V6:
- Moved uci.c to mhi directory.
- Updated Kconfig to add module information.
- Updated Makefile to rename uci object file name as mhi_uci
- Removed kref for open count
V5:
- Removed mhi_uci_drv structure.
- Used idr instead of creating global list of uci devices.
- Used kref instead of local ref counting for uci device and
open count.
- Removed unlikely macro.
V4:
- Fix locking to protect proper struct members.
- Updated documentation describing uci client driver use cases.
- Fixed uci ref counting in mhi_uci_open for error case.
- Addressed style related review comments.
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 userspace client interface
bus: mhi: Add userspace client interface driver
Documentation/mhi/index.rst | 1 +
Documentation/mhi/uci.rst | 39 +++
drivers/bus/mhi/Kconfig | 13 +
drivers/bus/mhi/Makefile | 4 +
drivers/bus/mhi/core/internal.h | 1 -
drivers/bus/mhi/core/main.c | 12 +
drivers/bus/mhi/uci.c | 657 ++++++++++++++++++++++++++++++++++++++++
include/linux/mhi.h | 12 +
8 files changed, 738 insertions(+), 1 deletion(-)
create mode 100644 Documentation/mhi/uci.rst
create mode 100644 drivers/bus/mhi/uci.c
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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 <[email protected]>
---
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 2cff5dd..0599e7d 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)
+{
+ 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 a35d876..6565528 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -600,6 +600,15 @@ 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
+ * Get # of TD available 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);
+
+/**
* 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
"user space client interface driver" is a very generic and there is
absolutel no explanation in this cover letter. What is this supposed
to be?
On Wed, Sep 16, 2020 at 12:56:04PM -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 <[email protected]>
> ---
> 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 2cff5dd..0599e7d 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)
> +{
> + 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);
Hmm, so this is essentially a wrapper for get_nr_avail_ring_elements().
Why can't you call this API directly?
> +}
> +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 a35d876..6565528 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -600,6 +600,15 @@ 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
mhi_get_nr_free_descriptors?
> + * Get # of TD available 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 enum with start of "("
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
>