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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2009, Microsoft Corporation.4 *5 * Authors:6 *   Haiyang Zhang <haiyangz@microsoft.com>7 *   Hank Janssen  <hjanssen@microsoft.com>8 */9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 11#include <linux/kernel.h>12#include <linux/sched.h>13#include <linux/wait.h>14#include <linux/mm.h>15#include <linux/delay.h>16#include <linux/io.h>17#include <linux/slab.h>18#include <linux/netdevice.h>19#include <linux/if_ether.h>20#include <linux/vmalloc.h>21#include <linux/rtnetlink.h>22#include <linux/prefetch.h>23#include <linux/filter.h>24 25#include <asm/sync_bitops.h>26#include <asm/mshyperv.h>27 28#include "hyperv_net.h"29#include "netvsc_trace.h"30 31/*32 * Switch the data path from the synthetic interface to the VF33 * interface.34 */35int netvsc_switch_datapath(struct net_device *ndev, bool vf)36{37	struct net_device_context *net_device_ctx = netdev_priv(ndev);38	struct hv_device *dev = net_device_ctx->device_ctx;39	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);40	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;41	int ret, retry = 0;42 43	/* Block sending traffic to VF if it's about to be gone */44	if (!vf)45		net_device_ctx->data_path_is_vf = vf;46 47	memset(init_pkt, 0, sizeof(struct nvsp_message));48	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;49	if (vf)50		init_pkt->msg.v4_msg.active_dp.active_datapath =51			NVSP_DATAPATH_VF;52	else53		init_pkt->msg.v4_msg.active_dp.active_datapath =54			NVSP_DATAPATH_SYNTHETIC;55 56again:57	trace_nvsp_send(ndev, init_pkt);58 59	ret = vmbus_sendpacket(dev->channel, init_pkt,60			       sizeof(struct nvsp_message),61			       (unsigned long)init_pkt, VM_PKT_DATA_INBAND,62			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);63 64	/* If failed to switch to/from VF, let data_path_is_vf stay false,65	 * so we use synthetic path to send data.66	 */67	if (ret) {68		if (ret != -EAGAIN) {69			netdev_err(ndev,70				   "Unable to send sw datapath msg, err: %d\n",71				   ret);72			return ret;73		}74 75		if (retry++ < RETRY_MAX) {76			usleep_range(RETRY_US_LO, RETRY_US_HI);77			goto again;78		} else {79			netdev_err(80				ndev,81				"Retry failed to send sw datapath msg, err: %d\n",82				ret);83			return ret;84		}85	}86 87	wait_for_completion(&nv_dev->channel_init_wait);88	net_device_ctx->data_path_is_vf = vf;89 90	return 0;91}92 93/* Worker to setup sub channels on initial setup94 * Initial hotplug event occurs in softirq context95 * and can't wait for channels.96 */97static void netvsc_subchan_work(struct work_struct *w)98{99	struct netvsc_device *nvdev =100		container_of(w, struct netvsc_device, subchan_work);101	struct rndis_device *rdev;102	int i, ret;103 104	/* Avoid deadlock with device removal already under RTNL */105	if (!rtnl_trylock()) {106		schedule_work(w);107		return;108	}109 110	rdev = nvdev->extension;111	if (rdev) {112		ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);113		if (ret == 0) {114			netif_device_attach(rdev->ndev);115		} else {116			/* fallback to only primary channel */117			for (i = 1; i < nvdev->num_chn; i++)118				netif_napi_del(&nvdev->chan_table[i].napi);119 120			nvdev->max_chn = 1;121			nvdev->num_chn = 1;122		}123	}124 125	rtnl_unlock();126}127 128static struct netvsc_device *alloc_net_device(void)129{130	struct netvsc_device *net_device;131 132	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);133	if (!net_device)134		return NULL;135 136	init_waitqueue_head(&net_device->wait_drain);137	net_device->destroy = false;138	net_device->tx_disable = true;139 140	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;141	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;142 143	init_completion(&net_device->channel_init_wait);144	init_waitqueue_head(&net_device->subchan_open);145	INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);146 147	return net_device;148}149 150static void free_netvsc_device(struct rcu_head *head)151{152	struct netvsc_device *nvdev153		= container_of(head, struct netvsc_device, rcu);154	int i;155 156	kfree(nvdev->extension);157 158	if (!nvdev->recv_buf_gpadl_handle.decrypted)159		vfree(nvdev->recv_buf);160	if (!nvdev->send_buf_gpadl_handle.decrypted)161		vfree(nvdev->send_buf);162	bitmap_free(nvdev->send_section_map);163 164	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {165		xdp_rxq_info_unreg(&nvdev->chan_table[i].xdp_rxq);166		kfree(nvdev->chan_table[i].recv_buf);167		vfree(nvdev->chan_table[i].mrc.slots);168	}169 170	kfree(nvdev);171}172 173static void free_netvsc_device_rcu(struct netvsc_device *nvdev)174{175	call_rcu(&nvdev->rcu, free_netvsc_device);176}177 178static void netvsc_revoke_recv_buf(struct hv_device *device,179				   struct netvsc_device *net_device,180				   struct net_device *ndev)181{182	struct nvsp_message *revoke_packet;183	int ret;184 185	/*186	 * If we got a section count, it means we received a187	 * SendReceiveBufferComplete msg (ie sent188	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need189	 * to send a revoke msg here190	 */191	if (net_device->recv_section_cnt) {192		/* Send the revoke receive buffer */193		revoke_packet = &net_device->revoke_packet;194		memset(revoke_packet, 0, sizeof(struct nvsp_message));195 196		revoke_packet->hdr.msg_type =197			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;198		revoke_packet->msg.v1_msg.199		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;200 201		trace_nvsp_send(ndev, revoke_packet);202 203		ret = vmbus_sendpacket(device->channel,204				       revoke_packet,205				       sizeof(struct nvsp_message),206				       VMBUS_RQST_ID_NO_RESPONSE,207				       VM_PKT_DATA_INBAND, 0);208		/* If the failure is because the channel is rescinded;209		 * ignore the failure since we cannot send on a rescinded210		 * channel. This would allow us to properly cleanup211		 * even when the channel is rescinded.212		 */213		if (device->channel->rescind)214			ret = 0;215		/*216		 * If we failed here, we might as well return and217		 * have a leak rather than continue and a bugchk218		 */219		if (ret != 0) {220			netdev_err(ndev, "unable to send "221				"revoke receive buffer to netvsp\n");222			return;223		}224		net_device->recv_section_cnt = 0;225	}226}227 228static void netvsc_revoke_send_buf(struct hv_device *device,229				   struct netvsc_device *net_device,230				   struct net_device *ndev)231{232	struct nvsp_message *revoke_packet;233	int ret;234 235	/* Deal with the send buffer we may have setup.236	 * If we got a  send section size, it means we received a237	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent238	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need239	 * to send a revoke msg here240	 */241	if (net_device->send_section_cnt) {242		/* Send the revoke receive buffer */243		revoke_packet = &net_device->revoke_packet;244		memset(revoke_packet, 0, sizeof(struct nvsp_message));245 246		revoke_packet->hdr.msg_type =247			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;248		revoke_packet->msg.v1_msg.revoke_send_buf.id =249			NETVSC_SEND_BUFFER_ID;250 251		trace_nvsp_send(ndev, revoke_packet);252 253		ret = vmbus_sendpacket(device->channel,254				       revoke_packet,255				       sizeof(struct nvsp_message),256				       VMBUS_RQST_ID_NO_RESPONSE,257				       VM_PKT_DATA_INBAND, 0);258 259		/* If the failure is because the channel is rescinded;260		 * ignore the failure since we cannot send on a rescinded261		 * channel. This would allow us to properly cleanup262		 * even when the channel is rescinded.263		 */264		if (device->channel->rescind)265			ret = 0;266 267		/* If we failed here, we might as well return and268		 * have a leak rather than continue and a bugchk269		 */270		if (ret != 0) {271			netdev_err(ndev, "unable to send "272				   "revoke send buffer to netvsp\n");273			return;274		}275		net_device->send_section_cnt = 0;276	}277}278 279static void netvsc_teardown_recv_gpadl(struct hv_device *device,280				       struct netvsc_device *net_device,281				       struct net_device *ndev)282{283	int ret;284 285	if (net_device->recv_buf_gpadl_handle.gpadl_handle) {286		ret = vmbus_teardown_gpadl(device->channel,287					   &net_device->recv_buf_gpadl_handle);288 289		/* If we failed here, we might as well return and have a leak290		 * rather than continue and a bugchk291		 */292		if (ret != 0) {293			netdev_err(ndev,294				   "unable to teardown receive buffer's gpadl\n");295			return;296		}297	}298}299 300static void netvsc_teardown_send_gpadl(struct hv_device *device,301				       struct netvsc_device *net_device,302				       struct net_device *ndev)303{304	int ret;305 306	if (net_device->send_buf_gpadl_handle.gpadl_handle) {307		ret = vmbus_teardown_gpadl(device->channel,308					   &net_device->send_buf_gpadl_handle);309 310		/* If we failed here, we might as well return and have a leak311		 * rather than continue and a bugchk312		 */313		if (ret != 0) {314			netdev_err(ndev,315				   "unable to teardown send buffer's gpadl\n");316			return;317		}318	}319}320 321int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)322{323	struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];324	int node = cpu_to_node(nvchan->channel->target_cpu);325	size_t size;326 327	size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);328	nvchan->mrc.slots = vzalloc_node(size, node);329	if (!nvchan->mrc.slots)330		nvchan->mrc.slots = vzalloc(size);331 332	return nvchan->mrc.slots ? 0 : -ENOMEM;333}334 335static int netvsc_init_buf(struct hv_device *device,336			   struct netvsc_device *net_device,337			   const struct netvsc_device_info *device_info)338{339	struct nvsp_1_message_send_receive_buffer_complete *resp;340	struct net_device *ndev = hv_get_drvdata(device);341	struct nvsp_message *init_packet;342	unsigned int buf_size;343	int i, ret = 0;344 345	/* Get receive buffer area. */346	buf_size = device_info->recv_sections * device_info->recv_section_size;347	buf_size = roundup(buf_size, PAGE_SIZE);348 349	/* Legacy hosts only allow smaller receive buffer */350	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)351		buf_size = min_t(unsigned int, buf_size,352				 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);353 354	net_device->recv_buf = vzalloc(buf_size);355	if (!net_device->recv_buf) {356		netdev_err(ndev,357			   "unable to allocate receive buffer of size %u\n",358			   buf_size);359		ret = -ENOMEM;360		goto cleanup;361	}362 363	net_device->recv_buf_size = buf_size;364 365	/*366	 * Establish the gpadl handle for this buffer on this367	 * channel.  Note: This call uses the vmbus connection rather368	 * than the channel to establish the gpadl handle.369	 */370	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,371				    buf_size,372				    &net_device->recv_buf_gpadl_handle);373	if (ret != 0) {374		netdev_err(ndev,375			"unable to establish receive buffer's gpadl\n");376		goto cleanup;377	}378 379	/* Notify the NetVsp of the gpadl handle */380	init_packet = &net_device->channel_init_pkt;381	memset(init_packet, 0, sizeof(struct nvsp_message));382	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;383	init_packet->msg.v1_msg.send_recv_buf.384		gpadl_handle = net_device->recv_buf_gpadl_handle.gpadl_handle;385	init_packet->msg.v1_msg.386		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;387 388	trace_nvsp_send(ndev, init_packet);389 390	/* Send the gpadl notification request */391	ret = vmbus_sendpacket(device->channel, init_packet,392			       sizeof(struct nvsp_message),393			       (unsigned long)init_packet,394			       VM_PKT_DATA_INBAND,395			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);396	if (ret != 0) {397		netdev_err(ndev,398			"unable to send receive buffer's gpadl to netvsp\n");399		goto cleanup;400	}401 402	wait_for_completion(&net_device->channel_init_wait);403 404	/* Check the response */405	resp = &init_packet->msg.v1_msg.send_recv_buf_complete;406	if (resp->status != NVSP_STAT_SUCCESS) {407		netdev_err(ndev,408			   "Unable to complete receive buffer initialization with NetVsp - status %d\n",409			   resp->status);410		ret = -EINVAL;411		goto cleanup;412	}413 414	/* Parse the response */415	netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",416		   resp->num_sections, resp->sections[0].sub_alloc_size,417		   resp->sections[0].num_sub_allocs);418 419	/* There should only be one section for the entire receive buffer */420	if (resp->num_sections != 1 || resp->sections[0].offset != 0) {421		ret = -EINVAL;422		goto cleanup;423	}424 425	net_device->recv_section_size = resp->sections[0].sub_alloc_size;426	net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;427 428	/* Ensure buffer will not overflow */429	if (net_device->recv_section_size < NETVSC_MTU_MIN || (u64)net_device->recv_section_size *430	    (u64)net_device->recv_section_cnt > (u64)buf_size) {431		netdev_err(ndev, "invalid recv_section_size %u\n",432			   net_device->recv_section_size);433		ret = -EINVAL;434		goto cleanup;435	}436 437	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {438		struct netvsc_channel *nvchan = &net_device->chan_table[i];439 440		nvchan->recv_buf = kzalloc(net_device->recv_section_size, GFP_KERNEL);441		if (nvchan->recv_buf == NULL) {442			ret = -ENOMEM;443			goto cleanup;444		}445	}446 447	/* Setup receive completion ring.448	 * Add 1 to the recv_section_cnt because at least one entry in a449	 * ring buffer has to be empty.450	 */451	net_device->recv_completion_cnt = net_device->recv_section_cnt + 1;452	ret = netvsc_alloc_recv_comp_ring(net_device, 0);453	if (ret)454		goto cleanup;455 456	/* Now setup the send buffer. */457	buf_size = device_info->send_sections * device_info->send_section_size;458	buf_size = round_up(buf_size, PAGE_SIZE);459 460	net_device->send_buf = vzalloc(buf_size);461	if (!net_device->send_buf) {462		netdev_err(ndev, "unable to allocate send buffer of size %u\n",463			   buf_size);464		ret = -ENOMEM;465		goto cleanup;466	}467	net_device->send_buf_size = buf_size;468 469	/* Establish the gpadl handle for this buffer on this470	 * channel.  Note: This call uses the vmbus connection rather471	 * than the channel to establish the gpadl handle.472	 */473	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,474				    buf_size,475				    &net_device->send_buf_gpadl_handle);476	if (ret != 0) {477		netdev_err(ndev,478			   "unable to establish send buffer's gpadl\n");479		goto cleanup;480	}481 482	/* Notify the NetVsp of the gpadl handle */483	init_packet = &net_device->channel_init_pkt;484	memset(init_packet, 0, sizeof(struct nvsp_message));485	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;486	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =487		net_device->send_buf_gpadl_handle.gpadl_handle;488	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;489 490	trace_nvsp_send(ndev, init_packet);491 492	/* Send the gpadl notification request */493	ret = vmbus_sendpacket(device->channel, init_packet,494			       sizeof(struct nvsp_message),495			       (unsigned long)init_packet,496			       VM_PKT_DATA_INBAND,497			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);498	if (ret != 0) {499		netdev_err(ndev,500			   "unable to send send buffer's gpadl to netvsp\n");501		goto cleanup;502	}503 504	wait_for_completion(&net_device->channel_init_wait);505 506	/* Check the response */507	if (init_packet->msg.v1_msg.508	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {509		netdev_err(ndev, "Unable to complete send buffer "510			   "initialization with NetVsp - status %d\n",511			   init_packet->msg.v1_msg.512			   send_send_buf_complete.status);513		ret = -EINVAL;514		goto cleanup;515	}516 517	/* Parse the response */518	net_device->send_section_size = init_packet->msg.519				v1_msg.send_send_buf_complete.section_size;520	if (net_device->send_section_size < NETVSC_MTU_MIN) {521		netdev_err(ndev, "invalid send_section_size %u\n",522			   net_device->send_section_size);523		ret = -EINVAL;524		goto cleanup;525	}526 527	/* Section count is simply the size divided by the section size. */528	net_device->send_section_cnt = buf_size / net_device->send_section_size;529 530	netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",531		   net_device->send_section_size, net_device->send_section_cnt);532 533	/* Setup state for managing the send buffer. */534	net_device->send_section_map = bitmap_zalloc(net_device->send_section_cnt,535						     GFP_KERNEL);536	if (!net_device->send_section_map) {537		ret = -ENOMEM;538		goto cleanup;539	}540 541	goto exit;542 543cleanup:544	netvsc_revoke_recv_buf(device, net_device, ndev);545	netvsc_revoke_send_buf(device, net_device, ndev);546	netvsc_teardown_recv_gpadl(device, net_device, ndev);547	netvsc_teardown_send_gpadl(device, net_device, ndev);548 549exit:550	return ret;551}552 553/* Negotiate NVSP protocol version */554static int negotiate_nvsp_ver(struct hv_device *device,555			      struct netvsc_device *net_device,556			      struct nvsp_message *init_packet,557			      u32 nvsp_ver)558{559	struct net_device *ndev = hv_get_drvdata(device);560	int ret;561 562	memset(init_packet, 0, sizeof(struct nvsp_message));563	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;564	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;565	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;566	trace_nvsp_send(ndev, init_packet);567 568	/* Send the init request */569	ret = vmbus_sendpacket(device->channel, init_packet,570			       sizeof(struct nvsp_message),571			       (unsigned long)init_packet,572			       VM_PKT_DATA_INBAND,573			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);574 575	if (ret != 0)576		return ret;577 578	wait_for_completion(&net_device->channel_init_wait);579 580	if (init_packet->msg.init_msg.init_complete.status !=581	    NVSP_STAT_SUCCESS)582		return -EINVAL;583 584	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)585		return 0;586 587	/* NVSPv2 or later: Send NDIS config */588	memset(init_packet, 0, sizeof(struct nvsp_message));589	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;590	init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;591	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;592 593	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {594		if (hv_is_isolation_supported())595			netdev_info(ndev, "SR-IOV not advertised by guests on the host supporting isolation\n");596		else597			init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;598 599		/* Teaming bit is needed to receive link speed updates */600		init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;601	}602 603	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)604		init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;605 606	trace_nvsp_send(ndev, init_packet);607 608	ret = vmbus_sendpacket(device->channel, init_packet,609				sizeof(struct nvsp_message),610				VMBUS_RQST_ID_NO_RESPONSE,611				VM_PKT_DATA_INBAND, 0);612 613	return ret;614}615 616static int netvsc_connect_vsp(struct hv_device *device,617			      struct netvsc_device *net_device,618			      const struct netvsc_device_info *device_info)619{620	struct net_device *ndev = hv_get_drvdata(device);621	static const u32 ver_list[] = {622		NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,623		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,624		NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61625	};626	struct nvsp_message *init_packet;627	int ndis_version, i, ret;628 629	init_packet = &net_device->channel_init_pkt;630 631	/* Negotiate the latest NVSP protocol supported */632	for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)633		if (negotiate_nvsp_ver(device, net_device, init_packet,634				       ver_list[i])  == 0) {635			net_device->nvsp_version = ver_list[i];636			break;637		}638 639	if (i < 0) {640		ret = -EPROTO;641		goto cleanup;642	}643 644	if (hv_is_isolation_supported() && net_device->nvsp_version < NVSP_PROTOCOL_VERSION_61) {645		netdev_err(ndev, "Invalid NVSP version 0x%x (expected >= 0x%x) from the host supporting isolation\n",646			   net_device->nvsp_version, NVSP_PROTOCOL_VERSION_61);647		ret = -EPROTO;648		goto cleanup;649	}650 651	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);652 653	/* Send the ndis version */654	memset(init_packet, 0, sizeof(struct nvsp_message));655 656	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)657		ndis_version = 0x00060001;658	else659		ndis_version = 0x0006001e;660 661	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;662	init_packet->msg.v1_msg.663		send_ndis_ver.ndis_major_ver =664				(ndis_version & 0xFFFF0000) >> 16;665	init_packet->msg.v1_msg.666		send_ndis_ver.ndis_minor_ver =667				ndis_version & 0xFFFF;668 669	trace_nvsp_send(ndev, init_packet);670 671	/* Send the init request */672	ret = vmbus_sendpacket(device->channel, init_packet,673				sizeof(struct nvsp_message),674				VMBUS_RQST_ID_NO_RESPONSE,675				VM_PKT_DATA_INBAND, 0);676	if (ret != 0)677		goto cleanup;678 679 680	ret = netvsc_init_buf(device, net_device, device_info);681 682cleanup:683	return ret;684}685 686/*687 * netvsc_device_remove - Callback when the root bus device is removed688 */689void netvsc_device_remove(struct hv_device *device)690{691	struct net_device *ndev = hv_get_drvdata(device);692	struct net_device_context *net_device_ctx = netdev_priv(ndev);693	struct netvsc_device *net_device694		= rtnl_dereference(net_device_ctx->nvdev);695	int i;696 697	/*698	 * Revoke receive buffer. If host is pre-Win2016 then tear down699	 * receive buffer GPADL. Do the same for send buffer.700	 */701	netvsc_revoke_recv_buf(device, net_device, ndev);702	if (vmbus_proto_version < VERSION_WIN10)703		netvsc_teardown_recv_gpadl(device, net_device, ndev);704 705	netvsc_revoke_send_buf(device, net_device, ndev);706	if (vmbus_proto_version < VERSION_WIN10)707		netvsc_teardown_send_gpadl(device, net_device, ndev);708 709	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);710 711	/* Disable NAPI and disassociate its context from the device. */712	for (i = 0; i < net_device->num_chn; i++) {713		/* See also vmbus_reset_channel_cb(). */714		/* only disable enabled NAPI channel */715		if (i < ndev->real_num_rx_queues)716			napi_disable(&net_device->chan_table[i].napi);717 718		netif_napi_del(&net_device->chan_table[i].napi);719	}720 721	/*722	 * At this point, no one should be accessing net_device723	 * except in here724	 */725	netdev_dbg(ndev, "net device safe to remove\n");726 727	/* Now, we can close the channel safely */728	vmbus_close(device->channel);729 730	/*731	 * If host is Win2016 or higher then we do the GPADL tear down732	 * here after VMBus is closed.733	*/734	if (vmbus_proto_version >= VERSION_WIN10) {735		netvsc_teardown_recv_gpadl(device, net_device, ndev);736		netvsc_teardown_send_gpadl(device, net_device, ndev);737	}738 739	/* Release all resources */740	free_netvsc_device_rcu(net_device);741}742 743#define RING_AVAIL_PERCENT_HIWATER 20744#define RING_AVAIL_PERCENT_LOWATER 10745 746static inline void netvsc_free_send_slot(struct netvsc_device *net_device,747					 u32 index)748{749	sync_change_bit(index, net_device->send_section_map);750}751 752static void netvsc_send_tx_complete(struct net_device *ndev,753				    struct netvsc_device *net_device,754				    struct vmbus_channel *channel,755				    const struct vmpacket_descriptor *desc,756				    int budget)757{758	struct net_device_context *ndev_ctx = netdev_priv(ndev);759	struct sk_buff *skb;760	u16 q_idx = 0;761	int queue_sends;762	u64 cmd_rqst;763 764	cmd_rqst = channel->request_addr_callback(channel, desc->trans_id);765	if (cmd_rqst == VMBUS_RQST_ERROR) {766		netdev_err(ndev, "Invalid transaction ID %llx\n", desc->trans_id);767		return;768	}769 770	skb = (struct sk_buff *)(unsigned long)cmd_rqst;771 772	/* Notify the layer above us */773	if (likely(skb)) {774		struct hv_netvsc_packet *packet775			= (struct hv_netvsc_packet *)skb->cb;776		u32 send_index = packet->send_buf_index;777		struct netvsc_stats_tx *tx_stats;778 779		if (send_index != NETVSC_INVALID_INDEX)780			netvsc_free_send_slot(net_device, send_index);781		q_idx = packet->q_idx;782 783		tx_stats = &net_device->chan_table[q_idx].tx_stats;784 785		u64_stats_update_begin(&tx_stats->syncp);786		tx_stats->packets += packet->total_packets;787		tx_stats->bytes += packet->total_bytes;788		u64_stats_update_end(&tx_stats->syncp);789 790		netvsc_dma_unmap(ndev_ctx->device_ctx, packet);791		napi_consume_skb(skb, budget);792	}793 794	queue_sends =795		atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);796 797	if (unlikely(net_device->destroy)) {798		if (queue_sends == 0)799			wake_up(&net_device->wait_drain);800	} else {801		struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);802 803		if (netif_tx_queue_stopped(txq) && !net_device->tx_disable &&804		    (hv_get_avail_to_write_percent(&channel->outbound) >805		     RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {806			netif_tx_wake_queue(txq);807			ndev_ctx->eth_stats.wake_queue++;808		}809	}810}811 812static void netvsc_send_completion(struct net_device *ndev,813				   struct netvsc_device *net_device,814				   struct vmbus_channel *incoming_channel,815				   const struct vmpacket_descriptor *desc,816				   int budget)817{818	const struct nvsp_message *nvsp_packet;819	u32 msglen = hv_pkt_datalen(desc);820	struct nvsp_message *pkt_rqst;821	u64 cmd_rqst;822	u32 status;823 824	/* First check if this is a VMBUS completion without data payload */825	if (!msglen) {826		cmd_rqst = incoming_channel->request_addr_callback(incoming_channel,827								   desc->trans_id);828		if (cmd_rqst == VMBUS_RQST_ERROR) {829			netdev_err(ndev, "Invalid transaction ID %llx\n", desc->trans_id);830			return;831		}832 833		pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;834		switch (pkt_rqst->hdr.msg_type) {835		case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:836			complete(&net_device->channel_init_wait);837			break;838 839		default:840			netdev_err(ndev, "Unexpected VMBUS completion!!\n");841		}842		return;843	}844 845	/* Ensure packet is big enough to read header fields */846	if (msglen < sizeof(struct nvsp_message_header)) {847		netdev_err(ndev, "nvsp_message length too small: %u\n", msglen);848		return;849	}850 851	nvsp_packet = hv_pkt_data(desc);852	switch (nvsp_packet->hdr.msg_type) {853	case NVSP_MSG_TYPE_INIT_COMPLETE:854		if (msglen < sizeof(struct nvsp_message_header) +855				sizeof(struct nvsp_message_init_complete)) {856			netdev_err(ndev, "nvsp_msg length too small: %u\n",857				   msglen);858			return;859		}860		break;861 862	case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:863		if (msglen < sizeof(struct nvsp_message_header) +864				sizeof(struct nvsp_1_message_send_receive_buffer_complete)) {865			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",866				   msglen);867			return;868		}869		break;870 871	case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:872		if (msglen < sizeof(struct nvsp_message_header) +873				sizeof(struct nvsp_1_message_send_send_buffer_complete)) {874			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",875				   msglen);876			return;877		}878		break;879 880	case NVSP_MSG5_TYPE_SUBCHANNEL:881		if (msglen < sizeof(struct nvsp_message_header) +882				sizeof(struct nvsp_5_subchannel_complete)) {883			netdev_err(ndev, "nvsp_msg5 length too small: %u\n",884				   msglen);885			return;886		}887		break;888 889	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:890		if (msglen < sizeof(struct nvsp_message_header) +891		    sizeof(struct nvsp_1_message_send_rndis_packet_complete)) {892			if (net_ratelimit())893				netdev_err(ndev, "nvsp_rndis_pkt_complete length too small: %u\n",894					   msglen);895			return;896		}897 898		/* If status indicates an error, output a message so we know899		 * there's a problem. But process the completion anyway so the900		 * resources are released.901		 */902		status = nvsp_packet->msg.v1_msg.send_rndis_pkt_complete.status;903		if (status != NVSP_STAT_SUCCESS && net_ratelimit())904			netdev_err(ndev, "nvsp_rndis_pkt_complete error status: %x\n",905				   status);906 907		netvsc_send_tx_complete(ndev, net_device, incoming_channel,908					desc, budget);909		return;910 911	default:912		netdev_err(ndev,913			   "Unknown send completion type %d received!!\n",914			   nvsp_packet->hdr.msg_type);915		return;916	}917 918	/* Copy the response back */919	memcpy(&net_device->channel_init_pkt, nvsp_packet,920	       sizeof(struct nvsp_message));921	complete(&net_device->channel_init_wait);922}923 924static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)925{926	unsigned long *map_addr = net_device->send_section_map;927	unsigned int i;928 929	for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {930		if (sync_test_and_set_bit(i, map_addr) == 0)931			return i;932	}933 934	return NETVSC_INVALID_INDEX;935}936 937static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,938				    unsigned int section_index,939				    u32 pend_size,940				    struct hv_netvsc_packet *packet,941				    struct rndis_message *rndis_msg,942				    struct hv_page_buffer *pb,943				    bool xmit_more)944{945	char *start = net_device->send_buf;946	char *dest = start + (section_index * net_device->send_section_size)947		     + pend_size;948	int i;949	u32 padding = 0;950	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :951		packet->page_buf_cnt;952	u32 remain;953 954	/* Add padding */955	remain = packet->total_data_buflen & (net_device->pkt_align - 1);956	if (xmit_more && remain) {957		padding = net_device->pkt_align - remain;958		rndis_msg->msg_len += padding;959		packet->total_data_buflen += padding;960	}961 962	for (i = 0; i < page_count; i++) {963		char *src = phys_to_virt(pb[i].pfn << HV_HYP_PAGE_SHIFT);964		u32 offset = pb[i].offset;965		u32 len = pb[i].len;966 967		memcpy(dest, (src + offset), len);968		dest += len;969	}970 971	if (padding)972		memset(dest, 0, padding);973}974 975void netvsc_dma_unmap(struct hv_device *hv_dev,976		      struct hv_netvsc_packet *packet)977{978	int i;979 980	if (!hv_is_isolation_supported())981		return;982 983	if (!packet->dma_range)984		return;985 986	for (i = 0; i < packet->page_buf_cnt; i++)987		dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,988				 packet->dma_range[i].mapping_size,989				 DMA_TO_DEVICE);990 991	kfree(packet->dma_range);992}993 994/* netvsc_dma_map - Map swiotlb bounce buffer with data page of995 * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation996 * VM.997 *998 * In isolation VM, netvsc send buffer has been marked visible to999 * host and so the data copied to send buffer doesn't need to use1000 * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer()1001 * may not be copied to send buffer and so these pages need to be1002 * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do1003 * that. The pfns in the struct hv_page_buffer need to be converted1004 * to bounce buffer's pfn. The loop here is necessary because the1005 * entries in the page buffer array are not necessarily full1006 * pages of data.  Each entry in the array has a separate offset and1007 * len that may be non-zero, even for entries in the middle of the1008 * array.  And the entries are not physically contiguous.  So each1009 * entry must be individually mapped rather than as a contiguous unit.1010 * So not use dma_map_sg() here.1011 */1012static int netvsc_dma_map(struct hv_device *hv_dev,1013			  struct hv_netvsc_packet *packet,1014			  struct hv_page_buffer *pb)1015{1016	u32 page_count = packet->page_buf_cnt;1017	dma_addr_t dma;1018	int i;1019 1020	if (!hv_is_isolation_supported())1021		return 0;1022 1023	packet->dma_range = kcalloc(page_count,1024				    sizeof(*packet->dma_range),1025				    GFP_ATOMIC);1026	if (!packet->dma_range)1027		return -ENOMEM;1028 1029	for (i = 0; i < page_count; i++) {1030		char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT)1031					 + pb[i].offset);1032		u32 len = pb[i].len;1033 1034		dma = dma_map_single(&hv_dev->device, src, len,1035				     DMA_TO_DEVICE);1036		if (dma_mapping_error(&hv_dev->device, dma)) {1037			kfree(packet->dma_range);1038			return -ENOMEM;1039		}1040 1041		/* pb[].offset and pb[].len are not changed during dma mapping1042		 * and so not reassign.1043		 */1044		packet->dma_range[i].dma = dma;1045		packet->dma_range[i].mapping_size = len;1046		pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;1047	}1048 1049	return 0;1050}1051 1052static inline int netvsc_send_pkt(1053	struct hv_device *device,1054	struct hv_netvsc_packet *packet,1055	struct netvsc_device *net_device,1056	struct hv_page_buffer *pb,1057	struct sk_buff *skb)1058{1059	struct nvsp_message nvmsg;1060	struct nvsp_1_message_send_rndis_packet *rpkt =1061		&nvmsg.msg.v1_msg.send_rndis_pkt;1062	struct netvsc_channel * const nvchan =1063		&net_device->chan_table[packet->q_idx];1064	struct vmbus_channel *out_channel = nvchan->channel;1065	struct net_device *ndev = hv_get_drvdata(device);1066	struct net_device_context *ndev_ctx = netdev_priv(ndev);1067	struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);1068	u64 req_id;1069	int ret;1070	u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);1071 1072	memset(&nvmsg, 0, sizeof(struct nvsp_message));1073	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;1074	if (skb)1075		rpkt->channel_type = 0;		/* 0 is RMC_DATA */1076	else1077		rpkt->channel_type = 1;		/* 1 is RMC_CONTROL */1078 1079	rpkt->send_buf_section_index = packet->send_buf_index;1080	if (packet->send_buf_index == NETVSC_INVALID_INDEX)1081		rpkt->send_buf_section_size = 0;1082	else1083		rpkt->send_buf_section_size = packet->total_data_buflen;1084 1085	req_id = (ulong)skb;1086 1087	if (out_channel->rescind)1088		return -ENODEV;1089 1090	trace_nvsp_send_pkt(ndev, out_channel, rpkt);1091 1092	packet->dma_range = NULL;1093	if (packet->page_buf_cnt) {1094		if (packet->cp_partial)1095			pb += packet->rmsg_pgcnt;1096 1097		ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);1098		if (ret) {1099			ret = -EAGAIN;1100			goto exit;1101		}1102 1103		ret = vmbus_sendpacket_pagebuffer(out_channel,1104						  pb, packet->page_buf_cnt,1105						  &nvmsg, sizeof(nvmsg),1106						  req_id);1107 1108		if (ret)1109			netvsc_dma_unmap(ndev_ctx->device_ctx, packet);1110	} else {1111		ret = vmbus_sendpacket(out_channel,1112				       &nvmsg, sizeof(nvmsg),1113				       req_id, VM_PKT_DATA_INBAND,1114				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);1115	}1116 1117exit:1118	if (ret == 0) {1119		atomic_inc_return(&nvchan->queue_sends);1120 1121		if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {1122			netif_tx_stop_queue(txq);1123			ndev_ctx->eth_stats.stop_queue++;1124		}1125	} else if (ret == -EAGAIN) {1126		netif_tx_stop_queue(txq);1127		ndev_ctx->eth_stats.stop_queue++;1128	} else {1129		netdev_err(ndev,1130			   "Unable to send packet pages %u len %u, ret %d\n",1131			   packet->page_buf_cnt, packet->total_data_buflen,1132			   ret);1133	}1134 1135	if (netif_tx_queue_stopped(txq) &&1136	    atomic_read(&nvchan->queue_sends) < 1 &&1137	    !net_device->tx_disable) {1138		netif_tx_wake_queue(txq);1139		ndev_ctx->eth_stats.wake_queue++;1140		if (ret == -EAGAIN)1141			ret = -ENOSPC;1142	}1143 1144	return ret;1145}1146 1147/* Move packet out of multi send data (msd), and clear msd */1148static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,1149				struct sk_buff **msd_skb,1150				struct multi_send_data *msdp)1151{1152	*msd_skb = msdp->skb;1153	*msd_send = msdp->pkt;1154	msdp->skb = NULL;1155	msdp->pkt = NULL;1156	msdp->count = 0;1157}1158 1159/* RCU already held by caller */1160/* Batching/bouncing logic is designed to attempt to optimize1161 * performance.1162 *1163 * For small, non-LSO packets we copy the packet to a send buffer1164 * which is pre-registered with the Hyper-V side. This enables the1165 * hypervisor to avoid remapping the aperture to access the packet1166 * descriptor and data.1167 *1168 * If we already started using a buffer and the netdev is transmitting1169 * a burst of packets, keep on copying into the buffer until it is1170 * full or we are done collecting a burst. If there is an existing1171 * buffer with space for the RNDIS descriptor but not the packet, copy1172 * the RNDIS descriptor to the buffer, keeping the packet in place.1173 *1174 * If we do batching and send more than one packet using a single1175 * NetVSC message, free the SKBs of the packets copied, except for the1176 * last packet. This is done to streamline the handling of the case1177 * where the last packet only had the RNDIS descriptor copied to the1178 * send buffer, with the data pointers included in the NetVSC message.1179 */1180int netvsc_send(struct net_device *ndev,1181		struct hv_netvsc_packet *packet,1182		struct rndis_message *rndis_msg,1183		struct hv_page_buffer *pb,1184		struct sk_buff *skb,1185		bool xdp_tx)1186{1187	struct net_device_context *ndev_ctx = netdev_priv(ndev);1188	struct netvsc_device *net_device1189		= rcu_dereference_bh(ndev_ctx->nvdev);1190	struct hv_device *device = ndev_ctx->device_ctx;1191	int ret = 0;1192	struct netvsc_channel *nvchan;1193	u32 pktlen = packet->total_data_buflen, msd_len = 0;1194	unsigned int section_index = NETVSC_INVALID_INDEX;1195	struct multi_send_data *msdp;1196	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;1197	struct sk_buff *msd_skb = NULL;1198	bool try_batch, xmit_more;1199 1200	/* If device is rescinded, return error and packet will get dropped. */1201	if (unlikely(!net_device || net_device->destroy))1202		return -ENODEV;1203 1204	nvchan = &net_device->chan_table[packet->q_idx];1205	packet->send_buf_index = NETVSC_INVALID_INDEX;1206	packet->cp_partial = false;1207 1208	/* Send a control message or XDP packet directly without accessing1209	 * msd (Multi-Send Data) field which may be changed during data packet1210	 * processing.1211	 */1212	if (!skb || xdp_tx)1213		return netvsc_send_pkt(device, packet, net_device, pb, skb);1214 1215	/* batch packets in send buffer if possible */1216	msdp = &nvchan->msd;1217	if (msdp->pkt)1218		msd_len = msdp->pkt->total_data_buflen;1219 1220	try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;1221	if (try_batch && msd_len + pktlen + net_device->pkt_align <1222	    net_device->send_section_size) {1223		section_index = msdp->pkt->send_buf_index;1224 1225	} else if (try_batch && msd_len + packet->rmsg_size <1226		   net_device->send_section_size) {1227		section_index = msdp->pkt->send_buf_index;1228		packet->cp_partial = true;1229 1230	} else if (pktlen + net_device->pkt_align <1231		   net_device->send_section_size) {1232		section_index = netvsc_get_next_send_section(net_device);1233		if (unlikely(section_index == NETVSC_INVALID_INDEX)) {1234			++ndev_ctx->eth_stats.tx_send_full;1235		} else {1236			move_pkt_msd(&msd_send, &msd_skb, msdp);1237			msd_len = 0;1238		}1239	}1240 1241	/* Keep aggregating only if stack says more data is coming1242	 * and not doing mixed modes send and not flow blocked1243	 */1244	xmit_more = netdev_xmit_more() &&1245		!packet->cp_partial &&1246		!netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));1247 1248	if (section_index != NETVSC_INVALID_INDEX) {1249		netvsc_copy_to_send_buf(net_device,1250					section_index, msd_len,1251					packet, rndis_msg, pb, xmit_more);1252 1253		packet->send_buf_index = section_index;1254 1255		if (packet->cp_partial) {1256			packet->page_buf_cnt -= packet->rmsg_pgcnt;1257			packet->total_data_buflen = msd_len + packet->rmsg_size;1258		} else {1259			packet->page_buf_cnt = 0;1260			packet->total_data_buflen += msd_len;1261		}1262 1263		if (msdp->pkt) {1264			packet->total_packets += msdp->pkt->total_packets;1265			packet->total_bytes += msdp->pkt->total_bytes;1266		}1267 1268		if (msdp->skb)1269			dev_consume_skb_any(msdp->skb);1270 1271		if (xmit_more) {1272			msdp->skb = skb;1273			msdp->pkt = packet;1274			msdp->count++;1275		} else {1276			cur_send = packet;1277			msdp->skb = NULL;1278			msdp->pkt = NULL;1279			msdp->count = 0;1280		}1281	} else {1282		move_pkt_msd(&msd_send, &msd_skb, msdp);1283		cur_send = packet;1284	}1285 1286	if (msd_send) {1287		int m_ret = netvsc_send_pkt(device, msd_send, net_device,1288					    NULL, msd_skb);1289 1290		if (m_ret != 0) {1291			netvsc_free_send_slot(net_device,1292					      msd_send->send_buf_index);1293			dev_kfree_skb_any(msd_skb);1294		}1295	}1296 1297	if (cur_send)1298		ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);1299 1300	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)1301		netvsc_free_send_slot(net_device, section_index);1302 1303	return ret;1304}1305 1306/* Send pending recv completions */1307static int send_recv_completions(struct net_device *ndev,1308				 struct netvsc_device *nvdev,1309				 struct netvsc_channel *nvchan)1310{1311	struct multi_recv_comp *mrc = &nvchan->mrc;1312	struct recv_comp_msg {1313		struct nvsp_message_header hdr;1314		u32 status;1315	}  __packed;1316	struct recv_comp_msg msg = {1317		.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,1318	};1319	int ret;1320 1321	while (mrc->first != mrc->next) {1322		const struct recv_comp_data *rcd1323			= mrc->slots + mrc->first;1324 1325		msg.status = rcd->status;1326		ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),1327				       rcd->tid, VM_PKT_COMP, 0);1328		if (unlikely(ret)) {1329			struct net_device_context *ndev_ctx = netdev_priv(ndev);1330 1331			++ndev_ctx->eth_stats.rx_comp_busy;1332			return ret;1333		}1334 1335		if (++mrc->first == nvdev->recv_completion_cnt)1336			mrc->first = 0;1337	}1338 1339	/* receive completion ring has been emptied */1340	if (unlikely(nvdev->destroy))1341		wake_up(&nvdev->wait_drain);1342 1343	return 0;1344}1345 1346/* Count how many receive completions are outstanding */1347static void recv_comp_slot_avail(const struct netvsc_device *nvdev,1348				 const struct multi_recv_comp *mrc,1349				 u32 *filled, u32 *avail)1350{1351	u32 count = nvdev->recv_completion_cnt;1352 1353	if (mrc->next >= mrc->first)1354		*filled = mrc->next - mrc->first;1355	else1356		*filled = (count - mrc->first) + mrc->next;1357 1358	*avail = count - *filled - 1;1359}1360 1361/* Add receive complete to ring to send to host. */1362static void enq_receive_complete(struct net_device *ndev,1363				 struct netvsc_device *nvdev, u16 q_idx,1364				 u64 tid, u32 status)1365{1366	struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];1367	struct multi_recv_comp *mrc = &nvchan->mrc;1368	struct recv_comp_data *rcd;1369	u32 filled, avail;1370 1371	recv_comp_slot_avail(nvdev, mrc, &filled, &avail);1372 1373	if (unlikely(filled > NAPI_POLL_WEIGHT)) {1374		send_recv_completions(ndev, nvdev, nvchan);1375		recv_comp_slot_avail(nvdev, mrc, &filled, &avail);1376	}1377 1378	if (unlikely(!avail)) {1379		netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",1380			   q_idx, tid);1381		return;1382	}1383 1384	rcd = mrc->slots + mrc->next;1385	rcd->tid = tid;1386	rcd->status = status;1387 1388	if (++mrc->next == nvdev->recv_completion_cnt)1389		mrc->next = 0;1390}1391 1392static int netvsc_receive(struct net_device *ndev,1393			  struct netvsc_device *net_device,1394			  struct netvsc_channel *nvchan,1395			  const struct vmpacket_descriptor *desc)1396{1397	struct net_device_context *net_device_ctx = netdev_priv(ndev);1398	struct vmbus_channel *channel = nvchan->channel;1399	const struct vmtransfer_page_packet_header *vmxferpage_packet1400		= container_of(desc, const struct vmtransfer_page_packet_header, d);1401	const struct nvsp_message *nvsp = hv_pkt_data(desc);1402	u32 msglen = hv_pkt_datalen(desc);1403	u16 q_idx = channel->offermsg.offer.sub_channel_index;1404	char *recv_buf = net_device->recv_buf;1405	u32 status = NVSP_STAT_SUCCESS;1406	int i;1407	int count = 0;1408 1409	/* Ensure packet is big enough to read header fields */1410	if (msglen < sizeof(struct nvsp_message_header)) {1411		netif_err(net_device_ctx, rx_err, ndev,1412			  "invalid nvsp header, length too small: %u\n",1413			  msglen);1414		return 0;1415	}1416 1417	/* Make sure this is a valid nvsp packet */1418	if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {1419		netif_err(net_device_ctx, rx_err, ndev,1420			  "Unknown nvsp packet type received %u\n",1421			  nvsp->hdr.msg_type);1422		return 0;1423	}1424 1425	/* Validate xfer page pkt header */1426	if ((desc->offset8 << 3) < sizeof(struct vmtransfer_page_packet_header)) {1427		netif_err(net_device_ctx, rx_err, ndev,1428			  "Invalid xfer page pkt, offset too small: %u\n",1429			  desc->offset8 << 3);1430		return 0;1431	}1432 1433	if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {1434		netif_err(net_device_ctx, rx_err, ndev,1435			  "Invalid xfer page set id - expecting %x got %x\n",1436			  NETVSC_RECEIVE_BUFFER_ID,1437			  vmxferpage_packet->xfer_pageset_id);1438		return 0;1439	}1440 1441	count = vmxferpage_packet->range_cnt;1442 1443	/* Check count for a valid value */1444	if (NETVSC_XFER_HEADER_SIZE(count) > desc->offset8 << 3) {1445		netif_err(net_device_ctx, rx_err, ndev,1446			  "Range count is not valid: %d\n",1447			  count);1448		return 0;1449	}1450 1451	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */1452	for (i = 0; i < count; i++) {1453		u32 offset = vmxferpage_packet->ranges[i].byte_offset;1454		u32 buflen = vmxferpage_packet->ranges[i].byte_count;1455		void *data;1456		int ret;1457 1458		if (unlikely(offset > net_device->recv_buf_size ||1459			     buflen > net_device->recv_buf_size - offset)) {1460			nvchan->rsc.cnt = 0;1461			status = NVSP_STAT_FAIL;1462			netif_err(net_device_ctx, rx_err, ndev,1463				  "Packet offset:%u + len:%u too big\n",1464				  offset, buflen);1465 1466			continue;1467		}1468 1469		/* We're going to copy (sections of) the packet into nvchan->recv_buf;1470		 * make sure that nvchan->recv_buf is large enough to hold the packet.1471		 */1472		if (unlikely(buflen > net_device->recv_section_size)) {1473			nvchan->rsc.cnt = 0;1474			status = NVSP_STAT_FAIL;1475			netif_err(net_device_ctx, rx_err, ndev,1476				  "Packet too big: buflen=%u recv_section_size=%u\n",1477				  buflen, net_device->recv_section_size);1478 1479			continue;1480		}1481 1482		data = recv_buf + offset;1483 1484		nvchan->rsc.is_last = (i == count - 1);1485 1486		trace_rndis_recv(ndev, q_idx, data);1487 1488		/* Pass it to the upper layer */1489		ret = rndis_filter_receive(ndev, net_device,1490					   nvchan, data, buflen);1491 1492		if (unlikely(ret != NVSP_STAT_SUCCESS)) {1493			/* Drop incomplete packet */1494			nvchan->rsc.cnt = 0;1495			status = NVSP_STAT_FAIL;1496		}1497	}1498 1499	enq_receive_complete(ndev, net_device, q_idx,1500			     vmxferpage_packet->d.trans_id, status);1501 1502	return count;1503}1504 1505static void netvsc_send_table(struct net_device *ndev,1506			      struct netvsc_device *nvscdev,1507			      const struct nvsp_message *nvmsg,1508			      u32 msglen)1509{1510	struct net_device_context *net_device_ctx = netdev_priv(ndev);1511	u32 count, offset, *tab;1512	int i;1513 1514	/* Ensure packet is big enough to read send_table fields */1515	if (msglen < sizeof(struct nvsp_message_header) +1516		     sizeof(struct nvsp_5_send_indirect_table)) {1517		netdev_err(ndev, "nvsp_v5_msg length too small: %u\n", msglen);1518		return;1519	}1520 1521	count = nvmsg->msg.v5_msg.send_table.count;1522	offset = nvmsg->msg.v5_msg.send_table.offset;1523 1524	if (count != VRSS_SEND_TAB_SIZE) {1525		netdev_err(ndev, "Received wrong send-table size:%u\n", count);1526		return;1527	}1528 1529	/* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be1530	 * wrong due to a host bug. So fix the offset here.1531	 */1532	if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&1533	    msglen >= sizeof(struct nvsp_message_header) +1534	    sizeof(union nvsp_6_message_uber) + count * sizeof(u32))1535		offset = sizeof(struct nvsp_message_header) +1536			 sizeof(union nvsp_6_message_uber);1537 1538	/* Boundary check for all versions */1539	if (msglen < count * sizeof(u32) || offset > msglen - count * sizeof(u32)) {1540		netdev_err(ndev, "Received send-table offset too big:%u\n",1541			   offset);1542		return;1543	}1544 1545	tab = (void *)nvmsg + offset;1546 1547	for (i = 0; i < count; i++)1548		net_device_ctx->tx_table[i] = tab[i];1549}1550 1551static void netvsc_send_vf(struct net_device *ndev,1552			   const struct nvsp_message *nvmsg,1553			   u32 msglen)1554{1555	struct net_device_context *net_device_ctx = netdev_priv(ndev);1556 1557	/* Ensure packet is big enough to read its fields */1558	if (msglen < sizeof(struct nvsp_message_header) +1559		     sizeof(struct nvsp_4_send_vf_association)) {1560		netdev_err(ndev, "nvsp_v4_msg length too small: %u\n", msglen);1561		return;1562	}1563 1564	net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;1565	net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;1566 1567	if (net_device_ctx->vf_alloc)1568		complete(&net_device_ctx->vf_add);1569 1570	netdev_info(ndev, "VF slot %u %s\n",1571		    net_device_ctx->vf_serial,1572		    net_device_ctx->vf_alloc ? "added" : "removed");1573}1574 1575static void netvsc_receive_inband(struct net_device *ndev,1576				  struct netvsc_device *nvscdev,1577				  const struct vmpacket_descriptor *desc)1578{1579	const struct nvsp_message *nvmsg = hv_pkt_data(desc);1580	u32 msglen = hv_pkt_datalen(desc);1581 1582	/* Ensure packet is big enough to read header fields */1583	if (msglen < sizeof(struct nvsp_message_header)) {1584		netdev_err(ndev, "inband nvsp_message length too small: %u\n", msglen);1585		return;1586	}1587 1588	switch (nvmsg->hdr.msg_type) {1589	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:1590		netvsc_send_table(ndev, nvscdev, nvmsg, msglen);1591		break;1592 1593	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:1594		if (hv_is_isolation_supported())1595			netdev_err(ndev, "Ignore VF_ASSOCIATION msg from the host supporting isolation\n");1596		else1597			netvsc_send_vf(ndev, nvmsg, msglen);1598		break;1599	}1600}1601 1602static int netvsc_process_raw_pkt(struct hv_device *device,1603				  struct netvsc_channel *nvchan,1604				  struct netvsc_device *net_device,1605				  struct net_device *ndev,1606				  const struct vmpacket_descriptor *desc,1607				  int budget)1608{1609	struct vmbus_channel *channel = nvchan->channel;1610	const struct nvsp_message *nvmsg = hv_pkt_data(desc);1611 1612	trace_nvsp_recv(ndev, channel, nvmsg);1613 1614	switch (desc->type) {1615	case VM_PKT_COMP:1616		netvsc_send_completion(ndev, net_device, channel, desc, budget);1617		break;1618 1619	case VM_PKT_DATA_USING_XFER_PAGES:1620		return netvsc_receive(ndev, net_device, nvchan, desc);1621 1622	case VM_PKT_DATA_INBAND:1623		netvsc_receive_inband(ndev, net_device, desc);1624		break;1625 1626	default:1627		netdev_err(ndev, "unhandled packet type %d, tid %llx\n",1628			   desc->type, desc->trans_id);1629		break;1630	}1631 1632	return 0;1633}1634 1635static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)1636{1637	struct vmbus_channel *primary = channel->primary_channel;1638 1639	return primary ? primary->device_obj : channel->device_obj;1640}1641 1642/* Network processing softirq1643 * Process data in incoming ring buffer from host1644 * Stops when ring is empty or budget is met or exceeded.1645 */1646int netvsc_poll(struct napi_struct *napi, int budget)1647{1648	struct netvsc_channel *nvchan1649		= container_of(napi, struct netvsc_channel, napi);1650	struct netvsc_device *net_device = nvchan->net_device;1651	struct vmbus_channel *channel = nvchan->channel;1652	struct hv_device *device = netvsc_channel_to_device(channel);1653	struct net_device *ndev = hv_get_drvdata(device);1654	int work_done = 0;1655	int ret;1656 1657	/* If starting a new interval */1658	if (!nvchan->desc)1659		nvchan->desc = hv_pkt_iter_first(channel);1660 1661	nvchan->xdp_flush = false;1662 1663	while (nvchan->desc && work_done < budget) {1664		work_done += netvsc_process_raw_pkt(device, nvchan, net_device,1665						    ndev, nvchan->desc, budget);1666		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);1667	}1668 1669	if (nvchan->xdp_flush)1670		xdp_do_flush();1671 1672	/* Send any pending receive completions */1673	ret = send_recv_completions(ndev, net_device, nvchan);1674 1675	/* If it did not exhaust NAPI budget this time1676	 *  and not doing busy poll1677	 * then re-enable host interrupts1678	 *  and reschedule if ring is not empty1679	 *   or sending receive completion failed.1680	 */1681	if (work_done < budget &&1682	    napi_complete_done(napi, work_done) &&1683	    (ret || hv_end_read(&channel->inbound)) &&1684	    napi_schedule_prep(napi)) {1685		hv_begin_read(&channel->inbound);1686		__napi_schedule(napi);1687	}1688 1689	/* Driver may overshoot since multiple packets per descriptor */1690	return min(work_done, budget);1691}1692 1693/* Call back when data is available in host ring buffer.1694 * Processing is deferred until network softirq (NAPI)1695 */1696void netvsc_channel_cb(void *context)1697{1698	struct netvsc_channel *nvchan = context;1699	struct vmbus_channel *channel = nvchan->channel;1700	struct hv_ring_buffer_info *rbi = &channel->inbound;1701 1702	/* preload first vmpacket descriptor */1703	prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);1704 1705	if (napi_schedule_prep(&nvchan->napi)) {1706		/* disable interrupts from host */1707		hv_begin_read(rbi);1708 1709		__napi_schedule_irqoff(&nvchan->napi);1710	}1711}1712 1713/*1714 * netvsc_device_add - Callback when the device belonging to this1715 * driver is added1716 */1717struct netvsc_device *netvsc_device_add(struct hv_device *device,1718				const struct netvsc_device_info *device_info)1719{1720	int i, ret = 0;1721	struct netvsc_device *net_device;1722	struct net_device *ndev = hv_get_drvdata(device);1723	struct net_device_context *net_device_ctx = netdev_priv(ndev);1724 1725	net_device = alloc_net_device();1726	if (!net_device)1727		return ERR_PTR(-ENOMEM);1728 1729	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)1730		net_device_ctx->tx_table[i] = 0;1731 1732	/* Because the device uses NAPI, all the interrupt batching and1733	 * control is done via Net softirq, not the channel handling1734	 */1735	set_channel_read_mode(device->channel, HV_CALL_ISR);1736 1737	/* If we're reopening the device we may have multiple queues, fill the1738	 * chn_table with the default channel to use it before subchannels are1739	 * opened.1740	 * Initialize the channel state before we open;1741	 * we can be interrupted as soon as we open the channel.1742	 */1743 1744	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {1745		struct netvsc_channel *nvchan = &net_device->chan_table[i];1746 1747		nvchan->channel = device->channel;1748		nvchan->net_device = net_device;1749		u64_stats_init(&nvchan->tx_stats.syncp);1750		u64_stats_init(&nvchan->rx_stats.syncp);1751 1752		ret = xdp_rxq_info_reg(&nvchan->xdp_rxq, ndev, i, 0);1753 1754		if (ret) {1755			netdev_err(ndev, "xdp_rxq_info_reg fail: %d\n", ret);1756			goto cleanup2;1757		}1758 1759		ret = xdp_rxq_info_reg_mem_model(&nvchan->xdp_rxq,1760						 MEM_TYPE_PAGE_SHARED, NULL);1761 1762		if (ret) {1763			netdev_err(ndev, "xdp reg_mem_model fail: %d\n", ret);1764			goto cleanup2;1765		}1766	}1767 1768	/* Enable NAPI handler before init callbacks */1769	netif_napi_add(ndev, &net_device->chan_table[0].napi, netvsc_poll);1770 1771	/* Open the channel */1772	device->channel->next_request_id_callback = vmbus_next_request_id;1773	device->channel->request_addr_callback = vmbus_request_addr;1774	device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);1775	device->channel->max_pkt_size = NETVSC_MAX_PKT_SIZE;1776 1777	ret = vmbus_open(device->channel, netvsc_ring_bytes,1778			 netvsc_ring_bytes,  NULL, 0,1779			 netvsc_channel_cb, net_device->chan_table);1780 1781	if (ret != 0) {1782		netdev_err(ndev, "unable to open channel: %d\n", ret);1783		goto cleanup;1784	}1785 1786	/* Channel is opened */1787	netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");1788 1789	napi_enable(&net_device->chan_table[0].napi);1790 1791	/* Connect with the NetVsp */1792	ret = netvsc_connect_vsp(device, net_device, device_info);1793	if (ret != 0) {1794		netdev_err(ndev,1795			"unable to connect to NetVSP - %d\n", ret);1796		goto close;1797	}1798 1799	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is1800	 * populated.1801	 */1802	rcu_assign_pointer(net_device_ctx->nvdev, net_device);1803 1804	return net_device;1805 1806close:1807	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);1808	napi_disable(&net_device->chan_table[0].napi);1809 1810	/* Now, we can close the channel safely */1811	vmbus_close(device->channel);1812 1813cleanup:1814	netif_napi_del(&net_device->chan_table[0].napi);1815 1816cleanup2:1817	free_netvsc_device(&net_device->rcu);1818 1819	return ERR_PTR(ret);1820}1821