diff options
Diffstat (limited to 'drivers/hv/channel.c')
| -rw-r--r-- | drivers/hv/channel.c | 829 |
1 files changed, 829 insertions, 0 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c new file mode 100644 index 00000000000..284cf66489f --- /dev/null +++ b/drivers/hv/channel.c @@ -0,0 +1,829 @@ +/* + * Copyright (c) 2009, Microsoft Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple + * Place - Suite 330, Boston, MA 02111-1307 USA. + * + * Authors: + * Haiyang Zhang <haiyangz@microsoft.com> + * Hank Janssen <hjanssen@microsoft.com> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/hyperv.h> +#include <linux/uio.h> + +#include "hyperv_vmbus.h" + +#define NUM_PAGES_SPANNED(addr, len) \ +((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT)) + +/* + * vmbus_setevent- Trigger an event notification on the specified + * channel. + */ +static void vmbus_setevent(struct vmbus_channel *channel) +{ + struct hv_monitor_page *monitorpage; + + if (channel->offermsg.monitor_allocated) { + /* Each u32 represents 32 channels */ + sync_set_bit(channel->offermsg.child_relid & 31, + (unsigned long *) vmbus_connection.send_int_page + + (channel->offermsg.child_relid >> 5)); + + /* Get the child to parent monitor page */ + monitorpage = vmbus_connection.monitor_pages[1]; + + sync_set_bit(channel->monitor_bit, + (unsigned long *)&monitorpage->trigger_group + [channel->monitor_grp].pending); + + } else { + vmbus_set_event(channel); + } +} + +/* + * vmbus_open - Open the specified channel. + */ +int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, + u32 recv_ringbuffer_size, void *userdata, u32 userdatalen, + void (*onchannelcallback)(void *context), void *context) +{ + struct vmbus_channel_open_channel *open_msg; + struct vmbus_channel_msginfo *open_info = NULL; + void *in, *out; + unsigned long flags; + int ret, t, err = 0; + + spin_lock_irqsave(&newchannel->sc_lock, flags); + if (newchannel->state == CHANNEL_OPEN_STATE) { + newchannel->state = CHANNEL_OPENING_STATE; + } else { + spin_unlock_irqrestore(&newchannel->sc_lock, flags); + return -EINVAL; + } + spin_unlock_irqrestore(&newchannel->sc_lock, flags); + + newchannel->onchannel_callback = onchannelcallback; + newchannel->channel_callback_context = context; + + /* Allocate the ring buffer */ + out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, + get_order(send_ringbuffer_size + recv_ringbuffer_size)); + + if (!out) + return -ENOMEM; + + + in = (void *)((unsigned long)out + send_ringbuffer_size); + + newchannel->ringbuffer_pages = out; + newchannel->ringbuffer_pagecount = (send_ringbuffer_size + + recv_ringbuffer_size) >> PAGE_SHIFT; + + ret = hv_ringbuffer_init( + &newchannel->outbound, out, send_ringbuffer_size); + + if (ret != 0) { + err = ret; + goto error0; + } + + ret = hv_ringbuffer_init( + &newchannel->inbound, in, recv_ringbuffer_size); + if (ret != 0) { + err = ret; + goto error0; + } + + + /* Establish the gpadl for the ring buffer */ + newchannel->ringbuffer_gpadlhandle = 0; + + ret = vmbus_establish_gpadl(newchannel, + newchannel->outbound.ring_buffer, + send_ringbuffer_size + + recv_ringbuffer_size, + &newchannel->ringbuffer_gpadlhandle); + + if (ret != 0) { + err = ret; + goto error0; + } + + /* Create and init the channel open message */ + open_info = kmalloc(sizeof(*open_info) + + sizeof(struct vmbus_channel_open_channel), + GFP_KERNEL); + if (!open_info) { + err = -ENOMEM; + goto error0; + } + + init_completion(&open_info->waitevent); + + open_msg = (struct vmbus_channel_open_channel *)open_info->msg; + open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL; + open_msg->openid = newchannel->offermsg.child_relid; + open_msg->child_relid = newchannel->offermsg.child_relid; + open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle; + open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >> + PAGE_SHIFT; + open_msg->target_vp = newchannel->target_vp; + + if (userdatalen > MAX_USER_DEFINED_BYTES) { + err = -EINVAL; + goto error0; + } + + if (userdatalen) + memcpy(open_msg->userdata, userdata, userdatalen); + + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_add_tail(&open_info->msglistentry, + &vmbus_connection.chn_msg_list); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + + ret = vmbus_post_msg(open_msg, + sizeof(struct vmbus_channel_open_channel)); + + if (ret != 0) + goto error1; + + t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ); + if (t == 0) { + err = -ETIMEDOUT; + goto error1; + } + + + if (open_info->response.open_result.status) + err = open_info->response.open_result.status; + + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_del(&open_info->msglistentry); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + + if (err == 0) + newchannel->state = CHANNEL_OPENED_STATE; + + kfree(open_info); + return err; + +error1: + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_del(&open_info->msglistentry); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + +error0: + free_pages((unsigned long)out, + get_order(send_ringbuffer_size + recv_ringbuffer_size)); + kfree(open_info); + return err; +} +EXPORT_SYMBOL_GPL(vmbus_open); + +/* + * create_gpadl_header - Creates a gpadl for the specified buffer + */ +static int create_gpadl_header(void *kbuffer, u32 size, + struct vmbus_channel_msginfo **msginfo, + u32 *messagecount) +{ + int i; + int pagecount; + struct vmbus_channel_gpadl_header *gpadl_header; + struct vmbus_channel_gpadl_body *gpadl_body; + struct vmbus_channel_msginfo *msgheader; + struct vmbus_channel_msginfo *msgbody = NULL; + u32 msgsize; + + int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; + + pagecount = size >> PAGE_SHIFT; + + /* do we need a gpadl body msg */ + pfnsize = MAX_SIZE_CHANNEL_MESSAGE - + sizeof(struct vmbus_channel_gpadl_header) - + sizeof(struct gpa_range); + pfncount = pfnsize / sizeof(u64); + + if (pagecount > pfncount) { + /* we need a gpadl body */ + /* fill in the header */ + msgsize = sizeof(struct vmbus_channel_msginfo) + + sizeof(struct vmbus_channel_gpadl_header) + + sizeof(struct gpa_range) + pfncount * sizeof(u64); + msgheader = kzalloc(msgsize, GFP_KERNEL); + if (!msgheader) + goto nomem; + + INIT_LIST_HEAD(&msgheader->submsglist); + msgheader->msgsize = msgsize; + + gpadl_header = (struct vmbus_channel_gpadl_header *) + msgheader->msg; + gpadl_header->rangecount = 1; + gpadl_header->range_buflen = sizeof(struct gpa_range) + + pagecount * sizeof(u64); + gpadl_header->range[0].byte_offset = 0; + gpadl_header->range[0].byte_count = size; + for (i = 0; i < pfncount; i++) + gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys( + kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT; + *msginfo = msgheader; + *messagecount = 1; + + pfnsum = pfncount; + pfnleft = pagecount - pfncount; + + /* how many pfns can we fit */ + pfnsize = MAX_SIZE_CHANNEL_MESSAGE - + sizeof(struct vmbus_channel_gpadl_body); + pfncount = pfnsize / sizeof(u64); + + /* fill in the body */ + while (pfnleft) { + if (pfnleft > pfncount) + pfncurr = pfncount; + else + pfncurr = pfnleft; + + msgsize = sizeof(struct vmbus_channel_msginfo) + + sizeof(struct vmbus_channel_gpadl_body) + + pfncurr * sizeof(u64); + msgbody = kzalloc(msgsize, GFP_KERNEL); + + if (!msgbody) { + struct vmbus_channel_msginfo *pos = NULL; + struct vmbus_channel_msginfo *tmp = NULL; + /* + * Free up all the allocated messages. + */ + list_for_each_entry_safe(pos, tmp, + &msgheader->submsglist, + msglistentry) { + + list_del(&pos->msglistentry); + kfree(pos); + } + + goto nomem; + } + + msgbody->msgsize = msgsize; + (*messagecount)++; + gpadl_body = + (struct vmbus_channel_gpadl_body *)msgbody->msg; + + /* + * Gpadl is u32 and we are using a pointer which could + * be 64-bit + * This is governed by the guest/host protocol and + * so the hypervisor gurantees that this is ok. + */ + for (i = 0; i < pfncurr; i++) + gpadl_body->pfn[i] = slow_virt_to_phys( + kbuffer + PAGE_SIZE * (pfnsum + i)) >> + PAGE_SHIFT; + + /* add to msg header */ + list_add_tail(&msgbody->msglistentry, + &msgheader->submsglist); + pfnsum += pfncurr; + pfnleft -= pfncurr; + } + } else { + /* everything fits in a header */ + msgsize = sizeof(struct vmbus_channel_msginfo) + + sizeof(struct vmbus_channel_gpadl_header) + + sizeof(struct gpa_range) + pagecount * sizeof(u64); + msgheader = kzalloc(msgsize, GFP_KERNEL); + if (msgheader == NULL) + goto nomem; + msgheader->msgsize = msgsize; + + gpadl_header = (struct vmbus_channel_gpadl_header *) + msgheader->msg; + gpadl_header->rangecount = 1; + gpadl_header->range_buflen = sizeof(struct gpa_range) + + pagecount * sizeof(u64); + gpadl_header->range[0].byte_offset = 0; + gpadl_header->range[0].byte_count = size; + for (i = 0; i < pagecount; i++) + gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys( + kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT; + + *msginfo = msgheader; + *messagecount = 1; + } + + return 0; +nomem: + kfree(msgheader); + kfree(msgbody); + return -ENOMEM; +} + +/* + * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer + * + * @channel: a channel + * @kbuffer: from kmalloc or vmalloc + * @size: page-size multiple + * @gpadl_handle: some funky thing + */ +int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, + u32 size, u32 *gpadl_handle) +{ + struct vmbus_channel_gpadl_header *gpadlmsg; + struct vmbus_channel_gpadl_body *gpadl_body; + struct vmbus_channel_msginfo *msginfo = NULL; + struct vmbus_channel_msginfo *submsginfo; + u32 msgcount; + struct list_head *curr; + u32 next_gpadl_handle; + unsigned long flags; + int ret = 0; + int t; + + next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle); + atomic_inc(&vmbus_connection.next_gpadl_handle); + + ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount); + if (ret) + return ret; + + init_completion(&msginfo->waitevent); + + gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; + gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; + gpadlmsg->child_relid = channel->offermsg.child_relid; + gpadlmsg->gpadl = next_gpadl_handle; + + + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_add_tail(&msginfo->msglistentry, + &vmbus_connection.chn_msg_list); + + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + + ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - + sizeof(*msginfo)); + if (ret != 0) + goto cleanup; + + if (msgcount > 1) { + list_for_each(curr, &msginfo->submsglist) { + + submsginfo = (struct vmbus_channel_msginfo *)curr; + gpadl_body = + (struct vmbus_channel_gpadl_body *)submsginfo->msg; + + gpadl_body->header.msgtype = + CHANNELMSG_GPADL_BODY; + gpadl_body->gpadl = next_gpadl_handle; + + ret = vmbus_post_msg(gpadl_body, + submsginfo->msgsize - + sizeof(*submsginfo)); + if (ret != 0) + goto cleanup; + + } + } + t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); + BUG_ON(t == 0); + + + /* At this point, we received the gpadl created msg */ + *gpadl_handle = gpadlmsg->gpadl; + +cleanup: + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_del(&msginfo->msglistentry); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + + kfree(msginfo); + return ret; +} +EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); + +/* + * vmbus_teardown_gpadl -Teardown the specified GPADL handle + */ +int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle) +{ + struct vmbus_channel_gpadl_teardown *msg; + struct vmbus_channel_msginfo *info; + unsigned long flags; + int ret, t; + + info = kmalloc(sizeof(*info) + + sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); + if (!info) + return -ENOMEM; + + init_completion(&info->waitevent); + + msg = (struct vmbus_channel_gpadl_teardown *)info->msg; + + msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; + msg->child_relid = channel->offermsg.child_relid; + msg->gpadl = gpadl_handle; + + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_add_tail(&info->msglistentry, + &vmbus_connection.chn_msg_list); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + ret = vmbus_post_msg(msg, + sizeof(struct vmbus_channel_gpadl_teardown)); + + BUG_ON(ret != 0); + t = wait_for_completion_timeout(&info->waitevent, 5*HZ); + BUG_ON(t == 0); + + /* Received a torndown response */ + spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); + list_del(&info->msglistentry); + spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); + + kfree(info); + return ret; +} +EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); + +static void reset_channel_cb(void *arg) +{ + struct vmbus_channel *channel = arg; + + channel->onchannel_callback = NULL; +} + +static void vmbus_close_internal(struct vmbus_channel *channel) +{ + struct vmbus_channel_close_channel *msg; + int ret; + + channel->state = CHANNEL_OPEN_STATE; + channel->sc_creation_callback = NULL; + /* Stop callback and cancel the timer asap */ + if (channel->target_cpu != smp_processor_id()) + smp_call_function_single(channel->target_cpu, reset_channel_cb, + channel, true); + else + reset_channel_cb(channel); + + /* Send a closing message */ + + msg = &channel->close_msg.msg; + + msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; + msg->child_relid = channel->offermsg.child_relid; + + ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel)); + + BUG_ON(ret != 0); + /* Tear down the gpadl for the channel's ring buffer */ + if (channel->ringbuffer_gpadlhandle) + vmbus_teardown_gpadl(channel, + channel->ringbuffer_gpadlhandle); + + /* Cleanup the ring buffers for this channel */ + hv_ringbuffer_cleanup(&channel->outbound); + hv_ringbuffer_cleanup(&channel->inbound); + + free_pages((unsigned long)channel->ringbuffer_pages, + get_order(channel->ringbuffer_pagecount * PAGE_SIZE)); + + +} + +/* + * vmbus_close - Close the specified channel + */ +void vmbus_close(struct vmbus_channel *channel) +{ + struct list_head *cur, *tmp; + struct vmbus_channel *cur_channel; + + if (channel->primary_channel != NULL) { + /* + * We will only close sub-channels when + * the primary is closed. + */ + return; + } + /* + * Close all the sub-channels first and then close the + * primary channel. + */ + list_for_each_safe(cur, tmp, &channel->sc_list) { + cur_channel = list_entry(cur, struct vmbus_channel, sc_list); + if (cur_channel->state != CHANNEL_OPENED_STATE) + continue; + vmbus_close_internal(cur_channel); + } + /* + * Now close the primary. + */ + vmbus_close_internal(channel); +} +EXPORT_SYMBOL_GPL(vmbus_close); + +/** + * vmbus_sendpacket() - Send the specified buffer on the given channel + * @channel: Pointer to vmbus_channel structure. + * @buffer: Pointer to the buffer you want to receive the data into. + * @bufferlen: Maximum size of what the the buffer will hold + * @requestid: Identifier of the request + * @type: Type of packet that is being send e.g. negotiate, time + * packet etc. + * + * Sends data in @buffer directly to hyper-v via the vmbus + * This will send the data unparsed to hyper-v. + * + * Mainly used by Hyper-V drivers. + */ +int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, + u32 bufferlen, u64 requestid, + enum vmbus_packet_type type, u32 flags) +{ + struct vmpacket_descriptor desc; + u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; + u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); + struct kvec bufferlist[3]; + u64 aligned_data = 0; + int ret; + bool signal = false; + + + /* Setup the descriptor */ + desc.type = type; /* VmbusPacketTypeDataInBand; */ + desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ + /* in 8-bytes granularity */ + desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; + desc.len8 = (u16)(packetlen_aligned >> 3); + desc.trans_id = requestid; + + bufferlist[0].iov_base = &desc; + bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor); + 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(vmbus_sendpacket); + +/* + * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer + * packets using a GPADL Direct packet type. + */ +int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, + struct hv_page_buffer pagebuffers[], + u32 pagecount, void *buffer, u32 bufferlen, + u64 requestid) +{ + int ret; + int i; + struct vmbus_channel_packet_page_buffer desc; + u32 descsize; + u32 packetlen; + u32 packetlen_aligned; + struct kvec bufferlist[3]; + u64 aligned_data = 0; + bool signal = false; + + if (pagecount > MAX_PAGE_BUFFER_COUNT) + return -EINVAL; + + + /* + * Adjust the size down since vmbus_channel_packet_page_buffer is the + * largest size we support + */ + descsize = sizeof(struct vmbus_channel_packet_page_buffer) - + ((MAX_PAGE_BUFFER_COUNT - pagecount) * + sizeof(struct hv_page_buffer)); + packetlen = descsize + 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 = descsize >> 3; /* in 8-bytes grandularity */ + desc.length8 = (u16)(packetlen_aligned >> 3); + desc.transactionid = requestid; + desc.rangecount = pagecount; + + for (i = 0; i < pagecount; i++) { + desc.range[i].len = pagebuffers[i].len; + desc.range[i].offset = pagebuffers[i].offset; + desc.range[i].pfn = pagebuffers[i].pfn; + } + + bufferlist[0].iov_base = &desc; + bufferlist[0].iov_len = descsize; + 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_pagebuffer); + +/* + * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet + * using a GPADL Direct packet type. + */ +int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel, + struct hv_multipage_buffer *multi_pagebuffer, + void *buffer, u32 bufferlen, u64 requestid) +{ + int ret; + struct vmbus_channel_packet_multipage_buffer desc; + u32 descsize; + u32 packetlen; + u32 packetlen_aligned; + struct kvec bufferlist[3]; + u64 aligned_data = 0; + bool signal = false; + u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset, + multi_pagebuffer->len); + + if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT) + return -EINVAL; + + /* + * Adjust the size down since vmbus_channel_packet_multipage_buffer is + * the largest size we support + */ + descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) - + ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) * + sizeof(u64)); + packetlen = descsize + 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 = descsize >> 3; /* in 8-bytes grandularity */ + desc.length8 = (u16)(packetlen_aligned >> 3); + desc.transactionid = requestid; + desc.rangecount = 1; + + desc.range.len = multi_pagebuffer->len; + desc.range.offset = multi_pagebuffer->offset; + + memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array, + pfncount * sizeof(u64)); + + bufferlist[0].iov_base = &desc; + bufferlist[0].iov_len = descsize; + 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_multipagebuffer); + +/** + * vmbus_recvpacket() - Retrieve the user packet on the specified channel + * @channel: Pointer to vmbus_channel structure. + * @buffer: Pointer to the buffer you want to receive the data into. + * @bufferlen: Maximum size of what the the buffer will hold + * @buffer_actual_len: The actual size of the data after it was received + * @requestid: Identifier of the request + * + * Receives directly from the hyper-v vmbus and puts the data it received + * into Buffer. This will receive the data unparsed from hyper-v. + * + * Mainly used by Hyper-V drivers. + */ +int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, + u32 bufferlen, u32 *buffer_actual_len, u64 *requestid) +{ + struct vmpacket_descriptor desc; + u32 packetlen; + u32 userlen; + int ret; + bool signal = false; + + *buffer_actual_len = 0; + *requestid = 0; + + + ret = hv_ringbuffer_peek(&channel->inbound, &desc, + sizeof(struct vmpacket_descriptor)); + if (ret != 0) + return 0; + + packetlen = desc.len8 << 3; + userlen = packetlen - (desc.offset8 << 3); + + *buffer_actual_len = userlen; + + if (userlen > bufferlen) { + + pr_err("Buffer too small - got %d needs %d\n", + bufferlen, userlen); + return -ETOOSMALL; + } + + *requestid = desc.trans_id; + + /* Copy over the packet to the user buffer */ + ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen, + (desc.offset8 << 3), &signal); + + if (signal) + vmbus_setevent(channel); + + return 0; +} +EXPORT_SYMBOL(vmbus_recvpacket); + +/* + * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel + */ +int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, + u32 bufferlen, u32 *buffer_actual_len, + u64 *requestid) +{ + struct vmpacket_descriptor desc; + u32 packetlen; + int ret; + bool signal = false; + + *buffer_actual_len = 0; + *requestid = 0; + + + ret = hv_ringbuffer_peek(&channel->inbound, &desc, + sizeof(struct vmpacket_descriptor)); + if (ret != 0) + return 0; + + + packetlen = desc.len8 << 3; + + *buffer_actual_len = packetlen; + + if (packetlen > bufferlen) { + pr_err("Buffer too small - needed %d bytes but " + "got space for only %d bytes\n", + packetlen, bufferlen); + return -ENOBUFS; + } + + *requestid = desc.trans_id; + + /* Copy over the entire packet to the user buffer */ + ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0, + &signal); + + if (signal) + vmbus_setevent(channel); + + return ret; +} +EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); |