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_type; 91 int gso_size; 92 }; 93 94 #define GSO_BIT(type) \ 95 (1 << XEN_NETIF_GSO_TYPE_ ## type) 96 97 /* Discriminate from any valid pending_idx value. */ 98 #define INVALID_PENDING_IDX 0xFFFF 99 100 #define MAX_BUFFER_OFFSET PAGE_SIZE 101 102 #define MAX_PENDING_REQS 256 103 104 /* It's possible for an skb to have a maximal number of frags 105 * but still be less than MAX_BUFFER_OFFSET in size. Thus the 106 * worst-case number of copy operations is MAX_SKB_FRAGS per 107 * ring slot. 108 */ 109 #define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE) 110 111 struct xenvif { 112 /* Unique identifier for this interface. */ 113 domid_t domid; 114 unsigned int handle; 115 116 /* Use NAPI for guest TX */ 117 struct napi_struct napi; 118 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 119 unsigned int tx_irq; 120 /* Only used when feature-split-event-channels = 1 */ 121 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */ 122 struct xen_netif_tx_back_ring tx; 123 struct sk_buff_head tx_queue; 124 struct page *mmap_pages[MAX_PENDING_REQS]; 125 pending_ring_idx_t pending_prod; 126 pending_ring_idx_t pending_cons; 127 u16 pending_ring[MAX_PENDING_REQS]; 128 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS]; 129 130 /* Coalescing tx requests before copying makes number of grant 131 * copy ops greater or equal to number of slots required. In 132 * worst case a tx request consumes 2 gnttab_copy. 133 */ 134 struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS]; 135 136 137 /* Use kthread for guest RX */ 138 struct task_struct *task; 139 wait_queue_head_t wq; 140 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 141 unsigned int rx_irq; 142 /* Only used when feature-split-event-channels = 1 */ 143 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ 144 struct xen_netif_rx_back_ring rx; 145 struct sk_buff_head rx_queue; 146 147 /* Allow xenvif_start_xmit() to peek ahead in the rx request 148 * ring. This is a prediction of what rx_req_cons will be 149 * once all queued skbs are put on the ring. 150 */ 151 RING_IDX rx_req_cons_peek; 152 153 /* This array is allocated seperately as it is large */ 154 struct gnttab_copy *grant_copy_op; 155 156 /* We create one meta structure per ring request we consume, so 157 * the maximum number is the same as the ring size. 158 */ 159 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE]; 160 161 u8 fe_dev_addr[6]; 162 163 /* Frontend feature information. */ 164 int gso_mask; 165 int gso_prefix_mask; 166 167 u8 can_sg:1; 168 u8 ip_csum:1; 169 u8 ipv6_csum:1; 170 171 /* Internal feature information. */ 172 u8 can_queue:1; /* can queue packets for receiver? */ 173 174 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */ 175 unsigned long credit_bytes; 176 unsigned long credit_usec; 177 unsigned long remaining_credit; 178 struct timer_list credit_timeout; 179 u64 credit_window_start; 180 181 /* Statistics */ 182 unsigned long rx_gso_checksum_fixup; 183 184 /* Miscellaneous private stuff. */ 185 struct net_device *dev; 186 }; 187 188 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif) 189 { 190 return to_xenbus_device(vif->dev->dev.parent); 191 } 192 193 struct xenvif *xenvif_alloc(struct device *parent, 194 domid_t domid, 195 unsigned int handle); 196 197 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, 198 unsigned long rx_ring_ref, unsigned int tx_evtchn, 199 unsigned int rx_evtchn); 200 void xenvif_disconnect(struct xenvif *vif); 201 void xenvif_free(struct xenvif *vif); 202 203 int xenvif_xenbus_init(void); 204 void xenvif_xenbus_fini(void); 205 206 int xenvif_schedulable(struct xenvif *vif); 207 208 int xenvif_rx_ring_full(struct xenvif *vif); 209 210 int xenvif_must_stop_queue(struct xenvif *vif); 211 212 /* (Un)Map communication rings. */ 213 void xenvif_unmap_frontend_rings(struct xenvif *vif); 214 int xenvif_map_frontend_rings(struct xenvif *vif, 215 grant_ref_t tx_ring_ref, 216 grant_ref_t rx_ring_ref); 217 218 /* Check for SKBs from frontend and schedule backend processing */ 219 void xenvif_check_rx_xenvif(struct xenvif *vif); 220 221 /* Queue an SKB for transmission to the frontend */ 222 void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb); 223 /* Notify xenvif that ring now has space to send an skb to the frontend */ 224 void xenvif_notify_tx_completion(struct xenvif *vif); 225 226 /* Prevent the device from generating any further traffic. */ 227 void xenvif_carrier_off(struct xenvif *vif); 228 229 /* Returns number of ring slots required to send an skb to the frontend */ 230 unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb); 231 232 int xenvif_tx_action(struct xenvif *vif, int budget); 233 void xenvif_rx_action(struct xenvif *vif); 234 235 int xenvif_kthread(void *data); 236 237 extern bool separate_tx_rx_irq; 238 239 #endif /* __XEN_NETBACK__COMMON_H__ */ 240