Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/ieee1394/linux1394-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: (26 commits)
  firewire: fw-sbp2: Use sbp2 device-provided mgt orb timeout for logins
  firewire: fw-sbp2: increase login orb reply timeout, fix "failed to login"
  firewire: replace subtraction with bitwise and
  firewire: fw-core: react on bus resets while the config ROM is being fetched
  firewire: enforce access order between generation and node ID, fix "giving up on config rom"
  firewire: fw-cdev: use device generation, not card generation
  firewire: fw-sbp2: use device generation, not card generation
  firewire: fw-sbp2: try to increase reconnect_hold (speed up reconnection)
  firewire: fw-sbp2: skip unnecessary logout
  firewire vs. ieee1394: clarify MAINTAINERS
  firewire: fw-ohci: Dynamically allocate buffers for DMA descriptors
  firewire: fw-ohci: CycleTooLong interrupt management
  firewire: Fix extraction of source node id
  firewire: fw-ohci: Bug fixes for packet-per-buffer support
  firewire: fw-ohci: Fix for dualbuffer three-or-more buffers
  firewire: fw-sbp2: remove unused misleading macro
  firewire: fw-sbp2: prepare for s/g chaining
  firewire: fw-sbp2: refactor workq and kref handling
  ieee1394: ohci1394: don't schedule IT tasklets on IR events
  ieee1394: sbp2: raise default transfer size limit
  ...

MAINTAINERS

@@ -1595,7 +1595,7 @@ P:	Alexander Viro
 M:	viro@zeniv.linux.org.uk
 S:	Maintained
 
-FIREWIRE SUBSYSTEM
+FIREWIRE SUBSYSTEM (drivers/firewire, <linux/firewire*.h>)
 P:	Kristian Hoegsberg, Stefan Richter
 M:	krh@redhat.com, stefanr@s5r6.in-berlin.de
 L:	linux1394-devel@lists.sourceforge.net
@@ -1917,7 +1917,7 @@ L:	linux-ide@vger.kernel.org
 L:	linux-scsi@vger.kernel.org
 S:	Orphan
 
-IEEE 1394 SUBSYSTEM
+IEEE 1394 SUBSYSTEM (drivers/ieee1394)
 P:	Ben Collins
 M:	ben.collins@ubuntu.com
 P:	Stefan Richter

drivers/firewire/fw-cdev.c

@@ -206,12 +206,13 @@ fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
 
 	event->closure	     = client->bus_reset_closure;
 	event->type          = FW_CDEV_EVENT_BUS_RESET;
+	event->generation    = client->device->generation;
+	smp_rmb();           /* node_id must not be older than generation */
 	event->node_id       = client->device->node_id;
 	event->local_node_id = card->local_node->node_id;
 	event->bm_node_id    = 0; /* FIXME: We don't track the BM. */
 	event->irm_node_id   = card->irm_node->node_id;
 	event->root_node_id  = card->root_node->node_id;
-	event->generation    = card->generation;
 }
 
 static void

drivers/firewire/fw-device.c

@@ -27,6 +27,7 @@
 #include <linux/idr.h>
 #include <linux/rwsem.h>
 #include <asm/semaphore.h>
+#include <asm/system.h>
 #include <linux/ctype.h>
 #include "fw-transaction.h"
 #include "fw-topology.h"
@@ -182,9 +183,14 @@ static void fw_device_release(struct device *dev)
 
 int fw_device_enable_phys_dma(struct fw_device *device)
 {
+	int generation = device->generation;
+
+	/* device->node_id, accessed below, must not be older than generation */
+	smp_rmb();
+
 	return device->card->driver->enable_phys_dma(device->card,
 						     device->node_id,
-						     device->generation);
+						     generation);
 }
 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 
@@ -384,17 +390,21 @@ complete_transaction(struct fw_card *card, int rcode,
 	complete(&callback_data->done);
 }
 
-static int read_rom(struct fw_device *device, int index, u32 * data)
+static int
+read_rom(struct fw_device *device, int generation, int index, u32 *data)
 {
 	struct read_quadlet_callback_data callback_data;
 	struct fw_transaction t;
 	u64 offset;
 
+	/* device->node_id, accessed below, must not be older than generation */
+	smp_rmb();
+
 	init_completion(&callback_data.done);
 
 	offset = 0xfffff0000400ULL + index * 4;
 	fw_send_request(device->card, &t, TCODE_READ_QUADLET_REQUEST,
-			device->node_id, device->generation, device->max_speed,
+			device->node_id, generation, device->max_speed,
 			offset, NULL, 4, complete_transaction, &callback_data);
 
 	wait_for_completion(&callback_data.done);
@@ -404,7 +414,14 @@ static int read_rom(struct fw_device *device, int index, u32 * data)
 	return callback_data.rcode;
 }
 
-static int read_bus_info_block(struct fw_device *device)
+/*
+ * Read the bus info block, perform a speed probe, and read all of the rest of
+ * the config ROM.  We do all this with a cached bus generation.  If the bus
+ * generation changes under us, read_bus_info_block will fail and get retried.
+ * It's better to start all over in this case because the node from which we
+ * are reading the ROM may have changed the ROM during the reset.
+ */
+static int read_bus_info_block(struct fw_device *device, int generation)
 {
 	static u32 rom[256];
 	u32 stack[16], sp, key;
@@ -414,7 +431,7 @@ static int read_bus_info_block(struct fw_device *device)
 
 	/* First read the bus info block. */
 	for (i = 0; i < 5; i++) {
-		if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 			return -1;
 		/*
 		 * As per IEEE1212 7.2, during power-up, devices can
@@ -449,7 +466,8 @@ static int read_bus_info_block(struct fw_device *device)
 			device->max_speed = device->card->link_speed;
 
 		while (device->max_speed > SCODE_100) {
-			if (read_rom(device, 0, &dummy) == RCODE_COMPLETE)
+			if (read_rom(device, generation, 0, &dummy) ==
+			    RCODE_COMPLETE)
 				break;
 			device->max_speed--;
 		}
@@ -482,7 +500,7 @@ static int read_bus_info_block(struct fw_device *device)
 			return -1;
 
 		/* Read header quadlet for the block to get the length. */
-		if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 			return -1;
 		end = i + (rom[i] >> 16) + 1;
 		i++;
@@ -501,7 +519,8 @@ static int read_bus_info_block(struct fw_device *device)
 		 * it references another block, and push it in that case.
 		 */
 		while (i < end) {
-			if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+			if (read_rom(device, generation, i, &rom[i]) !=
+			    RCODE_COMPLETE)
 				return -1;
 			if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
 			    sp < ARRAY_SIZE(stack))
@@ -648,7 +667,7 @@ static void fw_device_init(struct work_struct *work)
 	 * device.
 	 */
 
-	if (read_bus_info_block(device) < 0) {
+	if (read_bus_info_block(device, device->generation) < 0) {
 		if (device->config_rom_retries < MAX_RETRIES) {
 			device->config_rom_retries++;
 			schedule_delayed_work(&device->work, RETRY_DELAY);
@@ -801,6 +820,7 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 
 		device = node->data;
 		device->node_id = node->node_id;
+		smp_wmb();  /* update node_id before generation */
 		device->generation = card->generation;
 		if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
 			PREPARE_DELAYED_WORK(&device->work, fw_device_update);

drivers/firewire/fw-device.h

@@ -35,6 +35,18 @@ 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.
+ */
 struct fw_device {
 	atomic_t state;
 	struct fw_node *node;