[PATCH v2] bus: mhi: core: Add an API for auto queueing buffers for DL channel
From: Manivannan Sadhasivam <hidden>
Date: 2021-12-07 07:13:49
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 Cc: Jakub Kicinski <kuba@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Loic Poulain <redacted> Signed-off-by: Loic Poulain <redacted> Signed-off-by: Manivannan Sadhasivam <redacted> --- Changes in v2: * Rebased on top of 5.16-rc1 * Fixed an issue reported by kernel test bot * CCed netdev folks and Greg * Slight change to the commit subject for reflecting "core" sub-directory 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 9d72b1d1e986..e2e10474a9d9 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h@@ -682,8 +682,12 @@ 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 930aba666b67..ffde617f93a3 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,
@@ -1610,8 +1613,7 @@ 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) +static 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;
@@ -1622,7 +1624,7 @@ 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; }
@@ -1640,8 +1642,19 @@ 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