xref: /linux/drivers/rpmsg/virtio_rpmsg_bus.c (revision 4f6b838c378a52ea3ae0b15f12ca8a20849072fa)
1c3bab824SSuman Anna // SPDX-License-Identifier: GPL-2.0
2bcabbccaSOhad Ben-Cohen /*
3bcabbccaSOhad Ben-Cohen  * Virtio-based remote processor messaging bus
4bcabbccaSOhad Ben-Cohen  *
5bcabbccaSOhad Ben-Cohen  * Copyright (C) 2011 Texas Instruments, Inc.
6bcabbccaSOhad Ben-Cohen  * Copyright (C) 2011 Google, Inc.
7bcabbccaSOhad Ben-Cohen  *
8bcabbccaSOhad Ben-Cohen  * Ohad Ben-Cohen <ohad@wizery.com>
9bcabbccaSOhad Ben-Cohen  * Brian Swetland <swetland@google.com>
10bcabbccaSOhad Ben-Cohen  */
11bcabbccaSOhad Ben-Cohen 
12bcabbccaSOhad Ben-Cohen #define pr_fmt(fmt) "%s: " fmt, __func__
13bcabbccaSOhad Ben-Cohen 
146de1c933SLoic Pallardy #include <linux/dma-mapping.h>
156de1c933SLoic Pallardy #include <linux/idr.h>
166de1c933SLoic Pallardy #include <linux/jiffies.h>
17bcabbccaSOhad Ben-Cohen #include <linux/kernel.h>
18bcabbccaSOhad Ben-Cohen #include <linux/module.h>
196de1c933SLoic Pallardy #include <linux/mutex.h>
206de1c933SLoic Pallardy #include <linux/of_device.h>
216de1c933SLoic Pallardy #include <linux/rpmsg.h>
226de1c933SLoic Pallardy #include <linux/scatterlist.h>
236de1c933SLoic Pallardy #include <linux/slab.h>
246de1c933SLoic Pallardy #include <linux/sched.h>
25bcabbccaSOhad Ben-Cohen #include <linux/virtio.h>
26111d1089SGuennadi Liakhovetski #include <linux/virtio_byteorder.h>
27bcabbccaSOhad Ben-Cohen #include <linux/virtio_ids.h>
28bcabbccaSOhad Ben-Cohen #include <linux/virtio_config.h>
29bcabbccaSOhad Ben-Cohen #include <linux/wait.h>
30bcabbccaSOhad Ben-Cohen 
318b881c07SBjorn Andersson #include "rpmsg_internal.h"
328b881c07SBjorn Andersson 
33bcabbccaSOhad Ben-Cohen /**
34bcabbccaSOhad Ben-Cohen  * struct virtproc_info - virtual remote processor state
35bcabbccaSOhad Ben-Cohen  * @vdev:	the virtio device
36bcabbccaSOhad Ben-Cohen  * @rvq:	rx virtqueue
37bcabbccaSOhad Ben-Cohen  * @svq:	tx virtqueue
38bcabbccaSOhad Ben-Cohen  * @rbufs:	kernel address of rx buffers
39bcabbccaSOhad Ben-Cohen  * @sbufs:	kernel address of tx buffers
40b1b98914SSuman Anna  * @num_bufs:	total number of buffers for rx and tx
41f93848f9SLoic Pallardy  * @buf_size:   size of one rx or tx buffer
42bcabbccaSOhad Ben-Cohen  * @last_sbuf:	index of last tx buffer used
43bcabbccaSOhad Ben-Cohen  * @bufs_dma:	dma base addr of the buffers
44bcabbccaSOhad Ben-Cohen  * @tx_lock:	protects svq, sbufs and sleepers, to allow concurrent senders.
45bcabbccaSOhad Ben-Cohen  *		sending a message might require waking up a dozing remote
46bcabbccaSOhad Ben-Cohen  *		processor, which involves sleeping, hence the mutex.
47bcabbccaSOhad Ben-Cohen  * @endpoints:	idr of local endpoints, allows fast retrieval
48bcabbccaSOhad Ben-Cohen  * @endpoints_lock: lock of the endpoints set
49bcabbccaSOhad Ben-Cohen  * @sendq:	wait queue of sending contexts waiting for a tx buffers
50bcabbccaSOhad Ben-Cohen  * @sleepers:	number of senders that are waiting for a tx buffer
51bcabbccaSOhad Ben-Cohen  * @ns_ept:	the bus's name service endpoint
52bcabbccaSOhad Ben-Cohen  *
53bcabbccaSOhad Ben-Cohen  * This structure stores the rpmsg state of a given virtio remote processor
54bcabbccaSOhad Ben-Cohen  * device (there might be several virtio proc devices for each physical
55bcabbccaSOhad Ben-Cohen  * remote processor).
56bcabbccaSOhad Ben-Cohen  */
57bcabbccaSOhad Ben-Cohen struct virtproc_info {
58bcabbccaSOhad Ben-Cohen 	struct virtio_device *vdev;
59bcabbccaSOhad Ben-Cohen 	struct virtqueue *rvq, *svq;
60bcabbccaSOhad Ben-Cohen 	void *rbufs, *sbufs;
61b1b98914SSuman Anna 	unsigned int num_bufs;
62f93848f9SLoic Pallardy 	unsigned int buf_size;
63bcabbccaSOhad Ben-Cohen 	int last_sbuf;
64bcabbccaSOhad Ben-Cohen 	dma_addr_t bufs_dma;
65bcabbccaSOhad Ben-Cohen 	struct mutex tx_lock;
66bcabbccaSOhad Ben-Cohen 	struct idr endpoints;
67bcabbccaSOhad Ben-Cohen 	struct mutex endpoints_lock;
68bcabbccaSOhad Ben-Cohen 	wait_queue_head_t sendq;
69bcabbccaSOhad Ben-Cohen 	atomic_t sleepers;
70bcabbccaSOhad Ben-Cohen 	struct rpmsg_endpoint *ns_ept;
71bcabbccaSOhad Ben-Cohen };
72bcabbccaSOhad Ben-Cohen 
73e88dae5dSBjorn Andersson /* The feature bitmap for virtio rpmsg */
74e88dae5dSBjorn Andersson #define VIRTIO_RPMSG_F_NS	0 /* RP supports name service notifications */
75e88dae5dSBjorn Andersson 
76e88dae5dSBjorn Andersson /**
77e88dae5dSBjorn Andersson  * struct rpmsg_hdr - common header for all rpmsg messages
78e88dae5dSBjorn Andersson  * @src: source address
79e88dae5dSBjorn Andersson  * @dst: destination address
80e88dae5dSBjorn Andersson  * @reserved: reserved for future use
81e88dae5dSBjorn Andersson  * @len: length of payload (in bytes)
82e88dae5dSBjorn Andersson  * @flags: message flags
83e88dae5dSBjorn Andersson  * @data: @len bytes of message payload data
84e88dae5dSBjorn Andersson  *
85e88dae5dSBjorn Andersson  * Every message sent(/received) on the rpmsg bus begins with this header.
86e88dae5dSBjorn Andersson  */
87e88dae5dSBjorn Andersson struct rpmsg_hdr {
88111d1089SGuennadi Liakhovetski 	__virtio32 src;
89111d1089SGuennadi Liakhovetski 	__virtio32 dst;
90111d1089SGuennadi Liakhovetski 	__virtio32 reserved;
91111d1089SGuennadi Liakhovetski 	__virtio16 len;
92111d1089SGuennadi Liakhovetski 	__virtio16 flags;
934f05fc33SGustavo A. R. Silva 	u8 data[];
94e88dae5dSBjorn Andersson } __packed;
95e88dae5dSBjorn Andersson 
96e88dae5dSBjorn Andersson /**
97e88dae5dSBjorn Andersson  * struct rpmsg_ns_msg - dynamic name service announcement message
98e88dae5dSBjorn Andersson  * @name: name of remote service that is published
99e88dae5dSBjorn Andersson  * @addr: address of remote service that is published
100e88dae5dSBjorn Andersson  * @flags: indicates whether service is created or destroyed
101e88dae5dSBjorn Andersson  *
102e88dae5dSBjorn Andersson  * This message is sent across to publish a new service, or announce
103e88dae5dSBjorn Andersson  * about its removal. When we receive these messages, an appropriate
104e88dae5dSBjorn Andersson  * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
105e88dae5dSBjorn Andersson  * or ->remove() handler of the appropriate rpmsg driver will be invoked
106e88dae5dSBjorn Andersson  * (if/as-soon-as one is registered).
107e88dae5dSBjorn Andersson  */
108e88dae5dSBjorn Andersson struct rpmsg_ns_msg {
109e88dae5dSBjorn Andersson 	char name[RPMSG_NAME_SIZE];
110111d1089SGuennadi Liakhovetski 	__virtio32 addr;
111111d1089SGuennadi Liakhovetski 	__virtio32 flags;
112e88dae5dSBjorn Andersson } __packed;
113e88dae5dSBjorn Andersson 
114e88dae5dSBjorn Andersson /**
115e88dae5dSBjorn Andersson  * enum rpmsg_ns_flags - dynamic name service announcement flags
116e88dae5dSBjorn Andersson  *
117e88dae5dSBjorn Andersson  * @RPMSG_NS_CREATE: a new remote service was just created
118e88dae5dSBjorn Andersson  * @RPMSG_NS_DESTROY: a known remote service was just destroyed
119e88dae5dSBjorn Andersson  */
120e88dae5dSBjorn Andersson enum rpmsg_ns_flags {
121e88dae5dSBjorn Andersson 	RPMSG_NS_CREATE		= 0,
122e88dae5dSBjorn Andersson 	RPMSG_NS_DESTROY	= 1,
123e88dae5dSBjorn Andersson };
124e88dae5dSBjorn Andersson 
1253bf950ffSBjorn Andersson /**
126*6c09ea0bSArnaud Pouliquen  * struct virtio_rpmsg_channel - rpmsg channel descriptor
127*6c09ea0bSArnaud Pouliquen  * @rpdev: the rpmsg channel device
128*6c09ea0bSArnaud Pouliquen  * @vrp: the virtio remote processor device this channel belongs to
129*6c09ea0bSArnaud Pouliquen  *
130*6c09ea0bSArnaud Pouliquen  * This structure stores the channel that links the rpmsg device to the virtio
131*6c09ea0bSArnaud Pouliquen  * remote processor device.
1323bf950ffSBjorn Andersson  */
1333bf950ffSBjorn Andersson struct virtio_rpmsg_channel {
1343bf950ffSBjorn Andersson 	struct rpmsg_device rpdev;
1353bf950ffSBjorn Andersson 
1363bf950ffSBjorn Andersson 	struct virtproc_info *vrp;
1373bf950ffSBjorn Andersson };
1383bf950ffSBjorn Andersson 
1393bf950ffSBjorn Andersson #define to_virtio_rpmsg_channel(_rpdev) \
1403bf950ffSBjorn Andersson 	container_of(_rpdev, struct virtio_rpmsg_channel, rpdev)
1413bf950ffSBjorn Andersson 
142bcabbccaSOhad Ben-Cohen /*
143b1b98914SSuman Anna  * We're allocating buffers of 512 bytes each for communications. The
144b1b98914SSuman Anna  * number of buffers will be computed from the number of buffers supported
145b1b98914SSuman Anna  * by the vring, upto a maximum of 512 buffers (256 in each direction).
146bcabbccaSOhad Ben-Cohen  *
147bcabbccaSOhad Ben-Cohen  * Each buffer will have 16 bytes for the msg header and 496 bytes for
148bcabbccaSOhad Ben-Cohen  * the payload.
149bcabbccaSOhad Ben-Cohen  *
150b1b98914SSuman Anna  * This will utilize a maximum total space of 256KB for the buffers.
151bcabbccaSOhad Ben-Cohen  *
152bcabbccaSOhad Ben-Cohen  * We might also want to add support for user-provided buffers in time.
153bcabbccaSOhad Ben-Cohen  * This will allow bigger buffer size flexibility, and can also be used
154bcabbccaSOhad Ben-Cohen  * to achieve zero-copy messaging.
155bcabbccaSOhad Ben-Cohen  *
156bcabbccaSOhad Ben-Cohen  * Note that these numbers are purely a decision of this driver - we
157bcabbccaSOhad Ben-Cohen  * can change this without changing anything in the firmware of the remote
158bcabbccaSOhad Ben-Cohen  * processor.
159bcabbccaSOhad Ben-Cohen  */
160b1b98914SSuman Anna #define MAX_RPMSG_NUM_BUFS	(512)
161f93848f9SLoic Pallardy #define MAX_RPMSG_BUF_SIZE	(512)
162bcabbccaSOhad Ben-Cohen 
163bcabbccaSOhad Ben-Cohen /*
164bcabbccaSOhad Ben-Cohen  * Local addresses are dynamically allocated on-demand.
165bcabbccaSOhad Ben-Cohen  * We do not dynamically assign addresses from the low 1024 range,
166bcabbccaSOhad Ben-Cohen  * in order to reserve that address range for predefined services.
167bcabbccaSOhad Ben-Cohen  */
168bcabbccaSOhad Ben-Cohen #define RPMSG_RESERVED_ADDRESSES	(1024)
169bcabbccaSOhad Ben-Cohen 
170bcabbccaSOhad Ben-Cohen /* Address 53 is reserved for advertising remote services */
171bcabbccaSOhad Ben-Cohen #define RPMSG_NS_ADDR			(53)
172bcabbccaSOhad Ben-Cohen 
1738a228ecfSBjorn Andersson static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept);
1748a228ecfSBjorn Andersson static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
1758a228ecfSBjorn Andersson static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
1768a228ecfSBjorn Andersson 			       u32 dst);
1778a228ecfSBjorn Andersson static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
1788a228ecfSBjorn Andersson 					u32 dst, void *data, int len);
1798a228ecfSBjorn Andersson static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
1808a228ecfSBjorn Andersson static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
1818a228ecfSBjorn Andersson 				  int len, u32 dst);
1828a228ecfSBjorn Andersson static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
1838a228ecfSBjorn Andersson 					   u32 dst, void *data, int len);
184bcabbccaSOhad Ben-Cohen 
1858a228ecfSBjorn Andersson static const struct rpmsg_endpoint_ops virtio_endpoint_ops = {
1868a228ecfSBjorn Andersson 	.destroy_ept = virtio_rpmsg_destroy_ept,
1878a228ecfSBjorn Andersson 	.send = virtio_rpmsg_send,
1888a228ecfSBjorn Andersson 	.sendto = virtio_rpmsg_sendto,
1898a228ecfSBjorn Andersson 	.send_offchannel = virtio_rpmsg_send_offchannel,
1908a228ecfSBjorn Andersson 	.trysend = virtio_rpmsg_trysend,
1918a228ecfSBjorn Andersson 	.trysendto = virtio_rpmsg_trysendto,
1928a228ecfSBjorn Andersson 	.trysend_offchannel = virtio_rpmsg_trysend_offchannel,
1938a228ecfSBjorn Andersson };
1948a228ecfSBjorn Andersson 
1955a081caaSOhad Ben-Cohen /**
1969dd87c2aSLoic Pallardy  * rpmsg_sg_init - initialize scatterlist according to cpu address location
1979dd87c2aSLoic Pallardy  * @sg: scatterlist to fill
1989dd87c2aSLoic Pallardy  * @cpu_addr: virtual address of the buffer
1999dd87c2aSLoic Pallardy  * @len: buffer length
2009dd87c2aSLoic Pallardy  *
2019dd87c2aSLoic Pallardy  * An internal function filling scatterlist according to virtual address
2029dd87c2aSLoic Pallardy  * location (in vmalloc or in kernel).
2039dd87c2aSLoic Pallardy  */
2049dd87c2aSLoic Pallardy static void
2059dd87c2aSLoic Pallardy rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
2069dd87c2aSLoic Pallardy {
2079dd87c2aSLoic Pallardy 	if (is_vmalloc_addr(cpu_addr)) {
2089dd87c2aSLoic Pallardy 		sg_init_table(sg, 1);
2099dd87c2aSLoic Pallardy 		sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
2109dd87c2aSLoic Pallardy 			    offset_in_page(cpu_addr));
2119dd87c2aSLoic Pallardy 	} else {
2129dd87c2aSLoic Pallardy 		WARN_ON(!virt_addr_valid(cpu_addr));
2139dd87c2aSLoic Pallardy 		sg_init_one(sg, cpu_addr, len);
2149dd87c2aSLoic Pallardy 	}
2159dd87c2aSLoic Pallardy }
2169dd87c2aSLoic Pallardy 
2179dd87c2aSLoic Pallardy /**
2185a081caaSOhad Ben-Cohen  * __ept_release() - deallocate an rpmsg endpoint
2195a081caaSOhad Ben-Cohen  * @kref: the ept's reference count
2205a081caaSOhad Ben-Cohen  *
2215a081caaSOhad Ben-Cohen  * This function deallocates an ept, and is invoked when its @kref refcount
2225a081caaSOhad Ben-Cohen  * drops to zero.
2235a081caaSOhad Ben-Cohen  *
2245a081caaSOhad Ben-Cohen  * Never invoke this function directly!
2255a081caaSOhad Ben-Cohen  */
2265a081caaSOhad Ben-Cohen static void __ept_release(struct kref *kref)
2275a081caaSOhad Ben-Cohen {
2285a081caaSOhad Ben-Cohen 	struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
2295a081caaSOhad Ben-Cohen 						  refcount);
2305a081caaSOhad Ben-Cohen 	/*
2315a081caaSOhad Ben-Cohen 	 * At this point no one holds a reference to ept anymore,
2325a081caaSOhad Ben-Cohen 	 * so we can directly free it
2335a081caaSOhad Ben-Cohen 	 */
2345a081caaSOhad Ben-Cohen 	kfree(ept);
2355a081caaSOhad Ben-Cohen }
2365a081caaSOhad Ben-Cohen 
237bcabbccaSOhad Ben-Cohen /* for more info, see below documentation of rpmsg_create_ept() */
238bcabbccaSOhad Ben-Cohen static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
23992e1de51SBjorn Andersson 						 struct rpmsg_device *rpdev,
2400963679cSAnna, Suman 						 rpmsg_rx_cb_t cb,
241bcabbccaSOhad Ben-Cohen 						 void *priv, u32 addr)
242bcabbccaSOhad Ben-Cohen {
243d0ffce77STejun Heo 	int id_min, id_max, id;
244bcabbccaSOhad Ben-Cohen 	struct rpmsg_endpoint *ept;
245bcabbccaSOhad Ben-Cohen 	struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev;
246bcabbccaSOhad Ben-Cohen 
247bcabbccaSOhad Ben-Cohen 	ept = kzalloc(sizeof(*ept), GFP_KERNEL);
248a8bb3fd9SAnna, Suman 	if (!ept)
249bcabbccaSOhad Ben-Cohen 		return NULL;
250bcabbccaSOhad Ben-Cohen 
2515a081caaSOhad Ben-Cohen 	kref_init(&ept->refcount);
25215fd943aSOhad Ben-Cohen 	mutex_init(&ept->cb_lock);
2535a081caaSOhad Ben-Cohen 
254bcabbccaSOhad Ben-Cohen 	ept->rpdev = rpdev;
255bcabbccaSOhad Ben-Cohen 	ept->cb = cb;
256bcabbccaSOhad Ben-Cohen 	ept->priv = priv;
2578a228ecfSBjorn Andersson 	ept->ops = &virtio_endpoint_ops;
258bcabbccaSOhad Ben-Cohen 
259bcabbccaSOhad Ben-Cohen 	/* do we need to allocate a local address ? */
260d0ffce77STejun Heo 	if (addr == RPMSG_ADDR_ANY) {
261d0ffce77STejun Heo 		id_min = RPMSG_RESERVED_ADDRESSES;
262d0ffce77STejun Heo 		id_max = 0;
263d0ffce77STejun Heo 	} else {
264d0ffce77STejun Heo 		id_min = addr;
265d0ffce77STejun Heo 		id_max = addr + 1;
266d0ffce77STejun Heo 	}
267bcabbccaSOhad Ben-Cohen 
268bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->endpoints_lock);
269bcabbccaSOhad Ben-Cohen 
270bcabbccaSOhad Ben-Cohen 	/* bind the endpoint to an rpmsg address (and allocate one if needed) */
271d0ffce77STejun Heo 	id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL);
272d0ffce77STejun Heo 	if (id < 0) {
273d0ffce77STejun Heo 		dev_err(dev, "idr_alloc failed: %d\n", id);
274bcabbccaSOhad Ben-Cohen 		goto free_ept;
275bcabbccaSOhad Ben-Cohen 	}
276d0ffce77STejun Heo 	ept->addr = id;
277bcabbccaSOhad Ben-Cohen 
278bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->endpoints_lock);
279bcabbccaSOhad Ben-Cohen 
280bcabbccaSOhad Ben-Cohen 	return ept;
281bcabbccaSOhad Ben-Cohen 
282bcabbccaSOhad Ben-Cohen free_ept:
283bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->endpoints_lock);
2845a081caaSOhad Ben-Cohen 	kref_put(&ept->refcount, __ept_release);
285bcabbccaSOhad Ben-Cohen 	return NULL;
286bcabbccaSOhad Ben-Cohen }
287bcabbccaSOhad Ben-Cohen 
28836b72c7dSBjorn Andersson static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev,
28936b72c7dSBjorn Andersson 						      rpmsg_rx_cb_t cb,
29036b72c7dSBjorn Andersson 						      void *priv,
29136b72c7dSBjorn Andersson 						      struct rpmsg_channel_info chinfo)
29236b72c7dSBjorn Andersson {
2933bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
2943bf950ffSBjorn Andersson 
2953bf950ffSBjorn Andersson 	return __rpmsg_create_ept(vch->vrp, rpdev, cb, priv, chinfo.src);
29636b72c7dSBjorn Andersson }
29736b72c7dSBjorn Andersson 
298bcabbccaSOhad Ben-Cohen /**
299fa2d7795SOhad Ben-Cohen  * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
300fa2d7795SOhad Ben-Cohen  * @vrp: virtproc which owns this ept
301fa2d7795SOhad Ben-Cohen  * @ept: endpoing to destroy
302fa2d7795SOhad Ben-Cohen  *
303fa2d7795SOhad Ben-Cohen  * An internal function which destroy an ept without assuming it is
304fa2d7795SOhad Ben-Cohen  * bound to an rpmsg channel. This is needed for handling the internal
305fa2d7795SOhad Ben-Cohen  * name service endpoint, which isn't bound to an rpmsg channel.
306fa2d7795SOhad Ben-Cohen  * See also __rpmsg_create_ept().
307fa2d7795SOhad Ben-Cohen  */
308fa2d7795SOhad Ben-Cohen static void
309fa2d7795SOhad Ben-Cohen __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
310fa2d7795SOhad Ben-Cohen {
31115fd943aSOhad Ben-Cohen 	/* make sure new inbound messages can't find this ept anymore */
312fa2d7795SOhad Ben-Cohen 	mutex_lock(&vrp->endpoints_lock);
313fa2d7795SOhad Ben-Cohen 	idr_remove(&vrp->endpoints, ept->addr);
314fa2d7795SOhad Ben-Cohen 	mutex_unlock(&vrp->endpoints_lock);
315fa2d7795SOhad Ben-Cohen 
31615fd943aSOhad Ben-Cohen 	/* make sure in-flight inbound messages won't invoke cb anymore */
31715fd943aSOhad Ben-Cohen 	mutex_lock(&ept->cb_lock);
31815fd943aSOhad Ben-Cohen 	ept->cb = NULL;
31915fd943aSOhad Ben-Cohen 	mutex_unlock(&ept->cb_lock);
32015fd943aSOhad Ben-Cohen 
3215a081caaSOhad Ben-Cohen 	kref_put(&ept->refcount, __ept_release);
322fa2d7795SOhad Ben-Cohen }
323fa2d7795SOhad Ben-Cohen 
3248a228ecfSBjorn Andersson static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
3258a228ecfSBjorn Andersson {
3263bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(ept->rpdev);
3273bf950ffSBjorn Andersson 
3283bf950ffSBjorn Andersson 	__rpmsg_destroy_ept(vch->vrp, ept);
3298a228ecfSBjorn Andersson }
3308a228ecfSBjorn Andersson 
33136b72c7dSBjorn Andersson static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev)
33236b72c7dSBjorn Andersson {
3333bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
3343bf950ffSBjorn Andersson 	struct virtproc_info *vrp = vch->vrp;
33536b72c7dSBjorn Andersson 	struct device *dev = &rpdev->dev;
33636b72c7dSBjorn Andersson 	int err = 0;
33736b72c7dSBjorn Andersson 
338bcabbccaSOhad Ben-Cohen 	/* need to tell remote processor's name service about this channel ? */
339b2599ebfSHenri Roosen 	if (rpdev->announce && rpdev->ept &&
340bcabbccaSOhad Ben-Cohen 	    virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) {
341bcabbccaSOhad Ben-Cohen 		struct rpmsg_ns_msg nsm;
342bcabbccaSOhad Ben-Cohen 
343bcabbccaSOhad Ben-Cohen 		strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
344111d1089SGuennadi Liakhovetski 		nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
345111d1089SGuennadi Liakhovetski 		nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_CREATE);
346bcabbccaSOhad Ben-Cohen 
3472a48d732SBjorn Andersson 		err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
348bcabbccaSOhad Ben-Cohen 		if (err)
349bcabbccaSOhad Ben-Cohen 			dev_err(dev, "failed to announce service %d\n", err);
350bcabbccaSOhad Ben-Cohen 	}
351bcabbccaSOhad Ben-Cohen 
352bcabbccaSOhad Ben-Cohen 	return err;
353bcabbccaSOhad Ben-Cohen }
354bcabbccaSOhad Ben-Cohen 
35536b72c7dSBjorn Andersson static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev)
356bcabbccaSOhad Ben-Cohen {
3573bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
3583bf950ffSBjorn Andersson 	struct virtproc_info *vrp = vch->vrp;
35936b72c7dSBjorn Andersson 	struct device *dev = &rpdev->dev;
360bcabbccaSOhad Ben-Cohen 	int err = 0;
361bcabbccaSOhad Ben-Cohen 
362bcabbccaSOhad Ben-Cohen 	/* tell remote processor's name service we're removing this channel */
363b2599ebfSHenri Roosen 	if (rpdev->announce && rpdev->ept &&
364bcabbccaSOhad Ben-Cohen 	    virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) {
365bcabbccaSOhad Ben-Cohen 		struct rpmsg_ns_msg nsm;
366bcabbccaSOhad Ben-Cohen 
367bcabbccaSOhad Ben-Cohen 		strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
368111d1089SGuennadi Liakhovetski 		nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
369111d1089SGuennadi Liakhovetski 		nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_DESTROY);
370bcabbccaSOhad Ben-Cohen 
3712a48d732SBjorn Andersson 		err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
372bcabbccaSOhad Ben-Cohen 		if (err)
373bcabbccaSOhad Ben-Cohen 			dev_err(dev, "failed to announce service %d\n", err);
374bcabbccaSOhad Ben-Cohen 	}
375bcabbccaSOhad Ben-Cohen 
37636b72c7dSBjorn Andersson 	return err;
37736b72c7dSBjorn Andersson }
37836b72c7dSBjorn Andersson 
37936b72c7dSBjorn Andersson static const struct rpmsg_device_ops virtio_rpmsg_ops = {
38036b72c7dSBjorn Andersson 	.create_ept = virtio_rpmsg_create_ept,
38136b72c7dSBjorn Andersson 	.announce_create = virtio_rpmsg_announce_create,
38236b72c7dSBjorn Andersson 	.announce_destroy = virtio_rpmsg_announce_destroy,
38336b72c7dSBjorn Andersson };
38436b72c7dSBjorn Andersson 
385b0b03b81SBjorn Andersson static void virtio_rpmsg_release_device(struct device *dev)
386b0b03b81SBjorn Andersson {
387b0b03b81SBjorn Andersson 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
388b0b03b81SBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
389b0b03b81SBjorn Andersson 
390b0b03b81SBjorn Andersson 	kfree(vch);
391b0b03b81SBjorn Andersson }
392b0b03b81SBjorn Andersson 
393bcabbccaSOhad Ben-Cohen /*
394bcabbccaSOhad Ben-Cohen  * create an rpmsg channel using its name and address info.
395bcabbccaSOhad Ben-Cohen  * this function will be used to create both static and dynamic
396bcabbccaSOhad Ben-Cohen  * channels.
397bcabbccaSOhad Ben-Cohen  */
39892e1de51SBjorn Andersson static struct rpmsg_device *rpmsg_create_channel(struct virtproc_info *vrp,
399bcabbccaSOhad Ben-Cohen 						 struct rpmsg_channel_info *chinfo)
400bcabbccaSOhad Ben-Cohen {
4013bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch;
40292e1de51SBjorn Andersson 	struct rpmsg_device *rpdev;
403bcabbccaSOhad Ben-Cohen 	struct device *tmp, *dev = &vrp->vdev->dev;
404bcabbccaSOhad Ben-Cohen 	int ret;
405bcabbccaSOhad Ben-Cohen 
406bcabbccaSOhad Ben-Cohen 	/* make sure a similar channel doesn't already exist */
4078b881c07SBjorn Andersson 	tmp = rpmsg_find_device(dev, chinfo);
408bcabbccaSOhad Ben-Cohen 	if (tmp) {
409bcabbccaSOhad Ben-Cohen 		/* decrement the matched device's refcount back */
410bcabbccaSOhad Ben-Cohen 		put_device(tmp);
411bcabbccaSOhad Ben-Cohen 		dev_err(dev, "channel %s:%x:%x already exist\n",
412bcabbccaSOhad Ben-Cohen 				chinfo->name, chinfo->src, chinfo->dst);
413bcabbccaSOhad Ben-Cohen 		return NULL;
414bcabbccaSOhad Ben-Cohen 	}
415bcabbccaSOhad Ben-Cohen 
4163bf950ffSBjorn Andersson 	vch = kzalloc(sizeof(*vch), GFP_KERNEL);
4173bf950ffSBjorn Andersson 	if (!vch)
418bcabbccaSOhad Ben-Cohen 		return NULL;
419bcabbccaSOhad Ben-Cohen 
4203bf950ffSBjorn Andersson 	/* Link the channel to our vrp */
4213bf950ffSBjorn Andersson 	vch->vrp = vrp;
4223bf950ffSBjorn Andersson 
4233bf950ffSBjorn Andersson 	/* Assign public information to the rpmsg_device */
4243bf950ffSBjorn Andersson 	rpdev = &vch->rpdev;
425bcabbccaSOhad Ben-Cohen 	rpdev->src = chinfo->src;
426bcabbccaSOhad Ben-Cohen 	rpdev->dst = chinfo->dst;
42736b72c7dSBjorn Andersson 	rpdev->ops = &virtio_rpmsg_ops;
428bcabbccaSOhad Ben-Cohen 
429bcabbccaSOhad Ben-Cohen 	/*
430bcabbccaSOhad Ben-Cohen 	 * rpmsg server channels has predefined local address (for now),
431bcabbccaSOhad Ben-Cohen 	 * and their existence needs to be announced remotely
432bcabbccaSOhad Ben-Cohen 	 */
433c8ced113SAndrew F. Davis 	rpdev->announce = rpdev->src != RPMSG_ADDR_ANY;
434bcabbccaSOhad Ben-Cohen 
435bcabbccaSOhad Ben-Cohen 	strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE);
436bcabbccaSOhad Ben-Cohen 
4376eed598aSBjorn Andersson 	rpdev->dev.parent = &vrp->vdev->dev;
438b0b03b81SBjorn Andersson 	rpdev->dev.release = virtio_rpmsg_release_device;
4396eed598aSBjorn Andersson 	ret = rpmsg_register_device(rpdev);
4406eed598aSBjorn Andersson 	if (ret)
4416eed598aSBjorn Andersson 		return NULL;
4426eed598aSBjorn Andersson 
4436eed598aSBjorn Andersson 	return rpdev;
4446eed598aSBjorn Andersson }
4456eed598aSBjorn Andersson 
446bcabbccaSOhad Ben-Cohen /* super simple buffer "allocator" that is just enough for now */
447bcabbccaSOhad Ben-Cohen static void *get_a_tx_buf(struct virtproc_info *vrp)
448bcabbccaSOhad Ben-Cohen {
449bcabbccaSOhad Ben-Cohen 	unsigned int len;
450bcabbccaSOhad Ben-Cohen 	void *ret;
451bcabbccaSOhad Ben-Cohen 
452bcabbccaSOhad Ben-Cohen 	/* support multiple concurrent senders */
453bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->tx_lock);
454bcabbccaSOhad Ben-Cohen 
455bcabbccaSOhad Ben-Cohen 	/*
456bcabbccaSOhad Ben-Cohen 	 * either pick the next unused tx buffer
457bcabbccaSOhad Ben-Cohen 	 * (half of our buffers are used for sending messages)
458bcabbccaSOhad Ben-Cohen 	 */
459b1b98914SSuman Anna 	if (vrp->last_sbuf < vrp->num_bufs / 2)
460f93848f9SLoic Pallardy 		ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++;
461bcabbccaSOhad Ben-Cohen 	/* or recycle a used one */
462bcabbccaSOhad Ben-Cohen 	else
463bcabbccaSOhad Ben-Cohen 		ret = virtqueue_get_buf(vrp->svq, &len);
464bcabbccaSOhad Ben-Cohen 
465bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->tx_lock);
466bcabbccaSOhad Ben-Cohen 
467bcabbccaSOhad Ben-Cohen 	return ret;
468bcabbccaSOhad Ben-Cohen }
469bcabbccaSOhad Ben-Cohen 
470bcabbccaSOhad Ben-Cohen /**
471bcabbccaSOhad Ben-Cohen  * rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed
472bcabbccaSOhad Ben-Cohen  * @vrp: virtual remote processor state
473bcabbccaSOhad Ben-Cohen  *
474bcabbccaSOhad Ben-Cohen  * This function is called before a sender is blocked, waiting for
475bcabbccaSOhad Ben-Cohen  * a tx buffer to become available.
476bcabbccaSOhad Ben-Cohen  *
477bcabbccaSOhad Ben-Cohen  * If we already have blocking senders, this function merely increases
478bcabbccaSOhad Ben-Cohen  * the "sleepers" reference count, and exits.
479bcabbccaSOhad Ben-Cohen  *
480bcabbccaSOhad Ben-Cohen  * Otherwise, if this is the first sender to block, we also enable
481bcabbccaSOhad Ben-Cohen  * virtio's tx callbacks, so we'd be immediately notified when a tx
482bcabbccaSOhad Ben-Cohen  * buffer is consumed (we rely on virtio's tx callback in order
483bcabbccaSOhad Ben-Cohen  * to wake up sleeping senders as soon as a tx buffer is used by the
484bcabbccaSOhad Ben-Cohen  * remote processor).
485bcabbccaSOhad Ben-Cohen  */
486bcabbccaSOhad Ben-Cohen static void rpmsg_upref_sleepers(struct virtproc_info *vrp)
487bcabbccaSOhad Ben-Cohen {
488bcabbccaSOhad Ben-Cohen 	/* support multiple concurrent senders */
489bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->tx_lock);
490bcabbccaSOhad Ben-Cohen 
491bcabbccaSOhad Ben-Cohen 	/* are we the first sleeping context waiting for tx buffers ? */
492bcabbccaSOhad Ben-Cohen 	if (atomic_inc_return(&vrp->sleepers) == 1)
493bcabbccaSOhad Ben-Cohen 		/* enable "tx-complete" interrupts before dozing off */
494bcabbccaSOhad Ben-Cohen 		virtqueue_enable_cb(vrp->svq);
495bcabbccaSOhad Ben-Cohen 
496bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->tx_lock);
497bcabbccaSOhad Ben-Cohen }
498bcabbccaSOhad Ben-Cohen 
499bcabbccaSOhad Ben-Cohen /**
500bcabbccaSOhad Ben-Cohen  * rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed
501bcabbccaSOhad Ben-Cohen  * @vrp: virtual remote processor state
502bcabbccaSOhad Ben-Cohen  *
503bcabbccaSOhad Ben-Cohen  * This function is called after a sender, that waited for a tx buffer
504bcabbccaSOhad Ben-Cohen  * to become available, is unblocked.
505bcabbccaSOhad Ben-Cohen  *
506bcabbccaSOhad Ben-Cohen  * If we still have blocking senders, this function merely decreases
507bcabbccaSOhad Ben-Cohen  * the "sleepers" reference count, and exits.
508bcabbccaSOhad Ben-Cohen  *
509bcabbccaSOhad Ben-Cohen  * Otherwise, if there are no more blocking senders, we also disable
510bcabbccaSOhad Ben-Cohen  * virtio's tx callbacks, to avoid the overhead incurred with handling
511bcabbccaSOhad Ben-Cohen  * those (now redundant) interrupts.
512bcabbccaSOhad Ben-Cohen  */
513bcabbccaSOhad Ben-Cohen static void rpmsg_downref_sleepers(struct virtproc_info *vrp)
514bcabbccaSOhad Ben-Cohen {
515bcabbccaSOhad Ben-Cohen 	/* support multiple concurrent senders */
516bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->tx_lock);
517bcabbccaSOhad Ben-Cohen 
518bcabbccaSOhad Ben-Cohen 	/* are we the last sleeping context waiting for tx buffers ? */
519bcabbccaSOhad Ben-Cohen 	if (atomic_dec_and_test(&vrp->sleepers))
520bcabbccaSOhad Ben-Cohen 		/* disable "tx-complete" interrupts */
521bcabbccaSOhad Ben-Cohen 		virtqueue_disable_cb(vrp->svq);
522bcabbccaSOhad Ben-Cohen 
523bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->tx_lock);
524bcabbccaSOhad Ben-Cohen }
525bcabbccaSOhad Ben-Cohen 
526bcabbccaSOhad Ben-Cohen /**
527bcabbccaSOhad Ben-Cohen  * rpmsg_send_offchannel_raw() - send a message across to the remote processor
528bcabbccaSOhad Ben-Cohen  * @rpdev: the rpmsg channel
529bcabbccaSOhad Ben-Cohen  * @src: source address
530bcabbccaSOhad Ben-Cohen  * @dst: destination address
531bcabbccaSOhad Ben-Cohen  * @data: payload of message
532bcabbccaSOhad Ben-Cohen  * @len: length of payload
533bcabbccaSOhad Ben-Cohen  * @wait: indicates whether caller should block in case no TX buffers available
534bcabbccaSOhad Ben-Cohen  *
535bcabbccaSOhad Ben-Cohen  * This function is the base implementation for all of the rpmsg sending API.
536bcabbccaSOhad Ben-Cohen  *
537bcabbccaSOhad Ben-Cohen  * It will send @data of length @len to @dst, and say it's from @src. The
538bcabbccaSOhad Ben-Cohen  * message will be sent to the remote processor which the @rpdev channel
539bcabbccaSOhad Ben-Cohen  * belongs to.
540bcabbccaSOhad Ben-Cohen  *
541bcabbccaSOhad Ben-Cohen  * The message is sent using one of the TX buffers that are available for
542bcabbccaSOhad Ben-Cohen  * communication with this remote processor.
543bcabbccaSOhad Ben-Cohen  *
544bcabbccaSOhad Ben-Cohen  * If @wait is true, the caller will be blocked until either a TX buffer is
545bcabbccaSOhad Ben-Cohen  * available, or 15 seconds elapses (we don't want callers to
546bcabbccaSOhad Ben-Cohen  * sleep indefinitely due to misbehaving remote processors), and in that
547bcabbccaSOhad Ben-Cohen  * case -ERESTARTSYS is returned. The number '15' itself was picked
548bcabbccaSOhad Ben-Cohen  * arbitrarily; there's little point in asking drivers to provide a timeout
549bcabbccaSOhad Ben-Cohen  * value themselves.
550bcabbccaSOhad Ben-Cohen  *
551bcabbccaSOhad Ben-Cohen  * Otherwise, if @wait is false, and there are no TX buffers available,
552bcabbccaSOhad Ben-Cohen  * the function will immediately fail, and -ENOMEM will be returned.
553bcabbccaSOhad Ben-Cohen  *
554bcabbccaSOhad Ben-Cohen  * Normally drivers shouldn't use this function directly; instead, drivers
555bcabbccaSOhad Ben-Cohen  * should use the appropriate rpmsg_{try}send{to, _offchannel} API
556bcabbccaSOhad Ben-Cohen  * (see include/linux/rpmsg.h).
557bcabbccaSOhad Ben-Cohen  *
558bcabbccaSOhad Ben-Cohen  * Returns 0 on success and an appropriate error value on failure.
559bcabbccaSOhad Ben-Cohen  */
5608a228ecfSBjorn Andersson static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
5618a228ecfSBjorn Andersson 				     u32 src, u32 dst,
562bcabbccaSOhad Ben-Cohen 				     void *data, int len, bool wait)
563bcabbccaSOhad Ben-Cohen {
5643bf950ffSBjorn Andersson 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
5653bf950ffSBjorn Andersson 	struct virtproc_info *vrp = vch->vrp;
566bcabbccaSOhad Ben-Cohen 	struct device *dev = &rpdev->dev;
567bcabbccaSOhad Ben-Cohen 	struct scatterlist sg;
568bcabbccaSOhad Ben-Cohen 	struct rpmsg_hdr *msg;
569bcabbccaSOhad Ben-Cohen 	int err;
570bcabbccaSOhad Ben-Cohen 
571bcabbccaSOhad Ben-Cohen 	/* bcasting isn't allowed */
572bcabbccaSOhad Ben-Cohen 	if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) {
573bcabbccaSOhad Ben-Cohen 		dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst);
574bcabbccaSOhad Ben-Cohen 		return -EINVAL;
575bcabbccaSOhad Ben-Cohen 	}
576bcabbccaSOhad Ben-Cohen 
577bcabbccaSOhad Ben-Cohen 	/*
578bcabbccaSOhad Ben-Cohen 	 * We currently use fixed-sized buffers, and therefore the payload
579bcabbccaSOhad Ben-Cohen 	 * length is limited.
580bcabbccaSOhad Ben-Cohen 	 *
581bcabbccaSOhad Ben-Cohen 	 * One of the possible improvements here is either to support
582bcabbccaSOhad Ben-Cohen 	 * user-provided buffers (and then we can also support zero-copy
583bcabbccaSOhad Ben-Cohen 	 * messaging), or to improve the buffer allocator, to support
584bcabbccaSOhad Ben-Cohen 	 * variable-length buffer sizes.
585bcabbccaSOhad Ben-Cohen 	 */
586f93848f9SLoic Pallardy 	if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) {
587bcabbccaSOhad Ben-Cohen 		dev_err(dev, "message is too big (%d)\n", len);
588bcabbccaSOhad Ben-Cohen 		return -EMSGSIZE;
589bcabbccaSOhad Ben-Cohen 	}
590bcabbccaSOhad Ben-Cohen 
591bcabbccaSOhad Ben-Cohen 	/* grab a buffer */
592bcabbccaSOhad Ben-Cohen 	msg = get_a_tx_buf(vrp);
593bcabbccaSOhad Ben-Cohen 	if (!msg && !wait)
594bcabbccaSOhad Ben-Cohen 		return -ENOMEM;
595bcabbccaSOhad Ben-Cohen 
596bcabbccaSOhad Ben-Cohen 	/* no free buffer ? wait for one (but bail after 15 seconds) */
597bcabbccaSOhad Ben-Cohen 	while (!msg) {
598bcabbccaSOhad Ben-Cohen 		/* enable "tx-complete" interrupts, if not already enabled */
599bcabbccaSOhad Ben-Cohen 		rpmsg_upref_sleepers(vrp);
600bcabbccaSOhad Ben-Cohen 
601bcabbccaSOhad Ben-Cohen 		/*
602bcabbccaSOhad Ben-Cohen 		 * sleep until a free buffer is available or 15 secs elapse.
603bcabbccaSOhad Ben-Cohen 		 * the timeout period is not configurable because there's
604bcabbccaSOhad Ben-Cohen 		 * little point in asking drivers to specify that.
605bcabbccaSOhad Ben-Cohen 		 * if later this happens to be required, it'd be easy to add.
606bcabbccaSOhad Ben-Cohen 		 */
607bcabbccaSOhad Ben-Cohen 		err = wait_event_interruptible_timeout(vrp->sendq,
608bcabbccaSOhad Ben-Cohen 					(msg = get_a_tx_buf(vrp)),
609bcabbccaSOhad Ben-Cohen 					msecs_to_jiffies(15000));
610bcabbccaSOhad Ben-Cohen 
611bcabbccaSOhad Ben-Cohen 		/* disable "tx-complete" interrupts if we're the last sleeper */
612bcabbccaSOhad Ben-Cohen 		rpmsg_downref_sleepers(vrp);
613bcabbccaSOhad Ben-Cohen 
614bcabbccaSOhad Ben-Cohen 		/* timeout ? */
615bcabbccaSOhad Ben-Cohen 		if (!err) {
616bcabbccaSOhad Ben-Cohen 			dev_err(dev, "timeout waiting for a tx buffer\n");
617bcabbccaSOhad Ben-Cohen 			return -ERESTARTSYS;
618bcabbccaSOhad Ben-Cohen 		}
619bcabbccaSOhad Ben-Cohen 	}
620bcabbccaSOhad Ben-Cohen 
621111d1089SGuennadi Liakhovetski 	msg->len = cpu_to_virtio16(vrp->vdev, len);
622bcabbccaSOhad Ben-Cohen 	msg->flags = 0;
623111d1089SGuennadi Liakhovetski 	msg->src = cpu_to_virtio32(vrp->vdev, src);
624111d1089SGuennadi Liakhovetski 	msg->dst = cpu_to_virtio32(vrp->vdev, dst);
625bcabbccaSOhad Ben-Cohen 	msg->reserved = 0;
626bcabbccaSOhad Ben-Cohen 	memcpy(msg->data, data, len);
627bcabbccaSOhad Ben-Cohen 
628bcabbccaSOhad Ben-Cohen 	dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n",
629111d1089SGuennadi Liakhovetski 		src, dst, len, msg->flags, msg->reserved);
630211e3a93SAnna, Suman #if defined(CONFIG_DYNAMIC_DEBUG)
631211e3a93SAnna, Suman 	dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1,
632111d1089SGuennadi Liakhovetski 			 msg, sizeof(*msg) + len, true);
633211e3a93SAnna, Suman #endif
634bcabbccaSOhad Ben-Cohen 
6359dd87c2aSLoic Pallardy 	rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
636bcabbccaSOhad Ben-Cohen 
637bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->tx_lock);
638bcabbccaSOhad Ben-Cohen 
639bcabbccaSOhad Ben-Cohen 	/* add message to the remote processor's virtqueue */
640cee51d69SRusty Russell 	err = virtqueue_add_outbuf(vrp->svq, &sg, 1, msg, GFP_KERNEL);
64157e1a373SRusty Russell 	if (err) {
642bcabbccaSOhad Ben-Cohen 		/*
643bcabbccaSOhad Ben-Cohen 		 * need to reclaim the buffer here, otherwise it's lost
644bcabbccaSOhad Ben-Cohen 		 * (memory won't leak, but rpmsg won't use it again for TX).
645bcabbccaSOhad Ben-Cohen 		 * this will wait for a buffer management overhaul.
646bcabbccaSOhad Ben-Cohen 		 */
647cee51d69SRusty Russell 		dev_err(dev, "virtqueue_add_outbuf failed: %d\n", err);
648bcabbccaSOhad Ben-Cohen 		goto out;
649bcabbccaSOhad Ben-Cohen 	}
650bcabbccaSOhad Ben-Cohen 
651bcabbccaSOhad Ben-Cohen 	/* tell the remote processor it has a pending message to read */
652bcabbccaSOhad Ben-Cohen 	virtqueue_kick(vrp->svq);
653bcabbccaSOhad Ben-Cohen out:
654bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->tx_lock);
655bcabbccaSOhad Ben-Cohen 	return err;
656bcabbccaSOhad Ben-Cohen }
657bcabbccaSOhad Ben-Cohen 
6588a228ecfSBjorn Andersson static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
6598a228ecfSBjorn Andersson {
6608a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
6618a228ecfSBjorn Andersson 	u32 src = ept->addr, dst = rpdev->dst;
6628a228ecfSBjorn Andersson 
6638a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
6648a228ecfSBjorn Andersson }
6658a228ecfSBjorn Andersson 
6668a228ecfSBjorn Andersson static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
6678a228ecfSBjorn Andersson 			       u32 dst)
6688a228ecfSBjorn Andersson {
6698a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
6708a228ecfSBjorn Andersson 	u32 src = ept->addr;
6718a228ecfSBjorn Andersson 
6728a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
6738a228ecfSBjorn Andersson }
6748a228ecfSBjorn Andersson 
6758a228ecfSBjorn Andersson static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
6768a228ecfSBjorn Andersson 					u32 dst, void *data, int len)
6778a228ecfSBjorn Andersson {
6788a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
6798a228ecfSBjorn Andersson 
6808a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
6818a228ecfSBjorn Andersson }
6828a228ecfSBjorn Andersson 
6838a228ecfSBjorn Andersson static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
6848a228ecfSBjorn Andersson {
6858a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
6868a228ecfSBjorn Andersson 	u32 src = ept->addr, dst = rpdev->dst;
6878a228ecfSBjorn Andersson 
6888a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
6898a228ecfSBjorn Andersson }
6908a228ecfSBjorn Andersson 
6918a228ecfSBjorn Andersson static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
6928a228ecfSBjorn Andersson 				  int len, u32 dst)
6938a228ecfSBjorn Andersson {
6948a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
6958a228ecfSBjorn Andersson 	u32 src = ept->addr;
6968a228ecfSBjorn Andersson 
6978a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
6988a228ecfSBjorn Andersson }
6998a228ecfSBjorn Andersson 
7008a228ecfSBjorn Andersson static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
7018a228ecfSBjorn Andersson 					   u32 dst, void *data, int len)
7028a228ecfSBjorn Andersson {
7038a228ecfSBjorn Andersson 	struct rpmsg_device *rpdev = ept->rpdev;
7048a228ecfSBjorn Andersson 
7058a228ecfSBjorn Andersson 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
7068a228ecfSBjorn Andersson }
7078a228ecfSBjorn Andersson 
7081aa7d6a5SRobert Tivy static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
7091aa7d6a5SRobert Tivy 			     struct rpmsg_hdr *msg, unsigned int len)
710bcabbccaSOhad Ben-Cohen {
711bcabbccaSOhad Ben-Cohen 	struct rpmsg_endpoint *ept;
712bcabbccaSOhad Ben-Cohen 	struct scatterlist sg;
713111d1089SGuennadi Liakhovetski 	unsigned int msg_len = virtio16_to_cpu(vrp->vdev, msg->len);
714bcabbccaSOhad Ben-Cohen 	int err;
715bcabbccaSOhad Ben-Cohen 
716bcabbccaSOhad Ben-Cohen 	dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n",
717111d1089SGuennadi Liakhovetski 		virtio32_to_cpu(vrp->vdev, msg->src),
718111d1089SGuennadi Liakhovetski 		virtio32_to_cpu(vrp->vdev, msg->dst), msg_len,
719111d1089SGuennadi Liakhovetski 		virtio16_to_cpu(vrp->vdev, msg->flags),
720111d1089SGuennadi Liakhovetski 		virtio32_to_cpu(vrp->vdev, msg->reserved));
721211e3a93SAnna, Suman #if defined(CONFIG_DYNAMIC_DEBUG)
722211e3a93SAnna, Suman 	dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1,
723111d1089SGuennadi Liakhovetski 			 msg, sizeof(*msg) + msg_len, true);
724211e3a93SAnna, Suman #endif
725bcabbccaSOhad Ben-Cohen 
7269648224eSOhad Ben-Cohen 	/*
7279648224eSOhad Ben-Cohen 	 * We currently use fixed-sized buffers, so trivially sanitize
7289648224eSOhad Ben-Cohen 	 * the reported payload length.
7299648224eSOhad Ben-Cohen 	 */
730f93848f9SLoic Pallardy 	if (len > vrp->buf_size ||
731111d1089SGuennadi Liakhovetski 	    msg_len > (len - sizeof(struct rpmsg_hdr))) {
732111d1089SGuennadi Liakhovetski 		dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len);
7331aa7d6a5SRobert Tivy 		return -EINVAL;
7349648224eSOhad Ben-Cohen 	}
7359648224eSOhad Ben-Cohen 
736bcabbccaSOhad Ben-Cohen 	/* use the dst addr to fetch the callback of the appropriate user */
737bcabbccaSOhad Ben-Cohen 	mutex_lock(&vrp->endpoints_lock);
7385a081caaSOhad Ben-Cohen 
739111d1089SGuennadi Liakhovetski 	ept = idr_find(&vrp->endpoints, virtio32_to_cpu(vrp->vdev, msg->dst));
7405a081caaSOhad Ben-Cohen 
7415a081caaSOhad Ben-Cohen 	/* let's make sure no one deallocates ept while we use it */
7425a081caaSOhad Ben-Cohen 	if (ept)
7435a081caaSOhad Ben-Cohen 		kref_get(&ept->refcount);
7445a081caaSOhad Ben-Cohen 
745bcabbccaSOhad Ben-Cohen 	mutex_unlock(&vrp->endpoints_lock);
746bcabbccaSOhad Ben-Cohen 
74715fd943aSOhad Ben-Cohen 	if (ept) {
74815fd943aSOhad Ben-Cohen 		/* make sure ept->cb doesn't go away while we use it */
74915fd943aSOhad Ben-Cohen 		mutex_lock(&ept->cb_lock);
75015fd943aSOhad Ben-Cohen 
75115fd943aSOhad Ben-Cohen 		if (ept->cb)
752111d1089SGuennadi Liakhovetski 			ept->cb(ept->rpdev, msg->data, msg_len, ept->priv,
753111d1089SGuennadi Liakhovetski 				virtio32_to_cpu(vrp->vdev, msg->src));
75415fd943aSOhad Ben-Cohen 
75515fd943aSOhad Ben-Cohen 		mutex_unlock(&ept->cb_lock);
756bcabbccaSOhad Ben-Cohen 
7575a081caaSOhad Ben-Cohen 		/* farewell, ept, we don't need you anymore */
7585a081caaSOhad Ben-Cohen 		kref_put(&ept->refcount, __ept_release);
75915fd943aSOhad Ben-Cohen 	} else
7608a168ca7SMasanari Iida 		dev_warn(dev, "msg received with no recipient\n");
7615a081caaSOhad Ben-Cohen 
762f1d9e9c7SOhad Ben-Cohen 	/* publish the real size of the buffer */
7639dd87c2aSLoic Pallardy 	rpmsg_sg_init(&sg, msg, vrp->buf_size);
764bcabbccaSOhad Ben-Cohen 
765bcabbccaSOhad Ben-Cohen 	/* add the buffer back to the remote processor's virtqueue */
766cee51d69SRusty Russell 	err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
767bcabbccaSOhad Ben-Cohen 	if (err < 0) {
768bcabbccaSOhad Ben-Cohen 		dev_err(dev, "failed to add a virtqueue buffer: %d\n", err);
7691aa7d6a5SRobert Tivy 		return err;
7701aa7d6a5SRobert Tivy 	}
7711aa7d6a5SRobert Tivy 
7721aa7d6a5SRobert Tivy 	return 0;
7731aa7d6a5SRobert Tivy }
7741aa7d6a5SRobert Tivy 
7751aa7d6a5SRobert Tivy /* called when an rx buffer is used, and it's time to digest a message */
7761aa7d6a5SRobert Tivy static void rpmsg_recv_done(struct virtqueue *rvq)
7771aa7d6a5SRobert Tivy {
7781aa7d6a5SRobert Tivy 	struct virtproc_info *vrp = rvq->vdev->priv;
7791aa7d6a5SRobert Tivy 	struct device *dev = &rvq->vdev->dev;
7801aa7d6a5SRobert Tivy 	struct rpmsg_hdr *msg;
7811aa7d6a5SRobert Tivy 	unsigned int len, msgs_received = 0;
7821aa7d6a5SRobert Tivy 	int err;
7831aa7d6a5SRobert Tivy 
7841aa7d6a5SRobert Tivy 	msg = virtqueue_get_buf(rvq, &len);
7851aa7d6a5SRobert Tivy 	if (!msg) {
7861aa7d6a5SRobert Tivy 		dev_err(dev, "uhm, incoming signal, but no used buffer ?\n");
787bcabbccaSOhad Ben-Cohen 		return;
788bcabbccaSOhad Ben-Cohen 	}
789bcabbccaSOhad Ben-Cohen 
7901aa7d6a5SRobert Tivy 	while (msg) {
7911aa7d6a5SRobert Tivy 		err = rpmsg_recv_single(vrp, dev, msg, len);
7921aa7d6a5SRobert Tivy 		if (err)
7931aa7d6a5SRobert Tivy 			break;
7941aa7d6a5SRobert Tivy 
7951aa7d6a5SRobert Tivy 		msgs_received++;
7961aa7d6a5SRobert Tivy 
7971aa7d6a5SRobert Tivy 		msg = virtqueue_get_buf(rvq, &len);
7986c49fbe3SLee Jones 	}
7991aa7d6a5SRobert Tivy 
8001aa7d6a5SRobert Tivy 	dev_dbg(dev, "Received %u messages\n", msgs_received);
8011aa7d6a5SRobert Tivy 
802bcabbccaSOhad Ben-Cohen 	/* tell the remote processor we added another available rx buffer */
8031aa7d6a5SRobert Tivy 	if (msgs_received)
804bcabbccaSOhad Ben-Cohen 		virtqueue_kick(vrp->rvq);
805bcabbccaSOhad Ben-Cohen }
806bcabbccaSOhad Ben-Cohen 
807bcabbccaSOhad Ben-Cohen /*
808bcabbccaSOhad Ben-Cohen  * This is invoked whenever the remote processor completed processing
809bcabbccaSOhad Ben-Cohen  * a TX msg we just sent it, and the buffer is put back to the used ring.
810bcabbccaSOhad Ben-Cohen  *
811bcabbccaSOhad Ben-Cohen  * Normally, though, we suppress this "tx complete" interrupt in order to
812bcabbccaSOhad Ben-Cohen  * avoid the incurred overhead.
813bcabbccaSOhad Ben-Cohen  */
814bcabbccaSOhad Ben-Cohen static void rpmsg_xmit_done(struct virtqueue *svq)
815bcabbccaSOhad Ben-Cohen {
816bcabbccaSOhad Ben-Cohen 	struct virtproc_info *vrp = svq->vdev->priv;
817bcabbccaSOhad Ben-Cohen 
818bcabbccaSOhad Ben-Cohen 	dev_dbg(&svq->vdev->dev, "%s\n", __func__);
819bcabbccaSOhad Ben-Cohen 
820bcabbccaSOhad Ben-Cohen 	/* wake up potential senders that are waiting for a tx buffer */
821bcabbccaSOhad Ben-Cohen 	wake_up_interruptible(&vrp->sendq);
822bcabbccaSOhad Ben-Cohen }
823bcabbccaSOhad Ben-Cohen 
824bcabbccaSOhad Ben-Cohen /* invoked when a name service announcement arrives */
8254b83c52aSBjorn Andersson static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
826bcabbccaSOhad Ben-Cohen 		       void *priv, u32 src)
827bcabbccaSOhad Ben-Cohen {
828bcabbccaSOhad Ben-Cohen 	struct rpmsg_ns_msg *msg = data;
82992e1de51SBjorn Andersson 	struct rpmsg_device *newch;
830bcabbccaSOhad Ben-Cohen 	struct rpmsg_channel_info chinfo;
831bcabbccaSOhad Ben-Cohen 	struct virtproc_info *vrp = priv;
832bcabbccaSOhad Ben-Cohen 	struct device *dev = &vrp->vdev->dev;
833bcabbccaSOhad Ben-Cohen 	int ret;
834bcabbccaSOhad Ben-Cohen 
835211e3a93SAnna, Suman #if defined(CONFIG_DYNAMIC_DEBUG)
836211e3a93SAnna, Suman 	dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
837211e3a93SAnna, Suman 			 data, len, true);
838211e3a93SAnna, Suman #endif
839bcabbccaSOhad Ben-Cohen 
840bcabbccaSOhad Ben-Cohen 	if (len != sizeof(*msg)) {
841bcabbccaSOhad Ben-Cohen 		dev_err(dev, "malformed ns msg (%d)\n", len);
8424b83c52aSBjorn Andersson 		return -EINVAL;
843bcabbccaSOhad Ben-Cohen 	}
844bcabbccaSOhad Ben-Cohen 
845bcabbccaSOhad Ben-Cohen 	/*
846bcabbccaSOhad Ben-Cohen 	 * the name service ept does _not_ belong to a real rpmsg channel,
847bcabbccaSOhad Ben-Cohen 	 * and is handled by the rpmsg bus itself.
848bcabbccaSOhad Ben-Cohen 	 * for sanity reasons, make sure a valid rpdev has _not_ sneaked
849bcabbccaSOhad Ben-Cohen 	 * in somehow.
850bcabbccaSOhad Ben-Cohen 	 */
851bcabbccaSOhad Ben-Cohen 	if (rpdev) {
852bcabbccaSOhad Ben-Cohen 		dev_err(dev, "anomaly: ns ept has an rpdev handle\n");
8534b83c52aSBjorn Andersson 		return -EINVAL;
854bcabbccaSOhad Ben-Cohen 	}
855bcabbccaSOhad Ben-Cohen 
856bcabbccaSOhad Ben-Cohen 	/* don't trust the remote processor for null terminating the name */
857bcabbccaSOhad Ben-Cohen 	msg->name[RPMSG_NAME_SIZE - 1] = '\0';
858bcabbccaSOhad Ben-Cohen 
859bcabbccaSOhad Ben-Cohen 	strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
860bcabbccaSOhad Ben-Cohen 	chinfo.src = RPMSG_ADDR_ANY;
861111d1089SGuennadi Liakhovetski 	chinfo.dst = virtio32_to_cpu(vrp->vdev, msg->addr);
862bcabbccaSOhad Ben-Cohen 
863111d1089SGuennadi Liakhovetski 	dev_info(dev, "%sing channel %s addr 0x%x\n",
864111d1089SGuennadi Liakhovetski 		 virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY ?
865111d1089SGuennadi Liakhovetski 		 "destroy" : "creat", msg->name, chinfo.dst);
866111d1089SGuennadi Liakhovetski 
867111d1089SGuennadi Liakhovetski 	if (virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY) {
8685e619b48SBjorn Andersson 		ret = rpmsg_unregister_device(&vrp->vdev->dev, &chinfo);
869bcabbccaSOhad Ben-Cohen 		if (ret)
870bcabbccaSOhad Ben-Cohen 			dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
871bcabbccaSOhad Ben-Cohen 	} else {
872bcabbccaSOhad Ben-Cohen 		newch = rpmsg_create_channel(vrp, &chinfo);
873bcabbccaSOhad Ben-Cohen 		if (!newch)
874bcabbccaSOhad Ben-Cohen 			dev_err(dev, "rpmsg_create_channel failed\n");
875bcabbccaSOhad Ben-Cohen 	}
8764b83c52aSBjorn Andersson 
8774b83c52aSBjorn Andersson 	return 0;
878bcabbccaSOhad Ben-Cohen }
879bcabbccaSOhad Ben-Cohen 
880bcabbccaSOhad Ben-Cohen static int rpmsg_probe(struct virtio_device *vdev)
881bcabbccaSOhad Ben-Cohen {
882bcabbccaSOhad Ben-Cohen 	vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done };
883f7ad26ffSStefan Hajnoczi 	static const char * const names[] = { "input", "output" };
884bcabbccaSOhad Ben-Cohen 	struct virtqueue *vqs[2];
885bcabbccaSOhad Ben-Cohen 	struct virtproc_info *vrp;
886bcabbccaSOhad Ben-Cohen 	void *bufs_va;
887bcabbccaSOhad Ben-Cohen 	int err = 0, i;
888b1b98914SSuman Anna 	size_t total_buf_space;
88971e4b8bfSMichael S. Tsirkin 	bool notify;
890bcabbccaSOhad Ben-Cohen 
891bcabbccaSOhad Ben-Cohen 	vrp = kzalloc(sizeof(*vrp), GFP_KERNEL);
892bcabbccaSOhad Ben-Cohen 	if (!vrp)
893bcabbccaSOhad Ben-Cohen 		return -ENOMEM;
894bcabbccaSOhad Ben-Cohen 
895bcabbccaSOhad Ben-Cohen 	vrp->vdev = vdev;
896bcabbccaSOhad Ben-Cohen 
897bcabbccaSOhad Ben-Cohen 	idr_init(&vrp->endpoints);
898bcabbccaSOhad Ben-Cohen 	mutex_init(&vrp->endpoints_lock);
899bcabbccaSOhad Ben-Cohen 	mutex_init(&vrp->tx_lock);
900bcabbccaSOhad Ben-Cohen 	init_waitqueue_head(&vrp->sendq);
901bcabbccaSOhad Ben-Cohen 
902bcabbccaSOhad Ben-Cohen 	/* We expect two virtqueues, rx and tx (and in this order) */
9039b2bbdb2SMichael S. Tsirkin 	err = virtio_find_vqs(vdev, 2, vqs, vq_cbs, names, NULL);
904bcabbccaSOhad Ben-Cohen 	if (err)
905bcabbccaSOhad Ben-Cohen 		goto free_vrp;
906bcabbccaSOhad Ben-Cohen 
907bcabbccaSOhad Ben-Cohen 	vrp->rvq = vqs[0];
908bcabbccaSOhad Ben-Cohen 	vrp->svq = vqs[1];
909bcabbccaSOhad Ben-Cohen 
910b1b98914SSuman Anna 	/* we expect symmetric tx/rx vrings */
911b1b98914SSuman Anna 	WARN_ON(virtqueue_get_vring_size(vrp->rvq) !=
912b1b98914SSuman Anna 		virtqueue_get_vring_size(vrp->svq));
913b1b98914SSuman Anna 
914b1b98914SSuman Anna 	/* we need less buffers if vrings are small */
915b1b98914SSuman Anna 	if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2)
916b1b98914SSuman Anna 		vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2;
917b1b98914SSuman Anna 	else
918b1b98914SSuman Anna 		vrp->num_bufs = MAX_RPMSG_NUM_BUFS;
919b1b98914SSuman Anna 
920f93848f9SLoic Pallardy 	vrp->buf_size = MAX_RPMSG_BUF_SIZE;
921f93848f9SLoic Pallardy 
922f93848f9SLoic Pallardy 	total_buf_space = vrp->num_bufs * vrp->buf_size;
923b1b98914SSuman Anna 
924bcabbccaSOhad Ben-Cohen 	/* allocate coherent memory for the buffers */
925d999b622SLoic Pallardy 	bufs_va = dma_alloc_coherent(vdev->dev.parent,
926b1b98914SSuman Anna 				     total_buf_space, &vrp->bufs_dma,
927b1b98914SSuman Anna 				     GFP_KERNEL);
9283119b487SWei Yongjun 	if (!bufs_va) {
9293119b487SWei Yongjun 		err = -ENOMEM;
930bcabbccaSOhad Ben-Cohen 		goto vqs_del;
9313119b487SWei Yongjun 	}
932bcabbccaSOhad Ben-Cohen 
933de4064afSSuman Anna 	dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n",
9348d95b322SAnna, Suman 		bufs_va, &vrp->bufs_dma);
935bcabbccaSOhad Ben-Cohen 
936bcabbccaSOhad Ben-Cohen 	/* half of the buffers is dedicated for RX */
937bcabbccaSOhad Ben-Cohen 	vrp->rbufs = bufs_va;
938bcabbccaSOhad Ben-Cohen 
939bcabbccaSOhad Ben-Cohen 	/* and half is dedicated for TX */
940b1b98914SSuman Anna 	vrp->sbufs = bufs_va + total_buf_space / 2;
941bcabbccaSOhad Ben-Cohen 
942bcabbccaSOhad Ben-Cohen 	/* set up the receive buffers */
943b1b98914SSuman Anna 	for (i = 0; i < vrp->num_bufs / 2; i++) {
944bcabbccaSOhad Ben-Cohen 		struct scatterlist sg;
945f93848f9SLoic Pallardy 		void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
946bcabbccaSOhad Ben-Cohen 
9479dd87c2aSLoic Pallardy 		rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
948bcabbccaSOhad Ben-Cohen 
949cee51d69SRusty Russell 		err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
950bcabbccaSOhad Ben-Cohen 					  GFP_KERNEL);
95157e1a373SRusty Russell 		WARN_ON(err); /* sanity check; this can't really happen */
952bcabbccaSOhad Ben-Cohen 	}
953bcabbccaSOhad Ben-Cohen 
954bcabbccaSOhad Ben-Cohen 	/* suppress "tx-complete" interrupts */
955bcabbccaSOhad Ben-Cohen 	virtqueue_disable_cb(vrp->svq);
956bcabbccaSOhad Ben-Cohen 
957bcabbccaSOhad Ben-Cohen 	vdev->priv = vrp;
958bcabbccaSOhad Ben-Cohen 
959bcabbccaSOhad Ben-Cohen 	/* if supported by the remote processor, enable the name service */
960bcabbccaSOhad Ben-Cohen 	if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) {
961bcabbccaSOhad Ben-Cohen 		/* a dedicated endpoint handles the name service msgs */
962bcabbccaSOhad Ben-Cohen 		vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb,
963bcabbccaSOhad Ben-Cohen 						vrp, RPMSG_NS_ADDR);
964bcabbccaSOhad Ben-Cohen 		if (!vrp->ns_ept) {
965bcabbccaSOhad Ben-Cohen 			dev_err(&vdev->dev, "failed to create the ns ept\n");
966bcabbccaSOhad Ben-Cohen 			err = -ENOMEM;
967bcabbccaSOhad Ben-Cohen 			goto free_coherent;
968bcabbccaSOhad Ben-Cohen 		}
969bcabbccaSOhad Ben-Cohen 	}
970bcabbccaSOhad Ben-Cohen 
97171e4b8bfSMichael S. Tsirkin 	/*
97271e4b8bfSMichael S. Tsirkin 	 * Prepare to kick but don't notify yet - we can't do this before
97371e4b8bfSMichael S. Tsirkin 	 * device is ready.
97471e4b8bfSMichael S. Tsirkin 	 */
97571e4b8bfSMichael S. Tsirkin 	notify = virtqueue_kick_prepare(vrp->rvq);
97671e4b8bfSMichael S. Tsirkin 
97771e4b8bfSMichael S. Tsirkin 	/* From this point on, we can notify and get callbacks. */
97871e4b8bfSMichael S. Tsirkin 	virtio_device_ready(vdev);
97971e4b8bfSMichael S. Tsirkin 
980bcabbccaSOhad Ben-Cohen 	/* tell the remote processor it can start sending messages */
98171e4b8bfSMichael S. Tsirkin 	/*
98271e4b8bfSMichael S. Tsirkin 	 * this might be concurrent with callbacks, but we are only
98371e4b8bfSMichael S. Tsirkin 	 * doing notify, not a full kick here, so that's ok.
98471e4b8bfSMichael S. Tsirkin 	 */
98571e4b8bfSMichael S. Tsirkin 	if (notify)
98671e4b8bfSMichael S. Tsirkin 		virtqueue_notify(vrp->rvq);
987bcabbccaSOhad Ben-Cohen 
988bcabbccaSOhad Ben-Cohen 	dev_info(&vdev->dev, "rpmsg host is online\n");
989bcabbccaSOhad Ben-Cohen 
990bcabbccaSOhad Ben-Cohen 	return 0;
991bcabbccaSOhad Ben-Cohen 
992bcabbccaSOhad Ben-Cohen free_coherent:
993d999b622SLoic Pallardy 	dma_free_coherent(vdev->dev.parent, total_buf_space,
994eeb0074fSFernando Guzman Lugo 			  bufs_va, vrp->bufs_dma);
995bcabbccaSOhad Ben-Cohen vqs_del:
996bcabbccaSOhad Ben-Cohen 	vdev->config->del_vqs(vrp->vdev);
997bcabbccaSOhad Ben-Cohen free_vrp:
998bcabbccaSOhad Ben-Cohen 	kfree(vrp);
999bcabbccaSOhad Ben-Cohen 	return err;
1000bcabbccaSOhad Ben-Cohen }
1001bcabbccaSOhad Ben-Cohen 
1002bcabbccaSOhad Ben-Cohen static int rpmsg_remove_device(struct device *dev, void *data)
1003bcabbccaSOhad Ben-Cohen {
1004bcabbccaSOhad Ben-Cohen 	device_unregister(dev);
1005bcabbccaSOhad Ben-Cohen 
1006bcabbccaSOhad Ben-Cohen 	return 0;
1007bcabbccaSOhad Ben-Cohen }
1008bcabbccaSOhad Ben-Cohen 
10090fe763c5SGreg Kroah-Hartman static void rpmsg_remove(struct virtio_device *vdev)
1010bcabbccaSOhad Ben-Cohen {
1011bcabbccaSOhad Ben-Cohen 	struct virtproc_info *vrp = vdev->priv;
1012f93848f9SLoic Pallardy 	size_t total_buf_space = vrp->num_bufs * vrp->buf_size;
1013bcabbccaSOhad Ben-Cohen 	int ret;
1014bcabbccaSOhad Ben-Cohen 
1015bcabbccaSOhad Ben-Cohen 	vdev->config->reset(vdev);
1016bcabbccaSOhad Ben-Cohen 
1017bcabbccaSOhad Ben-Cohen 	ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device);
1018bcabbccaSOhad Ben-Cohen 	if (ret)
1019bcabbccaSOhad Ben-Cohen 		dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret);
1020bcabbccaSOhad Ben-Cohen 
1021fa2d7795SOhad Ben-Cohen 	if (vrp->ns_ept)
1022fa2d7795SOhad Ben-Cohen 		__rpmsg_destroy_ept(vrp, vrp->ns_ept);
1023fa2d7795SOhad Ben-Cohen 
1024bcabbccaSOhad Ben-Cohen 	idr_destroy(&vrp->endpoints);
1025bcabbccaSOhad Ben-Cohen 
1026bcabbccaSOhad Ben-Cohen 	vdev->config->del_vqs(vrp->vdev);
1027bcabbccaSOhad Ben-Cohen 
1028d999b622SLoic Pallardy 	dma_free_coherent(vdev->dev.parent, total_buf_space,
1029bcabbccaSOhad Ben-Cohen 			  vrp->rbufs, vrp->bufs_dma);
1030bcabbccaSOhad Ben-Cohen 
1031bcabbccaSOhad Ben-Cohen 	kfree(vrp);
1032bcabbccaSOhad Ben-Cohen }
1033bcabbccaSOhad Ben-Cohen 
1034bcabbccaSOhad Ben-Cohen static struct virtio_device_id id_table[] = {
1035bcabbccaSOhad Ben-Cohen 	{ VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID },
1036bcabbccaSOhad Ben-Cohen 	{ 0 },
1037bcabbccaSOhad Ben-Cohen };
1038bcabbccaSOhad Ben-Cohen 
1039bcabbccaSOhad Ben-Cohen static unsigned int features[] = {
1040bcabbccaSOhad Ben-Cohen 	VIRTIO_RPMSG_F_NS,
1041bcabbccaSOhad Ben-Cohen };
1042bcabbccaSOhad Ben-Cohen 
1043bcabbccaSOhad Ben-Cohen static struct virtio_driver virtio_ipc_driver = {
1044bcabbccaSOhad Ben-Cohen 	.feature_table	= features,
1045bcabbccaSOhad Ben-Cohen 	.feature_table_size = ARRAY_SIZE(features),
1046bcabbccaSOhad Ben-Cohen 	.driver.name	= KBUILD_MODNAME,
1047bcabbccaSOhad Ben-Cohen 	.driver.owner	= THIS_MODULE,
1048bcabbccaSOhad Ben-Cohen 	.id_table	= id_table,
1049bcabbccaSOhad Ben-Cohen 	.probe		= rpmsg_probe,
10500fe763c5SGreg Kroah-Hartman 	.remove		= rpmsg_remove,
1051bcabbccaSOhad Ben-Cohen };
1052bcabbccaSOhad Ben-Cohen 
1053bcabbccaSOhad Ben-Cohen static int __init rpmsg_init(void)
1054bcabbccaSOhad Ben-Cohen {
1055bcabbccaSOhad Ben-Cohen 	int ret;
1056bcabbccaSOhad Ben-Cohen 
1057bcabbccaSOhad Ben-Cohen 	ret = register_virtio_driver(&virtio_ipc_driver);
10585e619b48SBjorn Andersson 	if (ret)
1059bcabbccaSOhad Ben-Cohen 		pr_err("failed to register virtio driver: %d\n", ret);
1060bcabbccaSOhad Ben-Cohen 
1061bcabbccaSOhad Ben-Cohen 	return ret;
1062bcabbccaSOhad Ben-Cohen }
106396342526SFederico Fuga subsys_initcall(rpmsg_init);
1064bcabbccaSOhad Ben-Cohen 
1065bcabbccaSOhad Ben-Cohen static void __exit rpmsg_fini(void)
1066bcabbccaSOhad Ben-Cohen {
1067bcabbccaSOhad Ben-Cohen 	unregister_virtio_driver(&virtio_ipc_driver);
1068bcabbccaSOhad Ben-Cohen }
1069bcabbccaSOhad Ben-Cohen module_exit(rpmsg_fini);
1070bcabbccaSOhad Ben-Cohen 
1071bcabbccaSOhad Ben-Cohen MODULE_DEVICE_TABLE(virtio, id_table);
1072bcabbccaSOhad Ben-Cohen MODULE_DESCRIPTION("Virtio-based remote processor messaging bus");
1073bcabbccaSOhad Ben-Cohen MODULE_LICENSE("GPL v2");
1074