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 struct pending_tx_info { 52 struct xen_netif_tx_request req; /* tx request */ 53 /* Callback data for released SKBs. The callback is always 54 * xenvif_zerocopy_callback, desc contains the pending_idx, which is 55 * also an index in pending_tx_info array. It is initialized in 56 * xenvif_alloc and it never changes. 57 * skb_shinfo(skb)->destructor_arg points to the first mapped slot's 58 * callback_struct in this array of struct pending_tx_info's, then ctx 59 * to the next, or NULL if there is no more slot for this skb. 60 * ubuf_to_vif is a helper which finds the struct xenvif from a pointer 61 * to this field. 62 */ 63 struct ubuf_info callback_struct; 64 }; 65 66 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) 67 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) 68 69 struct xenvif_rx_meta { 70 int id; 71 int size; 72 int gso_type; 73 int gso_size; 74 }; 75 76 #define GSO_BIT(type) \ 77 (1 << XEN_NETIF_GSO_TYPE_ ## type) 78 79 /* Discriminate from any valid pending_idx value. */ 80 #define INVALID_PENDING_IDX 0xFFFF 81 82 #define MAX_BUFFER_OFFSET PAGE_SIZE 83 84 #define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE 85 86 /* It's possible for an skb to have a maximal number of frags 87 * but still be less than MAX_BUFFER_OFFSET in size. Thus the 88 * worst-case number of copy operations is MAX_SKB_FRAGS per 89 * ring slot. 90 */ 91 #define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE) 92 93 #define NETBACK_INVALID_HANDLE -1 94 95 /* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating 96 * the maximum slots a valid packet can use. Now this value is defined 97 * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by 98 * all backend. 99 */ 100 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN 101 102 struct xenvif { 103 /* Unique identifier for this interface. */ 104 domid_t domid; 105 unsigned int handle; 106 107 /* Is this interface disabled? True when backend discovers 108 * frontend is rogue. 109 */ 110 bool disabled; 111 112 /* Use NAPI for guest TX */ 113 struct napi_struct napi; 114 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 115 unsigned int tx_irq; 116 /* Only used when feature-split-event-channels = 1 */ 117 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */ 118 struct xen_netif_tx_back_ring tx; 119 struct sk_buff_head tx_queue; 120 struct page *mmap_pages[MAX_PENDING_REQS]; 121 pending_ring_idx_t pending_prod; 122 pending_ring_idx_t pending_cons; 123 u16 pending_ring[MAX_PENDING_REQS]; 124 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS]; 125 grant_handle_t grant_tx_handle[MAX_PENDING_REQS]; 126 127 struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS]; 128 struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS]; 129 struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS]; 130 /* passed to gnttab_[un]map_refs with pages under (un)mapping */ 131 struct page *pages_to_map[MAX_PENDING_REQS]; 132 struct page *pages_to_unmap[MAX_PENDING_REQS]; 133 134 /* This prevents zerocopy callbacks to race over dealloc_ring */ 135 spinlock_t callback_lock; 136 /* This prevents dealloc thread and NAPI instance to race over response 137 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err 138 * it only protect response creation 139 */ 140 spinlock_t response_lock; 141 pending_ring_idx_t dealloc_prod; 142 pending_ring_idx_t dealloc_cons; 143 u16 dealloc_ring[MAX_PENDING_REQS]; 144 struct task_struct *dealloc_task; 145 wait_queue_head_t dealloc_wq; 146 147 /* Use kthread for guest RX */ 148 struct task_struct *task; 149 wait_queue_head_t wq; 150 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ 151 unsigned int rx_irq; 152 /* Only used when feature-split-event-channels = 1 */ 153 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ 154 struct xen_netif_rx_back_ring rx; 155 struct sk_buff_head rx_queue; 156 RING_IDX rx_last_skb_slots; 157 bool rx_queue_purge; 158 159 struct timer_list wake_queue; 160 161 /* This array is allocated seperately as it is large */ 162 struct gnttab_copy *grant_copy_op; 163 164 /* We create one meta structure per ring request we consume, so 165 * the maximum number is the same as the ring size. 166 */ 167 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE]; 168 169 u8 fe_dev_addr[6]; 170 171 /* Frontend feature information. */ 172 int gso_mask; 173 int gso_prefix_mask; 174 175 u8 can_sg:1; 176 u8 ip_csum:1; 177 u8 ipv6_csum:1; 178 179 /* Internal feature information. */ 180 u8 can_queue:1; /* can queue packets for receiver? */ 181 182 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */ 183 unsigned long credit_bytes; 184 unsigned long credit_usec; 185 unsigned long remaining_credit; 186 struct timer_list credit_timeout; 187 u64 credit_window_start; 188 189 /* Statistics */ 190 unsigned long rx_gso_checksum_fixup; 191 unsigned long tx_zerocopy_sent; 192 unsigned long tx_zerocopy_success; 193 unsigned long tx_zerocopy_fail; 194 unsigned long tx_frag_overflow; 195 196 /* Miscellaneous private stuff. */ 197 struct net_device *dev; 198 }; 199 200 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif) 201 { 202 return to_xenbus_device(vif->dev->dev.parent); 203 } 204 205 struct xenvif *xenvif_alloc(struct device *parent, 206 domid_t domid, 207 unsigned int handle); 208 209 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, 210 unsigned long rx_ring_ref, unsigned int tx_evtchn, 211 unsigned int rx_evtchn); 212 void xenvif_disconnect(struct xenvif *vif); 213 void xenvif_free(struct xenvif *vif); 214 215 int xenvif_xenbus_init(void); 216 void xenvif_xenbus_fini(void); 217 218 int xenvif_schedulable(struct xenvif *vif); 219 220 int xenvif_must_stop_queue(struct xenvif *vif); 221 222 /* (Un)Map communication rings. */ 223 void xenvif_unmap_frontend_rings(struct xenvif *vif); 224 int xenvif_map_frontend_rings(struct xenvif *vif, 225 grant_ref_t tx_ring_ref, 226 grant_ref_t rx_ring_ref); 227 228 /* Check for SKBs from frontend and schedule backend processing */ 229 void xenvif_check_rx_xenvif(struct xenvif *vif); 230 231 /* Prevent the device from generating any further traffic. */ 232 void xenvif_carrier_off(struct xenvif *vif); 233 234 int xenvif_tx_action(struct xenvif *vif, int budget); 235 236 int xenvif_kthread_guest_rx(void *data); 237 void xenvif_kick_thread(struct xenvif *vif); 238 239 int xenvif_dealloc_kthread(void *data); 240 241 /* Determine whether the needed number of slots (req) are available, 242 * and set req_event if not. 243 */ 244 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed); 245 246 void xenvif_stop_queue(struct xenvif *vif); 247 248 /* Callback from stack when TX packet can be released */ 249 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); 250 251 /* Unmap a pending page and release it back to the guest */ 252 void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx); 253 254 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif) 255 { 256 return MAX_PENDING_REQS - 257 vif->pending_prod + vif->pending_cons; 258 } 259 260 /* Callback from stack when TX packet can be released */ 261 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); 262 263 extern bool separate_tx_rx_irq; 264 265 extern unsigned int rx_drain_timeout_msecs; 266 extern unsigned int rx_drain_timeout_jiffies; 267 268 #endif /* __XEN_NETBACK__COMMON_H__ */ 269