X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Ffirewire%2Ffw-device.h;h=42305bbac72fb3237c5826c7b6671bc64b6cc931;hb=96e2e6fafaedd83bd899f682907e14d1eec17390;hp=894d4a92a18ec9186787e391594f5c2e5c0c2c40;hpb=1316ff5d52a8caf76da3c5fb351699f9fcc07b4a;p=linux-2.6

diff --git a/drivers/firewire/fw-device.h b/drivers/firewire/fw-device.h
index 894d4a92a1..42305bbac7 100644
--- a/drivers/firewire/fw-device.h
+++ b/drivers/firewire/fw-device.h
@@ -21,6 +21,7 @@
 
 #include <linux/fs.h>
 #include <linux/cdev.h>
+#include <linux/rwsem.h>
 #include <asm/atomic.h>
 
 enum fw_device_state {
@@ -35,15 +36,32 @@ struct fw_attribute_group {
 	struct attribute *attrs[11];
 };
 
+/*
+ * Note, fw_device.generation always has to be read before fw_device.node_id.
+ * Use SMP memory barriers to ensure this.  Otherwise requests will be sent
+ * to an outdated node_id if the generation was updated in the meantime due
+ * to a bus reset.
+ *
+ * Likewise, fw-core will take care to update .node_id before .generation so
+ * that whenever fw_device.generation is current WRT the actual bus generation,
+ * fw_device.node_id is guaranteed to be current too.
+ *
+ * The same applies to fw_device.card->node_id vs. fw_device.generation.
+ *
+ * fw_device.config_rom and fw_device.config_rom_length may be accessed during
+ * the lifetime of any fw_unit belonging to the fw_device, before device_del()
+ * was called on the last fw_unit.  Alternatively, they may be accessed while
+ * holding fw_device_rwsem.
+ */
 struct fw_device {
 	atomic_t state;
 	struct fw_node *node;
 	int node_id;
 	int generation;
 	unsigned max_speed;
+	bool cmc;
 	struct fw_card *card;
 	struct device device;
-	struct list_head link;
 	struct list_head client_list;
 	u32 *config_rom;
 	size_t config_rom_length;
@@ -52,40 +70,63 @@ struct fw_device {
 	struct fw_attribute_group attribute_group;
 };
 
-static inline struct fw_device *
-fw_device(struct device *dev)
+static inline struct fw_device *fw_device(struct device *dev)
 {
 	return container_of(dev, struct fw_device, device);
 }
 
-static inline int
-fw_device_is_shutdown(struct fw_device *device)
+static inline int fw_device_is_shutdown(struct fw_device *device)
 {
 	return atomic_read(&device->state) == FW_DEVICE_SHUTDOWN;
 }
 
-struct fw_device *fw_device_get(struct fw_device *device);
-void fw_device_put(struct fw_device *device);
+static inline struct fw_device *fw_device_get(struct fw_device *device)
+{
+	get_device(&device->device);
+
+	return device;
+}
+
+static inline void fw_device_put(struct fw_device *device)
+{
+	put_device(&device->device);
+}
+
+struct fw_device *fw_device_get_by_devt(dev_t devt);
 int fw_device_enable_phys_dma(struct fw_device *device);
 
 void fw_device_cdev_update(struct fw_device *device);
 void fw_device_cdev_remove(struct fw_device *device);
 
-struct fw_device *fw_device_from_devt(dev_t devt);
+extern struct rw_semaphore fw_device_rwsem;
 extern int fw_cdev_major;
 
+/*
+ * fw_unit.directory must not be accessed after device_del(&fw_unit.device).
+ */
 struct fw_unit {
 	struct device device;
 	u32 *directory;
 	struct fw_attribute_group attribute_group;
 };
 
-static inline struct fw_unit *
-fw_unit(struct device *dev)
+static inline struct fw_unit *fw_unit(struct device *dev)
 {
 	return container_of(dev, struct fw_unit, device);
 }
 
+static inline struct fw_unit *fw_unit_get(struct fw_unit *unit)
+{
+	get_device(&unit->device);
+
+	return unit;
+}
+
+static inline void fw_unit_put(struct fw_unit *unit)
+{
+	put_device(&unit->device);
+}
+
 #define CSR_OFFSET	0x40
 #define CSR_LEAF	0x80
 #define CSR_DIRECTORY	0xc0