diff options
Diffstat (limited to 'kernel/drivers/net/xen-netback/common.h')
| -rw-r--r-- | kernel/drivers/net/xen-netback/common.h | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/kernel/drivers/net/xen-netback/common.h b/kernel/drivers/net/xen-netback/common.h new file mode 100644 index 000000000..8a495b318 --- /dev/null +++ b/kernel/drivers/net/xen-netback/common.h @@ -0,0 +1,347 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef __XEN_NETBACK__COMMON_H__ +#define __XEN_NETBACK__COMMON_H__ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ + +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/ip.h> +#include <linux/in.h> +#include <linux/io.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/wait.h> +#include <linux/sched.h> + +#include <xen/interface/io/netif.h> +#include <xen/interface/grant_table.h> +#include <xen/grant_table.h> +#include <xen/xenbus.h> +#include <linux/debugfs.h> + +typedef unsigned int pending_ring_idx_t; +#define INVALID_PENDING_RING_IDX (~0U) + +struct pending_tx_info { + struct xen_netif_tx_request req; /* tx request */ + /* Callback data for released SKBs. The callback is always + * xenvif_zerocopy_callback, desc contains the pending_idx, which is + * also an index in pending_tx_info array. It is initialized in + * xenvif_alloc and it never changes. + * skb_shinfo(skb)->destructor_arg points to the first mapped slot's + * callback_struct in this array of struct pending_tx_info's, then ctx + * to the next, or NULL if there is no more slot for this skb. + * ubuf_to_vif is a helper which finds the struct xenvif from a pointer + * to this field. + */ + struct ubuf_info callback_struct; +}; + +#define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) +#define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) + +struct xenvif_rx_meta { + int id; + int size; + int gso_type; + int gso_size; +}; + +#define GSO_BIT(type) \ + (1 << XEN_NETIF_GSO_TYPE_ ## type) + +/* Discriminate from any valid pending_idx value. */ +#define INVALID_PENDING_IDX 0xFFFF + +#define MAX_BUFFER_OFFSET PAGE_SIZE + +#define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE + +/* It's possible for an skb to have a maximal number of frags + * but still be less than MAX_BUFFER_OFFSET in size. Thus the + * worst-case number of copy operations is MAX_SKB_FRAGS per + * ring slot. + */ +#define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE) + +#define NETBACK_INVALID_HANDLE -1 + +/* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating + * the maximum slots a valid packet can use. Now this value is defined + * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by + * all backend. + */ +#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN + +/* Queue name is interface name with "-qNNN" appended */ +#define QUEUE_NAME_SIZE (IFNAMSIZ + 5) + +/* IRQ name is queue name with "-tx" or "-rx" appended */ +#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) + +struct xenvif; + +struct xenvif_stats { + /* Stats fields to be updated per-queue. + * A subset of struct net_device_stats that contains only the + * fields that are updated in netback.c for each queue. + */ + unsigned int rx_bytes; + unsigned int rx_packets; + unsigned int tx_bytes; + unsigned int tx_packets; + + /* Additional stats used by xenvif */ + unsigned long rx_gso_checksum_fixup; + unsigned long tx_zerocopy_sent; + unsigned long tx_zerocopy_success; + unsigned long tx_zerocopy_fail; + unsigned long tx_frag_overflow; +}; + +struct xenvif_queue { /* Per-queue data for xenvif */ + unsigned int id; /* Queue ID, 0-based */ + char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ + struct xenvif *vif; /* Parent VIF */ + + /* Use NAPI for guest TX */ + struct napi_struct napi; + /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ + unsigned int tx_irq; + /* Only used when feature-split-event-channels = 1 */ + char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ + struct xen_netif_tx_back_ring tx; + struct sk_buff_head tx_queue; + struct page *mmap_pages[MAX_PENDING_REQS]; + pending_ring_idx_t pending_prod; + pending_ring_idx_t pending_cons; + u16 pending_ring[MAX_PENDING_REQS]; + struct pending_tx_info pending_tx_info[MAX_PENDING_REQS]; + grant_handle_t grant_tx_handle[MAX_PENDING_REQS]; + + struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS]; + struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS]; + struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS]; + /* passed to gnttab_[un]map_refs with pages under (un)mapping */ + struct page *pages_to_map[MAX_PENDING_REQS]; + struct page *pages_to_unmap[MAX_PENDING_REQS]; + + /* This prevents zerocopy callbacks to race over dealloc_ring */ + spinlock_t callback_lock; + /* This prevents dealloc thread and NAPI instance to race over response + * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err + * it only protect response creation + */ + spinlock_t response_lock; + pending_ring_idx_t dealloc_prod; + pending_ring_idx_t dealloc_cons; + u16 dealloc_ring[MAX_PENDING_REQS]; + struct task_struct *dealloc_task; + wait_queue_head_t dealloc_wq; + atomic_t inflight_packets; + + /* Use kthread for guest RX */ + struct task_struct *task; + wait_queue_head_t wq; + /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ + unsigned int rx_irq; + /* Only used when feature-split-event-channels = 1 */ + char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ + struct xen_netif_rx_back_ring rx; + struct sk_buff_head rx_queue; + + unsigned int rx_queue_max; + unsigned int rx_queue_len; + unsigned long last_rx_time; + bool stalled; + + struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS]; + + /* We create one meta structure per ring request we consume, so + * the maximum number is the same as the ring size. + */ + struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE]; + + /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */ + unsigned long credit_bytes; + unsigned long credit_usec; + unsigned long remaining_credit; + struct timer_list credit_timeout; + u64 credit_window_start; + + /* Statistics */ + struct xenvif_stats stats; +}; + +/* Maximum number of Rx slots a to-guest packet may use, including the + * slot needed for GSO meta-data. + */ +#define XEN_NETBK_RX_SLOTS_MAX (MAX_SKB_FRAGS + 1) + +enum state_bit_shift { + /* This bit marks that the vif is connected */ + VIF_STATUS_CONNECTED, +}; + +struct xenvif { + /* Unique identifier for this interface. */ + domid_t domid; + unsigned int handle; + + u8 fe_dev_addr[6]; + + /* Frontend feature information. */ + int gso_mask; + int gso_prefix_mask; + + u8 can_sg:1; + u8 ip_csum:1; + u8 ipv6_csum:1; + + /* Is this interface disabled? True when backend discovers + * frontend is rogue. + */ + bool disabled; + unsigned long status; + unsigned long drain_timeout; + unsigned long stall_timeout; + + /* Queues */ + struct xenvif_queue *queues; + unsigned int num_queues; /* active queues, resource allocated */ + unsigned int stalled_queues; + + struct xenbus_watch credit_watch; + + spinlock_t lock; + +#ifdef CONFIG_DEBUG_FS + struct dentry *xenvif_dbg_root; +#endif + + /* Miscellaneous private stuff. */ + struct net_device *dev; +}; + +struct xenvif_rx_cb { + unsigned long expires; + int meta_slots_used; +}; + +#define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb) + +static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif) +{ + return to_xenbus_device(vif->dev->dev.parent); +} + +void xenvif_tx_credit_callback(unsigned long data); + +struct xenvif *xenvif_alloc(struct device *parent, + domid_t domid, + unsigned int handle); + +int xenvif_init_queue(struct xenvif_queue *queue); +void xenvif_deinit_queue(struct xenvif_queue *queue); + +int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, + unsigned long rx_ring_ref, unsigned int tx_evtchn, + unsigned int rx_evtchn); +void xenvif_disconnect(struct xenvif *vif); +void xenvif_free(struct xenvif *vif); + +int xenvif_xenbus_init(void); +void xenvif_xenbus_fini(void); + +int xenvif_schedulable(struct xenvif *vif); + +int xenvif_queue_stopped(struct xenvif_queue *queue); +void xenvif_wake_queue(struct xenvif_queue *queue); + +/* (Un)Map communication rings. */ +void xenvif_unmap_frontend_rings(struct xenvif_queue *queue); +int xenvif_map_frontend_rings(struct xenvif_queue *queue, + grant_ref_t tx_ring_ref, + grant_ref_t rx_ring_ref); + +/* Check for SKBs from frontend and schedule backend processing */ +void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue); + +/* Prevent the device from generating any further traffic. */ +void xenvif_carrier_off(struct xenvif *vif); + +int xenvif_tx_action(struct xenvif_queue *queue, int budget); + +int xenvif_kthread_guest_rx(void *data); +void xenvif_kick_thread(struct xenvif_queue *queue); + +int xenvif_dealloc_kthread(void *data); + +void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb); + +/* Determine whether the needed number of slots (req) are available, + * and set req_event if not. + */ +bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed); + +void xenvif_carrier_on(struct xenvif *vif); + +/* Callback from stack when TX packet can be released */ +void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); + +/* Unmap a pending page and release it back to the guest */ +void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx); + +static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue) +{ + return MAX_PENDING_REQS - + queue->pending_prod + queue->pending_cons; +} + +/* Callback from stack when TX packet can be released */ +void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); + +irqreturn_t xenvif_interrupt(int irq, void *dev_id); + +extern bool separate_tx_rx_irq; + +extern unsigned int rx_drain_timeout_msecs; +extern unsigned int rx_stall_timeout_msecs; +extern unsigned int xenvif_max_queues; + +#ifdef CONFIG_DEBUG_FS +extern struct dentry *xen_netback_dbg_root; +#endif + +void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue, + struct sk_buff *skb); +void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue); + +#endif /* __XEN_NETBACK__COMMON_H__ */ |