VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

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author: Peter Hurley <peter@hurleysoftware.com> 2012-08-19 02:50:02 -0400 committer: Stefan Richter <stefanr@s5r6.in-berlin.de> 2012-09-28 11:47:41 +0200 commit: 35202f7d8420fff586b372422a2419affeaba8ef parent: 52439d605d6604c15954281a1d2831471dbd024c
Commit Summary:
firewire: remove global lock around address handlers, convert to RCU
Diffstat:
1 file changed, 11 insertions, 9 deletions
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 87d6f2d2f02d..d39cfa45817a 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;
 	}
@@ -588,7 +589,7 @@ 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;
 		}
@@ -609,8 +610,9 @@ EXPORT_SYMBOL(fw_core_add_address_handler);
 void fw_core_remove_address_handler(struct fw_address_handler *handler)
 {
 	spin_lock_bh(&address_handler_lock);
-	list_del(&handler->link);
+	list_del_rcu(&handler->link);
 	spin_unlock_bh(&address_handler_lock);
+	synchronize_rcu();
 }
 EXPORT_SYMBOL(fw_core_remove_address_handler);
 
@@ -844,7 +846,7 @@ 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 +855,7 @@ 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 +888,8 @@ 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 +898,7 @@ 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);
 }