1 /* 2 * This program is free software; you can redistribute it and/or 3 * modify it under the terms of the GNU General Public License version 2 4 * as published by the Free Software Foundation; or, when distributed 5 * separately from the Linux kernel or incorporated into other 6 * software packages, subject to the following license: 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a copy 9 * of this source file (the "Software"), to deal in the Software without 10 * restriction, including without limitation the rights to use, copy, modify, 11 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 12 * and to permit persons to whom the Software is furnished to do so, subject to 13 * the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included in 16 * all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 24 * IN THE SOFTWARE. 25 */ 26 27 #ifndef __XEN_NETBACK__COMMON_H__ 28 #define __XEN_NETBACK__COMMON_H__ 29 30 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ 31 32 #include <linux/module.h> 33 #include <linux/interrupt.h> 34 #include <linux/slab.h> 35 #include <linux/ip.h> 36 #include <linux/in.h> 37 #include <linux/io.h> 38 #include <linux/netdevice.h> 39 #include <linux/etherdevice.h> 40 #include <linux/wait.h> 41 #include <linux/sched.h> 42 43 #include <xen/interface/io/netif.h> 44 #include <xen/interface/grant_table.h> 45 #include <xen/grant_table.h> 46 #include <xen/xenbus.h> 47 48 typedef unsigned int pending_ring_idx_t; 49 #define INVALID_PENDING_RING_IDX (~0U) 50 51 /* For the head field in pending_tx_info: it is used to indicate 52 * whether this tx info is the head of one or more coalesced requests. 53 * 54 * When head != INVALID_PENDING_RING_IDX, it means the start of a new 55 * tx requests queue and the end of previous queue. 56 * 57 * An example sequence of head fields (I = INVALID_PENDING_RING_IDX): 58 * 59 * ...|0 I I I|5 I|9 I I I|... 60 * -->|<-INUSE---------------- 61 * 62 * After consuming the first slot(s) we have: 63 * 64 * ...|V V V V|5 I|9 I I I|... 65 * -----FREE->|<-INUSE-------- 66 * 67 * where V stands for "valid pending ring index". Any number other 68 * than INVALID_PENDING_RING_IDX is OK. These entries are considered 69 * free and can contain any number other than 70 * INVALID_PENDING_RING_IDX. In practice we use 0. 71 * 72 * The in use non-INVALID_PENDING_RING_IDX (say 0, 5 and 9 in the 73 * above example) number is the index into pending_tx_info and 74 * mmap_pages arrays. 75 */ 76 struct pending_tx_info { 77 struct xen_netif_tx_request req; /* coalesced tx request */ 78 pending_ring_idx_t head; /* head != INVALID_PENDING_RING_IDX 79 * if it is head of one or more tx 80 * reqs 81 */ 82 }; 83 84 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) 85 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) 86 87 struct xenvif_rx_meta { 88 int id; 89 int size; 90 int gso_size; 91 }; 92 93 /* Discriminate from any valid pending_idx value. */ 94 #define INVALID_PENDING_IDX 0xFFFF 95 96 #define MAX_BUFFER_OFFSET PAGE_SIZE 97 98 #define MAX_PENDING_REQS 256 99 100 struct xenvif { 101 /* Unique identifier for this interface. */ 102 domid_t domid; 103 unsigned int handle; 104 105 /* Use NAPI for guest TX */ 106 struct napi_struct napi; 107 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 108 unsigned int tx_irq; 109 /* Only used when feature-split-event-channels = 1 */ 110 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */ 111 struct xen_netif_tx_back_ring tx; 112 struct sk_buff_head tx_queue; 113 struct page *mmap_pages[MAX_PENDING_REQS]; 114 pending_ring_idx_t pending_prod; 115 pending_ring_idx_t pending_cons; 116 u16 pending_ring[MAX_PENDING_REQS]; 117 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS]; 118 119 /* Coalescing tx requests before copying makes number of grant 120 * copy ops greater or equal to number of slots required. In 121 * worst case a tx request consumes 2 gnttab_copy. 122 */ 123 struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS]; 124 125 126 /* Use kthread for guest RX */ 127 struct task_struct *task; 128 wait_queue_head_t wq; 129 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 130 unsigned int rx_irq; 131 /* Only used when feature-split-event-channels = 1 */ 132 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ 133 struct xen_netif_rx_back_ring rx; 134 struct sk_buff_head rx_queue; 135 136 /* Allow xenvif_start_xmit() to peek ahead in the rx request 137 * ring. This is a prediction of what rx_req_cons will be 138 * once all queued skbs are put on the ring. 139 */ 140 RING_IDX rx_req_cons_peek; 141 142 /* Given MAX_BUFFER_OFFSET of 4096 the worst case is that each 143 * head/fragment page uses 2 copy operations because it 144 * straddles two buffers in the frontend. 145 */ 146 struct gnttab_copy grant_copy_op[2*XEN_NETIF_RX_RING_SIZE]; 147 struct xenvif_rx_meta meta[2*XEN_NETIF_RX_RING_SIZE]; 148 149 150 u8 fe_dev_addr[6]; 151 152 /* Frontend feature information. */ 153 u8 can_sg:1; 154 u8 gso:1; 155 u8 gso_prefix:1; 156 u8 csum:1; 157 158 /* Internal feature information. */ 159 u8 can_queue:1; /* can queue packets for receiver? */ 160 161 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */ 162 unsigned long credit_bytes; 163 unsigned long credit_usec; 164 unsigned long remaining_credit; 165 struct timer_list credit_timeout; 166 167 /* Statistics */ 168 unsigned long rx_gso_checksum_fixup; 169 170 /* Miscellaneous private stuff. */ 171 struct net_device *dev; 172 }; 173 174 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif) 175 { 176 return to_xenbus_device(vif->dev->dev.parent); 177 } 178 179 struct xenvif *xenvif_alloc(struct device *parent, 180 domid_t domid, 181 unsigned int handle); 182 183 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, 184 unsigned long rx_ring_ref, unsigned int tx_evtchn, 185 unsigned int rx_evtchn); 186 void xenvif_disconnect(struct xenvif *vif); 187 void xenvif_free(struct xenvif *vif); 188 189 int xenvif_xenbus_init(void); 190 void xenvif_xenbus_fini(void); 191 192 int xenvif_schedulable(struct xenvif *vif); 193 194 int xenvif_rx_ring_full(struct xenvif *vif); 195 196 int xenvif_must_stop_queue(struct xenvif *vif); 197 198 /* (Un)Map communication rings. */ 199 void xenvif_unmap_frontend_rings(struct xenvif *vif); 200 int xenvif_map_frontend_rings(struct xenvif *vif, 201 grant_ref_t tx_ring_ref, 202 grant_ref_t rx_ring_ref); 203 204 /* Check for SKBs from frontend and schedule backend processing */ 205 void xenvif_check_rx_xenvif(struct xenvif *vif); 206 207 /* Queue an SKB for transmission to the frontend */ 208 void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb); 209 /* Notify xenvif that ring now has space to send an skb to the frontend */ 210 void xenvif_notify_tx_completion(struct xenvif *vif); 211 212 /* Prevent the device from generating any further traffic. */ 213 void xenvif_carrier_off(struct xenvif *vif); 214 215 /* Returns number of ring slots required to send an skb to the frontend */ 216 unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb); 217 218 int xenvif_tx_action(struct xenvif *vif, int budget); 219 void xenvif_rx_action(struct xenvif *vif); 220 221 int xenvif_kthread(void *data); 222 223 extern bool separate_tx_rx_irq; 224 225 #endif /* __XEN_NETBACK__COMMON_H__ */ 226