[permalink] [raw]

Subject: [PATCH v9 09/11] rpmsg: char: Add possibility to use default endpoint of the rpmsg device

Current implementation create/destroy a new endpoint on each
rpmsg_eptdev_open/rpmsg_eptdev_release calls.

For a rpmsg device created by the NS announcement a default endpoint is created.
In this case we have to reuse the default rpmsg device endpoint associated to
the channel instead of creating a new one.

This patch prepares the introduction of a rpmsg channel device for the
char device. The rpmsg channel device will require a default endpoint to
communicate to the remote processor.

Add the default_ept field in rpmsg_eptdev structure.This pointer
determines the behavior on rpmsg_eptdev_open and rpmsg_eptdev_release call.

- If default_ept == NULL:
Use the legacy behavior by creating a new endpoint each time
rpmsg_eptdev_open is called and release it when rpmsg_eptdev_release
is called on /dev/rpmsgX device open/close.

- If default_ept is set:
use the rpmsg device default endpoint for the communication.

Add protection in rpmsg_eptdev_ioctl to prevent to destroy a default endpoint.

Signed-off-by: Arnaud Pouliquen <[email protected]>
---
drivers/rpmsg/rpmsg_char.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index e7bc7dcdba63..97843838d960 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -50,6 +50,8 @@ static DEFINE_IDA(rpmsg_minor_ida);
* @queue_lock: synchronization of @queue operations
* @queue: incoming message queue
* @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.
*/
struct rpmsg_eptdev {
struct device dev;
@@ -60,10 +62,12 @@ struct rpmsg_eptdev {

struct mutex ept_lock;
struct rpmsg_endpoint *ept;
+ struct rpmsg_endpoint *default_ept;

spinlock_t queue_lock;
struct sk_buff_head queue;
wait_queue_head_t readq;
+
};

int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
@@ -121,7 +125,15 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)

get_device(dev);

- ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+ /*
+ * If the default_ept is set, the rpmsg device default endpoint is used.
+ * Else a new endpoint is created on open that will be destroyed on release.
+ */
+ if (eptdev->default_ept)
+ ept = eptdev->default_ept;
+ else
+ ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+
if (!ept) {
dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
put_device(dev);
@@ -142,7 +154,8 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
/* Close the endpoint, if it's not already destroyed by the parent */
mutex_lock(&eptdev->ept_lock);
if (eptdev->ept) {
- rpmsg_destroy_ept(eptdev->ept);
+ if (!eptdev->default_ept)
+ rpmsg_destroy_ept(eptdev->ept);
eptdev->ept = NULL;
}
mutex_unlock(&eptdev->ept_lock);
@@ -269,6 +282,10 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
if (cmd != RPMSG_DESTROY_EPT_IOCTL)
return -EINVAL;

+ /* Don't allow to destroy a default endpoint. */
+ if (eptdev->default_ept)
+ return -EINVAL;
+
return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
}

--
2.25.1

2022-01-24 19:02:46

by Arnaud Pouliquen

[permalink] [raw]

Subject: [PATCH v9 08/11] rpmsg: char: Refactor rpmsg_chrdev_eptdev_create function

Introduce the rpmsg_chrdev_eptdev_alloc and rpmsg_chrdev_eptdev_add
internal function to split the allocation part from the device add.

This patch prepares the introduction of a rpmsg channel device for the
char device. An default endpoint will be created,
referenced in the rpmsg_eptdev structure before adding the devices.

Signed-off-by: Arnaud Pouliquen <[email protected]>
---
drivers/rpmsg/rpmsg_char.c | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index fcd583472d5a..e7bc7dcdba63 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -327,20 +327,18 @@ static void rpmsg_eptdev_release_device(struct device *dev)
kfree(eptdev);
}

-int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
- struct rpmsg_channel_info chinfo)
+static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev,
+ struct device *parent)
{
struct rpmsg_eptdev *eptdev;
struct device *dev;
- int ret;

eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
if (!eptdev)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

dev = &eptdev->dev;
eptdev->rpdev = rpdev;
- eptdev->chinfo = chinfo;

mutex_init(&eptdev->ept_lock);
spin_lock_init(&eptdev->queue_lock);
@@ -356,6 +354,16 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
eptdev->cdev.owner = THIS_MODULE;

+ return eptdev;
+}
+
+static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
+{
+ struct device *dev = &eptdev->dev;
+ int ret;
+
+ eptdev->chinfo = chinfo;
+
ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
if (ret < 0)
goto free_eptdev;
@@ -386,6 +394,21 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent

return ret;
}
+
+int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
+ struct rpmsg_channel_info chinfo)
+{
+ struct rpmsg_eptdev *eptdev;
+ int ret;
+
+ eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
+ if (IS_ERR(eptdev))
+ return PTR_ERR(eptdev);
+
+ ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+
+ return ret;
+}
EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);

static int rpmsg_chrdev_init(void)
--
2.25.1

2022-01-24 19:02:50

by Arnaud Pouliquen

[permalink] [raw]

On Fri, 25 Mar 2022 at 11:05, Arnaud POULIQUEN
<[email protected]> wrote:
>
>
>
> On 3/25/22 16:59, Mathieu Poirier wrote:
> > On Thu, Mar 24, 2022 at 06:36:23PM +0100, Arnaud POULIQUEN wrote:
> >> Hi Bjorn,
> >>
> >> On 1/24/22 11:25, Arnaud Pouliquen wrote:
> >>> Updates from V8 [1]:
> >>> - rebase on 5.17-rc1 + rpmsg char cdev release fixes[2][3]
> >>> - updates based on Bjorn Andersson's comments:
> >>> - remove rpmsg_create_default_ept API, set directly the ept->priv in rpmsg_chrdev_probe
> >>> function.
> >>> - rework commit message in [8/9]rpmsg: char: Introduce the "rpmsg-raw" channel
> >>>
> >>> Patchset description:
> >>>
> >>> The current rpmsg_char module implements a /dev/rpmsg_ctrl interface that provides the ability to
> >>> instantiate char devices (/dev/rpmsgX) associated with an rpmsg endpoint for communication with the
> >>> remote processor.
> >>> This implementation fits with QCOM rpmsg backend but not with the magement by chanel implemented
> >>> in the generic rpmsg virtio backend.
> >>> This series restructures the rpmsg_char driver to decorrelate the control part from the data part
> >>> in order to improve its compatible with the rpmsg virtio backend.
> >>>
> >>> Objective:
> >>> - Expose a /dev/rpmsg_ctrlX interface for the application that is no longer dedicated to the
> >>> rpmsg_char but generalized to all rpmsg services. This offers capability to create and destroy
> >>> rpmsg channels from a user's application initiative (using the new RPMSG_CREATE_DEV_IOCTL and
> >>> RPMSG_DESTROY_DEV_IOCTL controls).
> >>> An application will be able to create/establish an rpmsg communication channel to communicate
> >>> with the remote processor, and not only wait the remote processor initiative.
> >>> This is interesting for example to establish a temporary communication link for diagnosis,
> >>> calibration, debugging... or instantiate new data flows on some user actions.
> >>> - Add capability to probe the rpmsg_char device at the initiative of the remote processor
> >>> (rpmsg service announcement mechanism).
> >>> This allows platforms based on the rpmsg virtio backend to create the /dev/rpmgX interface with
> >>> a rpmsg name service announcement.
> >>>
> >>> Subsets:
> >>> - Extract the control part of the char dev and create the rpmsg_ctrl.c file (patches 1 to 6)
> >>> - Introduce the "rpmsg-raw" channel in rpmsg_char(patches 7 to 10)
> >>> - Introduce the RPMSG_CREATE_DEV_IOCTL IOCTL and RPMSG_DESTROY_DEV_IOCTL to instantiate RPMsg
> >>> devices (patch 11)
> >>> The application can then create or release a channel by specifying:
> >>> - the name service of the device to instantiate.
> >>> - the source address.
> >>> - the destination address.
> >>>
> >>> This series has be applied and tested on 'commit e783362eb54c ("Linux 5.17-rc1") +
> >>> rpmsg_char cdev release fixes [2][3]
> >>>
> >>> [1] https://lkml.org/lkml/2021/12/7/186
> >>> [2] https://lkml.org/lkml/2022/1/10/1129
> >>> [3] https://lkml.org/lkml/2022/1/10/1130
> >>>
> >>> Arnaud Pouliquen (11):
> >>> rpmsg: char: Export eptdev create and destroy functions
> >>> rpmsg: Create the rpmsg class in core instead of in rpmsg char
> >>> rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl
> >>
> >>
> >>> arm: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
> >>> RISC-V: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
> >>> arm64: defconfig: Config that had RPMSG_CHAR now gets RPMSG_CTRL
> >>
> >> Thank you for merging this series!
> >>
> >> I can't see in the "for next" branch[1] the 3 patches above that update configs
> >> Are you expecting a specific action from me?
> >
> > Those patches will need to go through the Arm, RISC-V and arm64 subsystems. The
> > mailing list for those subsystems has been CC'ed but that isn't enough to get
> > the maintainers' attention.
> >
> > I suggest sending another patchset with those 3 patches that CC the maintainers
> > directly. For the Arm patch I suggest adding Linus Walleij.
>
> I will do what you suggest.
>
> My concerns in this case is about the scheduling of the integration.
> I suppose that sending a second patchset for configs requests that the
> rpmsg char series is first applied

Right, but the rpmsg_char series has been applied.

> But on the other hand this may lead to some failures as the RPMSG_CTRL is now
> needed to create the /dev/rpmsg_ctrl0
>

Possibly, but right now there is no other way.

> so probably, I need to do this as fixup patch.
>

Indeed, this can be applied as a fix in rc1.

> FYI the RISC-V patch as been reviewed by Anup Patel
>

... but Anup does not maintain any of the defconfig files.

> Thanks,
> Arnaud
>
> >
> > Thanks,
> > Mathieu
> >
> >>
> >> [1]https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git
> >>
> >> Regards,
> >> Arnaud
> >>
> >>> rpmsg: Update rpmsg_chrdev_register_device function
> >>> rpmsg: char: Refactor rpmsg_chrdev_eptdev_create function
> >>> rpmsg: char: Add possibility to use default endpoint of the rpmsg
> >>> device
> >>> rpmsg: char: Introduce the "rpmsg-raw" channel
> >>> rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls
> >>>
> >>> arch/arm/configs/qcom_defconfig | 1 +
> >>> arch/arm64/configs/defconfig | 1 +
> >>> arch/riscv/configs/defconfig | 1 +
> >>> arch/riscv/configs/rv32_defconfig | 1 +
> >>> drivers/rpmsg/Kconfig | 8 +
> >>> drivers/rpmsg/Makefile | 1 +
> >>> drivers/rpmsg/qcom_glink_native.c | 2 +-
> >>> drivers/rpmsg/qcom_smd.c | 2 +-
> >>> drivers/rpmsg/rpmsg_char.c | 231 +++++++++++-----------------
> >>> drivers/rpmsg/rpmsg_char.h | 46 ++++++
> >>> drivers/rpmsg/rpmsg_core.c | 15 +-
> >>> drivers/rpmsg/rpmsg_ctrl.c | 243 ++++++++++++++++++++++++++++++
> >>> drivers/rpmsg/rpmsg_internal.h | 10 +-
> >>> drivers/rpmsg/virtio_rpmsg_bus.c | 2 +-
> >>> include/uapi/linux/rpmsg.h | 10 ++
> >>> 15 files changed, 419 insertions(+), 155 deletions(-)
> >>> create mode 100644 drivers/rpmsg/rpmsg_char.h
> >>> create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
> >>>

2022-03-25 20:16:11

by Arnaud Pouliquen

[permalink] [raw]

Subject: Re: [PATCH v9 00/11] Restructure the rpmsg_char driver and introduce rpmsg_ctrl driver

On 3/25/22 18:27, Mathieu Poirier wrote:
> On Fri, 25 Mar 2022 at 11:05, Arnaud POULIQUEN
> <[email protected]> wrote:
>>
>>
>>
>> On 3/25/22 16:59, Mathieu Poirier wrote:
>>> On Thu, Mar 24, 2022 at 06:36:23PM +0100, Arnaud POULIQUEN wrote:
>>>> Hi Bjorn,
>>>>
>>>> On 1/24/22 11:25, Arnaud Pouliquen wrote:
>>>>> Updates from V8 [1]:
>>>>> - rebase on 5.17-rc1 + rpmsg char cdev release fixes[2][3]
>>>>> - updates based on Bjorn Andersson's comments:
>>>>> - remove rpmsg_create_default_ept API, set directly the ept->priv in rpmsg_chrdev_probe
>>>>> function.
>>>>> - rework commit message in [8/9]rpmsg: char: Introduce the "rpmsg-raw" channel
>>>>>
>>>>> Patchset description:
>>>>>
>>>>> The current rpmsg_char module implements a /dev/rpmsg_ctrl interface that provides the ability to
>>>>> instantiate char devices (/dev/rpmsgX) associated with an rpmsg endpoint for communication with the
>>>>> remote processor.
>>>>> This implementation fits with QCOM rpmsg backend but not with the magement by chanel implemented
>>>>> in the generic rpmsg virtio backend.
>>>>> This series restructures the rpmsg_char driver to decorrelate the control part from the data part
>>>>> in order to improve its compatible with the rpmsg virtio backend.
>>>>>
>>>>> Objective:
>>>>> - Expose a /dev/rpmsg_ctrlX interface for the application that is no longer dedicated to the
>>>>> rpmsg_char but generalized to all rpmsg services. This offers capability to create and destroy
>>>>> rpmsg channels from a user's application initiative (using the new RPMSG_CREATE_DEV_IOCTL and
>>>>> RPMSG_DESTROY_DEV_IOCTL controls).
>>>>> An application will be able to create/establish an rpmsg communication channel to communicate
>>>>> with the remote processor, and not only wait the remote processor initiative.
>>>>> This is interesting for example to establish a temporary communication link for diagnosis,
>>>>> calibration, debugging... or instantiate new data flows on some user actions.
>>>>> - Add capability to probe the rpmsg_char device at the initiative of the remote processor
>>>>> (rpmsg service announcement mechanism).
>>>>> This allows platforms based on the rpmsg virtio backend to create the /dev/rpmgX interface with
>>>>> a rpmsg name service announcement.
>>>>>
>>>>> Subsets:
>>>>> - Extract the control part of the char dev and create the rpmsg_ctrl.c file (patches 1 to 6)
>>>>> - Introduce the "rpmsg-raw" channel in rpmsg_char(patches 7 to 10)
>>>>> - Introduce the RPMSG_CREATE_DEV_IOCTL IOCTL and RPMSG_DESTROY_DEV_IOCTL to instantiate RPMsg
>>>>> devices (patch 11)
>>>>> The application can then create or release a channel by specifying:
>>>>> - the name service of the device to instantiate.
>>>>> - the source address.
>>>>> - the destination address.
>>>>>
>>>>> This series has be applied and tested on 'commit e783362eb54c ("Linux 5.17-rc1") +
>>>>> rpmsg_char cdev release fixes [2][3]
>>>>>
>>>>> [1] https://lkml.org/lkml/2021/12/7/186
>>>>> [2] https://lkml.org/lkml/2022/1/10/1129
>>>>> [3] https://lkml.org/lkml/2022/1/10/1130
>>>>>
>>>>> Arnaud Pouliquen (11):
>>>>> rpmsg: char: Export eptdev create and destroy functions
>>>>> rpmsg: Create the rpmsg class in core instead of in rpmsg char
>>>>> rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl
>>>>
>>>>
>>>>> arm: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
>>>>> RISC-V: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
>>>>> arm64: defconfig: Config that had RPMSG_CHAR now gets RPMSG_CTRL
>>>>
>>>> Thank you for merging this series!
>>>>
>>>> I can't see in the "for next" branch[1] the 3 patches above that update configs
>>>> Are you expecting a specific action from me?
>>>
>>> Those patches will need to go through the Arm, RISC-V and arm64 subsystems. The
>>> mailing list for those subsystems has been CC'ed but that isn't enough to get
>>> the maintainers' attention.
>>>
>>> I suggest sending another patchset with those 3 patches that CC the maintainers
>>> directly. For the Arm patch I suggest adding Linus Walleij.
>>
>> I will do what you suggest.
>>
>> My concerns in this case is about the scheduling of the integration.
>> I suppose that sending a second patchset for configs requests that the
>> rpmsg char series is first applied
>
> Right, but the rpmsg_char series has been applied.
>
>> But on the other hand this may lead to some failures as the RPMSG_CTRL is now
>> needed to create the /dev/rpmsg_ctrl0
>>
>
> Possibly, but right now there is no other way.
>
>> so probably, I need to do this as fixup patch.
>>
>
> Indeed, this can be applied as a fix in rc1.

Yes, that's what I had in mind, I'll do it that way.

Thanks,
Arnaud

>
>> FYI the RISC-V patch as been reviewed by Anup Patel
>>
>
> ... but Anup does not maintain any of the defconfig files.
>
>> Thanks,
>> Arnaud
>>
>>>
>>> Thanks,
>>> Mathieu
>>>
>>>>
>>>> [1]https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git
>>>>
>>>> Regards,
>>>> Arnaud
>>>>
>>>>> rpmsg: Update rpmsg_chrdev_register_device function
>>>>> rpmsg: char: Refactor rpmsg_chrdev_eptdev_create function
>>>>> rpmsg: char: Add possibility to use default endpoint of the rpmsg
>>>>> device
>>>>> rpmsg: char: Introduce the "rpmsg-raw" channel
>>>>> rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls
>>>>>
>>>>> arch/arm/configs/qcom_defconfig | 1 +
>>>>> arch/arm64/configs/defconfig | 1 +
>>>>> arch/riscv/configs/defconfig | 1 +
>>>>> arch/riscv/configs/rv32_defconfig | 1 +
>>>>> drivers/rpmsg/Kconfig | 8 +
>>>>> drivers/rpmsg/Makefile | 1 +
>>>>> drivers/rpmsg/qcom_glink_native.c | 2 +-
>>>>> drivers/rpmsg/qcom_smd.c | 2 +-
>>>>> drivers/rpmsg/rpmsg_char.c | 231 +++++++++++-----------------
>>>>> drivers/rpmsg/rpmsg_char.h | 46 ++++++
>>>>> drivers/rpmsg/rpmsg_core.c | 15 +-
>>>>> drivers/rpmsg/rpmsg_ctrl.c | 243 ++++++++++++++++++++++++++++++
>>>>> drivers/rpmsg/rpmsg_internal.h | 10 +-
>>>>> drivers/rpmsg/virtio_rpmsg_bus.c | 2 +-
>>>>> include/uapi/linux/rpmsg.h | 10 ++
>>>>> 15 files changed, 419 insertions(+), 155 deletions(-)
>>>>> create mode 100644 drivers/rpmsg/rpmsg_char.h
>>>>> create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>>>>