[PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[Manivannan Sadhasivam]

Add a new API "mhi_prepare_for_transfer_autoqueue" for using with client
drivers like QRTR to request MHI core to autoqueue buffers for the DL
channel along with starting both UL and DL channels.

So far, the "auto_queue" flag specified by the controller drivers in
channel definition served this purpose but this will be removed at some
point in future.

Cc: netdev@vger.kernel.org
Co-developed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

Dave, Jakub: This patch should go through MHI tree. But since the QRTR driver
is also modified, this needs an Ack from you.

 drivers/bus/mhi/core/internal.h |  6 +++++-
 drivers/bus/mhi/core/main.c     | 21 +++++++++++++++++----
 include/linux/mhi.h             | 21 ++++++++++++++++-----
 net/qrtr/mhi.c                  |  2 +-
 4 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 3a732afaf73e..597da2cce069 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -681,8 +681,12 @@ void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl);
 void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
 		      struct image_info *img_info);
 void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl);
+
+/* Automatically allocate and queue inbound buffers */
+#define MHI_CH_INBOUND_ALLOC_BUFS BIT(0)
 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
-			struct mhi_chan *mhi_chan);
+			struct mhi_chan *mhi_chan, unsigned int flags);
+
 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
 		       struct mhi_chan *mhi_chan);
 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index b15c5bc37dd4..eaa1f62d16a5 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1430,7 +1430,7 @@ static void mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
 }
 
 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
-			struct mhi_chan *mhi_chan)
+			struct mhi_chan *mhi_chan, unsigned int flags)
 {
 	int ret = 0;
 	struct device *dev = &mhi_chan->mhi_dev->dev;
@@ -1455,6 +1455,9 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
 	if (ret)
 		goto error_pm_state;
 
+	if (mhi_chan->dir == DMA_FROM_DEVICE)
+		mhi_chan->pre_alloc = !!(flags & MHI_CH_INBOUND_ALLOC_BUFS);
+
 	/* Pre-allocate buffer for xfer ring */
 	if (mhi_chan->pre_alloc) {
 		int nr_el = get_nr_avail_ring_elements(mhi_cntrl,
@@ -1609,8 +1612,7 @@ void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan)
 	read_unlock_bh(&mhi_cntrl->pm_lock);
 }
 
-/* Move channel to start state */
-int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
+int __mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
 {
 	int ret, dir;
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
@@ -1621,7 +1623,7 @@ int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
 		if (!mhi_chan)
 			continue;
 
-		ret = mhi_prepare_channel(mhi_cntrl, mhi_chan);
+		ret = mhi_prepare_channel(mhi_cntrl, mhi_chan, flags);
 		if (ret)
 			goto error_open_chan;
 	}
@@ -1639,8 +1641,19 @@ int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
 
 	return ret;
 }
+
+int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
+{
+	return __mhi_prepare_for_transfer(mhi_dev, 0);
+}
 EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer);
 
+int mhi_prepare_for_transfer_autoqueue(struct mhi_device *mhi_dev)
+{
+	return __mhi_prepare_for_transfer(mhi_dev, MHI_CH_INBOUND_ALLOC_BUFS);
+}
+EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer_autoqueue);
+
 void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev)
 {
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 723985879035..271db1d6da85 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -717,15 +717,26 @@ void mhi_device_put(struct mhi_device *mhi_dev);
 
 /**
  * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
- *                            Allocate and initialize the channel context and
- *                            also issue the START channel command to both
- *                            channels. Channels can be started only if both
- *                            host and device execution environments match and
- *                            channels are in a DISABLED state.
  * @mhi_dev: Device associated with the channels
+ *
+ * Allocate and initialize the channel context and also issue the START channel
+ * command to both channels. Channels can be started only if both host and
+ * device execution environments match and channels are in a DISABLED state.
  */
 int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
 
+/**
+ * mhi_prepare_for_transfer_autoqueue - Setup UL and DL channels with auto queue
+ *                                      buffers for DL traffic
+ * @mhi_dev: Device associated with the channels
+ *
+ * Allocate and initialize the channel context and also issue the START channel
+ * command to both channels. Channels can be started only if both host and
+ * device execution environments match and channels are in a DISABLED state.
+ * The MHI core will automatically allocate and queue buffers for the DL traffic.
+ */
+int mhi_prepare_for_transfer_autoqueue(struct mhi_device *mhi_dev);
+
 /**
  * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
  *                               Issue the RESET channel command and let the
diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
index fa611678af05..18196e1c8c2f 100644
--- a/net/qrtr/mhi.c
+++ b/net/qrtr/mhi.c
@@ -79,7 +79,7 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 	int rc;
 
 	/* start channels */
-	rc = mhi_prepare_for_transfer(mhi_dev);
+	rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
 	if (rc)
 		return rc;
 
-- 
2.25.1

Re: [PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[Jakub Kicinski]

On Tue, 19 Oct 2021 19:14:51 +0530 Manivannan Sadhasivam wrote:
> Add a new API "mhi_prepare_for_transfer_autoqueue" for using with client
> drivers like QRTR to request MHI core to autoqueue buffers for the DL
> channel along with starting both UL and DL channels.
> 
> So far, the "auto_queue" flag specified by the controller drivers in
> channel definition served this purpose but this will be removed at some
> point in future.
> 
> Cc: netdev@vger.kernel.org
> Co-developed-by: Loic Poulain <loic.poulain@linaro.org>
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> 
> Dave, Jakub: This patch should go through MHI tree. But since the QRTR driver
> is also modified, this needs an Ack from you.

CCing us wouldn't hurt.

Speaking of people who aren't CCed I've seen Greg nack the flags
argument.

SMH

Re: [PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[Greg KH]

On Tue, Oct 19, 2021 at 07:49:18AM -0700, Jakub Kicinski wrote:
> On Tue, 19 Oct 2021 19:14:51 +0530 Manivannan Sadhasivam wrote:
> > Add a new API "mhi_prepare_for_transfer_autoqueue" for using with client
> > drivers like QRTR to request MHI core to autoqueue buffers for the DL
> > channel along with starting both UL and DL channels.
> > 
> > So far, the "auto_queue" flag specified by the controller drivers in
> > channel definition served this purpose but this will be removed at some
> > point in future.
> > 
> > Cc: netdev@vger.kernel.org
> > Co-developed-by: Loic Poulain <loic.poulain@linaro.org>
> > Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> > 
> > Dave, Jakub: This patch should go through MHI tree. But since the QRTR driver
> > is also modified, this needs an Ack from you.
> 
> CCing us wouldn't hurt.
> 
> Speaking of people who aren't CCed I've seen Greg nack the flags
> argument.

Yes, that type of api is not ok.

Re: [PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[Manivannan Sadhasivam]

On Tue, Oct 19, 2021 at 07:49:18AM -0700, Jakub Kicinski wrote:
> On Tue, 19 Oct 2021 19:14:51 +0530 Manivannan Sadhasivam wrote:
> > Add a new API "mhi_prepare_for_transfer_autoqueue" for using with client
> > drivers like QRTR to request MHI core to autoqueue buffers for the DL
> > channel along with starting both UL and DL channels.
> > 
> > So far, the "auto_queue" flag specified by the controller drivers in
> > channel definition served this purpose but this will be removed at some
> > point in future.
> > 
> > Cc: netdev@vger.kernel.org
> > Co-developed-by: Loic Poulain <loic.poulain@linaro.org>
> > Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> > 
> > Dave, Jakub: This patch should go through MHI tree. But since the QRTR driver
> > is also modified, this needs an Ack from you.
> 
> CCing us wouldn't hurt.
> 

Okay.

> Speaking of people who aren't CCed I've seen Greg nack the flags
> argument.
> 

I usually send patches to Greg during the PR time as MHI patches goes through
char-misc tree. I don't include him during the patch reviews.

And yes, Greg indeed NACK the API that had flags argument. But this one didn't.

Thanks,
Mani

> SMH

Re: [PATCH] bus: mhi: Add mhi_prepare_for_transfer_autoqueue API for DL auto queue

[kernel test robot]

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Hi Manivannan,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.15-rc6 next-20211019]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Manivannan-Sadhasivam/bus-mhi-Add-mhi_prepare_for_transfer_autoqueue-API-for-DL-auto-queue/20211019-221447
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 519d81956ee277b4419c723adfb154603c2565ba
config: hexagon-randconfig-r041-20211019 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project b37efed957ed0a0193d80020aefd55cb587dfc1f)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/434ab9e12f5e85c6d84c1a0524d850559b058291
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Manivannan-Sadhasivam/bus-mhi-Add-mhi_prepare_for_transfer_autoqueue-API-for-DL-auto-queue/20211019-221447
        git checkout 434ab9e12f5e85c6d84c1a0524d850559b058291
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=hexagon 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/bus/mhi/core/main.c:1615:5: warning: no previous prototype for function '__mhi_prepare_for_transfer' [-Wmissing-prototypes]
   int __mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
       ^
   drivers/bus/mhi/core/main.c:1615:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int __mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
   ^
   static 
   1 warning generated.


vim +/__mhi_prepare_for_transfer +1615 drivers/bus/mhi/core/main.c

  1614	
> 1615	int __mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
  1616	{
  1617		int ret, dir;
  1618		struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
  1619		struct mhi_chan *mhi_chan;
  1620	
  1621		for (dir = 0; dir < 2; dir++) {
  1622			mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
  1623			if (!mhi_chan)
  1624				continue;
  1625	
  1626			ret = mhi_prepare_channel(mhi_cntrl, mhi_chan, flags);
  1627			if (ret)
  1628				goto error_open_chan;
  1629		}
  1630	
  1631		return 0;
  1632	
  1633	error_open_chan:
  1634		for (--dir; dir >= 0; dir--) {
  1635			mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
  1636			if (!mhi_chan)
  1637				continue;
  1638	
  1639			mhi_unprepare_channel(mhi_cntrl, mhi_chan);
  1640		}
  1641	
  1642		return ret;
  1643	}
  1644	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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