mhi: core: Factorize mhi queuing

Instead of duplicating queuing procedure in mhi_queue_dma(),
mhi_queue_buf() and mhi_queue_skb(), add a new generic mhi_queue()
as common helper.

Note that the unified mhi_queue align pm_lock locking on mhi_queue_buf
behavior, taking it with irqsave variant (vs _bh for former queue_skb
and queue_dma version).

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 8576b0f03f2cd5d5b723b6a83d130e3f506d3f7c..b67c25491069b668175017e8b9c66090c5a2b017 100644 (file)
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -967,118 +967,88 @@ static bool mhi_is_ring_full(struct mhi_controller *mhi_cntrl,
        return (tmp == ring->rp);
 }
 
-int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
-                 struct sk_buff *skb, size_t len, enum mhi_flags mflags)
+static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
+                    enum dma_data_direction dir, enum mhi_flags mflags)
 {
        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;
-       struct mhi_buf_info buf_info = { };
+       unsigned long flags;
        int ret;
 
-       /* If MHI host pre-allocates buffers then client drivers cannot queue */
-       if (mhi_chan->pre_alloc)
-               return -EINVAL;
+       if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
+               return -EIO;
 
-       if (mhi_is_ring_full(mhi_cntrl, tre_ring))
-               return -ENOMEM;
+       read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
 
-       read_lock_bh(&mhi_cntrl->pm_lock);
-       if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
-               read_unlock_bh(&mhi_cntrl->pm_lock);
-               return -EIO;
+       ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
+       if (unlikely(ret)) {
+               ret = -ENOMEM;
+               goto exit_unlock;
        }
 
-       /* we're in M3 or transitioning to M3 */
+       ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
+       if (unlikely(ret))
+               goto exit_unlock;
+
+       /* trigger M3 exit if necessary */
        if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
                mhi_trigger_resume(mhi_cntrl);
 
-       /* Toggle wake to exit out of M2 */
+       /* Assert dev_wake (to exit/prevent M1/M2)*/
        mhi_cntrl->wake_toggle(mhi_cntrl);
 
-       buf_info.v_addr = skb->data;
-       buf_info.cb_buf = skb;
-       buf_info.len = len;
-
-       ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
-       if (unlikely(ret)) {
-               read_unlock_bh(&mhi_cntrl->pm_lock);
-               return ret;
-       }
-
        if (mhi_chan->dir == DMA_TO_DEVICE)
                atomic_inc(&mhi_cntrl->pending_pkts);
 
-       if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
-               read_lock_bh(&mhi_chan->lock);
-               mhi_ring_chan_db(mhi_cntrl, mhi_chan);
-               read_unlock_bh(&mhi_chan->lock);
+       if (unlikely(!MHI_DB_ACCESS_VALID(mhi_cntrl))) {
+               ret = -EIO;
+               goto exit_unlock;
        }
 
-       read_unlock_bh(&mhi_cntrl->pm_lock);
+       mhi_ring_chan_db(mhi_cntrl, mhi_chan);
 
-       return 0;
+exit_unlock:
+       read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
+
+       return ret;
 }
-EXPORT_SYMBOL_GPL(mhi_queue_skb);
 
-int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
-                 struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags)
+int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+                 struct sk_buff *skb, size_t len, enum mhi_flags mflags)
 {
-       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 device *dev = &mhi_cntrl->mhi_dev->dev;
-       struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
        struct mhi_buf_info buf_info = { };
-       int ret;
-
-       /* If MHI host pre-allocates buffers then client drivers cannot queue */
-       if (mhi_chan->pre_alloc)
-               return -EINVAL;
-
-       if (mhi_is_ring_full(mhi_cntrl, tre_ring))
-               return -ENOMEM;
 
-       read_lock_bh(&mhi_cntrl->pm_lock);
-       if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
-               dev_err(dev, "MHI is not in activate state, PM state: %s\n",
-                       to_mhi_pm_state_str(mhi_cntrl->pm_state));
-               read_unlock_bh(&mhi_cntrl->pm_lock);
+       buf_info.v_addr = skb->data;
+       buf_info.cb_buf = skb;
+       buf_info.len = len;
 
-               return -EIO;
-       }
+       if (unlikely(mhi_chan->pre_alloc))
+               return -EINVAL;
 
-       /* we're in M3 or transitioning to M3 */
-       if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
-               mhi_trigger_resume(mhi_cntrl);
+       return mhi_queue(mhi_dev, &buf_info, dir, mflags);
+}
+EXPORT_SYMBOL_GPL(mhi_queue_skb);
 
-       /* Toggle wake to exit out of M2 */
-       mhi_cntrl->wake_toggle(mhi_cntrl);
+int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+                 struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags)
+{
+       struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
+                                                            mhi_dev->dl_chan;
+       struct mhi_buf_info buf_info = { };
 
        buf_info.p_addr = mhi_buf->dma_addr;
        buf_info.cb_buf = mhi_buf;
        buf_info.pre_mapped = true;
        buf_info.len = len;
 
-       ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
-       if (unlikely(ret)) {
-               read_unlock_bh(&mhi_cntrl->pm_lock);
-               return ret;
-       }
-
-       if (mhi_chan->dir == DMA_TO_DEVICE)
-               atomic_inc(&mhi_cntrl->pending_pkts);
-
-       if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
-               read_lock_bh(&mhi_chan->lock);
-               mhi_ring_chan_db(mhi_cntrl, mhi_chan);
-               read_unlock_bh(&mhi_chan->lock);
-       }
-
-       read_unlock_bh(&mhi_cntrl->pm_lock);
+       if (unlikely(mhi_chan->pre_alloc))
+               return -EINVAL;
 
-       return 0;
+       return mhi_queue(mhi_dev, &buf_info, dir, mflags);
 }
 EXPORT_SYMBOL_GPL(mhi_queue_dma);
 
@@ -1132,57 +1102,13 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
 int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
                  void *buf, size_t len, enum mhi_flags mflags)
 {
-       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;
        struct mhi_buf_info buf_info = { };
-       unsigned long flags;
-       int ret;
-
-       /*
-        * this check here only as a guard, it's always
-        * possible mhi can enter error while executing rest of function,
-        * which is not fatal so we do not need to hold pm_lock
-        */
-       if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
-               return -EIO;
-
-       tre_ring = &mhi_chan->tre_ring;
-       if (mhi_is_ring_full(mhi_cntrl, tre_ring))
-               return -ENOMEM;
 
        buf_info.v_addr = buf;
        buf_info.cb_buf = buf;
        buf_info.len = len;
 
-       ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
-       if (unlikely(ret))
-               return ret;
-
-       read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
-
-       /* we're in M3 or transitioning to M3 */
-       if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
-               mhi_trigger_resume(mhi_cntrl);
-
-       /* Toggle wake to exit out of M2 */
-       mhi_cntrl->wake_toggle(mhi_cntrl);
-
-       if (mhi_chan->dir == DMA_TO_DEVICE)
-               atomic_inc(&mhi_cntrl->pending_pkts);
-
-       if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
-               unsigned long flags;
-
-               read_lock_irqsave(&mhi_chan->lock, flags);
-               mhi_ring_chan_db(mhi_cntrl, mhi_chan);
-               read_unlock_irqrestore(&mhi_chan->lock, flags);
-       }
-
-       read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
-
-       return 0;
+       return mhi_queue(mhi_dev, &buf_info, dir, mflags);
 }
 EXPORT_SYMBOL_GPL(mhi_queue_buf);