kernel/linux.git/drivers/hv/ring_buffer.c, branch v4.11.5

vmbus: replace modulus operation with subtraction

2017-02-14T18:20:35+00:00

Takes less clock cycles to check for ring wrap and subtract than to do a modulus instruction. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: constify parameters where possible

2017-02-14T18:20:35+00:00

Functions that just query state of ring buffer can have parameters marked const. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: expose hv_begin/end_read

2017-02-14T18:20:35+00:00

In order to implement NAPI in netvsc, the driver needs access to control host interrupt mask. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: remove conditional locking of vmbus_write

2017-02-14T18:20:35+00:00

All current usage of vmbus write uses the acquire_lock flag, therefore having it be optional is unnecessary. This also fixes a sparse warning since sparse doesn't like when a function has conditional locking. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: drop no longer used kick_q argument

2017-02-10T14:44:15+00:00

The flag to cause notification of host is unused after commit a01a291a282f7c2e ("Drivers: hv: vmbus: Base host signaling strictly on the ring state"). Therefore remove it from the ring buffer internal API. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Merge 4.10-rc7 into char-misc-next

2017-02-06T08:39:13+00:00

We want the hv and other fixes in here as well to handle merge and testing issues. Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()

2017-01-31T09:59:48+00:00

Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui Reported-by: Rolf Neugebauer Tested-by: Rolf Neugebauer Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Prevent sending data on a rescinded channel

2017-01-10T20:46:41+00:00

After the channel is rescinded, the host does not read from the rescinded channel. Fail writes to a channel that has already been rescinded. If we permit writes on a rescinded channel, since the host will not respond we will have situations where we will be unable to unload vmbus drivers that cannot have any outstanding requests to the host at the point they are unoaded. Signed-off-by: K. Y. Srinivasan Cc: Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the host

2016-11-07T09:01:18+00:00

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: vmbus: On write cleanup the logic to interrupt the host

2016-11-07T09:01:17+00:00

Signal the host when we determine the host is to be signaled. 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