Skip to content

Commit

Permalink
mhi: core: Factorize mhi queuing
Browse files Browse the repository at this point in the history 
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>
  • Loading branch information
Loic Poulain authored and Manivannan Sadhasivam committed Jan 21, 2021
1 parent cdce266 commit a8f75cb
Showing 1 changed file with 44 additions and 118 deletions.
162 changes: 44 additions & 118 deletions drivers/bus/mhi/core/main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down Expand Up @@ -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);

Expand Down

0 comments on commit a8f75cb

Please sign in to comment.