[PATCH 8/8] Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: 2020-06-17 16:49:25
Also in:
lkml
Subsystem:
hyper-v/azure core and drivers, the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds
The spinlock is (now) *not used to protect test-and-set accesses
to attributes of the structure or sc_list operations.
There is, AFAICT, a distinct lack of {WRITE,READ}_ONCE()s in the
handling of channel->state, but the changes below do not seem to
make things "worse". ;-)
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
drivers/hv/channel.c | 6 +-----
drivers/hv/channel_mgmt.c | 1 -
include/linux/hyperv.h | 6 ------
3 files changed, 1 insertion(+), 12 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 8848d1548b3f2..3ebda7707e46a 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c@@ -129,12 +129,8 @@ static int __vmbus_open(struct vmbus_channel *newchannel, send_pages = newchannel->ringbuffer_send_offset; recv_pages = newchannel->ringbuffer_pagecount - send_pages; - spin_lock_irqsave(&newchannel->lock, flags); - if (newchannel->state != CHANNEL_OPEN_STATE) { - spin_unlock_irqrestore(&newchannel->lock, flags); + if (newchannel->state != CHANNEL_OPEN_STATE) return -EINVAL; - } - spin_unlock_irqrestore(&newchannel->lock, flags); newchannel->state = CHANNEL_OPENING_STATE; newchannel->onchannel_callback = onchannelcallback;
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 92f8bb2077a94..591106cf58fc0 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c@@ -317,7 +317,6 @@ static struct vmbus_channel *alloc_channel(void) return NULL; spin_lock_init(&channel->sched_lock); - spin_lock_init(&channel->lock); init_completion(&channel->rescind_event); INIT_LIST_HEAD(&channel->sc_list);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 690394b79d727..38100e80360ac 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h@@ -840,12 +840,6 @@ struct vmbus_channel { */ void (*chn_rescind_callback)(struct vmbus_channel *channel); - /* - * The spinlock to protect the structure. It is being used to protect - * test-and-set access to various attributes of the structure as well - * as all sc_list operations. - */ - spinlock_t lock; /* * All Sub-channels of a primary channel are linked here. */
--
2.25.1