drm/nouveau/core: support versioned firmware loading

We have a need for this now with updated SEC2 LS FW images that have an
incompatible interface from the previous version.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvkm/core/firmware.h

@@ -3,7 +3,10 @@
 #define __NVKM_FIRMWARE_H__
 #include <core/subdev.h>
 
+int nvkm_firmware_get_version(const struct nvkm_subdev *, const char *fwname,
+			      int min_version, int max_version,
+			      const struct firmware **);
 int nvkm_firmware_get(const struct nvkm_subdev *, const char *fwname,
-		      const struct firmware **fw);
-void nvkm_firmware_put(const struct firmware *fw);
+		      const struct firmware **);
+void nvkm_firmware_put(const struct firmware *);
 #endif

drivers/gpu/drm/nouveau/nvkm/core/firmware.c

@@ -32,7 +32,8 @@
  * Firmware files released by NVIDIA will always follow this format.
  */
 int
-nvkm_firmware_get(const struct nvkm_subdev *subdev, const char *fwname,
+nvkm_firmware_get_version(const struct nvkm_subdev *subdev, const char *fwname,
+			  int min_version, int max_version,
 			  const struct firmware **fw)
 {
 	struct nvkm_device *device = subdev->device;
@@ -49,8 +50,29 @@ nvkm_firmware_get(const struct nvkm_subdev *subdev, const char *fwname,
 		cname[i] = tolower(cname[i]);
 	}
 
+	for (i = max_version; i >= min_version; i--) {
+		if (i != 0)
+			snprintf(f, sizeof(f), "nvidia/%s/%s-%d.bin", cname, fwname, i);
+		else
 			snprintf(f, sizeof(f), "nvidia/%s/%s.bin", cname, fwname);
-	return request_firmware(fw, f, device->dev);
+
+		if (!firmware_request_nowarn(fw, f, device->dev)) {
+			nvkm_debug(subdev, "firmware \"%s\" loaded\n", f);
+			return i;
+		}
+
+		nvkm_debug(subdev, "firmware \"%s\" unavailable\n", f);
+	}
+
+	nvkm_error(subdev, "failed to load firmware \"%s\"", fwname);
+	return -ENOENT;
+}
+
+int
+nvkm_firmware_get(const struct nvkm_subdev *subdev, const char *fwname,
+		  const struct firmware **fw)
+{
+	return nvkm_firmware_get_version(subdev, fwname, 0, 0, fw);
 }
 
 /**