change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/drivers/virtio/virtio.c
..
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 #include <linux/virtio.h>
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 #include <linux/spinlock.h>
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 #include <linux/virtio_config.h>
..
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@@ -161,17 +162,33 @@
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162
 
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 void virtio_add_status(struct virtio_device *dev, unsigned int status)
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 {
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+	might_sleep();
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 	dev->config->set_status(dev, dev->config->get_status(dev) | status);
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 }
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 EXPORT_SYMBOL_GPL(virtio_add_status);
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-int virtio_finalize_features(struct virtio_device *dev)
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+/* Do some validation, then set FEATURES_OK */
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+static int virtio_features_ok(struct virtio_device *dev)
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 {
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-	int ret = dev->config->finalize_features(dev);
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 	unsigned status;
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+	int ret;
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-	if (ret)
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-		return ret;
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+	might_sleep();
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+
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+	ret = arch_has_restricted_virtio_memory_access();
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+	if (ret) {
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+		if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
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+			dev_warn(&dev->dev,
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+				 "device must provide VIRTIO_F_VERSION_1\n");
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+			return -ENODEV;
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+		}
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+
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+		if (!virtio_has_feature(dev, VIRTIO_F_ACCESS_PLATFORM)) {
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+			dev_warn(&dev->dev,
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+				 "device must provide VIRTIO_F_ACCESS_PLATFORM\n");
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+			return -ENODEV;
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+		}
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+	}
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 	if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
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 		return 0;
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@@ -185,7 +202,6 @@
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 	}
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 	return 0;
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 }
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-EXPORT_SYMBOL_GPL(virtio_finalize_features);
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 static int virtio_dev_probe(struct device *_d)
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 {
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@@ -222,17 +238,6 @@
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 		driver_features_legacy = driver_features;
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 	}
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-	/*
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-	 * Some devices detect legacy solely via F_VERSION_1. Write
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-	 * F_VERSION_1 to force LE config space accesses before FEATURES_OK for
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-	 * these when needed.
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-	 */
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-	if (drv->validate && !virtio_legacy_is_little_endian()
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-			  && device_features & BIT_ULL(VIRTIO_F_VERSION_1)) {
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-		dev->features = BIT_ULL(VIRTIO_F_VERSION_1);
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-		dev->config->finalize_features(dev);
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-	}
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-
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 	if (device_features & (1ULL << VIRTIO_F_VERSION_1))
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 		dev->features = driver_features & device_features;
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 	else
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@@ -243,13 +248,26 @@
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 		if (device_features & (1ULL << i))
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 			__virtio_set_bit(dev, i);
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+	err = dev->config->finalize_features(dev);
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+	if (err)
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+		goto err;
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+
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 	if (drv->validate) {
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+		u64 features = dev->features;
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+
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 		err = drv->validate(dev);
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 		if (err)
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 			goto err;
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+
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+		/* Did validation change any features? Then write them again. */
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+		if (features != dev->features) {
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+			err = dev->config->finalize_features(dev);
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+			if (err)
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+				goto err;
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+		}
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 	}
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-	err = virtio_finalize_features(dev);
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+	err = virtio_features_ok(dev);
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 	if (err)
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 		goto err;
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@@ -365,6 +383,12 @@
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 }
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 EXPORT_SYMBOL_GPL(register_virtio_device);
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+bool is_virtio_device(struct device *dev)
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+{
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+	return dev->bus == &virtio_bus;
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+}
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+EXPORT_SYMBOL_GPL(is_virtio_device);
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+
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 void unregister_virtio_device(struct virtio_device *dev)
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 {
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 	int index = dev->index; /* save for after device release */
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@@ -395,6 +419,13 @@
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 	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
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 	int ret;
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+	/* Short path for stateful devices. Here we assume that if the device
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+	 * does not have a freeze callback, its state was not changed when
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+	 * suspended.
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+	 */
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+	if (drv && !drv->freeze)
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+		goto on_config_enable;
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+
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 	/* We always start by resetting the device, in case a previous
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 	 * driver messed it up. */
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 	dev->config->reset(dev);
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@@ -413,7 +444,11 @@
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 	/* We have a driver! */
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 	virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
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-	ret = virtio_finalize_features(dev);
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+	ret = dev->config->finalize_features(dev);
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+	if (ret)
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+		goto err;
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+
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+	ret = virtio_features_ok(dev);
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 	if (ret)
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 		goto err;
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@@ -426,6 +461,7 @@
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 	/* Finally, tell the device we're all set */
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 	virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
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+on_config_enable:
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 	virtio_config_enable(dev);
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 	return 0;