Re: [PATCH] mhi: core: Factorize mhi queuing

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Thu, Dec 10, 2020 at 12:31:32PM +0100, Loic Poulain wrote:
> 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.
> 

While doing the factoring, please don't make any additional changes. If you want
to do, then use incremental patches.

Thanks,
Mani

> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>  drivers/bus/mhi/core/main.c | 160 +++++++++++---------------------------------
>  1 file changed, 38 insertions(+), 122 deletions(-)
> 
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index 3871ef0..4fa4c88 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -963,118 +963,78 @@ 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);
> -
> -		return -EIO;
> -	}
> +	buf_info.v_addr = skb->data;
> +	buf_info.cb_buf = skb;
> +	buf_info.len = len;
>  
> -	/* 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_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);
> -
> -	return 0;
> +	return mhi_queue(mhi_dev, &buf_info, dir, mflags);
>  }
>  EXPORT_SYMBOL_GPL(mhi_queue_dma);
>  
> @@ -1128,57 +1088,13 @@ 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);
>  
> -- 
> 2.7.4
>