linux/drivers/net/xen-netback/common.h

345 lines
11 KiB
C

/*
* 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;
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;
bool full_coalesce;
};
#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);
}
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__ */