From 3372592a140db69fd63837e81f048ab4abf8111e Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sun, 6 Nov 2016 13:14:18 -0800 Subject: Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the host Signal the host when we determine the host is to be signaled - on th read path. The currrent code determines the need to signal in the ringbuffer code and actually issues the signal elsewhere. This can result in the host viewing this interrupt as spurious since the host may also poll the channel. Make the necessary adjustments. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel.c | 11 ++--------- drivers/hv/hyperv_vmbus.h | 4 ++-- drivers/hv/ring_buffer.c | 7 ++++--- include/linux/hyperv.h | 12 ++++++------ 4 files changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index 8a8148f7b842..5fb4c6d9209b 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -879,16 +879,9 @@ __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, bool raw) { - int ret; - bool signal = false; - - ret = hv_ringbuffer_read(&channel->inbound, buffer, bufferlen, - buffer_actual_len, requestid, &signal, raw); + return hv_ringbuffer_read(channel, buffer, bufferlen, + buffer_actual_len, requestid, raw); - if (signal) - vmbus_setevent(channel); - - return ret; } int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 2d42ebe2af6c..0675b395ce5c 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -532,9 +532,9 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, u32 kv_count, bool lock, bool kick_q); -int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, +int hv_ringbuffer_read(struct vmbus_channel *channel, void *buffer, u32 buflen, u32 *buffer_actual_len, - u64 *requestid, bool *signal, bool raw); + u64 *requestid, bool raw); void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, struct hv_ring_buffer_debug_info *debug_info); diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 4af71306d0ff..cd49cb17eb7f 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -353,9 +353,9 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, return 0; } -int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, +int hv_ringbuffer_read(struct vmbus_channel *channel, void *buffer, u32 buflen, u32 *buffer_actual_len, - u64 *requestid, bool *signal, bool raw) + u64 *requestid, bool raw) { u32 bytes_avail_toread; u32 next_read_location = 0; @@ -364,6 +364,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, u32 offset; u32 packetlen; int ret = 0; + struct hv_ring_buffer_info *inring_info = &channel->inbound; if (buflen <= 0) return -EINVAL; @@ -421,7 +422,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, /* Update the read index */ hv_set_next_read_location(inring_info, next_read_location); - *signal = hv_need_to_signal_on_read(inring_info); + hv_signal_on_read(channel); return ret; } diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 8cf78ed96747..fdb0a87323f3 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1487,10 +1487,11 @@ hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) * there is room for the producer to send the pending packet. */ -static inline bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) +static inline void hv_signal_on_read(struct vmbus_channel *channel) { u32 cur_write_sz; u32 pending_sz; + struct hv_ring_buffer_info *rbi = &channel->inbound; /* * Issue a full memory barrier before making the signaling decision. @@ -1508,14 +1509,14 @@ static inline bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); /* If the other end is not blocked on write don't bother. */ if (pending_sz == 0) - return false; + return; cur_write_sz = hv_get_bytes_to_write(rbi); if (cur_write_sz >= pending_sz) - return true; + vmbus_setevent(channel); - return false; + return; } /* @@ -1587,8 +1588,7 @@ static inline void commit_rd_index(struct vmbus_channel *channel) virt_rmb(); ring_info->ring_buffer->read_index = ring_info->priv_read_index; - if (hv_need_to_signal_on_read(ring_info)) - vmbus_set_event(channel); + hv_signal_on_read(channel); } -- cgit v1.2.3