From 33be96e47cc27f2f1a753a0707b02a73df8c8d46 Mon Sep 17 00:00:00 2001 From: Haiyang Zhang Date: Tue, 27 Mar 2012 13:20:45 +0000 Subject: net/hyperv: Add flow control based on hi/low watermark In the existing code, we only stop queue when the ringbuffer is full, so the current packet has to be dropped or retried from upper layer. This patch stops the tx queue when available ringbuffer is below the low watermark. So the ringbuffer still has small amount of space available for the current packet. This will reduce the overhead of retries on sending. Signed-off-by: Haiyang Zhang Reviewed-by: K. Y. Srinivasan Signed-off-by: David S. Miller --- include/linux/hyperv.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/hyperv.h') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 5852545e6bba..6af8738ae7e9 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -274,6 +274,33 @@ struct hv_ring_buffer_debug_info { u32 bytes_avail_towrite; }; + +/* + * + * hv_get_ringbuffer_availbytes() + * + * Get number of bytes available to read and to write to + * for the specified ring buffer + */ +static inline void +hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, + u32 *read, u32 *write) +{ + u32 read_loc, write_loc, dsize; + + smp_read_barrier_depends(); + + /* Capture the read/write indices before they changed */ + read_loc = rbi->ring_buffer->read_index; + write_loc = rbi->ring_buffer->write_index; + dsize = rbi->ring_datasize; + + *write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : + read_loc - write_loc; + *read = dsize - *write; +} + + /* * We use the same version numbering for all Hyper-V modules. * -- cgit v1.2.3 From c836d0ab70acf7b7bd2b698278e8abae9e6d9978 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sat, 12 May 2012 13:44:58 -0700 Subject: Drivers: hv: util: Properly handle version negotiations. The current version negotiation code is not "future proof". Fix this by allowing each service the flexibility to either specify the highest version it can support or it can support the highest version number the host is offering. Signed-off-by: K. Y. Srinivasan Reviewed-by: Haiyang Zhang Signed-off-by: Greg Kroah-Hartman --- include/linux/hyperv.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/hyperv.h') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 5852545e6bba..22172bd43745 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1035,8 +1035,10 @@ struct hyperv_service_callback { void (*callback) (void *context); }; +#define MAX_SRV_VER 0x7ffffff extern void vmbus_prep_negotiate_resp(struct icmsg_hdr *, - struct icmsg_negotiate *, u8 *); + struct icmsg_negotiate *, u8 *, int, + int); int hv_kvp_init(struct hv_util_service *); void hv_kvp_deinit(void); -- cgit v1.2.3