From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759382AbcJaFtk (ORCPT ); Mon, 31 Oct 2016 01:49:40 -0400 Received: from p3plsmtps2ded01.prod.phx3.secureserver.net ([208.109.80.58]:41698 "EHLO p3plsmtps2ded01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759048AbcJaFs7 (ORCPT ); Mon, 31 Oct 2016 01:48:59 -0400 x-originating-ip: 72.167.245.219 From: kys@exchange.microsoft.com To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com, leann.ogasawara@canonical.com, sthemmin@microsoft.com Cc: "K. Y. Srinivasan" Subject: [PATCH 15/15] Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the host Date: Mon, 31 Oct 2016 00:41:50 -0700 Message-Id: <1477899710-28675-15-git-send-email-kys@exchange.microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1477899710-28675-1-git-send-email-kys@exchange.microsoft.com> References: <1477899668-28635-1-git-send-email-kys@exchange.microsoft.com> <1477899710-28675-1-git-send-email-kys@exchange.microsoft.com> Reply-To: kys@microsoft.com X-CMAE-Envelope: MS4wfOoBE6Kf+u6UIOV3WwBQbJ1C3EsneSBC8gk3KzGgX+/PqWun4GoApn18mOd5vzem9bdUoMGbvp1DpHsiwosUTGjj6DFBy8UMZKLF9pjR3e5RtVut7qpY tvKJGldl1yVmMnPlGRIXpdREH2jPp/KbeGnUkUOk7QFpbK/trzsm/1qAl3U+EfK6/DWh/2Tg6sdfO/af11QSdsqOCaB5fVNpf6aaGr6maONiPIvaoTrpk5ct mmVn4Ujm5wbPyjBXSEzhC0UX+buA+qie0bcK0K6oPvuEakoPW5DMVX/bbVe8+gsdVhYlWztuTatWWDW08T6EZHHO2UuqOGN0XRIhdhfyD3YrnTMq813fAnnR FitJICXXqJ8M0+0h37SKkdwQ2OMXKkZ2Wyod11qRVS3a55yjW9mS8Sd6EN6P2Jy9kEBYrAnRtyPP6FA3S/zEteDvRL/v+OS98CjjQkbWYDslwc+Dehx2Pofc LtZXQj03c1owPP4nn0bmRjzDAB1WQfZCthxkNA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: K. Y. Srinivasan 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 --- 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 975c98a..bffdca3 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -878,16 +878,9 @@ __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 2d42ebe..0675b39 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 4af7130..cd49cb1 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 dd31882..2a52d9a 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1480,10 +1480,11 @@ 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. @@ -1501,14 +1502,14 @@ 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; } /* @@ -1580,8 +1581,7 @@ 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); } -- 1.7.4.1