Merge tag 'rpmsg-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc...

Pull rpmsg updates from Bjorn Andersson:
 "Add support for the GLINK flow control signals, and expose this to the
  user through the rpmsg_char interface. Add missing kstrdup() failure
  handling during allocation of GLINK channel objects"

* tag 'rpmsg-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux:
  rpmsg: glink: Avoid dereferencing NULL channel
  rpmsg: glink: Add check for kstrdup
  rpmsg: char: Add RPMSG GET/SET FLOWCONTROL IOCTL support
  rpmsg: glink: Add support to handle signals command
  rpmsg: core: Add signal API support

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 1beb40a..82d460f 100644 (file)
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -200,9 +200,15 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 #define GLINK_CMD_TX_DATA_CONT         12
 #define GLINK_CMD_READ_NOTIF           13
 #define GLINK_CMD_RX_DONE_W_REUSE      14
+#define GLINK_CMD_SIGNALS              15
 
 #define GLINK_FEATURE_INTENTLESS       BIT(1)
 
+#define NATIVE_DTR_SIG                 NATIVE_DSR_SIG
+#define NATIVE_DSR_SIG                 BIT(31)
+#define NATIVE_RTS_SIG                 NATIVE_CTS_SIG
+#define NATIVE_CTS_SIG                 BIT(30)
+
 static void qcom_glink_rx_done_work(struct work_struct *work);
 
 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
@@ -221,6 +227,10 @@ static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 
        channel->glink = glink;
        channel->name = kstrdup(name, GFP_KERNEL);
+       if (!channel->name) {
+               kfree(channel);
+               return ERR_PTR(-ENOMEM);
+       }
 
        init_completion(&channel->open_req);
        init_completion(&channel->open_ack);
@@ -1025,6 +1035,52 @@ static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
        return 0;
 }
 
+/**
+ * qcom_glink_set_flow_control() - convert a signal cmd to wire format and transmit
+ * @ept:       Rpmsg endpoint for channel.
+ * @pause:     Pause transmission
+ * @dst:       destination address of the endpoint
+ *
+ * Return: 0 on success or standard Linux error code.
+ */
+static int qcom_glink_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
+{
+       struct glink_channel *channel = to_glink_channel(ept);
+       struct qcom_glink *glink = channel->glink;
+       struct glink_msg msg;
+       u32 sigs = 0;
+
+       if (pause)
+               sigs |= NATIVE_DTR_SIG | NATIVE_RTS_SIG;
+
+       msg.cmd = cpu_to_le16(GLINK_CMD_SIGNALS);
+       msg.param1 = cpu_to_le16(channel->lcid);
+       msg.param2 = cpu_to_le32(sigs);
+
+       return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+}
+
+static void qcom_glink_handle_signals(struct qcom_glink *glink,
+                                     unsigned int rcid, unsigned int sigs)
+{
+       struct glink_channel *channel;
+       unsigned long flags;
+       bool enable;
+
+       spin_lock_irqsave(&glink->idr_lock, flags);
+       channel = idr_find(&glink->rcids, rcid);
+       spin_unlock_irqrestore(&glink->idr_lock, flags);
+       if (!channel) {
+               dev_err(glink->dev, "signal for non-existing channel\n");
+               return;
+       }
+
+       enable = sigs & NATIVE_DSR_SIG || sigs & NATIVE_CTS_SIG;
+
+       if (channel->ept.flow_cb)
+               channel->ept.flow_cb(channel->ept.rpdev, channel->ept.priv, enable);
+}
+
 void qcom_glink_native_rx(struct qcom_glink *glink)
 {
        struct glink_msg msg;
@@ -1086,6 +1142,10 @@ void qcom_glink_native_rx(struct qcom_glink *glink)
                        qcom_glink_handle_intent_req_ack(glink, param1, param2);
                        qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
                        break;
+               case GLINK_CMD_SIGNALS:
+                       qcom_glink_handle_signals(glink, param1, param2);
+                       qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+                       break;
                default:
                        dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
                        ret = -EINVAL;
@@ -1446,6 +1506,7 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
        .sendto = qcom_glink_sendto,
        .trysend = qcom_glink_trysend,
        .trysendto = qcom_glink_trysendto,
+       .set_flow_control = qcom_glink_set_flow_control,
 };
 
 static void qcom_glink_rpdev_release(struct device *dev)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index a271fce..09833ad 100644 (file)
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -52,6 +52,8 @@ static DEFINE_IDA(rpmsg_minor_ida);
  * @readq:     wait object for incoming queue
  * @default_ept: set to channel default endpoint if the default endpoint should be re-used
  *              on device open to prevent endpoint address update.
+ * remote_flow_restricted: to indicate if the remote has requested for flow to be limited
+ * remote_flow_updated: to indicate if the flow control has been requested
  */
 struct rpmsg_eptdev {
        struct device dev;
@@ -68,6 +70,8 @@ struct rpmsg_eptdev {
        struct sk_buff_head queue;
        wait_queue_head_t readq;
 
+       bool remote_flow_restricted;
+       bool remote_flow_updated;
 };
 
 int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
@@ -116,6 +120,18 @@ static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
        return 0;
 }
 
+static int rpmsg_ept_flow_cb(struct rpmsg_device *rpdev, void *priv, bool enable)
+{
+       struct rpmsg_eptdev *eptdev = priv;
+
+       eptdev->remote_flow_restricted = enable;
+       eptdev->remote_flow_updated = true;
+
+       wake_up_interruptible(&eptdev->readq);
+
+       return 0;
+}
+
 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
 {
        struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
@@ -152,6 +168,7 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
                return -EINVAL;
        }
 
+       ept->flow_cb = rpmsg_ept_flow_cb;
        eptdev->ept = ept;
        filp->private_data = eptdev;
        mutex_unlock(&eptdev->ept_lock);
@@ -172,6 +189,7 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
                eptdev->ept = NULL;
        }
        mutex_unlock(&eptdev->ept_lock);
+       eptdev->remote_flow_updated = false;
 
        /* Discard all SKBs */
        skb_queue_purge(&eptdev->queue);
@@ -285,6 +303,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
        if (!skb_queue_empty(&eptdev->queue))
                mask |= EPOLLIN | EPOLLRDNORM;
 
+       if (eptdev->remote_flow_updated)
+               mask |= EPOLLPRI;
+
        mutex_lock(&eptdev->ept_lock);
        mask |= rpmsg_poll(eptdev->ept, filp, wait);
        mutex_unlock(&eptdev->ept_lock);
@@ -297,14 +318,35 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
 {
        struct rpmsg_eptdev *eptdev = fp->private_data;
 
-       if (cmd != RPMSG_DESTROY_EPT_IOCTL)
-               return -EINVAL;
+       bool set;
+       int ret;
 
-       /* Don't allow to destroy a default endpoint. */
-       if (eptdev->default_ept)
-               return -EINVAL;
+       switch (cmd) {
+       case RPMSG_GET_OUTGOING_FLOWCONTROL:
+               eptdev->remote_flow_updated = false;
+               ret = put_user(eptdev->remote_flow_restricted, (int __user *)arg);
+               break;
+       case RPMSG_SET_INCOMING_FLOWCONTROL:
+               if (arg > 1) {
+                       ret = -EINVAL;
+                       break;
+               }
+               set = !!arg;
+               ret = rpmsg_set_flow_control(eptdev->ept, set, eptdev->chinfo.dst);
+               break;
+       case RPMSG_DESTROY_EPT_IOCTL:
+               /* Don't allow to destroy a default endpoint. */
+               if (eptdev->default_ept) {
+                       ret = -EINVAL;
+                       break;
+               }
+               ret = rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
+               break;
+       default:
+               ret = -EINVAL;
+       }
 
-       return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
+       return ret;
 }
 
 static const struct file_operations rpmsg_eptdev_fops = {

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 5039df7..32b550c 100644 (file)
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -331,6 +331,25 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
 
 /**
+ * rpmsg_set_flow_control() - request remote to pause/resume transmission
+ * @ept:       the rpmsg endpoint
+ * @pause:     pause transmission
+ * @dst:       destination address of the endpoint
+ *
+ * Return: 0 on success and an appropriate error value on failure.
+ */
+int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
+{
+       if (WARN_ON(!ept))
+               return -EINVAL;
+       if (!ept->ops->set_flow_control)
+               return -EOPNOTSUPP;
+
+       return ept->ops->set_flow_control(ept, pause, dst);
+}
+EXPORT_SYMBOL_GPL(rpmsg_set_flow_control);
+
+/**
  * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
  * @ept: the rpmsg endpoint
  *
@@ -539,6 +558,8 @@ static int rpmsg_dev_probe(struct device *dev)
 
                rpdev->ept = ept;
                rpdev->src = ept->addr;
+
+               ept->flow_cb = rpdrv->flowcontrol;
        }
 
        err = rpdrv->probe(rpdev);

diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 39b646d..b950d6f 100644 (file)
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -55,6 +55,7 @@ struct rpmsg_device_ops {
  * @trysendto:         see @rpmsg_trysendto(), optional
  * @trysend_offchannel:        see @rpmsg_trysend_offchannel(), optional
  * @poll:              see @rpmsg_poll(), optional
+ * @set_flow_control:  see @rpmsg_set_flow_control(), optional
  * @get_mtu:           see @rpmsg_get_mtu(), optional
  *
  * Indirection table for the operations that a rpmsg backend should implement.
@@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
                             void *data, int len);
        __poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
                             poll_table *wait);
+       int (*set_flow_control)(struct rpmsg_endpoint *ept, bool pause, u32 dst);
        ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
 };
 

diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 523c98b..90d8e44 100644 (file)
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -64,12 +64,14 @@ struct rpmsg_device {
 };
 
 typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
+typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool);
 
 /**
  * struct rpmsg_endpoint - binds a local rpmsg address to its user
  * @rpdev: rpmsg channel device
  * @refcount: when this drops to zero, the ept is deallocated
  * @cb: rx callback handler
+ * @flow_cb: remote flow control callback handler
  * @cb_lock: must be taken before accessing/changing @cb
  * @addr: local rpmsg address
  * @priv: private data for the driver's use
@@ -92,6 +94,7 @@ struct rpmsg_endpoint {
        struct rpmsg_device *rpdev;
        struct kref refcount;
        rpmsg_rx_cb_t cb;
+       rpmsg_flowcontrol_cb_t flow_cb;
        struct mutex cb_lock;
        u32 addr;
        void *priv;
@@ -106,6 +109,7 @@ struct rpmsg_endpoint {
  * @probe: invoked when a matching rpmsg channel (i.e. device) is found
  * @remove: invoked when the rpmsg channel is removed
  * @callback: invoked when an inbound message is received on the channel
+ * @flowcontrol: invoked when remote side flow control request is received
  */
 struct rpmsg_driver {
        struct device_driver drv;
@@ -113,6 +117,7 @@ struct rpmsg_driver {
        int (*probe)(struct rpmsg_device *dev);
        void (*remove)(struct rpmsg_device *dev);
        int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
+       int (*flowcontrol)(struct rpmsg_device *, void *, bool);
 };
 
 static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
@@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 
 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
 
+int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst);
+
 #else
 
 static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
@@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
        return -ENXIO;
 }
 
+static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
+{
+       /* This shouldn't be possible */
+       WARN_ON(1);
+
+       return -ENXIO;
+}
+
 #endif /* IS_ENABLED(CONFIG_RPMSG) */
 
 /* use a macro to avoid include chaining to get THIS_MODULE */

diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h
index 1637e68..f0c8da2 100644 (file)
--- a/include/uapi/linux/rpmsg.h
+++ b/include/uapi/linux/rpmsg.h
@@ -43,4 +43,14 @@ struct rpmsg_endpoint_info {
  */
 #define RPMSG_RELEASE_DEV_IOCTL        _IOW(0xb5, 0x4, struct rpmsg_endpoint_info)
 
+/**
+ * Get the flow control state of the remote rpmsg char device.
+ */
+#define RPMSG_GET_OUTGOING_FLOWCONTROL _IOR(0xb5, 0x5, int)
+
+/**
+ * Set the flow control state of the local rpmsg char device.
+ */
+#define RPMSG_SET_INCOMING_FLOWCONTROL _IOR(0xb5, 0x6, int)
+
 #endif