fans(late_bind);
+		drm_dbg(&xe->drm, "Number of Fans: %d\n", num_fans);
+		if (!num_fans)
+			return 0;
+	}
+
+	snprintf(lb_fw->blob_path, sizeof(lb_fw->blob_path), "xe/%s_8086_%04x_%04x_%04x.bin",
+		 fw_id_to_name[lb_fw->id], pdev->device,
+		 pdev->subsystem_vendor, pdev->subsystem_device);
+
+	drm_dbg(&xe->drm, "Request late binding firmware %s\n", lb_fw->blob_path);
+	ret = firmware_request_nowarn(&fw, lb_fw->blob_path, xe->drm.dev);
+	if (ret) {
+		drm_dbg(&xe->drm, "%s late binding fw not available for current device",
+			fw_id_to_name[lb_fw->id]);
+		return 0;
+	}
+
+	if (fw->size > XE_LB_MAX_PAYLOAD_SIZE) {
+		drm_err(&xe->drm, "Firmware %s size %zu is larger than max pay load size %u\n",
+			lb_fw->blob_path, fw->size, XE_LB_MAX_PAYLOAD_SIZE);
+		release_firmware(fw);
+		return -ENODATA;
+	}
+
+	lb_fw->payload_size = fw->size;
+	lb_fw->payload = drmm_kzalloc(&xe->drm, lb_fw->payload_size, GFP_KERNEL);
+	if (!lb_fw->payload) {
+		release_firmware(fw);
+		return -ENOMEM;
+	}
+
+	memcpy((void *)lb_fw->payload, fw->data, lb_fw->payload_size);
+	release_firmware(fw);
+
+	return 0;
+}
+
+static int xe_late_bind_fw_init(struct xe_late_bind *late_bind)
+{
+	int ret;
+	int fw_id;
+
+	for (fw_id = 0; fw_id < XE_LB_FW_MAX_ID; fw_id++) {
+		ret = __xe_late_bind_fw_init(late_bind, fw_id);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
 static int xe_late_bind_component_bind(struct device *xe_kdev,
 				       struct device *mei_kdev, void *data)
 {
@@ -80,5 +174,9 @@ int xe_late_bind_init(struct xe_late_bind *late_bind)
 		return err;
 	}
 
-	return devm_add_action_or_reset(xe->drm.dev, xe_late_bind_remove, late_bind);
+	err = devm_add_action_or_reset(xe->drm.dev, xe_late_bind_remove, late_bind);
+	if (err)
+		return err;
+
+	return xe_late_bind_fw_init(late_bind);
 }

drivers/gpu/drm/xe/xe_late_bind_fw_types.h

@@ -10,6 +10,34 @@
 #include <linux/mutex.h>
 #include <linux/types.h>
 
+#define XE_LB_MAX_PAYLOAD_SIZE SZ_4K
+
+/**
+ * xe_late_bind_fw_id - enum to determine late binding fw index
+ */
+enum xe_late_bind_fw_id {
+	XE_LB_FW_FAN_CONTROL = 0,
+	XE_LB_FW_MAX_ID
+};
+
+/**
+ * struct xe_late_bind_fw
+ */
+struct xe_late_bind_fw {
+	/** @id: firmware index */
+	u32 id;
+	/** @blob_path: firmware binary path */
+	char blob_path[PATH_MAX];
+	/** @type: firmware type */
+	u32  type;
+	/** @flags: firmware flags */
+	u32  flags;
+	/** @payload: to store the late binding blob */
+	const u8  *payload;
+	/** @payload_size: late binding blob payload_size */
+	size_t payload_size;
+};
+
 /**
  * struct xe_late_bind_component - Late Binding services component
  * @mei_dev: device that provide Late Binding service.
@@ -28,6 +56,8 @@ struct xe_late_bind_component {
 struct xe_late_bind {
 	/** @component: struct for communication with mei component */
 	struct xe_late_bind_component component;
+	/** @late_bind_fw: late binding firmware array */
+	struct xe_late_bind_fw late_bind_fw[XE_LB_FW_MAX_ID];
 };
 
 #endif