Merge tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire updates from Stefan Richter:
  - feed GUIDs of FireWire nodes to the random pool
  - more complete quirk handling of a TI S400B phy
  - avoid holding a core lock while calling into highlevel drivers

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: addendum to address handler RCU conversion
  firewire: remove global lock around address handlers, convert to RCU
  firewire: ohci: get IR bit from TSB41BA3D phy
  firewire: core: feed /dev/random with devices' GUIDs

4 files changed, 59 insertions, 17 deletions

diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 7a05fd24d68b..3873d535b28d 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -32,6 +32,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/random.h>
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -1066,6 +1067,8 @@ static void fw_device_init(struct work_struct *work)
 		device->config_rom_retries = 0;
 
 		set_broadcast_channel(device, device->generation);
+
+		add_device_randomness(&device->config_rom[3], 8);
 	}
 
 	/*
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 87d6f2d2f02d..28a94c7ec6e5 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -31,6 +31,7 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/rculist.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
@@ -489,7 +490,7 @@ static struct fw_address_handler *lookup_overlapping_address_handler(
 {
 	struct fw_address_handler *handler;
 
-	list_for_each_entry(handler, list, link) {
+	list_for_each_entry_rcu(handler, list, link) {
 		if (handler->offset < offset + length &&
 		    offset < handler->offset + handler->length)
 			return handler;
@@ -510,7 +511,7 @@ static struct fw_address_handler *lookup_enclosing_address_handler(
 {
 	struct fw_address_handler *handler;
 
-	list_for_each_entry(handler, list, link) {
+	list_for_each_entry_rcu(handler, list, link) {
 		if (is_enclosing_handler(handler, offset, length))
 			return handler;
 	}
@@ -518,7 +519,7 @@ static struct fw_address_handler *lookup_enclosing_address_handler(
 	return NULL;
 }
 
-static DEFINE_SPINLOCK(address_handler_lock);
+static DEFINE_SPINLOCK(address_handler_list_lock);
 static LIST_HEAD(address_handler_list);
 
 const struct fw_address_region fw_high_memory_region =
@@ -555,6 +556,7 @@ static bool is_in_fcp_region(u64 offset, size_t length)
  * the specified callback is invoked.  The parameters passed to the callback
  * give the details of the particular request.
  *
+ * To be called in process context.
  * Return value:  0 on success, non-zero otherwise.
  *
  * The start offset of the handler's address region is determined by
@@ -575,7 +577,7 @@ int fw_core_add_address_handler(struct fw_address_handler *handler,
 	    handler->length == 0)
 		return -EINVAL;
 
-	spin_lock_bh(&address_handler_lock);
+	spin_lock(&address_handler_list_lock);
 
 	handler->offset = region->start;
 	while (handler->offset + handler->length <= region->end) {
@@ -588,13 +590,13 @@ int fw_core_add_address_handler(struct fw_address_handler *handler,
 		if (other != NULL) {
 			handler->offset += other->length;
 		} else {
-			list_add_tail(&handler->link, &address_handler_list);
+			list_add_tail_rcu(&handler->link, &address_handler_list);
 			ret = 0;
 			break;
 		}
 	}
 
-	spin_unlock_bh(&address_handler_lock);
+	spin_unlock(&address_handler_list_lock);
 
 	return ret;
 }
@@ -603,14 +605,17 @@ EXPORT_SYMBOL(fw_core_add_address_handler);
 /**
  * fw_core_remove_address_handler() - unregister an address handler
  *
+ * To be called in process context.
+ *
  * When fw_core_remove_address_handler() returns, @handler->callback() is
  * guaranteed to not run on any CPU anymore.
  */
 void fw_core_remove_address_handler(struct fw_address_handler *handler)
 {
-	spin_lock_bh(&address_handler_lock);
-	list_del(&handler->link);
-	spin_unlock_bh(&address_handler_lock);
+	spin_lock(&address_handler_list_lock);
+	list_del_rcu(&handler->link);
+	spin_unlock(&address_handler_list_lock);
+	synchronize_rcu();
 }
 EXPORT_SYMBOL(fw_core_remove_address_handler);
 
@@ -844,7 +849,7 @@ static void handle_exclusive_region_request(struct fw_card *card,
 	if (tcode == TCODE_LOCK_REQUEST)
 		tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);
 
-	spin_lock_bh(&address_handler_lock);
+	rcu_read_lock();
 	handler = lookup_enclosing_address_handler(&address_handler_list,
 						   offset, request->length);
 	if (handler)
@@ -853,7 +858,7 @@ static void handle_exclusive_region_request(struct fw_card *card,
 					  p->generation, offset,
 					  request->data, request->length,
 					  handler->callback_data);
-	spin_unlock_bh(&address_handler_lock);
+	rcu_read_unlock();
 
 	if (!handler)
 		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
@@ -886,8 +891,8 @@ static void handle_fcp_region_request(struct fw_card *card,
 		return;
 	}
 
-	spin_lock_bh(&address_handler_lock);
-	list_for_each_entry(handler, &address_handler_list, link) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(handler, &address_handler_list, link) {
 		if (is_enclosing_handler(handler, offset, request->length))
 			handler->address_callback(card, NULL, tcode,
 						  destination, source,
@@ -896,7 +901,7 @@ static void handle_fcp_region_request(struct fw_card *card,
 						  request->length,
 						  handler->callback_data);
 	}
-	spin_unlock_bh(&address_handler_lock);
+	rcu_read_unlock();
 
 	fw_send_response(card, request, RCODE_COMPLETE);
 }
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index c788dbdaf3bc..834e71d2324d 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1777,11 +1777,35 @@ static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
 	return i;
 }
 
+static int initiated_reset(struct fw_ohci *ohci)
+{
+	int reg;
+	int ret = 0;
+
+	mutex_lock(&ohci->phy_reg_mutex);
+	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
+	if (reg >= 0) {
+		reg = read_phy_reg(ohci, 8);
+		reg |= 0x40;
+		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
+		if (reg >= 0) {
+			reg = read_phy_reg(ohci, 12); /* read register 12 */
+			if (reg >= 0) {
+				if ((reg & 0x08) == 0x08) {
+					/* bit 3 indicates "initiated reset" */
+					ret = 0x2;
+				}
+			}
+		}
+	}
+	mutex_unlock(&ohci->phy_reg_mutex);
+	return ret;
+}
+
 /*
  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
  * Construct the selfID from phy register contents.
- * FIXME:  How to determine the selfID.i flag?
  */
 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
 {
@@ -1814,6 +1838,8 @@ static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
 		self_id |= ((status & 0x3) << (6 - (i * 2)));
 	}
 
+	self_id |= initiated_reset(ohci);
+
 	pos = get_self_id_pos(ohci, self_id, self_id_count);
 	if (pos >= 0) {
 		memmove(&(ohci->self_id_buffer[pos+1]),
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index db04ec5121cb..191501afd7fb 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -265,8 +265,16 @@ typedef void (*fw_transaction_callback_t)(struct fw_card *card, int rcode,
 					  void *data, size_t length,
 					  void *callback_data);
 /*
- * Important note:  Except for the FCP registers, the callback must guarantee
- * that either fw_send_response() or kfree() is called on the @request.
+ * This callback handles an inbound request subaction.  It is called in
+ * RCU read-side context, therefore must not sleep.
+ *
+ * The callback should not initiate outbound request subactions directly.
+ * Otherwise there is a danger of recursion of inbound and outbound
+ * transactions from and to the local node.
+ *
+ * The callback is responsible that either fw_send_response() or kfree()
+ * is called on the @request, except for FCP registers for which the core
+ * takes care of that.
  */
 typedef void (*fw_address_callback_t)(struct fw_card *card,
 				      struct fw_request *request,