| Message ID | 20210604091406.15901-2-arnaud.pouliquen@foss.st.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rpmsg: ctrl: Add ability to instantiate rpmsg device locally | expand |
On Fri, Jun 04, 2021 at 11:14:03AM +0200, Arnaud Pouliquen wrote: > Implement the RPMSG_CREATE_DEV_IOCTL to allow the user application to > initiate a communication through a new rpmsg channel. > This Ioctl can be used to instantiate a local rpmsg device. > Depending on the back-end implementation, the associated rpmsg driver is > probed and a NS announcement can be sent to the remote processor. > > Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org> > Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> > --- > drivers/rpmsg/rpmsg_ctrl.c | 30 ++++++++++++++++++++++++++---- > include/uapi/linux/rpmsg.h | 5 +++++ > 2 files changed, 31 insertions(+), 4 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c > index eeb1708548c1..4aa962df3661 100644 > --- a/drivers/rpmsg/rpmsg_ctrl.c > +++ b/drivers/rpmsg/rpmsg_ctrl.c > @@ -23,6 +23,7 @@ > #include <uapi/linux/rpmsg.h> > > #include "rpmsg_char.h" > +#include "rpmsg_internal.h" > > static dev_t rpmsg_major; > > @@ -37,11 +38,13 @@ static DEFINE_IDA(rpmsg_minor_ida); > * @rpdev: underlaying rpmsg device > * @cdev: cdev for the ctrl device > * @dev: device for the ctrl device > + * @ctrl_lock: serialize the ioctrls. > */ > struct rpmsg_ctrldev { > struct rpmsg_device *rpdev; > struct cdev cdev; > struct device dev; > + struct mutex ctrl_lock; > }; > > static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) > @@ -70,9 +73,8 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, > void __user *argp = (void __user *)arg; > struct rpmsg_endpoint_info eptinfo; > struct rpmsg_channel_info chinfo; > - > - if (cmd != RPMSG_CREATE_EPT_IOCTL) > - return -EINVAL; > + struct rpmsg_device *rpdev; > + int ret = 0; > > if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) > return -EFAULT; > @@ -82,7 +84,26 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, > chinfo.src = eptinfo.src; > chinfo.dst = eptinfo.dst; > > - return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); > + mutex_lock(&ctrldev->ctrl_lock); Do we need a lock here? I thought the character device layer would guarantee accesses on a file handler would be atomic... Am I wrong? > + switch (cmd) { > + case RPMSG_CREATE_EPT_IOCTL: > + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); > + break; > + > + case RPMSG_CREATE_DEV_IOCTL: > + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); > + if (!rpdev) { > + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); > + ret = -ENXIO; > + } > + break; > + > + default: > + ret = -EINVAL; > + } > + mutex_unlock(&ctrldev->ctrl_lock); > + > + return ret; > }; > > static const struct file_operations rpmsg_ctrldev_fops = { > @@ -119,6 +140,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) > device_initialize(dev); > dev->parent = &rpdev->dev; > > + mutex_init(&ctrldev->ctrl_lock); > cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); > ctrldev->cdev.owner = THIS_MODULE; > > diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h > index f5ca8740f3fb..f9d5a74e7801 100644 > --- a/include/uapi/linux/rpmsg.h > +++ b/include/uapi/linux/rpmsg.h > @@ -33,4 +33,9 @@ struct rpmsg_endpoint_info { > */ > #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2) > > +/** > + * Instantiate a rpmsg service device. > + */ > +#define RPMSG_CREATE_DEV_IOCTL _IOW(0xb5, 0x3, struct rpmsg_endpoint_info) > + > #endif > -- > 2.17.1 >
Hello Mathieu, On 6/15/21 7:53 PM, Mathieu Poirier wrote: > On Fri, Jun 04, 2021 at 11:14:03AM +0200, Arnaud Pouliquen wrote: >> Implement the RPMSG_CREATE_DEV_IOCTL to allow the user application to >> initiate a communication through a new rpmsg channel. >> This Ioctl can be used to instantiate a local rpmsg device. >> Depending on the back-end implementation, the associated rpmsg driver is >> probed and a NS announcement can be sent to the remote processor. >> >> Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> >> --- >> drivers/rpmsg/rpmsg_ctrl.c | 30 ++++++++++++++++++++++++++---- >> include/uapi/linux/rpmsg.h | 5 +++++ >> 2 files changed, 31 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c >> index eeb1708548c1..4aa962df3661 100644 >> --- a/drivers/rpmsg/rpmsg_ctrl.c >> +++ b/drivers/rpmsg/rpmsg_ctrl.c >> @@ -23,6 +23,7 @@ >> #include <uapi/linux/rpmsg.h> >> >> #include "rpmsg_char.h" >> +#include "rpmsg_internal.h" >> >> static dev_t rpmsg_major; >> >> @@ -37,11 +38,13 @@ static DEFINE_IDA(rpmsg_minor_ida); >> * @rpdev: underlaying rpmsg device >> * @cdev: cdev for the ctrl device >> * @dev: device for the ctrl device >> + * @ctrl_lock: serialize the ioctrls. >> */ >> struct rpmsg_ctrldev { >> struct rpmsg_device *rpdev; >> struct cdev cdev; >> struct device dev; >> + struct mutex ctrl_lock; >> }; >> >> static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) >> @@ -70,9 +73,8 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >> void __user *argp = (void __user *)arg; >> struct rpmsg_endpoint_info eptinfo; >> struct rpmsg_channel_info chinfo; >> - >> - if (cmd != RPMSG_CREATE_EPT_IOCTL) >> - return -EINVAL; >> + struct rpmsg_device *rpdev; >> + int ret = 0; >> >> if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) >> return -EFAULT; >> @@ -82,7 +84,26 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >> chinfo.src = eptinfo.src; >> chinfo.dst = eptinfo.dst; >> >> - return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >> + mutex_lock(&ctrldev->ctrl_lock); > > Do we need a lock here? I thought the character device layer would guarantee > accesses on a file handler would be atomic... Am I wrong? > It is a good point! from my understanding, using "unlocked_ioctl" ops, the driver has to handle is own atomic protection. I will try to hack the code to verify this. Thanks, Arnaud >> + switch (cmd) { >> + case RPMSG_CREATE_EPT_IOCTL: >> + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >> + break; >> + >> + case RPMSG_CREATE_DEV_IOCTL: >> + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); >> + if (!rpdev) { >> + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); >> + ret = -ENXIO; >> + } >> + break; >> + >> + default: >> + ret = -EINVAL; >> + } >> + mutex_unlock(&ctrldev->ctrl_lock); >> + >> + return ret; >> }; >> >> static const struct file_operations rpmsg_ctrldev_fops = { >> @@ -119,6 +140,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) >> device_initialize(dev); >> dev->parent = &rpdev->dev; >> >> + mutex_init(&ctrldev->ctrl_lock); >> cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); >> ctrldev->cdev.owner = THIS_MODULE; >> >> diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h >> index f5ca8740f3fb..f9d5a74e7801 100644 >> --- a/include/uapi/linux/rpmsg.h >> +++ b/include/uapi/linux/rpmsg.h >> @@ -33,4 +33,9 @@ struct rpmsg_endpoint_info { >> */ >> #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2) >> >> +/** >> + * Instantiate a rpmsg service device. >> + */ >> +#define RPMSG_CREATE_DEV_IOCTL _IOW(0xb5, 0x3, struct rpmsg_endpoint_info) >> + >> #endif >> -- >> 2.17.1 >>
On 6/16/21 10:12 AM, Arnaud POULIQUEN wrote: > Hello Mathieu, > > On 6/15/21 7:53 PM, Mathieu Poirier wrote: >> On Fri, Jun 04, 2021 at 11:14:03AM +0200, Arnaud Pouliquen wrote: >>> Implement the RPMSG_CREATE_DEV_IOCTL to allow the user application to >>> initiate a communication through a new rpmsg channel. >>> This Ioctl can be used to instantiate a local rpmsg device. >>> Depending on the back-end implementation, the associated rpmsg driver is >>> probed and a NS announcement can be sent to the remote processor. >>> >>> Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org> >>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> >>> --- >>> drivers/rpmsg/rpmsg_ctrl.c | 30 ++++++++++++++++++++++++++---- >>> include/uapi/linux/rpmsg.h | 5 +++++ >>> 2 files changed, 31 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c >>> index eeb1708548c1..4aa962df3661 100644 >>> --- a/drivers/rpmsg/rpmsg_ctrl.c >>> +++ b/drivers/rpmsg/rpmsg_ctrl.c >>> @@ -23,6 +23,7 @@ >>> #include <uapi/linux/rpmsg.h> >>> >>> #include "rpmsg_char.h" >>> +#include "rpmsg_internal.h" >>> >>> static dev_t rpmsg_major; >>> >>> @@ -37,11 +38,13 @@ static DEFINE_IDA(rpmsg_minor_ida); >>> * @rpdev: underlaying rpmsg device >>> * @cdev: cdev for the ctrl device >>> * @dev: device for the ctrl device >>> + * @ctrl_lock: serialize the ioctrls. >>> */ >>> struct rpmsg_ctrldev { >>> struct rpmsg_device *rpdev; >>> struct cdev cdev; >>> struct device dev; >>> + struct mutex ctrl_lock; >>> }; >>> >>> static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) >>> @@ -70,9 +73,8 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >>> void __user *argp = (void __user *)arg; >>> struct rpmsg_endpoint_info eptinfo; >>> struct rpmsg_channel_info chinfo; >>> - >>> - if (cmd != RPMSG_CREATE_EPT_IOCTL) >>> - return -EINVAL; >>> + struct rpmsg_device *rpdev; >>> + int ret = 0; >>> >>> if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) >>> return -EFAULT; >>> @@ -82,7 +84,26 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, >>> chinfo.src = eptinfo.src; >>> chinfo.dst = eptinfo.dst; >>> >>> - return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >>> + mutex_lock(&ctrldev->ctrl_lock); >> >> Do we need a lock here? I thought the character device layer would guarantee >> accesses on a file handler would be atomic... Am I wrong? >> > > It is a good point! from my understanding, using "unlocked_ioctl" ops, the > driver has to handle is own atomic protection. > I will try to hack the code to verify this. I confirm without lock there is no atomic access, re-entrance is possible in rpmsg_ctrldev_ioctl. Keeping lock to serialize the controls seems safer to me to avoid race condition. Regards Arnaud > > Thanks, > Arnaud > >>> + switch (cmd) { >>> + case RPMSG_CREATE_EPT_IOCTL: >>> + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); >>> + break; >>> + >>> + case RPMSG_CREATE_DEV_IOCTL: >>> + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); >>> + if (!rpdev) { >>> + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); >>> + ret = -ENXIO; >>> + } >>> + break; >>> + >>> + default: >>> + ret = -EINVAL; >>> + } >>> + mutex_unlock(&ctrldev->ctrl_lock); >>> + >>> + return ret; >>> }; >>> >>> static const struct file_operations rpmsg_ctrldev_fops = { >>> @@ -119,6 +140,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) >>> device_initialize(dev); >>> dev->parent = &rpdev->dev; >>> >>> + mutex_init(&ctrldev->ctrl_lock); >>> cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); >>> ctrldev->cdev.owner = THIS_MODULE; >>> >>> diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h >>> index f5ca8740f3fb..f9d5a74e7801 100644 >>> --- a/include/uapi/linux/rpmsg.h >>> +++ b/include/uapi/linux/rpmsg.h >>> @@ -33,4 +33,9 @@ struct rpmsg_endpoint_info { >>> */ >>> #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2) >>> >>> +/** >>> + * Instantiate a rpmsg service device. >>> + */ >>> +#define RPMSG_CREATE_DEV_IOCTL _IOW(0xb5, 0x3, struct rpmsg_endpoint_info) >>> + >>> #endif >>> -- >>> 2.17.1 >>>
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c index eeb1708548c1..4aa962df3661 100644 --- a/drivers/rpmsg/rpmsg_ctrl.c +++ b/drivers/rpmsg/rpmsg_ctrl.c @@ -23,6 +23,7 @@ #include <uapi/linux/rpmsg.h> #include "rpmsg_char.h" +#include "rpmsg_internal.h" static dev_t rpmsg_major; @@ -37,11 +38,13 @@ static DEFINE_IDA(rpmsg_minor_ida); * @rpdev: underlaying rpmsg device * @cdev: cdev for the ctrl device * @dev: device for the ctrl device + * @ctrl_lock: serialize the ioctrls. */ struct rpmsg_ctrldev { struct rpmsg_device *rpdev; struct cdev cdev; struct device dev; + struct mutex ctrl_lock; }; static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) @@ -70,9 +73,8 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, void __user *argp = (void __user *)arg; struct rpmsg_endpoint_info eptinfo; struct rpmsg_channel_info chinfo; - - if (cmd != RPMSG_CREATE_EPT_IOCTL) - return -EINVAL; + struct rpmsg_device *rpdev; + int ret = 0; if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) return -EFAULT; @@ -82,7 +84,26 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, chinfo.src = eptinfo.src; chinfo.dst = eptinfo.dst; - return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); + mutex_lock(&ctrldev->ctrl_lock); + switch (cmd) { + case RPMSG_CREATE_EPT_IOCTL: + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); + break; + + case RPMSG_CREATE_DEV_IOCTL: + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); + if (!rpdev) { + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); + ret = -ENXIO; + } + break; + + default: + ret = -EINVAL; + } + mutex_unlock(&ctrldev->ctrl_lock); + + return ret; }; static const struct file_operations rpmsg_ctrldev_fops = { @@ -119,6 +140,7 @@ static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) device_initialize(dev); dev->parent = &rpdev->dev; + mutex_init(&ctrldev->ctrl_lock); cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); ctrldev->cdev.owner = THIS_MODULE; diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h index f5ca8740f3fb..f9d5a74e7801 100644 --- a/include/uapi/linux/rpmsg.h +++ b/include/uapi/linux/rpmsg.h @@ -33,4 +33,9 @@ struct rpmsg_endpoint_info { */ #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2) +/** + * Instantiate a rpmsg service device. + */ +#define RPMSG_CREATE_DEV_IOCTL _IOW(0xb5, 0x3, struct rpmsg_endpoint_info) + #endif
Implement the RPMSG_CREATE_DEV_IOCTL to allow the user application to initiate a communication through a new rpmsg channel. This Ioctl can be used to instantiate a local rpmsg device. Depending on the back-end implementation, the associated rpmsg driver is probed and a NS announcement can be sent to the remote processor. Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> --- drivers/rpmsg/rpmsg_ctrl.c | 30 ++++++++++++++++++++++++++---- include/uapi/linux/rpmsg.h | 5 +++++ 2 files changed, 31 insertions(+), 4 deletions(-)