mirror of https://gitee.com/openkylin/linux.git
1069 lines
30 KiB
C
1069 lines
30 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Virtio-based remote processor messaging bus
|
|
*
|
|
* Copyright (C) 2011 Texas Instruments, Inc.
|
|
* Copyright (C) 2011 Google, Inc.
|
|
*
|
|
* Ohad Ben-Cohen <ohad@wizery.com>
|
|
* Brian Swetland <swetland@google.com>
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "%s: " fmt, __func__
|
|
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/rpmsg.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/virtio.h>
|
|
#include <linux/virtio_byteorder.h>
|
|
#include <linux/virtio_ids.h>
|
|
#include <linux/virtio_config.h>
|
|
#include <linux/wait.h>
|
|
|
|
#include "rpmsg_internal.h"
|
|
|
|
/**
|
|
* struct virtproc_info - virtual remote processor state
|
|
* @vdev: the virtio device
|
|
* @rvq: rx virtqueue
|
|
* @svq: tx virtqueue
|
|
* @rbufs: kernel address of rx buffers
|
|
* @sbufs: kernel address of tx buffers
|
|
* @num_bufs: total number of buffers for rx and tx
|
|
* @buf_size: size of one rx or tx buffer
|
|
* @last_sbuf: index of last tx buffer used
|
|
* @bufs_dma: dma base addr of the buffers
|
|
* @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders.
|
|
* sending a message might require waking up a dozing remote
|
|
* processor, which involves sleeping, hence the mutex.
|
|
* @endpoints: idr of local endpoints, allows fast retrieval
|
|
* @endpoints_lock: lock of the endpoints set
|
|
* @sendq: wait queue of sending contexts waiting for a tx buffers
|
|
* @sleepers: number of senders that are waiting for a tx buffer
|
|
* @ns_ept: the bus's name service endpoint
|
|
*
|
|
* This structure stores the rpmsg state of a given virtio remote processor
|
|
* device (there might be several virtio proc devices for each physical
|
|
* remote processor).
|
|
*/
|
|
struct virtproc_info {
|
|
struct virtio_device *vdev;
|
|
struct virtqueue *rvq, *svq;
|
|
void *rbufs, *sbufs;
|
|
unsigned int num_bufs;
|
|
unsigned int buf_size;
|
|
int last_sbuf;
|
|
dma_addr_t bufs_dma;
|
|
struct mutex tx_lock;
|
|
struct idr endpoints;
|
|
struct mutex endpoints_lock;
|
|
wait_queue_head_t sendq;
|
|
atomic_t sleepers;
|
|
struct rpmsg_endpoint *ns_ept;
|
|
};
|
|
|
|
/* The feature bitmap for virtio rpmsg */
|
|
#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
|
|
|
|
/**
|
|
* struct rpmsg_hdr - common header for all rpmsg messages
|
|
* @src: source address
|
|
* @dst: destination address
|
|
* @reserved: reserved for future use
|
|
* @len: length of payload (in bytes)
|
|
* @flags: message flags
|
|
* @data: @len bytes of message payload data
|
|
*
|
|
* Every message sent(/received) on the rpmsg bus begins with this header.
|
|
*/
|
|
struct rpmsg_hdr {
|
|
__virtio32 src;
|
|
__virtio32 dst;
|
|
__virtio32 reserved;
|
|
__virtio16 len;
|
|
__virtio16 flags;
|
|
u8 data[];
|
|
} __packed;
|
|
|
|
/**
|
|
* struct rpmsg_ns_msg - dynamic name service announcement message
|
|
* @name: name of remote service that is published
|
|
* @addr: address of remote service that is published
|
|
* @flags: indicates whether service is created or destroyed
|
|
*
|
|
* This message is sent across to publish a new service, or announce
|
|
* about its removal. When we receive these messages, an appropriate
|
|
* rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
|
|
* or ->remove() handler of the appropriate rpmsg driver will be invoked
|
|
* (if/as-soon-as one is registered).
|
|
*/
|
|
struct rpmsg_ns_msg {
|
|
char name[RPMSG_NAME_SIZE];
|
|
__virtio32 addr;
|
|
__virtio32 flags;
|
|
} __packed;
|
|
|
|
/**
|
|
* enum rpmsg_ns_flags - dynamic name service announcement flags
|
|
*
|
|
* @RPMSG_NS_CREATE: a new remote service was just created
|
|
* @RPMSG_NS_DESTROY: a known remote service was just destroyed
|
|
*/
|
|
enum rpmsg_ns_flags {
|
|
RPMSG_NS_CREATE = 0,
|
|
RPMSG_NS_DESTROY = 1,
|
|
};
|
|
|
|
/**
|
|
* @vrp: the remote processor this channel belongs to
|
|
*/
|
|
struct virtio_rpmsg_channel {
|
|
struct rpmsg_device rpdev;
|
|
|
|
struct virtproc_info *vrp;
|
|
};
|
|
|
|
#define to_virtio_rpmsg_channel(_rpdev) \
|
|
container_of(_rpdev, struct virtio_rpmsg_channel, rpdev)
|
|
|
|
/*
|
|
* We're allocating buffers of 512 bytes each for communications. The
|
|
* number of buffers will be computed from the number of buffers supported
|
|
* by the vring, upto a maximum of 512 buffers (256 in each direction).
|
|
*
|
|
* Each buffer will have 16 bytes for the msg header and 496 bytes for
|
|
* the payload.
|
|
*
|
|
* This will utilize a maximum total space of 256KB for the buffers.
|
|
*
|
|
* We might also want to add support for user-provided buffers in time.
|
|
* This will allow bigger buffer size flexibility, and can also be used
|
|
* to achieve zero-copy messaging.
|
|
*
|
|
* Note that these numbers are purely a decision of this driver - we
|
|
* can change this without changing anything in the firmware of the remote
|
|
* processor.
|
|
*/
|
|
#define MAX_RPMSG_NUM_BUFS (512)
|
|
#define MAX_RPMSG_BUF_SIZE (512)
|
|
|
|
/*
|
|
* Local addresses are dynamically allocated on-demand.
|
|
* We do not dynamically assign addresses from the low 1024 range,
|
|
* in order to reserve that address range for predefined services.
|
|
*/
|
|
#define RPMSG_RESERVED_ADDRESSES (1024)
|
|
|
|
/* Address 53 is reserved for advertising remote services */
|
|
#define RPMSG_NS_ADDR (53)
|
|
|
|
static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept);
|
|
static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
|
|
static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
|
|
u32 dst);
|
|
static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
|
|
u32 dst, void *data, int len);
|
|
static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
|
|
static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
|
|
int len, u32 dst);
|
|
static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
|
|
u32 dst, void *data, int len);
|
|
|
|
static const struct rpmsg_endpoint_ops virtio_endpoint_ops = {
|
|
.destroy_ept = virtio_rpmsg_destroy_ept,
|
|
.send = virtio_rpmsg_send,
|
|
.sendto = virtio_rpmsg_sendto,
|
|
.send_offchannel = virtio_rpmsg_send_offchannel,
|
|
.trysend = virtio_rpmsg_trysend,
|
|
.trysendto = virtio_rpmsg_trysendto,
|
|
.trysend_offchannel = virtio_rpmsg_trysend_offchannel,
|
|
};
|
|
|
|
/**
|
|
* rpmsg_sg_init - initialize scatterlist according to cpu address location
|
|
* @sg: scatterlist to fill
|
|
* @cpu_addr: virtual address of the buffer
|
|
* @len: buffer length
|
|
*
|
|
* An internal function filling scatterlist according to virtual address
|
|
* location (in vmalloc or in kernel).
|
|
*/
|
|
static void
|
|
rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
|
|
{
|
|
if (is_vmalloc_addr(cpu_addr)) {
|
|
sg_init_table(sg, 1);
|
|
sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
|
|
offset_in_page(cpu_addr));
|
|
} else {
|
|
WARN_ON(!virt_addr_valid(cpu_addr));
|
|
sg_init_one(sg, cpu_addr, len);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* __ept_release() - deallocate an rpmsg endpoint
|
|
* @kref: the ept's reference count
|
|
*
|
|
* This function deallocates an ept, and is invoked when its @kref refcount
|
|
* drops to zero.
|
|
*
|
|
* Never invoke this function directly!
|
|
*/
|
|
static void __ept_release(struct kref *kref)
|
|
{
|
|
struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
|
|
refcount);
|
|
/*
|
|
* At this point no one holds a reference to ept anymore,
|
|
* so we can directly free it
|
|
*/
|
|
kfree(ept);
|
|
}
|
|
|
|
/* for more info, see below documentation of rpmsg_create_ept() */
|
|
static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
|
|
struct rpmsg_device *rpdev,
|
|
rpmsg_rx_cb_t cb,
|
|
void *priv, u32 addr)
|
|
{
|
|
int id_min, id_max, id;
|
|
struct rpmsg_endpoint *ept;
|
|
struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev;
|
|
|
|
ept = kzalloc(sizeof(*ept), GFP_KERNEL);
|
|
if (!ept)
|
|
return NULL;
|
|
|
|
kref_init(&ept->refcount);
|
|
mutex_init(&ept->cb_lock);
|
|
|
|
ept->rpdev = rpdev;
|
|
ept->cb = cb;
|
|
ept->priv = priv;
|
|
ept->ops = &virtio_endpoint_ops;
|
|
|
|
/* do we need to allocate a local address ? */
|
|
if (addr == RPMSG_ADDR_ANY) {
|
|
id_min = RPMSG_RESERVED_ADDRESSES;
|
|
id_max = 0;
|
|
} else {
|
|
id_min = addr;
|
|
id_max = addr + 1;
|
|
}
|
|
|
|
mutex_lock(&vrp->endpoints_lock);
|
|
|
|
/* bind the endpoint to an rpmsg address (and allocate one if needed) */
|
|
id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL);
|
|
if (id < 0) {
|
|
dev_err(dev, "idr_alloc failed: %d\n", id);
|
|
goto free_ept;
|
|
}
|
|
ept->addr = id;
|
|
|
|
mutex_unlock(&vrp->endpoints_lock);
|
|
|
|
return ept;
|
|
|
|
free_ept:
|
|
mutex_unlock(&vrp->endpoints_lock);
|
|
kref_put(&ept->refcount, __ept_release);
|
|
return NULL;
|
|
}
|
|
|
|
static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev,
|
|
rpmsg_rx_cb_t cb,
|
|
void *priv,
|
|
struct rpmsg_channel_info chinfo)
|
|
{
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
|
|
|
|
return __rpmsg_create_ept(vch->vrp, rpdev, cb, priv, chinfo.src);
|
|
}
|
|
|
|
/**
|
|
* __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
|
|
* @vrp: virtproc which owns this ept
|
|
* @ept: endpoing to destroy
|
|
*
|
|
* An internal function which destroy an ept without assuming it is
|
|
* bound to an rpmsg channel. This is needed for handling the internal
|
|
* name service endpoint, which isn't bound to an rpmsg channel.
|
|
* See also __rpmsg_create_ept().
|
|
*/
|
|
static void
|
|
__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
|
|
{
|
|
/* make sure new inbound messages can't find this ept anymore */
|
|
mutex_lock(&vrp->endpoints_lock);
|
|
idr_remove(&vrp->endpoints, ept->addr);
|
|
mutex_unlock(&vrp->endpoints_lock);
|
|
|
|
/* make sure in-flight inbound messages won't invoke cb anymore */
|
|
mutex_lock(&ept->cb_lock);
|
|
ept->cb = NULL;
|
|
mutex_unlock(&ept->cb_lock);
|
|
|
|
kref_put(&ept->refcount, __ept_release);
|
|
}
|
|
|
|
static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
|
|
{
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(ept->rpdev);
|
|
|
|
__rpmsg_destroy_ept(vch->vrp, ept);
|
|
}
|
|
|
|
static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev)
|
|
{
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
|
|
struct virtproc_info *vrp = vch->vrp;
|
|
struct device *dev = &rpdev->dev;
|
|
int err = 0;
|
|
|
|
/* need to tell remote processor's name service about this channel ? */
|
|
if (rpdev->announce && rpdev->ept &&
|
|
virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) {
|
|
struct rpmsg_ns_msg nsm;
|
|
|
|
strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
|
|
nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
|
|
nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_CREATE);
|
|
|
|
err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
|
|
if (err)
|
|
dev_err(dev, "failed to announce service %d\n", err);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev)
|
|
{
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
|
|
struct virtproc_info *vrp = vch->vrp;
|
|
struct device *dev = &rpdev->dev;
|
|
int err = 0;
|
|
|
|
/* tell remote processor's name service we're removing this channel */
|
|
if (rpdev->announce && rpdev->ept &&
|
|
virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) {
|
|
struct rpmsg_ns_msg nsm;
|
|
|
|
strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
|
|
nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
|
|
nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_DESTROY);
|
|
|
|
err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
|
|
if (err)
|
|
dev_err(dev, "failed to announce service %d\n", err);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static const struct rpmsg_device_ops virtio_rpmsg_ops = {
|
|
.create_ept = virtio_rpmsg_create_ept,
|
|
.announce_create = virtio_rpmsg_announce_create,
|
|
.announce_destroy = virtio_rpmsg_announce_destroy,
|
|
};
|
|
|
|
static void virtio_rpmsg_release_device(struct device *dev)
|
|
{
|
|
struct rpmsg_device *rpdev = to_rpmsg_device(dev);
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
|
|
|
|
kfree(vch);
|
|
}
|
|
|
|
/*
|
|
* create an rpmsg channel using its name and address info.
|
|
* this function will be used to create both static and dynamic
|
|
* channels.
|
|
*/
|
|
static struct rpmsg_device *rpmsg_create_channel(struct virtproc_info *vrp,
|
|
struct rpmsg_channel_info *chinfo)
|
|
{
|
|
struct virtio_rpmsg_channel *vch;
|
|
struct rpmsg_device *rpdev;
|
|
struct device *tmp, *dev = &vrp->vdev->dev;
|
|
int ret;
|
|
|
|
/* make sure a similar channel doesn't already exist */
|
|
tmp = rpmsg_find_device(dev, chinfo);
|
|
if (tmp) {
|
|
/* decrement the matched device's refcount back */
|
|
put_device(tmp);
|
|
dev_err(dev, "channel %s:%x:%x already exist\n",
|
|
chinfo->name, chinfo->src, chinfo->dst);
|
|
return NULL;
|
|
}
|
|
|
|
vch = kzalloc(sizeof(*vch), GFP_KERNEL);
|
|
if (!vch)
|
|
return NULL;
|
|
|
|
/* Link the channel to our vrp */
|
|
vch->vrp = vrp;
|
|
|
|
/* Assign public information to the rpmsg_device */
|
|
rpdev = &vch->rpdev;
|
|
rpdev->src = chinfo->src;
|
|
rpdev->dst = chinfo->dst;
|
|
rpdev->ops = &virtio_rpmsg_ops;
|
|
|
|
/*
|
|
* rpmsg server channels has predefined local address (for now),
|
|
* and their existence needs to be announced remotely
|
|
*/
|
|
rpdev->announce = rpdev->src != RPMSG_ADDR_ANY;
|
|
|
|
strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE);
|
|
|
|
rpdev->dev.parent = &vrp->vdev->dev;
|
|
rpdev->dev.release = virtio_rpmsg_release_device;
|
|
ret = rpmsg_register_device(rpdev);
|
|
if (ret)
|
|
return NULL;
|
|
|
|
return rpdev;
|
|
}
|
|
|
|
/* super simple buffer "allocator" that is just enough for now */
|
|
static void *get_a_tx_buf(struct virtproc_info *vrp)
|
|
{
|
|
unsigned int len;
|
|
void *ret;
|
|
|
|
/* support multiple concurrent senders */
|
|
mutex_lock(&vrp->tx_lock);
|
|
|
|
/*
|
|
* either pick the next unused tx buffer
|
|
* (half of our buffers are used for sending messages)
|
|
*/
|
|
if (vrp->last_sbuf < vrp->num_bufs / 2)
|
|
ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++;
|
|
/* or recycle a used one */
|
|
else
|
|
ret = virtqueue_get_buf(vrp->svq, &len);
|
|
|
|
mutex_unlock(&vrp->tx_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed
|
|
* @vrp: virtual remote processor state
|
|
*
|
|
* This function is called before a sender is blocked, waiting for
|
|
* a tx buffer to become available.
|
|
*
|
|
* If we already have blocking senders, this function merely increases
|
|
* the "sleepers" reference count, and exits.
|
|
*
|
|
* Otherwise, if this is the first sender to block, we also enable
|
|
* virtio's tx callbacks, so we'd be immediately notified when a tx
|
|
* buffer is consumed (we rely on virtio's tx callback in order
|
|
* to wake up sleeping senders as soon as a tx buffer is used by the
|
|
* remote processor).
|
|
*/
|
|
static void rpmsg_upref_sleepers(struct virtproc_info *vrp)
|
|
{
|
|
/* support multiple concurrent senders */
|
|
mutex_lock(&vrp->tx_lock);
|
|
|
|
/* are we the first sleeping context waiting for tx buffers ? */
|
|
if (atomic_inc_return(&vrp->sleepers) == 1)
|
|
/* enable "tx-complete" interrupts before dozing off */
|
|
virtqueue_enable_cb(vrp->svq);
|
|
|
|
mutex_unlock(&vrp->tx_lock);
|
|
}
|
|
|
|
/**
|
|
* rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed
|
|
* @vrp: virtual remote processor state
|
|
*
|
|
* This function is called after a sender, that waited for a tx buffer
|
|
* to become available, is unblocked.
|
|
*
|
|
* If we still have blocking senders, this function merely decreases
|
|
* the "sleepers" reference count, and exits.
|
|
*
|
|
* Otherwise, if there are no more blocking senders, we also disable
|
|
* virtio's tx callbacks, to avoid the overhead incurred with handling
|
|
* those (now redundant) interrupts.
|
|
*/
|
|
static void rpmsg_downref_sleepers(struct virtproc_info *vrp)
|
|
{
|
|
/* support multiple concurrent senders */
|
|
mutex_lock(&vrp->tx_lock);
|
|
|
|
/* are we the last sleeping context waiting for tx buffers ? */
|
|
if (atomic_dec_and_test(&vrp->sleepers))
|
|
/* disable "tx-complete" interrupts */
|
|
virtqueue_disable_cb(vrp->svq);
|
|
|
|
mutex_unlock(&vrp->tx_lock);
|
|
}
|
|
|
|
/**
|
|
* rpmsg_send_offchannel_raw() - send a message across to the remote processor
|
|
* @rpdev: the rpmsg channel
|
|
* @src: source address
|
|
* @dst: destination address
|
|
* @data: payload of message
|
|
* @len: length of payload
|
|
* @wait: indicates whether caller should block in case no TX buffers available
|
|
*
|
|
* This function is the base implementation for all of the rpmsg sending API.
|
|
*
|
|
* It will send @data of length @len to @dst, and say it's from @src. The
|
|
* message will be sent to the remote processor which the @rpdev channel
|
|
* belongs to.
|
|
*
|
|
* The message is sent using one of the TX buffers that are available for
|
|
* communication with this remote processor.
|
|
*
|
|
* If @wait is true, the caller will be blocked until either a TX buffer is
|
|
* available, or 15 seconds elapses (we don't want callers to
|
|
* sleep indefinitely due to misbehaving remote processors), and in that
|
|
* case -ERESTARTSYS is returned. The number '15' itself was picked
|
|
* arbitrarily; there's little point in asking drivers to provide a timeout
|
|
* value themselves.
|
|
*
|
|
* Otherwise, if @wait is false, and there are no TX buffers available,
|
|
* the function will immediately fail, and -ENOMEM will be returned.
|
|
*
|
|
* Normally drivers shouldn't use this function directly; instead, drivers
|
|
* should use the appropriate rpmsg_{try}send{to, _offchannel} API
|
|
* (see include/linux/rpmsg.h).
|
|
*
|
|
* Returns 0 on success and an appropriate error value on failure.
|
|
*/
|
|
static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
|
|
u32 src, u32 dst,
|
|
void *data, int len, bool wait)
|
|
{
|
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
|
|
struct virtproc_info *vrp = vch->vrp;
|
|
struct device *dev = &rpdev->dev;
|
|
struct scatterlist sg;
|
|
struct rpmsg_hdr *msg;
|
|
int err;
|
|
|
|
/* bcasting isn't allowed */
|
|
if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) {
|
|
dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* We currently use fixed-sized buffers, and therefore the payload
|
|
* length is limited.
|
|
*
|
|
* One of the possible improvements here is either to support
|
|
* user-provided buffers (and then we can also support zero-copy
|
|
* messaging), or to improve the buffer allocator, to support
|
|
* variable-length buffer sizes.
|
|
*/
|
|
if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) {
|
|
dev_err(dev, "message is too big (%d)\n", len);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
/* grab a buffer */
|
|
msg = get_a_tx_buf(vrp);
|
|
if (!msg && !wait)
|
|
return -ENOMEM;
|
|
|
|
/* no free buffer ? wait for one (but bail after 15 seconds) */
|
|
while (!msg) {
|
|
/* enable "tx-complete" interrupts, if not already enabled */
|
|
rpmsg_upref_sleepers(vrp);
|
|
|
|
/*
|
|
* sleep until a free buffer is available or 15 secs elapse.
|
|
* the timeout period is not configurable because there's
|
|
* little point in asking drivers to specify that.
|
|
* if later this happens to be required, it'd be easy to add.
|
|
*/
|
|
err = wait_event_interruptible_timeout(vrp->sendq,
|
|
(msg = get_a_tx_buf(vrp)),
|
|
msecs_to_jiffies(15000));
|
|
|
|
/* disable "tx-complete" interrupts if we're the last sleeper */
|
|
rpmsg_downref_sleepers(vrp);
|
|
|
|
/* timeout ? */
|
|
if (!err) {
|
|
dev_err(dev, "timeout waiting for a tx buffer\n");
|
|
return -ERESTARTSYS;
|
|
}
|
|
}
|
|
|
|
msg->len = cpu_to_virtio16(vrp->vdev, len);
|
|
msg->flags = 0;
|
|
msg->src = cpu_to_virtio32(vrp->vdev, src);
|
|
msg->dst = cpu_to_virtio32(vrp->vdev, dst);
|
|
msg->reserved = 0;
|
|
memcpy(msg->data, data, len);
|
|
|
|
dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n",
|
|
src, dst, len, msg->flags, msg->reserved);
|
|
#if defined(CONFIG_DYNAMIC_DEBUG)
|
|
dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1,
|
|
msg, sizeof(*msg) + len, true);
|
|
#endif
|
|
|
|
rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
|
|
|
|
mutex_lock(&vrp->tx_lock);
|
|
|
|
/* add message to the remote processor's virtqueue */
|
|
err = virtqueue_add_outbuf(vrp->svq, &sg, 1, msg, GFP_KERNEL);
|
|
if (err) {
|
|
/*
|
|
* need to reclaim the buffer here, otherwise it's lost
|
|
* (memory won't leak, but rpmsg won't use it again for TX).
|
|
* this will wait for a buffer management overhaul.
|
|
*/
|
|
dev_err(dev, "virtqueue_add_outbuf failed: %d\n", err);
|
|
goto out;
|
|
}
|
|
|
|
/* tell the remote processor it has a pending message to read */
|
|
virtqueue_kick(vrp->svq);
|
|
out:
|
|
mutex_unlock(&vrp->tx_lock);
|
|
return err;
|
|
}
|
|
|
|
static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
u32 src = ept->addr, dst = rpdev->dst;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
|
|
}
|
|
|
|
static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
|
|
u32 dst)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
u32 src = ept->addr;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
|
|
}
|
|
|
|
static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
|
|
u32 dst, void *data, int len)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
|
|
}
|
|
|
|
static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
u32 src = ept->addr, dst = rpdev->dst;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
|
|
}
|
|
|
|
static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
|
|
int len, u32 dst)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
u32 src = ept->addr;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
|
|
}
|
|
|
|
static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
|
|
u32 dst, void *data, int len)
|
|
{
|
|
struct rpmsg_device *rpdev = ept->rpdev;
|
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
|
|
}
|
|
|
|
static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
|
|
struct rpmsg_hdr *msg, unsigned int len)
|
|
{
|
|
struct rpmsg_endpoint *ept;
|
|
struct scatterlist sg;
|
|
unsigned int msg_len = virtio16_to_cpu(vrp->vdev, msg->len);
|
|
int err;
|
|
|
|
dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n",
|
|
virtio32_to_cpu(vrp->vdev, msg->src),
|
|
virtio32_to_cpu(vrp->vdev, msg->dst), msg_len,
|
|
virtio16_to_cpu(vrp->vdev, msg->flags),
|
|
virtio32_to_cpu(vrp->vdev, msg->reserved));
|
|
#if defined(CONFIG_DYNAMIC_DEBUG)
|
|
dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1,
|
|
msg, sizeof(*msg) + msg_len, true);
|
|
#endif
|
|
|
|
/*
|
|
* We currently use fixed-sized buffers, so trivially sanitize
|
|
* the reported payload length.
|
|
*/
|
|
if (len > vrp->buf_size ||
|
|
msg_len > (len - sizeof(struct rpmsg_hdr))) {
|
|
dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* use the dst addr to fetch the callback of the appropriate user */
|
|
mutex_lock(&vrp->endpoints_lock);
|
|
|
|
ept = idr_find(&vrp->endpoints, virtio32_to_cpu(vrp->vdev, msg->dst));
|
|
|
|
/* let's make sure no one deallocates ept while we use it */
|
|
if (ept)
|
|
kref_get(&ept->refcount);
|
|
|
|
mutex_unlock(&vrp->endpoints_lock);
|
|
|
|
if (ept) {
|
|
/* make sure ept->cb doesn't go away while we use it */
|
|
mutex_lock(&ept->cb_lock);
|
|
|
|
if (ept->cb)
|
|
ept->cb(ept->rpdev, msg->data, msg_len, ept->priv,
|
|
virtio32_to_cpu(vrp->vdev, msg->src));
|
|
|
|
mutex_unlock(&ept->cb_lock);
|
|
|
|
/* farewell, ept, we don't need you anymore */
|
|
kref_put(&ept->refcount, __ept_release);
|
|
} else
|
|
dev_warn(dev, "msg received with no recipient\n");
|
|
|
|
/* publish the real size of the buffer */
|
|
rpmsg_sg_init(&sg, msg, vrp->buf_size);
|
|
|
|
/* add the buffer back to the remote processor's virtqueue */
|
|
err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
|
|
if (err < 0) {
|
|
dev_err(dev, "failed to add a virtqueue buffer: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* called when an rx buffer is used, and it's time to digest a message */
|
|
static void rpmsg_recv_done(struct virtqueue *rvq)
|
|
{
|
|
struct virtproc_info *vrp = rvq->vdev->priv;
|
|
struct device *dev = &rvq->vdev->dev;
|
|
struct rpmsg_hdr *msg;
|
|
unsigned int len, msgs_received = 0;
|
|
int err;
|
|
|
|
msg = virtqueue_get_buf(rvq, &len);
|
|
if (!msg) {
|
|
dev_err(dev, "uhm, incoming signal, but no used buffer ?\n");
|
|
return;
|
|
}
|
|
|
|
while (msg) {
|
|
err = rpmsg_recv_single(vrp, dev, msg, len);
|
|
if (err)
|
|
break;
|
|
|
|
msgs_received++;
|
|
|
|
msg = virtqueue_get_buf(rvq, &len);
|
|
}
|
|
|
|
dev_dbg(dev, "Received %u messages\n", msgs_received);
|
|
|
|
/* tell the remote processor we added another available rx buffer */
|
|
if (msgs_received)
|
|
virtqueue_kick(vrp->rvq);
|
|
}
|
|
|
|
/*
|
|
* This is invoked whenever the remote processor completed processing
|
|
* a TX msg we just sent it, and the buffer is put back to the used ring.
|
|
*
|
|
* Normally, though, we suppress this "tx complete" interrupt in order to
|
|
* avoid the incurred overhead.
|
|
*/
|
|
static void rpmsg_xmit_done(struct virtqueue *svq)
|
|
{
|
|
struct virtproc_info *vrp = svq->vdev->priv;
|
|
|
|
dev_dbg(&svq->vdev->dev, "%s\n", __func__);
|
|
|
|
/* wake up potential senders that are waiting for a tx buffer */
|
|
wake_up_interruptible(&vrp->sendq);
|
|
}
|
|
|
|
/* invoked when a name service announcement arrives */
|
|
static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
|
|
void *priv, u32 src)
|
|
{
|
|
struct rpmsg_ns_msg *msg = data;
|
|
struct rpmsg_device *newch;
|
|
struct rpmsg_channel_info chinfo;
|
|
struct virtproc_info *vrp = priv;
|
|
struct device *dev = &vrp->vdev->dev;
|
|
int ret;
|
|
|
|
#if defined(CONFIG_DYNAMIC_DEBUG)
|
|
dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
|
|
data, len, true);
|
|
#endif
|
|
|
|
if (len != sizeof(*msg)) {
|
|
dev_err(dev, "malformed ns msg (%d)\n", len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* the name service ept does _not_ belong to a real rpmsg channel,
|
|
* and is handled by the rpmsg bus itself.
|
|
* for sanity reasons, make sure a valid rpdev has _not_ sneaked
|
|
* in somehow.
|
|
*/
|
|
if (rpdev) {
|
|
dev_err(dev, "anomaly: ns ept has an rpdev handle\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* don't trust the remote processor for null terminating the name */
|
|
msg->name[RPMSG_NAME_SIZE - 1] = '\0';
|
|
|
|
strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
|
|
chinfo.src = RPMSG_ADDR_ANY;
|
|
chinfo.dst = virtio32_to_cpu(vrp->vdev, msg->addr);
|
|
|
|
dev_info(dev, "%sing channel %s addr 0x%x\n",
|
|
virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY ?
|
|
"destroy" : "creat", msg->name, chinfo.dst);
|
|
|
|
if (virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY) {
|
|
ret = rpmsg_unregister_device(&vrp->vdev->dev, &chinfo);
|
|
if (ret)
|
|
dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
|
|
} else {
|
|
newch = rpmsg_create_channel(vrp, &chinfo);
|
|
if (!newch)
|
|
dev_err(dev, "rpmsg_create_channel failed\n");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rpmsg_probe(struct virtio_device *vdev)
|
|
{
|
|
vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done };
|
|
static const char * const names[] = { "input", "output" };
|
|
struct virtqueue *vqs[2];
|
|
struct virtproc_info *vrp;
|
|
void *bufs_va;
|
|
int err = 0, i;
|
|
size_t total_buf_space;
|
|
bool notify;
|
|
|
|
vrp = kzalloc(sizeof(*vrp), GFP_KERNEL);
|
|
if (!vrp)
|
|
return -ENOMEM;
|
|
|
|
vrp->vdev = vdev;
|
|
|
|
idr_init(&vrp->endpoints);
|
|
mutex_init(&vrp->endpoints_lock);
|
|
mutex_init(&vrp->tx_lock);
|
|
init_waitqueue_head(&vrp->sendq);
|
|
|
|
/* We expect two virtqueues, rx and tx (and in this order) */
|
|
err = virtio_find_vqs(vdev, 2, vqs, vq_cbs, names, NULL);
|
|
if (err)
|
|
goto free_vrp;
|
|
|
|
vrp->rvq = vqs[0];
|
|
vrp->svq = vqs[1];
|
|
|
|
/* we expect symmetric tx/rx vrings */
|
|
WARN_ON(virtqueue_get_vring_size(vrp->rvq) !=
|
|
virtqueue_get_vring_size(vrp->svq));
|
|
|
|
/* we need less buffers if vrings are small */
|
|
if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2)
|
|
vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2;
|
|
else
|
|
vrp->num_bufs = MAX_RPMSG_NUM_BUFS;
|
|
|
|
vrp->buf_size = MAX_RPMSG_BUF_SIZE;
|
|
|
|
total_buf_space = vrp->num_bufs * vrp->buf_size;
|
|
|
|
/* allocate coherent memory for the buffers */
|
|
bufs_va = dma_alloc_coherent(vdev->dev.parent,
|
|
total_buf_space, &vrp->bufs_dma,
|
|
GFP_KERNEL);
|
|
if (!bufs_va) {
|
|
err = -ENOMEM;
|
|
goto vqs_del;
|
|
}
|
|
|
|
dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n",
|
|
bufs_va, &vrp->bufs_dma);
|
|
|
|
/* half of the buffers is dedicated for RX */
|
|
vrp->rbufs = bufs_va;
|
|
|
|
/* and half is dedicated for TX */
|
|
vrp->sbufs = bufs_va + total_buf_space / 2;
|
|
|
|
/* set up the receive buffers */
|
|
for (i = 0; i < vrp->num_bufs / 2; i++) {
|
|
struct scatterlist sg;
|
|
void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
|
|
|
|
rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
|
|
|
|
err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
|
|
GFP_KERNEL);
|
|
WARN_ON(err); /* sanity check; this can't really happen */
|
|
}
|
|
|
|
/* suppress "tx-complete" interrupts */
|
|
virtqueue_disable_cb(vrp->svq);
|
|
|
|
vdev->priv = vrp;
|
|
|
|
/* if supported by the remote processor, enable the name service */
|
|
if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) {
|
|
/* a dedicated endpoint handles the name service msgs */
|
|
vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb,
|
|
vrp, RPMSG_NS_ADDR);
|
|
if (!vrp->ns_ept) {
|
|
dev_err(&vdev->dev, "failed to create the ns ept\n");
|
|
err = -ENOMEM;
|
|
goto free_coherent;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Prepare to kick but don't notify yet - we can't do this before
|
|
* device is ready.
|
|
*/
|
|
notify = virtqueue_kick_prepare(vrp->rvq);
|
|
|
|
/* From this point on, we can notify and get callbacks. */
|
|
virtio_device_ready(vdev);
|
|
|
|
/* tell the remote processor it can start sending messages */
|
|
/*
|
|
* this might be concurrent with callbacks, but we are only
|
|
* doing notify, not a full kick here, so that's ok.
|
|
*/
|
|
if (notify)
|
|
virtqueue_notify(vrp->rvq);
|
|
|
|
dev_info(&vdev->dev, "rpmsg host is online\n");
|
|
|
|
return 0;
|
|
|
|
free_coherent:
|
|
dma_free_coherent(vdev->dev.parent, total_buf_space,
|
|
bufs_va, vrp->bufs_dma);
|
|
vqs_del:
|
|
vdev->config->del_vqs(vrp->vdev);
|
|
free_vrp:
|
|
kfree(vrp);
|
|
return err;
|
|
}
|
|
|
|
static int rpmsg_remove_device(struct device *dev, void *data)
|
|
{
|
|
device_unregister(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void rpmsg_remove(struct virtio_device *vdev)
|
|
{
|
|
struct virtproc_info *vrp = vdev->priv;
|
|
size_t total_buf_space = vrp->num_bufs * vrp->buf_size;
|
|
int ret;
|
|
|
|
vdev->config->reset(vdev);
|
|
|
|
ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device);
|
|
if (ret)
|
|
dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret);
|
|
|
|
if (vrp->ns_ept)
|
|
__rpmsg_destroy_ept(vrp, vrp->ns_ept);
|
|
|
|
idr_destroy(&vrp->endpoints);
|
|
|
|
vdev->config->del_vqs(vrp->vdev);
|
|
|
|
dma_free_coherent(vdev->dev.parent, total_buf_space,
|
|
vrp->rbufs, vrp->bufs_dma);
|
|
|
|
kfree(vrp);
|
|
}
|
|
|
|
static struct virtio_device_id id_table[] = {
|
|
{ VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID },
|
|
{ 0 },
|
|
};
|
|
|
|
static unsigned int features[] = {
|
|
VIRTIO_RPMSG_F_NS,
|
|
};
|
|
|
|
static struct virtio_driver virtio_ipc_driver = {
|
|
.feature_table = features,
|
|
.feature_table_size = ARRAY_SIZE(features),
|
|
.driver.name = KBUILD_MODNAME,
|
|
.driver.owner = THIS_MODULE,
|
|
.id_table = id_table,
|
|
.probe = rpmsg_probe,
|
|
.remove = rpmsg_remove,
|
|
};
|
|
|
|
static int __init rpmsg_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_virtio_driver(&virtio_ipc_driver);
|
|
if (ret)
|
|
pr_err("failed to register virtio driver: %d\n", ret);
|
|
|
|
return ret;
|
|
}
|
|
subsys_initcall(rpmsg_init);
|
|
|
|
static void __exit rpmsg_fini(void)
|
|
{
|
|
unregister_virtio_driver(&virtio_ipc_driver);
|
|
}
|
|
module_exit(rpmsg_fini);
|
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table);
|
|
MODULE_DESCRIPTION("Virtio-based remote processor messaging bus");
|
|
MODULE_LICENSE("GPL v2");
|