From d61031ee8df6214d58371a1cc36a0591e242fba0 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Fri, 9 Jan 2015 23:54:34 -0800 Subject: Drivers: hv: vmbus: Support a vmbus API for efficiently sending page arrays Currently, the API for sending a multi-page buffer over VMBUS is limited to a maximum pfn array of MAX_MULTIPAGE_BUFFER_COUNT. This limitation is not imposed by the host and unnecessarily limits the maximum payload that can be sent. Implement an API that does not have this restriction. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'drivers/hv/channel.c') diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index c76ffbe59f65..18c4f23dacf1 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -683,6 +683,50 @@ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, } EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); +/* + * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet + * using a GPADL Direct packet type. + * The buffer includes the vmbus descriptor. + */ +int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel, + struct vmbus_packet_mpb_array *desc, + u32 desc_size, + void *buffer, u32 bufferlen, u64 requestid) +{ + int ret; + u32 packetlen; + u32 packetlen_aligned; + struct kvec bufferlist[3]; + u64 aligned_data = 0; + bool signal = false; + + packetlen = desc_size + bufferlen; + packetlen_aligned = ALIGN(packetlen, sizeof(u64)); + + /* Setup the descriptor */ + desc->type = VM_PKT_DATA_USING_GPA_DIRECT; + desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; + desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */ + desc->length8 = (u16)(packetlen_aligned >> 3); + desc->transactionid = requestid; + desc->rangecount = 1; + + bufferlist[0].iov_base = desc; + bufferlist[0].iov_len = desc_size; + bufferlist[1].iov_base = buffer; + bufferlist[1].iov_len = bufferlen; + bufferlist[2].iov_base = &aligned_data; + bufferlist[2].iov_len = (packetlen_aligned - packetlen); + + ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal); + + if (ret == 0 && signal) + vmbus_setevent(channel); + + return ret; +} +EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc); + /* * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet * using a GPADL Direct packet type. -- cgit v1.2.3