test_firmware: add test custom fallback trigger

We have no custom fallback mechanism test interface. Provide one.
This tests both the custom fallback mechanism and cancelling the
it.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lib/test_firmware.c

@@ -126,11 +126,56 @@ out:
 }
 static DEVICE_ATTR_WO(trigger_async_request);
 
+static ssize_t trigger_custom_fallback_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	int rc;
+	char *name;
+
+	name = kstrndup(buf, count, GFP_KERNEL);
+	if (!name)
+		return -ENOSPC;
+
+	pr_info("loading '%s' using custom fallback mechanism\n", name);
+
+	mutex_lock(&test_fw_mutex);
+	release_firmware(test_firmware);
+	test_firmware = NULL;
+	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, name,
+				     dev, GFP_KERNEL, NULL,
+				     trigger_async_request_cb);
+	if (rc) {
+		pr_info("async load of '%s' failed: %d\n", name, rc);
+		kfree(name);
+		goto out;
+	}
+	/* Free 'name' ASAP, to test for race conditions */
+	kfree(name);
+
+	wait_for_completion(&async_fw_done);
+
+	if (test_firmware) {
+		pr_info("loaded: %zu\n", test_firmware->size);
+		rc = count;
+	} else {
+		pr_err("failed to async load firmware\n");
+		rc = -ENODEV;
+	}
+
+out:
+	mutex_unlock(&test_fw_mutex);
+
+	return rc;
+}
+static DEVICE_ATTR_WO(trigger_custom_fallback);
+
 #define TEST_FW_DEV_ATTR(name)          &dev_attr_##name.attr
 
 static struct attribute *test_dev_attrs[] = {
 	TEST_FW_DEV_ATTR(trigger_request),
 	TEST_FW_DEV_ATTR(trigger_async_request),
+	TEST_FW_DEV_ATTR(trigger_custom_fallback),
 	NULL,
 };
 

tools/testing/selftests/firmware/fw_fallback.sh

@@ -83,6 +83,58 @@ load_fw_cancel()
 	wait
 }
 
+load_fw_custom()
+{
+	local name="$1"
+	local file="$2"
+
+	echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
+
+	# Give kernel a chance to react.
+	local timeout=10
+	while [ ! -e "$DIR"/"$name"/loading ]; do
+		sleep 0.1
+		timeout=$(( $timeout - 1 ))
+		if [ "$timeout" -eq 0 ]; then
+			echo "$0: firmware interface never appeared" >&2
+			exit 1
+		fi
+	done
+
+	echo 1 >"$DIR"/"$name"/loading
+	cat "$file" >"$DIR"/"$name"/data
+	echo 0 >"$DIR"/"$name"/loading
+
+	# Wait for request to finish.
+	wait
+}
+
+
+load_fw_custom_cancel()
+{
+	local name="$1"
+	local file="$2"
+
+	echo -n "$name" >"$DIR"/trigger_custom_fallback 2>/dev/null &
+
+	# Give kernel a chance to react.
+	local timeout=10
+	while [ ! -e "$DIR"/"$name"/loading ]; do
+		sleep 0.1
+		timeout=$(( $timeout - 1 ))
+		if [ "$timeout" -eq 0 ]; then
+			echo "$0: firmware interface never appeared" >&2
+			exit 1
+		fi
+	done
+
+	echo -1 >"$DIR"/"$name"/loading
+
+	# Wait for request to finish.
+	wait
+}
+
+
 trap "test_finish" EXIT
 
 # This is an unlikely real-world firmware content. :)
@@ -153,4 +205,20 @@ else
 	echo "$0: cancelling fallback mechanism works"
 fi
 
+load_fw_custom "$NAME" "$FW"
+if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
+	echo "$0: firmware was not loaded" >&2
+	exit 1
+else
+	echo "$0: custom fallback loading mechanism works"
+fi
+
+load_fw_custom_cancel "nope-$NAME" "$FW"
+if diff -q "$FW" /dev/test_firmware >/dev/null ; then
+	echo "$0: firmware was expected to be cancelled" >&2
+	exit 1
+else
+	echo "$0: cancelling custom fallback mechanism works"
+fi
+
 exit 0