1 files changed, 91 insertions, 39 deletions

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 6ac5ff20a2fe..01354b9de8b2 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -23,6 +23,7 @@
 #include <asm/byteorder.h>
 
 #include "core.h"
+#include <trace/events/firewire.h>
 
 #define define_fw_printk_level(func, kern_level)		\
 void func(const struct fw_card *card, const char *fmt, ...)	\
@@ -167,7 +168,6 @@ static size_t required_space(struct fw_descriptor *desc)
 int fw_core_add_descriptor(struct fw_descriptor *desc)
 {
 	size_t i;
-	int ret;
 
 	/*
 	 * Check descriptor is valid; the length of all blocks in the
@@ -181,29 +181,25 @@ int fw_core_add_descriptor(struct fw_descriptor *desc)
 	if (i != desc->length)
 		return -EINVAL;
 
-	mutex_lock(&card_mutex);
+	guard(mutex)(&card_mutex);
 
-	if (config_rom_length + required_space(desc) > 256) {
-		ret = -EBUSY;
-	} else {
-		list_add_tail(&desc->link, &descriptor_list);
-		config_rom_length += required_space(desc);
-		descriptor_count++;
-		if (desc->immediate > 0)
-			descriptor_count++;
-		update_config_roms();
-		ret = 0;
-	}
+	if (config_rom_length + required_space(desc) > 256)
+		return -EBUSY;
 
-	mutex_unlock(&card_mutex);
+	list_add_tail(&desc->link, &descriptor_list);
+	config_rom_length += required_space(desc);
+	descriptor_count++;
+	if (desc->immediate > 0)
+		descriptor_count++;
+	update_config_roms();
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(fw_core_add_descriptor);
 
 void fw_core_remove_descriptor(struct fw_descriptor *desc)
 {
-	mutex_lock(&card_mutex);
+	guard(mutex)(&card_mutex);
 
 	list_del(&desc->link);
 	config_rom_length -= required_space(desc);
@@ -211,8 +207,6 @@ void fw_core_remove_descriptor(struct fw_descriptor *desc)
 	if (desc->immediate > 0)
 		descriptor_count--;
 	update_config_roms();
-
-	mutex_unlock(&card_mutex);
 }
 EXPORT_SYMBOL(fw_core_remove_descriptor);
 
@@ -221,11 +215,15 @@ static int reset_bus(struct fw_card *card, bool short_reset)
 	int reg = short_reset ? 5 : 1;
 	int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
 
+	trace_bus_reset_initiate(card->index, card->generation, short_reset);
+
 	return card->driver->update_phy_reg(card, reg, 0, bit);
 }
 
 void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset)
 {
+	trace_bus_reset_schedule(card->index, card->generation, short_reset);
+
 	/* We don't try hard to sort out requests of long vs. short resets. */
 	card->br_short = short_reset;
 
@@ -244,6 +242,8 @@ static void br_work(struct work_struct *work)
 	/* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */
 	if (card->reset_jiffies != 0 &&
 	    time_before64(get_jiffies_64(), card->reset_jiffies + 2 * HZ)) {
+		trace_bus_reset_postpone(card->index, card->generation, card->br_short);
+
 		if (!queue_delayed_work(fw_workqueue, &card->br_work, 2 * HZ))
 			fw_card_put(card);
 		return;
@@ -374,11 +374,11 @@ static void bm_work(struct work_struct *work)
 
 		bm_id = be32_to_cpu(transaction_data[0]);
 
-		spin_lock_irq(&card->lock);
-		if (rcode == RCODE_COMPLETE && generation == card->generation)
-			card->bm_node_id =
-			    bm_id == 0x3f ? local_id : 0xffc0 | bm_id;
-		spin_unlock_irq(&card->lock);
+		scoped_guard(spinlock_irq, &card->lock) {
+			if (rcode == RCODE_COMPLETE && generation == card->generation)
+				card->bm_node_id =
+				    bm_id == 0x3f ? local_id : 0xffc0 | bm_id;
+		}
 
 		if (rcode == RCODE_COMPLETE && bm_id != 0x3f) {
 			/* Somebody else is BM.  Only act as IRM. */
@@ -429,7 +429,23 @@ static void bm_work(struct work_struct *work)
 	 */
 	card->bm_generation = generation;
 
-	if (root_device == NULL) {
+	if (card->gap_count == 0) {
+		/*
+		 * If self IDs have inconsistent gap counts, do a
+		 * bus reset ASAP. The config rom read might never
+		 * complete, so don't wait for it. However, still
+		 * send a PHY configuration packet prior to the
+		 * bus reset. The PHY configuration packet might
+		 * fail, but 1394-2008 8.4.5.2 explicitly permits
+		 * it in this case, so it should be safe to try.
+		 */
+		new_root_id = local_id;
+		/*
+		 * We must always send a bus reset if the gap count
+		 * is inconsistent, so bypass the 5-reset limit.
+		 */
+		card->bm_retries = 0;
+	} else if (root_device == NULL) {
 		/*
 		 * Either link_on is false, or we failed to read the
 		 * config rom.  In either case, pick another root.
@@ -484,7 +500,19 @@ static void bm_work(struct work_struct *work)
 		fw_notice(card, "phy config: new root=%x, gap_count=%d\n",
 			  new_root_id, gap_count);
 		fw_send_phy_config(card, new_root_id, generation, gap_count);
-		reset_bus(card, true);
+		/*
+		 * Where possible, use a short bus reset to minimize
+		 * disruption to isochronous transfers. But in the event
+		 * of a gap count inconsistency, use a long bus reset.
+		 *
+		 * As noted in 1394a 8.4.6.2, nodes on a mixed 1394/1394a bus
+		 * may set different gap counts after a bus reset. On a mixed
+		 * 1394/1394a bus, a short bus reset can get doubled. Some
+		 * nodes may treat the double reset as one bus reset and others
+		 * may treat it as two, causing a gap count inconsistency
+		 * again. Using a long bus reset prevents this.
+		 */
+		reset_bus(card, card->gap_count != 0);
 		/* Will allocate broadcast channel after the reset. */
 		goto out;
 	}
@@ -543,25 +571,47 @@ void fw_card_initialize(struct fw_card *card,
 }
 EXPORT_SYMBOL(fw_card_initialize);
 
-int fw_card_add(struct fw_card *card,
-		u32 max_receive, u32 link_speed, u64 guid)
+int fw_card_add(struct fw_card *card, u32 max_receive, u32 link_speed, u64 guid,
+		unsigned int supported_isoc_contexts)
 {
+	struct workqueue_struct *isoc_wq;
 	int ret;
 
+	// This workqueue should be:
+	//  * != WQ_BH			Sleepable.
+	//  * == WQ_UNBOUND		Any core can process data for isoc context. The
+	//				implementation of unit protocol could consumes the core
+	//				longer somehow.
+	//  * != WQ_MEM_RECLAIM		Not used for any backend of block device.
+	//  * == WQ_FREEZABLE		Isochronous communication is at regular interval in real
+	//				time, thus should be drained if possible at freeze phase.
+	//  * == WQ_HIGHPRI		High priority to process semi-realtime timestamped data.
+	//  * == WQ_SYSFS		Parameters are available via sysfs.
+	//  * max_active == n_it + n_ir	A hardIRQ could notify events for multiple isochronous
+	//				contexts if they are scheduled to the same cycle.
+	isoc_wq = alloc_workqueue("firewire-isoc-card%u",
+				  WQ_UNBOUND | WQ_FREEZABLE | WQ_HIGHPRI | WQ_SYSFS,
+				  supported_isoc_contexts, card->index);
+	if (!isoc_wq)
+		return -ENOMEM;
+
 	card->max_receive = max_receive;
 	card->link_speed = link_speed;
 	card->guid = guid;
 
-	mutex_lock(&card_mutex);
+	guard(mutex)(&card_mutex);
 
 	generate_config_rom(card, tmp_config_rom);
 	ret = card->driver->enable(card, tmp_config_rom, config_rom_length);
-	if (ret == 0)
-		list_add_tail(&card->link, &card_list);
+	if (ret < 0) {
+		destroy_workqueue(isoc_wq);
+		return ret;
+	}
 
-	mutex_unlock(&card_mutex);
+	card->isoc_wq = isoc_wq;
+	list_add_tail(&card->link, &card_list);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(fw_card_add);
 
@@ -679,29 +729,31 @@ EXPORT_SYMBOL_GPL(fw_card_release);
 void fw_core_remove_card(struct fw_card *card)
 {
 	struct fw_card_driver dummy_driver = dummy_driver_template;
-	unsigned long flags;
+
+	might_sleep();
 
 	card->driver->update_phy_reg(card, 4,
 				     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
 	fw_schedule_bus_reset(card, false, true);
 
-	mutex_lock(&card_mutex);
-	list_del_init(&card->link);
-	mutex_unlock(&card_mutex);
+	scoped_guard(mutex, &card_mutex)
+		list_del_init(&card->link);
 
 	/* Switch off most of the card driver interface. */
 	dummy_driver.free_iso_context	= card->driver->free_iso_context;
 	dummy_driver.stop_iso		= card->driver->stop_iso;
 	card->driver = &dummy_driver;
+	drain_workqueue(card->isoc_wq);
 
-	spin_lock_irqsave(&card->lock, flags);
-	fw_destroy_nodes(card);
-	spin_unlock_irqrestore(&card->lock, flags);
+	scoped_guard(spinlock_irqsave, &card->lock)
+		fw_destroy_nodes(card);
 
 	/* Wait for all users, especially device workqueue jobs, to finish. */
 	fw_card_put(card);
 	wait_for_completion(&card->done);
 
+	destroy_workqueue(card->isoc_wq);
+
 	WARN_ON(!list_empty(&card->transaction_list));
 }
 EXPORT_SYMBOL(fw_core_remove_card);