mbox series

[v3,0/4] user space client interface driver

Message ID 1591899224-3403-1-git-send-email-hemantk@codeaurora.org
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Series user space client interface driver | expand

Message

Hemant Kumar June 11, 2020, 6:13 p.m. UTC
V3: Added documentation for MHI UCI driver.

V2: Added mutex lock to prevent multiple readers to access same
mhi buffer which can result into use after free.

Hemant Kumar (4):
  bus: mhi: core: Add helper API to return number of free TREs
  bus: mhi: core: Move MHI_MAX_MTU to external header file
  docs: Add documentation for user space client interface
  bus: mhi: clients: Add user space client interface driver

 Documentation/mhi/index.rst      |   1 +
 Documentation/mhi/uci.rst        |  19 ++
 drivers/bus/mhi/Kconfig          |   2 +
 drivers/bus/mhi/Makefile         |   1 +
 drivers/bus/mhi/clients/Kconfig  |  16 +
 drivers/bus/mhi/clients/Makefile |   3 +
 drivers/bus/mhi/clients/uci.c    | 652 +++++++++++++++++++++++++++++++++++++++
 drivers/bus/mhi/core/main.c      |  12 +
 include/linux/mhi.h              |  12 +
 9 files changed, 718 insertions(+)
 create mode 100644 Documentation/mhi/uci.rst
 create mode 100644 drivers/bus/mhi/clients/Kconfig
 create mode 100644 drivers/bus/mhi/clients/Makefile
 create mode 100644 drivers/bus/mhi/clients/uci.c

Comments

Manivannan Sadhasivam June 19, 2020, 5:31 a.m. UTC | #1
On Thu, Jun 11, 2020 at 11:13:41AM -0700, Hemant Kumar wrote:
> Introduce mhi_get_no_free_descriptors() API to return number

> of TREs available to queue buffer. MHI clients can use this

> API to know before hand if ring is full without calling queue

> API.

> 

> Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>

> ---

>  drivers/bus/mhi/core/main.c | 12 ++++++++++++

>  include/linux/mhi.h         |  9 +++++++++

>  2 files changed, 21 insertions(+)

> 

> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c

> index d25f321..1bd3b1e 100644

> --- a/drivers/bus/mhi/core/main.c

> +++ b/drivers/bus/mhi/core/main.c

> @@ -258,6 +258,18 @@ int mhi_destroy_device(struct device *dev, void *data)

>  	return 0;

>  }

>  

> +int mhi_get_no_free_descriptors(struct mhi_device *mhi_dev,

> +				enum dma_data_direction dir)


How about "mhi_get_nr_free_descriptors"? Also align with '('

> +{

> +	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;

> +	struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?

> +		mhi_dev->ul_chan : mhi_dev->dl_chan;

> +	struct mhi_ring *tre_ring = &mhi_chan->tre_ring;

> +

> +	return get_nr_avail_ring_elements(mhi_cntrl, tre_ring);

> +}

> +EXPORT_SYMBOL_GPL(mhi_get_no_free_descriptors);

> +

>  void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)

>  {

>  	struct mhi_driver *mhi_drv;

> diff --git a/include/linux/mhi.h b/include/linux/mhi.h

> index 6af6bd6..a39b77d 100644

> --- a/include/linux/mhi.h

> +++ b/include/linux/mhi.h

> @@ -602,6 +602,15 @@ void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,

>  void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);

>  

>  /**

> + * mhi_get_no_free_descriptors - Get transfer ring length


Is the description correct? I'd suggest to just use the below one.

> + * Get # of TD available to queue buffers


How about, "Get # of available TREs to queue buffers"?

> + * @mhi_dev: Device associated with the channels

> + * @dir: Direction of the channel

> + */

> +int mhi_get_no_free_descriptors(struct mhi_device *mhi_dev,

> +				enum dma_data_direction dir);


Align this with '('

Thanks,
Mani

> +

> +/**

>   * mhi_prepare_for_power_up - Do pre-initialization before power up.

>   *                            This is optional, call this before power up if

>   *                            the controller does not want bus framework to

> -- 

> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,

> a Linux Foundation Collaborative Project

>
Manivannan Sadhasivam June 19, 2020, 5:33 a.m. UTC | #2
On Thu, Jun 11, 2020 at 11:13:42AM -0700, Hemant Kumar wrote:
> Currently this macro is defined in internal MHI header as

> a TRE length mask. Moving it to external header allows MHI

> client drivers to set this upper bound for the transmit

> buffer size.

> 


So we have 2 definitions for MHI_MAX_MTU now? Why can't you remove the one
available internally?

Thanks,
Mani

> Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>

> ---

>  include/linux/mhi.h | 3 +++

>  1 file changed, 3 insertions(+)

> 

> diff --git a/include/linux/mhi.h b/include/linux/mhi.h

> index a39b77d..ce43f74 100644

> --- a/include/linux/mhi.h

> +++ b/include/linux/mhi.h

> @@ -16,6 +16,9 @@

>  #include <linux/wait.h>

>  #include <linux/workqueue.h>

>  

> +/* MHI client drivers to set this upper bound for tx buffer */

> +#define MHI_MAX_MTU 0xffff

> +

>  #define MHI_VOTE_BUS BIT(0) /* do not disable the mhi bus */

>  #define MHI_VOTE_DEVICE BIT(1) /* prevent mhi device from entering lpm */

>  

> -- 

> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,

> a Linux Foundation Collaborative Project

>
Hemant Kumar June 25, 2020, 12:03 a.m. UTC | #3
Hi Mani

On 6/18/20 10:33 PM, Manivannan Sadhasivam wrote:
> On Thu, Jun 11, 2020 at 11:13:42AM -0700, Hemant Kumar wrote:

>> Currently this macro is defined in internal MHI header as

>> a TRE length mask. Moving it to external header allows MHI

>> client drivers to set this upper bound for the transmit

>> buffer size.

>>

> 

> So we have 2 definitions for MHI_MAX_MTU now? Why can't you remove the one

> available internally?

Good catch, let me fix that in next patch series.
> 

> Thanks,

> Mani

> 

>> Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>

>> ---

>>   include/linux/mhi.h | 3 +++

>>   1 file changed, 3 insertions(+)

>>

>> diff --git a/include/linux/mhi.h b/include/linux/mhi.h

>> index a39b77d..ce43f74 100644

>> --- a/include/linux/mhi.h

>> +++ b/include/linux/mhi.h

>> @@ -16,6 +16,9 @@

>>   #include <linux/wait.h>

>>   #include <linux/workqueue.h>

>>   

>> +/* MHI client drivers to set this upper bound for tx buffer */

>> +#define MHI_MAX_MTU 0xffff

>> +

>>   #define MHI_VOTE_BUS BIT(0) /* do not disable the mhi bus */

>>   #define MHI_VOTE_DEVICE BIT(1) /* prevent mhi device from entering lpm */

>>   

>> -- 

>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,

>> a Linux Foundation Collaborative Project

>>


-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project