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| author | K. Y. Srinivasan <kys@microsoft.com> | 2014-09-05 17:29:12 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-09-23 23:31:22 -0700 |
| commit | 046c7911b224267062ab1caeabbf11bc46e9c152 (patch) | |
| tree | f898990ae637ade8df913090aa45a34752f52801 /drivers/hv/ring_buffer.c | |
| parent | bc5a5b02331a3175a5fca20a4beba249e573b672 (diff) | |
| download | linux-046c7911b224267062ab1caeabbf11bc46e9c152.tar.gz | |
Drivers: hv: vmbus: Enable interrupt driven flow control
In win8 we have a feature that allows for interrupt driven flow management for host/guest communication. For instance, if the host were blocked because there was no space available in the ringbuffer, the host could request that the guest send an interrupt when space becomes available in the ringbuffer (when the guest drains the ringbuffer). While this feature was implemented in the guest a while ago, we had not advertised that the guest supported this feature. This patch advertises the support to the host. For pre-win8 hosts, this has no effect since the size of the ringbuffer control structure has not changed and all changes have been backward compatible - unused/reserved space has been used to implement this feature. In this version of the patch I have cleaned up the commit log based on feedback from Greg KH. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/ring_buffer.c')
| -rw-r--r-- | drivers/hv/ring_buffer.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 15db66b74141..6361d124f67d 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -361,6 +361,11 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, ring_info->ring_buffer->read_index = ring_info->ring_buffer->write_index = 0; + /* + * Set the feature bit for enabling flow control. + */ + ring_info->ring_buffer->feature_bits.value = 1; + ring_info->ring_size = buflen; ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); |