--- zzzz-none-000/linux-3.10.107/drivers/virtio/virtio.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/virtio/virtio.c 2021-02-04 17:41:59.000000000 +0000 @@ -3,6 +3,7 @@ #include #include #include +#include /* Unique numbering for virtio devices. */ static DEFINE_IDA(virtio_index_ida); @@ -13,18 +14,24 @@ struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%04x\n", dev->id.device); } +static DEVICE_ATTR_RO(device); + static ssize_t vendor_show(struct device *_d, struct device_attribute *attr, char *buf) { struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%04x\n", dev->id.vendor); } +static DEVICE_ATTR_RO(vendor); + static ssize_t status_show(struct device *_d, struct device_attribute *attr, char *buf) { struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); } +static DEVICE_ATTR_RO(status); + static ssize_t modalias_show(struct device *_d, struct device_attribute *attr, char *buf) { @@ -32,6 +39,8 @@ return sprintf(buf, "virtio:d%08Xv%08X\n", dev->id.device, dev->id.vendor); } +static DEVICE_ATTR_RO(modalias); + static ssize_t features_show(struct device *_d, struct device_attribute *attr, char *buf) { @@ -41,20 +50,23 @@ /* We actually represent this as a bitstring, as it could be * arbitrary length in future. */ - for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) + for (i = 0; i < sizeof(dev->features)*8; i++) len += sprintf(buf+len, "%c", - test_bit(i, dev->features) ? '1' : '0'); + __virtio_test_bit(dev, i) ? '1' : '0'); len += sprintf(buf+len, "\n"); return len; } -static struct device_attribute virtio_dev_attrs[] = { - __ATTR_RO(device), - __ATTR_RO(vendor), - __ATTR_RO(status), - __ATTR_RO(modalias), - __ATTR_RO(features), - __ATTR_NULL +static DEVICE_ATTR_RO(features); + +static struct attribute *virtio_dev_attrs[] = { + &dev_attr_device.attr, + &dev_attr_vendor.attr, + &dev_attr_status.attr, + &dev_attr_modalias.attr, + &dev_attr_features.attr, + NULL, }; +ATTRIBUTE_GROUPS(virtio_dev); static inline int virtio_id_match(const struct virtio_device *dev, const struct virtio_device_id *id) @@ -102,16 +114,83 @@ for (i = 0; i < drv->feature_table_size; i++) if (drv->feature_table[i] == fbit) return; + + if (drv->feature_table_legacy) { + for (i = 0; i < drv->feature_table_size_legacy; i++) + if (drv->feature_table_legacy[i] == fbit) + return; + } + BUG(); } EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); +static void __virtio_config_changed(struct virtio_device *dev) +{ + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + + if (!dev->config_enabled) + dev->config_change_pending = true; + else if (drv && drv->config_changed) + drv->config_changed(dev); +} + +void virtio_config_changed(struct virtio_device *dev) +{ + unsigned long flags; + + spin_lock_irqsave(&dev->config_lock, flags); + __virtio_config_changed(dev); + spin_unlock_irqrestore(&dev->config_lock, flags); +} +EXPORT_SYMBOL_GPL(virtio_config_changed); + +static void virtio_config_disable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_enabled = false; + spin_unlock_irq(&dev->config_lock); +} + +static void virtio_config_enable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_enabled = true; + if (dev->config_change_pending) + __virtio_config_changed(dev); + dev->config_change_pending = false; + spin_unlock_irq(&dev->config_lock); +} + +static int virtio_finalize_features(struct virtio_device *dev) +{ + int ret = dev->config->finalize_features(dev); + unsigned status; + + if (ret) + return ret; + + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) + return 0; + + add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); + status = dev->config->get_status(dev); + if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { + dev_err(&dev->dev, "virtio: device refuses features: %x\n", + status); + return -ENODEV; + } + return 0; +} + static int virtio_dev_probe(struct device *_d) { int err, i; struct virtio_device *dev = dev_to_virtio(_d); struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); - u32 device_features; + u64 device_features; + u64 driver_features; + u64 driver_features_legacy; /* We have a driver! */ add_status(dev, VIRTIO_CONFIG_S_DRIVER); @@ -119,32 +198,58 @@ /* Figure out what features the device supports. */ device_features = dev->config->get_features(dev); - /* Features supported by both device and driver into dev->features. */ - memset(dev->features, 0, sizeof(dev->features)); + /* Figure out what features the driver supports. */ + driver_features = 0; for (i = 0; i < drv->feature_table_size; i++) { unsigned int f = drv->feature_table[i]; - BUG_ON(f >= 32); - if (device_features & (1 << f)) - set_bit(f, dev->features); + BUG_ON(f >= 64); + driver_features |= (1ULL << f); } + /* Some drivers have a separate feature table for virtio v1.0 */ + if (drv->feature_table_legacy) { + driver_features_legacy = 0; + for (i = 0; i < drv->feature_table_size_legacy; i++) { + unsigned int f = drv->feature_table_legacy[i]; + BUG_ON(f >= 64); + driver_features_legacy |= (1ULL << f); + } + } else { + driver_features_legacy = driver_features; + } + + if (device_features & (1ULL << VIRTIO_F_VERSION_1)) + dev->features = driver_features & device_features; + else + dev->features = driver_features_legacy & device_features; + /* Transport features always preserved to pass to finalize_features. */ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) - if (device_features & (1 << i)) - set_bit(i, dev->features); + if (device_features & (1ULL << i)) + __virtio_set_bit(dev, i); - dev->config->finalize_features(dev); + err = virtio_finalize_features(dev); + if (err) + goto err; err = drv->probe(dev); if (err) - add_status(dev, VIRTIO_CONFIG_S_FAILED); - else { - add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); - if (drv->scan) - drv->scan(dev); - } + goto err; + + /* If probe didn't do it, mark device DRIVER_OK ourselves. */ + if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK)) + virtio_device_ready(dev); + if (drv->scan) + drv->scan(dev); + + virtio_config_enable(dev); + + return 0; +err: + add_status(dev, VIRTIO_CONFIG_S_FAILED); return err; + } static int virtio_dev_remove(struct device *_d) @@ -152,6 +257,8 @@ struct virtio_device *dev = dev_to_virtio(_d); struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + virtio_config_disable(dev); + drv->remove(dev); /* Driver should have reset device. */ @@ -165,7 +272,7 @@ static struct bus_type virtio_bus = { .name = "virtio", .match = virtio_dev_match, - .dev_attrs = virtio_dev_attrs, + .dev_groups = virtio_dev_groups, .uevent = virtio_uevent, .probe = virtio_dev_probe, .remove = virtio_dev_remove, @@ -200,6 +307,10 @@ dev->index = err; dev_set_name(&dev->dev, "virtio%u", dev->index); + spin_lock_init(&dev->config_lock); + dev->config_enabled = false; + dev->config_change_pending = false; + /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ dev->config->reset(dev); @@ -228,6 +339,69 @@ } EXPORT_SYMBOL_GPL(unregister_virtio_device); +#ifdef CONFIG_PM_SLEEP +int virtio_device_freeze(struct virtio_device *dev) +{ + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + + virtio_config_disable(dev); + + dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED; + + if (drv && drv->freeze) + return drv->freeze(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(virtio_device_freeze); + +int virtio_device_restore(struct virtio_device *dev) +{ + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + int ret; + + /* We always start by resetting the device, in case a previous + * driver messed it up. */ + dev->config->reset(dev); + + /* Acknowledge that we've seen the device. */ + add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); + + /* Maybe driver failed before freeze. + * Restore the failed status, for debugging. */ + if (dev->failed) + add_status(dev, VIRTIO_CONFIG_S_FAILED); + + if (!drv) + return 0; + + /* We have a driver! */ + add_status(dev, VIRTIO_CONFIG_S_DRIVER); + + ret = virtio_finalize_features(dev); + if (ret) + goto err; + + if (drv->restore) { + ret = drv->restore(dev); + if (ret) + goto err; + } + + /* Finally, tell the device we're all set */ + add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + + virtio_config_enable(dev); + + return 0; + +err: + add_status(dev, VIRTIO_CONFIG_S_FAILED); + return ret; +} +EXPORT_SYMBOL_GPL(virtio_device_restore); +#endif + static int virtio_init(void) { if (bus_register(&virtio_bus) != 0)