[mirror_ubuntu-eoan-kernel.git] / drivers / net / xen-netback / common.h

/*
 * 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>

typedef unsigned int pending_ring_idx_t;
#define INVALID_PENDING_RING_IDX (~0U)

/* For the head field in pending_tx_info: it is used to indicate
 * whether this tx info is the head of one or more coalesced requests.
 *
 * When head != INVALID_PENDING_RING_IDX, it means the start of a new
 * tx requests queue and the end of previous queue.
 *
 * An example sequence of head fields (I = INVALID_PENDING_RING_IDX):
 *
 * ...|0 I I I|5 I|9 I I I|...
 * -->|<-INUSE----------------
 *
 * After consuming the first slot(s) we have:
 *
 * ...|V V V V|5 I|9 I I I|...
 * -----FREE->|<-INUSE--------
 *
 * where V stands for "valid pending ring index". Any number other
 * than INVALID_PENDING_RING_IDX is OK. These entries are considered
 * free and can contain any number other than
 * INVALID_PENDING_RING_IDX. In practice we use 0.
 *
 * The in use non-INVALID_PENDING_RING_IDX (say 0, 5 and 9 in the
 * above example) number is the index into pending_tx_info and
 * mmap_pages arrays.
 */
struct pending_tx_info {
	struct xen_netif_tx_request req; /* coalesced tx request */
	pending_ring_idx_t head; /* head != INVALID_PENDING_RING_IDX
				  * if it is head of one or more tx
				  * reqs
				  */
};

#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 256

/* 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

struct xenvif {
	/* Unique identifier for this interface. */
	domid_t          domid;
	unsigned int     handle;

	/* 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[IFNAMSIZ+4]; /* DEVNAME-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];

	/* Coalescing tx requests before copying makes number of grant
	 * copy ops greater or equal to number of slots required. In
	 * worst case a tx request consumes 2 gnttab_copy.
	 */
	struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS];


	/* 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[IFNAMSIZ+4]; /* DEVNAME-rx */
	struct xen_netif_rx_back_ring rx;
	struct sk_buff_head rx_queue;
	RING_IDX rx_last_skb_slots;

	/* This array is allocated seperately as it is large */
	struct gnttab_copy *grant_copy_op;

	/* 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];

	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;

	/* Internal feature information. */
	u8 can_queue:1;	    /* can queue packets for receiver? */

	/* 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 */
	unsigned long rx_gso_checksum_fixup;

	/* Miscellaneous private stuff. */
	struct net_device *dev;
};

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_connect(struct xenvif *vif, 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_must_stop_queue(struct xenvif *vif);

/* (Un)Map communication rings. */
void xenvif_unmap_frontend_rings(struct xenvif *vif);
int xenvif_map_frontend_rings(struct xenvif *vif,
			      grant_ref_t tx_ring_ref,
			      grant_ref_t rx_ring_ref);

/* Check for SKBs from frontend and schedule backend processing */
void xenvif_check_rx_xenvif(struct xenvif *vif);

/* Prevent the device from generating any further traffic. */
void xenvif_carrier_off(struct xenvif *vif);

int xenvif_tx_action(struct xenvif *vif, int budget);

int xenvif_kthread_guest_rx(void *data);
void xenvif_kick_thread(struct xenvif *vif);

/* Determine whether the needed number of slots (req) are available,
 * and set req_event if not.
 */
bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed);

void xenvif_stop_queue(struct xenvif *vif);

static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
{
	return MAX_PENDING_REQS -
		vif->pending_prod + vif->pending_cons;
}

static inline bool xenvif_tx_pending_slots_available(struct xenvif *vif)
{
	return nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
		< MAX_PENDING_REQS;
}

/* Callback from stack when TX packet can be released */
void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);

extern bool separate_tx_rx_irq;

#endif /* __XEN_NETBACK__COMMON_H__ */
Commit	Line	Data
f942dc25 IC	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
b3f980bd WL	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;
82cada22	90	int gso_type;
b3f980bd WL	91	int gso_size;
	92	};
	93
82cada22 PD	94	#define GSO_BIT(type) \
	95	(1 << XEN_NETIF_GSO_TYPE_ ## type)
	96
b3f980bd WL	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
f942dc25	103
ac3d5ac2 PD	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
121fa4b7 ZK	111	#define NETBACK_INVALID_HANDLE -1
	112
	113	/* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
	114	* the maximum slots a valid packet can use. Now this value is defined
	115	* to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
	116	* all backend.
	117	*/
	118	#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
	119
f942dc25 IC	120	struct xenvif {
	121	/* Unique identifier for this interface. */
	122	domid_t domid;
	123	unsigned int handle;
	124
b3f980bd WL	125	/* Use NAPI for guest TX */
	126	struct napi_struct napi;
	127	/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
	128	unsigned int tx_irq;
	129	/* Only used when feature-split-event-channels = 1 */
	130	char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
	131	struct xen_netif_tx_back_ring tx;
	132	struct sk_buff_head tx_queue;
	133	struct page *mmap_pages[MAX_PENDING_REQS];
	134	pending_ring_idx_t pending_prod;
	135	pending_ring_idx_t pending_cons;
	136	u16 pending_ring[MAX_PENDING_REQS];
	137	struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
	138
	139	/* Coalescing tx requests before copying makes number of grant
	140	* copy ops greater or equal to number of slots required. In
	141	* worst case a tx request consumes 2 gnttab_copy.
	142	*/
	143	struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS];
f942dc25	144
f942dc25	145
b3f980bd WL	146	/* Use kthread for guest RX */
	147	struct task_struct *task;
	148	wait_queue_head_t wq;
e1f00a69	149	/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
e1f00a69 WL	150	unsigned int rx_irq;
e1f00a69 WL	151	/* Only used when feature-split-event-channels = 1 */
e1f00a69	152	char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
b3f980bd WL	153	struct xen_netif_rx_back_ring rx;
b3f980bd WL	154	struct sk_buff_head rx_queue;
9ab9831b	155	RING_IDX rx_last_skb_slots;
b3f980bd	156
ac3d5ac2 PD	157	/* This array is allocated seperately as it is large */
ac3d5ac2 PD	158	struct gnttab_copy *grant_copy_op;
f942dc25	159
ac3d5ac2 PD	160	/* We create one meta structure per ring request we consume, so
	161	* the maximum number is the same as the ring size.
	162	*/
	163	struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
b3f980bd WL	164
b3f980bd WL	165	u8 fe_dev_addr[6];
f942dc25	166
f942dc25	167	/* Frontend feature information. */
82cada22 PD	168	int gso_mask;
	169	int gso_prefix_mask;
	170
f942dc25	171	u8 can_sg:1;
146c8a77 PD	172	u8 ip_csum:1;
146c8a77 PD	173	u8 ipv6_csum:1;
f942dc25 IC	174
	175	/* Internal feature information. */
	176	u8 can_queue:1; /* can queue packets for receiver? */
	177
f942dc25 IC	178	/* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
	179	unsigned long credit_bytes;
	180	unsigned long credit_usec;
	181	unsigned long remaining_credit;
	182	struct timer_list credit_timeout;
059dfa6a	183	u64 credit_window_start;
f942dc25 IC	184
	185	/* Statistics */
	186	unsigned long rx_gso_checksum_fixup;
	187
	188	/* Miscellaneous private stuff. */
f942dc25	189	struct net_device *dev;
f942dc25 IC	190	};
f942dc25 IC	191
c9d63699 DV	192	static inline struct xenbus_device xenvif_to_xenbus_device(struct xenvif vif)
	193	{
	194	return to_xenbus_device(vif->dev->dev.parent);
	195	}
	196
f942dc25 IC	197	struct xenvif xenvif_alloc(struct device parent,
	198	domid_t domid,
	199	unsigned int handle);
	200
	201	int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
e1f00a69 WL	202	unsigned long rx_ring_ref, unsigned int tx_evtchn,
e1f00a69 WL	203	unsigned int rx_evtchn);
f942dc25	204	void xenvif_disconnect(struct xenvif *vif);
279f438e	205	void xenvif_free(struct xenvif *vif);
f942dc25	206
f942dc25	207	int xenvif_xenbus_init(void);
b103f358	208	void xenvif_xenbus_fini(void);
f942dc25 IC	209
	210	int xenvif_schedulable(struct xenvif *vif);
	211
7376419a	212	int xenvif_must_stop_queue(struct xenvif *vif);
f942dc25 IC	213
f942dc25 IC	214	/* (Un)Map communication rings. */
7376419a WL	215	void xenvif_unmap_frontend_rings(struct xenvif *vif);
	216	int xenvif_map_frontend_rings(struct xenvif *vif,
	217	grant_ref_t tx_ring_ref,
	218	grant_ref_t rx_ring_ref);
f942dc25	219
f942dc25	220	/* Check for SKBs from frontend and schedule backend processing */
7376419a	221	void xenvif_check_rx_xenvif(struct xenvif *vif);
f942dc25	222
48856286 IC	223	/* Prevent the device from generating any further traffic. */
	224	void xenvif_carrier_off(struct xenvif *vif);
	225
7376419a	226	int xenvif_tx_action(struct xenvif *vif, int budget);
b3f980bd	227
121fa4b7	228	int xenvif_kthread_guest_rx(void *data);
ca2f09f2 PD	229	void xenvif_kick_thread(struct xenvif *vif);
	230
	231	/* Determine whether the needed number of slots (req) are available,
	232	* and set req_event if not.
	233	*/
	234	bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed);
	235
	236	void xenvif_stop_queue(struct xenvif *vif);
b3f980bd	237
121fa4b7 ZK	238	static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
	239	{
	240	return MAX_PENDING_REQS -
	241	vif->pending_prod + vif->pending_cons;
	242	}
	243
	244	static inline bool xenvif_tx_pending_slots_available(struct xenvif *vif)
	245	{
	246	return nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
	247	< MAX_PENDING_REQS;
	248	}
	249
3e2234b3 ZK	250	/* Callback from stack when TX packet can be released */
	251	void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
	252
e1f00a69 WL	253	extern bool separate_tx_rx_irq;
e1f00a69 WL	254
f942dc25	255	#endif /* __XEN_NETBACK__COMMON_H__ */