From 8dd45f2ab005a1f3301296059b23b03ec3dbf79b Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sun, 25 Jun 2017 12:30:26 -0700 Subject: vmbus: refactor hv_signal_on_read The function hv_signal_on_read was defined in hyperv.h and only used in one place in ring_buffer code. Clearer to just move it inline there. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- include/linux/hyperv.h | 49 ------------------------------------------------- 1 file changed, 49 deletions(-) (limited to 'include/linux/hyperv.h') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 5e5f966bf37f..308e1f9706bb 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1471,55 +1471,6 @@ hv_get_ring_buffer(const struct hv_ring_buffer_info *ring_info) return ring_info->ring_buffer->buffer; } -/* - * To optimize the flow management on the send-side, - * when the sender is blocked because of lack of - * sufficient space in the ring buffer, potential the - * consumer of the ring buffer can signal the producer. - * This is controlled by the following parameters: - * - * 1. pending_send_sz: This is the size in bytes that the - * producer is trying to send. - * 2. The feature bit feat_pending_send_sz set to indicate if - * the consumer of the ring will signal when the ring - * state transitions from being full to a state where - * there is room for the producer to send the pending packet. - */ - -static inline void hv_signal_on_read(struct vmbus_channel *channel) -{ - u32 cur_write_sz, cached_write_sz; - u32 pending_sz; - struct hv_ring_buffer_info *rbi = &channel->inbound; - - /* - * Issue a full memory barrier before making the signaling decision. - * Here is the reason for having this barrier: - * If the reading of the pend_sz (in this function) - * were to be reordered and read before we commit the new read - * index (in the calling function) we could - * have a problem. If the host were to set the pending_sz after we - * have sampled pending_sz and go to sleep before we commit the - * read index, we could miss sending the interrupt. Issue a full - * memory barrier to address this. - */ - virt_mb(); - - 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; - - cur_write_sz = hv_get_bytes_to_write(rbi); - - if (cur_write_sz < pending_sz) - return; - - cached_write_sz = hv_get_cached_bytes_to_write(rbi); - if (cached_write_sz < pending_sz) - vmbus_setevent(channel); -} - /* * Mask off host interrupt callback notifications */ -- cgit v1.2.3