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-rw-r--r--drivers/hv/channel.c15
-rw-r--r--drivers/hv/channel_mgmt.c1
-rw-r--r--drivers/hv/hyperv_vmbus.h2
-rw-r--r--drivers/hv/ring_buffer.c13
-rw-r--r--include/linux/hyperv.h16
5 files changed, 37 insertions, 10 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index fcab234796ef..56dd261f7142 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -639,6 +639,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
u64 aligned_data = 0;
int ret;
bool signal = false;
+ bool lock = channel->acquire_ring_lock;
int num_vecs = ((bufferlen != 0) ? 3 : 1);
@@ -658,7 +659,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
- &signal);
+ &signal, lock);
/*
* Signalling the host is conditional on many factors:
@@ -738,6 +739,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
struct kvec bufferlist[3];
u64 aligned_data = 0;
bool signal = false;
+ bool lock = channel->acquire_ring_lock;
if (pagecount > MAX_PAGE_BUFFER_COUNT)
return -EINVAL;
@@ -774,7 +776,8 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+ ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+ &signal, lock);
/*
* Signalling the host is conditional on many factors:
@@ -837,6 +840,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
struct kvec bufferlist[3];
u64 aligned_data = 0;
bool signal = false;
+ bool lock = channel->acquire_ring_lock;
packetlen = desc_size + bufferlen;
packetlen_aligned = ALIGN(packetlen, sizeof(u64));
@@ -856,7 +860,8 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+ ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+ &signal, lock);
if (ret == 0 && signal)
vmbus_setevent(channel);
@@ -881,6 +886,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
struct kvec bufferlist[3];
u64 aligned_data = 0;
bool signal = false;
+ bool lock = channel->acquire_ring_lock;
u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
multi_pagebuffer->len);
@@ -919,7 +925,8 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+ ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+ &signal, lock);
if (ret == 0 && signal)
vmbus_setevent(channel);
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index cf311be88cb4..b40f429aaa13 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -259,6 +259,7 @@ static struct vmbus_channel *alloc_channel(void)
return NULL;
channel->id = atomic_inc_return(&chan_num);
+ channel->acquire_ring_lock = true;
spin_lock_init(&channel->inbound_lock);
spin_lock_init(&channel->lock);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index ac7aa303c37d..b9ea7f59036b 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -529,7 +529,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
struct kvec *kv_list,
- u32 kv_count, bool *signal);
+ u32 kv_count, bool *signal, bool lock);
int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
void *buffer, u32 buflen, u32 *buffer_actual_len,
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 1145f3b8e4e0..5613e2b5cff7 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -314,7 +314,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
/* Write to the ring buffer. */
int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
- struct kvec *kv_list, u32 kv_count, bool *signal)
+ struct kvec *kv_list, u32 kv_count, bool *signal, bool lock)
{
int i = 0;
u32 bytes_avail_towrite;
@@ -324,14 +324,15 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
u32 next_write_location;
u32 old_write;
u64 prev_indices = 0;
- unsigned long flags;
+ unsigned long flags = 0;
for (i = 0; i < kv_count; i++)
totalbytes_towrite += kv_list[i].iov_len;
totalbytes_towrite += sizeof(u64);
- spin_lock_irqsave(&outring_info->ring_lock, flags);
+ if (lock)
+ spin_lock_irqsave(&outring_info->ring_lock, flags);
hv_get_ringbuffer_availbytes(outring_info,
&bytes_avail_toread,
@@ -343,7 +344,8 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
* is empty since the read index == write index.
*/
if (bytes_avail_towrite <= totalbytes_towrite) {
- spin_unlock_irqrestore(&outring_info->ring_lock, flags);
+ if (lock)
+ spin_unlock_irqrestore(&outring_info->ring_lock, flags);
return -EAGAIN;
}
@@ -374,7 +376,8 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
hv_set_next_write_location(outring_info, next_write_location);
- spin_unlock_irqrestore(&outring_info->ring_lock, flags);
+ if (lock)
+ spin_unlock_irqrestore(&outring_info->ring_lock, flags);
*signal = hv_need_to_signal(old_write, outring_info);
return 0;
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c056f058dcf8..d23dab0d770b 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -811,8 +811,24 @@ struct vmbus_channel {
* signaling control.
*/
enum hv_signal_policy signal_policy;
+ /*
+ * On the channel send side, many of the VMBUS
+ * device drivers explicity serialize access to the
+ * outgoing ring buffer. Give more control to the
+ * VMBUS device drivers in terms how to serialize
+ * accesss to the outgoing ring buffer.
+ * The default behavior will be to aquire the
+ * ring lock to preserve the current behavior.
+ */
+ bool acquire_ring_lock;
+
};
+static inline void set_channel_lock_state(struct vmbus_channel *c, bool state)
+{
+ c->acquire_ring_lock = state;
+}
+
static inline bool is_hvsock_channel(const struct vmbus_channel *c)
{
return !!(c->offermsg.offer.chn_flags &