673 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			673 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /* MHI MBIM Network driver - Network/MBIM over MHI bus
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|  *
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|  * Copyright (C) 2021 Linaro Ltd <loic.poulain@linaro.org>
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|  *
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|  * This driver copy some code from cdc_ncm, which is:
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|  * Copyright (C) ST-Ericsson 2010-2012
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|  * and cdc_mbim, which is:
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|  * Copyright (c) 2012  Smith Micro Software, Inc.
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|  * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
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|  *
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|  */
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| 
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| #include <linux/ethtool.h>
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| #include <linux/if_arp.h>
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| #include <linux/if_vlan.h>
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| #include <linux/ip.h>
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| #include <linux/mhi.h>
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| #include <linux/mii.h>
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| #include <linux/mod_devicetable.h>
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| #include <linux/module.h>
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| #include <linux/netdevice.h>
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| #include <linux/skbuff.h>
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| #include <linux/u64_stats_sync.h>
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| #include <linux/usb.h>
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| #include <linux/usb/cdc.h>
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| #include <linux/usb/usbnet.h>
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| #include <linux/usb/cdc_ncm.h>
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| #include <linux/wwan.h>
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| 
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| /* 3500 allows to optimize skb allocation, the skbs will basically fit in
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|  * one 4K page. Large MBIM packets will simply be split over several MHI
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|  * transfers and chained by the MHI net layer (zerocopy).
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|  */
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| #define MHI_DEFAULT_MRU 3500
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| 
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| #define MHI_MBIM_DEFAULT_MTU 1500
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| #define MHI_MAX_BUF_SZ 0xffff
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| 
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| #define MBIM_NDP16_SIGN_MASK 0x00ffffff
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| 
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| #define MHI_MBIM_LINK_HASH_SIZE 8
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| #define LINK_HASH(session) ((session) % MHI_MBIM_LINK_HASH_SIZE)
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| 
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| #define WDS_BIND_MUX_DATA_PORT_MUX_ID 112
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| 
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| struct mhi_mbim_link {
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| 	struct mhi_mbim_context *mbim;
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| 	struct net_device *ndev;
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| 	unsigned int session;
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| 
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| 	/* stats */
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| 	u64_stats_t rx_packets;
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| 	u64_stats_t rx_bytes;
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| 	u64_stats_t rx_errors;
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| 	u64_stats_t tx_packets;
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| 	u64_stats_t tx_bytes;
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| 	u64_stats_t tx_errors;
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| 	u64_stats_t tx_dropped;
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| 	struct u64_stats_sync tx_syncp;
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| 	struct u64_stats_sync rx_syncp;
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| 
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| 	struct hlist_node hlnode;
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| };
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| 
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| struct mhi_mbim_context {
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| 	struct mhi_device *mdev;
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| 	struct sk_buff *skbagg_head;
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| 	struct sk_buff *skbagg_tail;
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| 	unsigned int mru;
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| 	u32 rx_queue_sz;
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| 	u16 rx_seq;
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| 	u16 tx_seq;
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| 	struct delayed_work rx_refill;
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| 	spinlock_t tx_lock;
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| 	struct hlist_head link_list[MHI_MBIM_LINK_HASH_SIZE];
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| };
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| 
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| struct mbim_tx_hdr {
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| 	struct usb_cdc_ncm_nth16 nth16;
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| 	struct usb_cdc_ncm_ndp16 ndp16;
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| 	struct usb_cdc_ncm_dpe16 dpe16[2];
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| } __packed;
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| 
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| static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
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| 						   unsigned int session)
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| {
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| 	struct mhi_mbim_link *link;
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| 
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| 	hlist_for_each_entry_rcu(link, &mbim->link_list[LINK_HASH(session)], hlnode) {
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| 		if (link->session == session)
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| 			return link;
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| 	}
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| 
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| 	return NULL;
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| }
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| 
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| static int mhi_mbim_get_link_mux_id(struct mhi_controller *cntrl)
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| {
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| 	if (strcmp(cntrl->name, "foxconn-dw5934e") == 0 ||
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| 	    strcmp(cntrl->name, "foxconn-t99w515") == 0)
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| 		return WDS_BIND_MUX_DATA_PORT_MUX_ID;
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| 
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| 	return 0;
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| }
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| 
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| static struct sk_buff *mbim_tx_fixup(struct sk_buff *skb, unsigned int session,
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| 				     u16 tx_seq)
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| {
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| 	unsigned int dgram_size = skb->len;
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| 	struct usb_cdc_ncm_nth16 *nth16;
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| 	struct usb_cdc_ncm_ndp16 *ndp16;
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| 	struct mbim_tx_hdr *mbim_hdr;
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| 
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| 	/* Only one NDP is sent, containing the IP packet (no aggregation) */
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| 
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| 	/* Ensure we have enough headroom for crafting MBIM header */
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| 	if (skb_cow_head(skb, sizeof(struct mbim_tx_hdr))) {
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| 		dev_kfree_skb_any(skb);
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| 		return NULL;
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| 	}
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| 
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| 	mbim_hdr = skb_push(skb, sizeof(struct mbim_tx_hdr));
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| 
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| 	/* Fill NTB header */
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| 	nth16 = &mbim_hdr->nth16;
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| 	nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
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| 	nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
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| 	nth16->wSequence = cpu_to_le16(tx_seq);
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| 	nth16->wBlockLength = cpu_to_le16(skb->len);
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| 	nth16->wNdpIndex = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
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| 
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| 	/* Fill the unique NDP */
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| 	ndp16 = &mbim_hdr->ndp16;
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| 	ndp16->dwSignature = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN | (session << 24));
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| 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16)
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| 					+ sizeof(struct usb_cdc_ncm_dpe16) * 2);
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| 	ndp16->wNextNdpIndex = 0;
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| 
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| 	/* Datagram follows the mbim header */
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| 	ndp16->dpe16[0].wDatagramIndex = cpu_to_le16(sizeof(struct mbim_tx_hdr));
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| 	ndp16->dpe16[0].wDatagramLength = cpu_to_le16(dgram_size);
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| 
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| 	/* null termination */
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| 	ndp16->dpe16[1].wDatagramIndex = 0;
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| 	ndp16->dpe16[1].wDatagramLength = 0;
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| 
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| 	return skb;
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| }
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| 
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| static netdev_tx_t mhi_mbim_ndo_xmit(struct sk_buff *skb, struct net_device *ndev)
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| {
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| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
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| 	struct mhi_mbim_context *mbim = link->mbim;
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| 	unsigned long flags;
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| 	int err = -ENOMEM;
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| 
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| 	/* Serialize MHI channel queuing and MBIM seq */
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| 	spin_lock_irqsave(&mbim->tx_lock, flags);
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| 
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| 	skb = mbim_tx_fixup(skb, link->session, mbim->tx_seq);
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| 	if (unlikely(!skb))
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| 		goto exit_unlock;
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| 
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| 	err = mhi_queue_skb(mbim->mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT);
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| 
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| 	if (mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE))
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| 		netif_stop_queue(ndev);
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| 
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| 	if (!err)
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| 		mbim->tx_seq++;
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| 
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| exit_unlock:
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| 	spin_unlock_irqrestore(&mbim->tx_lock, flags);
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| 
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| 	if (unlikely(err)) {
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| 		net_err_ratelimited("%s: Failed to queue TX buf (%d)\n",
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| 				    ndev->name, err);
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| 		dev_kfree_skb_any(skb);
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| 		goto exit_drop;
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| 	}
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| 
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| 	return NETDEV_TX_OK;
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| 
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| exit_drop:
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| 	u64_stats_update_begin(&link->tx_syncp);
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| 	u64_stats_inc(&link->tx_dropped);
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| 	u64_stats_update_end(&link->tx_syncp);
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| 
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| 	return NETDEV_TX_OK;
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| }
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| 
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| static int mbim_rx_verify_nth16(struct mhi_mbim_context *mbim, struct sk_buff *skb)
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| {
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| 	struct usb_cdc_ncm_nth16 *nth16;
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| 	int len;
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| 
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| 	if (skb->len < sizeof(struct usb_cdc_ncm_nth16) +
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| 			sizeof(struct usb_cdc_ncm_ndp16)) {
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| 		net_err_ratelimited("frame too short\n");
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| 		return -EINVAL;
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| 	}
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| 
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| 	nth16 = (struct usb_cdc_ncm_nth16 *)skb->data;
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| 
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| 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
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| 		net_err_ratelimited("invalid NTH16 signature <%#010x>\n",
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| 				    le32_to_cpu(nth16->dwSignature));
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| 		return -EINVAL;
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| 	}
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| 
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| 	/* No limit on the block length, except the size of the data pkt */
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| 	len = le16_to_cpu(nth16->wBlockLength);
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| 	if (len > skb->len) {
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| 		net_err_ratelimited("NTB does not fit into the skb %u/%u\n",
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| 				    len, skb->len);
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| 		return -EINVAL;
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| 	}
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| 
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| 	if (mbim->rx_seq + 1 != le16_to_cpu(nth16->wSequence) &&
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| 	    (mbim->rx_seq || le16_to_cpu(nth16->wSequence)) &&
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| 	    !(mbim->rx_seq == 0xffff && !le16_to_cpu(nth16->wSequence))) {
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| 		net_err_ratelimited("sequence number glitch prev=%d curr=%d\n",
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| 				    mbim->rx_seq, le16_to_cpu(nth16->wSequence));
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| 	}
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| 	mbim->rx_seq = le16_to_cpu(nth16->wSequence);
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| 
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| 	return le16_to_cpu(nth16->wNdpIndex);
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| }
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| 
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| static int mbim_rx_verify_ndp16(struct sk_buff *skb, struct usb_cdc_ncm_ndp16 *ndp16)
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| {
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| 	int ret;
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| 
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| 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
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| 		net_err_ratelimited("invalid DPT16 length <%u>\n",
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| 				    le16_to_cpu(ndp16->wLength));
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| 		return -EINVAL;
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| 	}
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| 
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| 	ret = ((le16_to_cpu(ndp16->wLength) - sizeof(struct usb_cdc_ncm_ndp16))
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| 			/ sizeof(struct usb_cdc_ncm_dpe16));
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| 	ret--; /* Last entry is always a NULL terminator */
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| 
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| 	if (sizeof(struct usb_cdc_ncm_ndp16) +
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| 	     ret * sizeof(struct usb_cdc_ncm_dpe16) > skb->len) {
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| 		net_err_ratelimited("Invalid nframes = %d\n", ret);
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| 		return -EINVAL;
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| 	}
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| 
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| 	return ret;
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| }
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| 
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| static void mhi_mbim_rx(struct mhi_mbim_context *mbim, struct sk_buff *skb)
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| {
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| 	int ndpoffset;
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| 
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| 	/* Check NTB header and retrieve first NDP offset */
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| 	ndpoffset = mbim_rx_verify_nth16(mbim, skb);
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| 	if (ndpoffset < 0) {
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| 		net_err_ratelimited("mbim: Incorrect NTB header\n");
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| 		goto error;
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| 	}
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| 
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| 	/* Process each NDP */
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| 	while (1) {
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| 		struct usb_cdc_ncm_ndp16 ndp16;
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| 		struct usb_cdc_ncm_dpe16 dpe16;
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| 		struct mhi_mbim_link *link;
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| 		int nframes, n, dpeoffset;
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| 		unsigned int session;
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| 
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| 		if (skb_copy_bits(skb, ndpoffset, &ndp16, sizeof(ndp16))) {
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| 			net_err_ratelimited("mbim: Incorrect NDP offset (%u)\n",
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| 					    ndpoffset);
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| 			goto error;
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| 		}
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| 
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| 		/* Check NDP header and retrieve number of datagrams */
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| 		nframes = mbim_rx_verify_ndp16(skb, &ndp16);
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| 		if (nframes < 0) {
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| 			net_err_ratelimited("mbim: Incorrect NDP16\n");
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| 			goto error;
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| 		}
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| 
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| 		 /* Only IP data type supported, no DSS in MHI context */
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| 		if ((ndp16.dwSignature & cpu_to_le32(MBIM_NDP16_SIGN_MASK))
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| 				!= cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN)) {
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| 			net_err_ratelimited("mbim: Unsupported NDP type\n");
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| 			goto next_ndp;
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| 		}
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| 
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| 		session = (le32_to_cpu(ndp16.dwSignature) & ~MBIM_NDP16_SIGN_MASK) >> 24;
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| 
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| 		rcu_read_lock();
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| 
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| 		link = mhi_mbim_get_link_rcu(mbim, session);
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| 		if (!link) {
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| 			net_err_ratelimited("mbim: bad packet session (%u)\n", session);
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| 			goto unlock;
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| 		}
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| 
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| 		/* de-aggregate and deliver IP packets */
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| 		dpeoffset = ndpoffset + sizeof(struct usb_cdc_ncm_ndp16);
 | |
| 		for (n = 0; n < nframes; n++, dpeoffset += sizeof(dpe16)) {
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| 			u16 dgram_offset, dgram_len;
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| 			struct sk_buff *skbn;
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| 
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| 			if (skb_copy_bits(skb, dpeoffset, &dpe16, sizeof(dpe16)))
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| 				break;
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| 
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| 			dgram_offset = le16_to_cpu(dpe16.wDatagramIndex);
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| 			dgram_len = le16_to_cpu(dpe16.wDatagramLength);
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| 
 | |
| 			if (!dgram_offset || !dgram_len)
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| 				break; /* null terminator */
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| 
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| 			skbn = netdev_alloc_skb(link->ndev, dgram_len);
 | |
| 			if (!skbn)
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| 				continue;
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| 
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| 			skb_put(skbn, dgram_len);
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| 			skb_copy_bits(skb, dgram_offset, skbn->data, dgram_len);
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| 
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| 			switch (skbn->data[0] & 0xf0) {
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| 			case 0x40:
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| 				skbn->protocol = htons(ETH_P_IP);
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| 				break;
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| 			case 0x60:
 | |
| 				skbn->protocol = htons(ETH_P_IPV6);
 | |
| 				break;
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| 			default:
 | |
| 				net_err_ratelimited("%s: unknown protocol\n",
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| 						    link->ndev->name);
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| 				dev_kfree_skb_any(skbn);
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| 				u64_stats_update_begin(&link->rx_syncp);
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| 				u64_stats_inc(&link->rx_errors);
 | |
| 				u64_stats_update_end(&link->rx_syncp);
 | |
| 				continue;
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| 			}
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| 
 | |
| 			u64_stats_update_begin(&link->rx_syncp);
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| 			u64_stats_inc(&link->rx_packets);
 | |
| 			u64_stats_add(&link->rx_bytes, skbn->len);
 | |
| 			u64_stats_update_end(&link->rx_syncp);
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| 
 | |
| 			netif_rx(skbn);
 | |
| 		}
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| unlock:
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| 		rcu_read_unlock();
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| next_ndp:
 | |
| 		/* Other NDP to process? */
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| 		ndpoffset = (int)le16_to_cpu(ndp16.wNextNdpIndex);
 | |
| 		if (!ndpoffset)
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| 			break;
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| 	}
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| 
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| 	/* free skb */
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| 	dev_consume_skb_any(skb);
 | |
| 	return;
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| error:
 | |
| 	dev_kfree_skb_any(skb);
 | |
| }
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| 
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| static struct sk_buff *mhi_net_skb_agg(struct mhi_mbim_context *mbim,
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| 				       struct sk_buff *skb)
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| {
 | |
| 	struct sk_buff *head = mbim->skbagg_head;
 | |
| 	struct sk_buff *tail = mbim->skbagg_tail;
 | |
| 
 | |
| 	/* This is non-paged skb chaining using frag_list */
 | |
| 	if (!head) {
 | |
| 		mbim->skbagg_head = skb;
 | |
| 		return skb;
 | |
| 	}
 | |
| 
 | |
| 	if (!skb_shinfo(head)->frag_list)
 | |
| 		skb_shinfo(head)->frag_list = skb;
 | |
| 	else
 | |
| 		tail->next = skb;
 | |
| 
 | |
| 	head->len += skb->len;
 | |
| 	head->data_len += skb->len;
 | |
| 	head->truesize += skb->truesize;
 | |
| 
 | |
| 	mbim->skbagg_tail = skb;
 | |
| 
 | |
| 	return mbim->skbagg_head;
 | |
| }
 | |
| 
 | |
| static void mhi_net_rx_refill_work(struct work_struct *work)
 | |
| {
 | |
| 	struct mhi_mbim_context *mbim = container_of(work, struct mhi_mbim_context,
 | |
| 						     rx_refill.work);
 | |
| 	struct mhi_device *mdev = mbim->mdev;
 | |
| 	int err;
 | |
| 
 | |
| 	while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
 | |
| 		struct sk_buff *skb = alloc_skb(mbim->mru, GFP_KERNEL);
 | |
| 
 | |
| 		if (unlikely(!skb))
 | |
| 			break;
 | |
| 
 | |
| 		err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb,
 | |
| 				    mbim->mru, MHI_EOT);
 | |
| 		if (unlikely(err)) {
 | |
| 			kfree_skb(skb);
 | |
| 			break;
 | |
| 		}
 | |
| 
 | |
| 		/* Do not hog the CPU if rx buffers are consumed faster than
 | |
| 		 * queued (unlikely).
 | |
| 		 */
 | |
| 		cond_resched();
 | |
| 	}
 | |
| 
 | |
| 	/* If we're still starved of rx buffers, reschedule later */
 | |
| 	if (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mbim->rx_queue_sz)
 | |
| 		schedule_delayed_work(&mbim->rx_refill, HZ / 2);
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_dl_callback(struct mhi_device *mhi_dev,
 | |
| 				 struct mhi_result *mhi_res)
 | |
| {
 | |
| 	struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
 | |
| 	struct sk_buff *skb = mhi_res->buf_addr;
 | |
| 	int free_desc_count;
 | |
| 
 | |
| 	free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
 | |
| 
 | |
| 	if (unlikely(mhi_res->transaction_status)) {
 | |
| 		switch (mhi_res->transaction_status) {
 | |
| 		case -EOVERFLOW:
 | |
| 			/* Packet has been split over multiple transfers */
 | |
| 			skb_put(skb, mhi_res->bytes_xferd);
 | |
| 			mhi_net_skb_agg(mbim, skb);
 | |
| 			break;
 | |
| 		case -ENOTCONN:
 | |
| 			/* MHI layer stopping/resetting the DL channel */
 | |
| 			dev_kfree_skb_any(skb);
 | |
| 			return;
 | |
| 		default:
 | |
| 			/* Unknown error, simply drop */
 | |
| 			dev_kfree_skb_any(skb);
 | |
| 		}
 | |
| 	} else {
 | |
| 		skb_put(skb, mhi_res->bytes_xferd);
 | |
| 
 | |
| 		if (mbim->skbagg_head) {
 | |
| 			/* Aggregate the final fragment */
 | |
| 			skb = mhi_net_skb_agg(mbim, skb);
 | |
| 			mbim->skbagg_head = NULL;
 | |
| 		}
 | |
| 
 | |
| 		mhi_mbim_rx(mbim, skb);
 | |
| 	}
 | |
| 
 | |
| 	/* Refill if RX buffers queue becomes low */
 | |
| 	if (free_desc_count >= mbim->rx_queue_sz / 2)
 | |
| 		schedule_delayed_work(&mbim->rx_refill, 0);
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_ndo_get_stats64(struct net_device *ndev,
 | |
| 				     struct rtnl_link_stats64 *stats)
 | |
| {
 | |
| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 | |
| 	unsigned int start;
 | |
| 
 | |
| 	do {
 | |
| 		start = u64_stats_fetch_begin(&link->rx_syncp);
 | |
| 		stats->rx_packets = u64_stats_read(&link->rx_packets);
 | |
| 		stats->rx_bytes = u64_stats_read(&link->rx_bytes);
 | |
| 		stats->rx_errors = u64_stats_read(&link->rx_errors);
 | |
| 	} while (u64_stats_fetch_retry(&link->rx_syncp, start));
 | |
| 
 | |
| 	do {
 | |
| 		start = u64_stats_fetch_begin(&link->tx_syncp);
 | |
| 		stats->tx_packets = u64_stats_read(&link->tx_packets);
 | |
| 		stats->tx_bytes = u64_stats_read(&link->tx_bytes);
 | |
| 		stats->tx_errors = u64_stats_read(&link->tx_errors);
 | |
| 		stats->tx_dropped = u64_stats_read(&link->tx_dropped);
 | |
| 	} while (u64_stats_fetch_retry(&link->tx_syncp, start));
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_ul_callback(struct mhi_device *mhi_dev,
 | |
| 				 struct mhi_result *mhi_res)
 | |
| {
 | |
| 	struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
 | |
| 	struct sk_buff *skb = mhi_res->buf_addr;
 | |
| 	struct net_device *ndev = skb->dev;
 | |
| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 | |
| 
 | |
| 	/* Hardware has consumed the buffer, so free the skb (which is not
 | |
| 	 * freed by the MHI stack) and perform accounting.
 | |
| 	 */
 | |
| 	dev_consume_skb_any(skb);
 | |
| 
 | |
| 	u64_stats_update_begin(&link->tx_syncp);
 | |
| 	if (unlikely(mhi_res->transaction_status)) {
 | |
| 		/* MHI layer stopping/resetting the UL channel */
 | |
| 		if (mhi_res->transaction_status == -ENOTCONN) {
 | |
| 			u64_stats_update_end(&link->tx_syncp);
 | |
| 			return;
 | |
| 		}
 | |
| 
 | |
| 		u64_stats_inc(&link->tx_errors);
 | |
| 	} else {
 | |
| 		u64_stats_inc(&link->tx_packets);
 | |
| 		u64_stats_add(&link->tx_bytes, mhi_res->bytes_xferd);
 | |
| 	}
 | |
| 	u64_stats_update_end(&link->tx_syncp);
 | |
| 
 | |
| 	if (netif_queue_stopped(ndev) && !mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE))
 | |
| 		netif_wake_queue(ndev);
 | |
| }
 | |
| 
 | |
| static int mhi_mbim_ndo_open(struct net_device *ndev)
 | |
| {
 | |
| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 | |
| 
 | |
| 	/* Feed the MHI rx buffer pool */
 | |
| 	schedule_delayed_work(&link->mbim->rx_refill, 0);
 | |
| 
 | |
| 	/* Carrier is established via out-of-band channel (e.g. qmi) */
 | |
| 	netif_carrier_on(ndev);
 | |
| 
 | |
| 	netif_start_queue(ndev);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int mhi_mbim_ndo_stop(struct net_device *ndev)
 | |
| {
 | |
| 	netif_stop_queue(ndev);
 | |
| 	netif_carrier_off(ndev);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static const struct net_device_ops mhi_mbim_ndo = {
 | |
| 	.ndo_open = mhi_mbim_ndo_open,
 | |
| 	.ndo_stop = mhi_mbim_ndo_stop,
 | |
| 	.ndo_start_xmit = mhi_mbim_ndo_xmit,
 | |
| 	.ndo_get_stats64 = mhi_mbim_ndo_get_stats64,
 | |
| };
 | |
| 
 | |
| static int mhi_mbim_newlink(void *ctxt, struct net_device *ndev, u32 if_id,
 | |
| 			    struct netlink_ext_ack *extack)
 | |
| {
 | |
| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 | |
| 	struct mhi_mbim_context *mbim = ctxt;
 | |
| 
 | |
| 	link->session = if_id;
 | |
| 	link->mbim = mbim;
 | |
| 	link->ndev = ndev;
 | |
| 	u64_stats_init(&link->rx_syncp);
 | |
| 	u64_stats_init(&link->tx_syncp);
 | |
| 
 | |
| 	rcu_read_lock();
 | |
| 	if (mhi_mbim_get_link_rcu(mbim, if_id)) {
 | |
| 		rcu_read_unlock();
 | |
| 		return -EEXIST;
 | |
| 	}
 | |
| 	rcu_read_unlock();
 | |
| 
 | |
| 	/* Already protected by RTNL lock */
 | |
| 	hlist_add_head_rcu(&link->hlnode, &mbim->link_list[LINK_HASH(if_id)]);
 | |
| 
 | |
| 	return register_netdevice(ndev);
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_dellink(void *ctxt, struct net_device *ndev,
 | |
| 			     struct list_head *head)
 | |
| {
 | |
| 	struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
 | |
| 
 | |
| 	hlist_del_init_rcu(&link->hlnode);
 | |
| 	synchronize_rcu();
 | |
| 
 | |
| 	unregister_netdevice_queue(ndev, head);
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_setup(struct net_device *ndev)
 | |
| {
 | |
| 	ndev->header_ops = NULL;  /* No header */
 | |
| 	ndev->type = ARPHRD_RAWIP;
 | |
| 	ndev->needed_headroom = sizeof(struct mbim_tx_hdr);
 | |
| 	ndev->hard_header_len = 0;
 | |
| 	ndev->addr_len = 0;
 | |
| 	ndev->flags = IFF_POINTOPOINT | IFF_NOARP;
 | |
| 	ndev->netdev_ops = &mhi_mbim_ndo;
 | |
| 	ndev->mtu = MHI_MBIM_DEFAULT_MTU;
 | |
| 	ndev->min_mtu = ETH_MIN_MTU;
 | |
| 	ndev->max_mtu = MHI_MAX_BUF_SZ - ndev->needed_headroom;
 | |
| 	ndev->tx_queue_len = 1000;
 | |
| 	ndev->needs_free_netdev = true;
 | |
| }
 | |
| 
 | |
| static const struct wwan_ops mhi_mbim_wwan_ops = {
 | |
| 	.priv_size = sizeof(struct mhi_mbim_link),
 | |
| 	.setup = mhi_mbim_setup,
 | |
| 	.newlink = mhi_mbim_newlink,
 | |
| 	.dellink = mhi_mbim_dellink,
 | |
| };
 | |
| 
 | |
| static int mhi_mbim_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
 | |
| {
 | |
| 	struct mhi_controller *cntrl = mhi_dev->mhi_cntrl;
 | |
| 	struct mhi_mbim_context *mbim;
 | |
| 	int err, link_id;
 | |
| 
 | |
| 	mbim = devm_kzalloc(&mhi_dev->dev, sizeof(*mbim), GFP_KERNEL);
 | |
| 	if (!mbim)
 | |
| 		return -ENOMEM;
 | |
| 
 | |
| 	spin_lock_init(&mbim->tx_lock);
 | |
| 	dev_set_drvdata(&mhi_dev->dev, mbim);
 | |
| 	mbim->mdev = mhi_dev;
 | |
| 	mbim->mru = mhi_dev->mhi_cntrl->mru ? mhi_dev->mhi_cntrl->mru : MHI_DEFAULT_MRU;
 | |
| 
 | |
| 	INIT_DELAYED_WORK(&mbim->rx_refill, mhi_net_rx_refill_work);
 | |
| 
 | |
| 	/* Start MHI channels */
 | |
| 	err = mhi_prepare_for_transfer(mhi_dev);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| 	/* Number of transfer descriptors determines size of the queue */
 | |
| 	mbim->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
 | |
| 
 | |
| 	/* Get the corresponding mux_id from mhi */
 | |
| 	link_id = mhi_mbim_get_link_mux_id(cntrl);
 | |
| 
 | |
| 	/* Register wwan link ops with MHI controller representing WWAN instance */
 | |
| 	return wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_mbim_wwan_ops, mbim, link_id);
 | |
| }
 | |
| 
 | |
| static void mhi_mbim_remove(struct mhi_device *mhi_dev)
 | |
| {
 | |
| 	struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
 | |
| 	struct mhi_controller *cntrl = mhi_dev->mhi_cntrl;
 | |
| 
 | |
| 	mhi_unprepare_from_transfer(mhi_dev);
 | |
| 	cancel_delayed_work_sync(&mbim->rx_refill);
 | |
| 	wwan_unregister_ops(&cntrl->mhi_dev->dev);
 | |
| 	kfree_skb(mbim->skbagg_head);
 | |
| 	dev_set_drvdata(&mhi_dev->dev, NULL);
 | |
| }
 | |
| 
 | |
| static const struct mhi_device_id mhi_mbim_id_table[] = {
 | |
| 	/* Hardware accelerated data PATH (to modem IPA), MBIM protocol */
 | |
| 	{ .chan = "IP_HW0_MBIM", .driver_data = 0 },
 | |
| 	{}
 | |
| };
 | |
| MODULE_DEVICE_TABLE(mhi, mhi_mbim_id_table);
 | |
| 
 | |
| static struct mhi_driver mhi_mbim_driver = {
 | |
| 	.probe = mhi_mbim_probe,
 | |
| 	.remove = mhi_mbim_remove,
 | |
| 	.dl_xfer_cb = mhi_mbim_dl_callback,
 | |
| 	.ul_xfer_cb = mhi_mbim_ul_callback,
 | |
| 	.id_table = mhi_mbim_id_table,
 | |
| 	.driver = {
 | |
| 		.name = "mhi_wwan_mbim",
 | |
| 	},
 | |
| };
 | |
| 
 | |
| module_mhi_driver(mhi_mbim_driver);
 | |
| 
 | |
| MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
 | |
| MODULE_DESCRIPTION("Network/MBIM over MHI");
 | |
| MODULE_LICENSE("GPL v2");
 |