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Commit 920d1841 authored by Sujeev Dias's avatar Sujeev Dias Committed by Gerrit - the friendly Code Review server
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mhi: core: add support for using pre-mapped buffers for data transfer 



Some MHI clients already pre-map the buffer before passing it to MHI
core layer. They do this when using memory reclaim algorithms and
wants to avoid mapping and unmapping buffers after each transfer.

CRs-Fixed: 2361266
Change-Id: If78d66c77c6887a1841a4d94108052e26b07c231
Signed-off-by: default avatarSujeev Dias <sdias@codeaurora.org>
parent 846dbfa1

drivers/bus/mhi/core/mhi_init.c

+4 −1
Original line number Diff line number Diff line
@@ -977,7 +977,6 @@ static int of_parse_ch_cfg(struct mhi_controller *mhi_cntrl, 
			mhi_chan->gen_tre = mhi_gen_tre;

			mhi_chan->queue_xfer = mhi_queue_buf;

			break;

		case MHI_XFER_RSC_SKB:

		case MHI_XFER_SKB:

			mhi_chan->queue_xfer = mhi_queue_skb;

			break;
@@ -988,6 +987,10 @@ static int of_parse_ch_cfg(struct mhi_controller *mhi_cntrl, 
		case MHI_XFER_NOP:

			mhi_chan->queue_xfer = mhi_queue_nop;

			break;

		case MHI_XFER_DMA:

		case MHI_XFER_RSC_DMA:

			mhi_chan->queue_xfer = mhi_queue_dma;

			break;

		default:

			goto error_chan_cfg;

		}

drivers/bus/mhi/core/mhi_internal.h

+5 −2
Original line number Diff line number Diff line
@@ -463,7 +463,8 @@ enum MHI_XFER_TYPE { 
	MHI_XFER_SKB,

	MHI_XFER_SCLIST,

	MHI_XFER_NOP, /* CPU offload channel, host does not accept transfer */

	MHI_XFER_RSC_SKB, /* RSC type, accept skb from client */

	MHI_XFER_DMA, /* receive dma address, already mapped by client */

	MHI_XFER_RSC_DMA, /* RSC type, accept premapped buffer */

};



#define NR_OF_CMD_RINGS (1)
@@ -559,6 +560,7 @@ struct mhi_buf_info { 
	size_t len;

	void *cb_buf;

	bool used; /* indicate element is free to use */

	bool pre_mapped; /* already pre-mapped by client */

	enum dma_data_direction dir;

};
@@ -703,7 +705,8 @@ int mhi_queue_sclist(struct mhi_device *mhi_dev, struct mhi_chan *mhi_chan, 
		  void *buf, size_t len, enum MHI_FLAGS mflags);

int mhi_queue_nop(struct mhi_device *mhi_dev, struct mhi_chan *mhi_chan,

		  void *buf, size_t len, enum MHI_FLAGS mflags);



int mhi_queue_dma(struct mhi_device *mhi_dev, struct mhi_chan *mhi_chan,

		  void *buf, size_t len, enum MHI_FLAGS mflags);



/* register access methods */

void mhi_db_brstmode(struct mhi_controller *mhi_cntrl, struct db_cfg *db_cfg,

drivers/bus/mhi/core/mhi_main.c

+96 −16
Original line number Diff line number Diff line
@@ -380,7 +380,6 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, 


	/* generate the tre */

	buf_info = buf_ring->wp;

	MHI_ASSERT(buf_info->used, "TRE Not Freed\n");

	buf_info->v_addr = skb->data;

	buf_info->cb_buf = skb;

	buf_info->wp = tre_ring->wp;
@@ -392,7 +391,96 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, 


	mhi_tre = tre_ring->wp;



	if (mhi_chan->xfer_type == MHI_XFER_RSC_SKB) {

	mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);

	mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_info->len);

	mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(1, 1, 0, 0);



	MHI_VERB("chan:%d WP:0x%llx TRE:0x%llx 0x%08x 0x%08x\n", mhi_chan->chan,

		 (u64)mhi_to_physical(tre_ring, mhi_tre), mhi_tre->ptr,

		 mhi_tre->dword[0], mhi_tre->dword[1]);



	/* increment WP */

	mhi_add_ring_element(mhi_cntrl, tre_ring);

	mhi_add_ring_element(mhi_cntrl, buf_ring);



	if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl->pm_state))) {

		read_lock_bh(&mhi_chan->lock);

		mhi_ring_chan_db(mhi_cntrl, mhi_chan);

		read_unlock_bh(&mhi_chan->lock);

	}



	if (mhi_chan->dir == DMA_FROM_DEVICE && assert_wake)

		mhi_cntrl->wake_put(mhi_cntrl, true);



	read_unlock_bh(&mhi_cntrl->pm_lock);



	return 0;



map_error:

	if (assert_wake)

		mhi_cntrl->wake_put(mhi_cntrl, false);



	read_unlock_bh(&mhi_cntrl->pm_lock);



	return ret;

}



int mhi_queue_dma(struct mhi_device *mhi_dev,

		  struct mhi_chan *mhi_chan,

		  void *buf,

		  size_t len,

		  enum MHI_FLAGS mflags)

{

	struct mhi_buf *mhi_buf = buf;

	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;

	struct mhi_ring *tre_ring = &mhi_chan->tre_ring;

	struct mhi_ring *buf_ring = &mhi_chan->buf_ring;

	struct mhi_buf_info *buf_info;

	struct mhi_tre *mhi_tre;

	bool assert_wake = false;



	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))) {

		MHI_VERB("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;

	}



	/* we're in M3 or transitioning to M3 */

	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {

		mhi_cntrl->runtime_get(mhi_cntrl, mhi_cntrl->priv_data);

		mhi_cntrl->runtime_put(mhi_cntrl, mhi_cntrl->priv_data);

	}



	/*

	 * For UL channels always assert WAKE until work is done,

	 * For DL channels only assert if MHI is in a LPM

	 */

	if (mhi_chan->dir == DMA_TO_DEVICE ||

	    (mhi_chan->dir == DMA_FROM_DEVICE &&

	     mhi_cntrl->pm_state != MHI_PM_M0)) {

		assert_wake = true;

		mhi_cntrl->wake_get(mhi_cntrl, false);

	}



	/* generate the tre */

	buf_info = buf_ring->wp;

	MHI_ASSERT(buf_info->used, "TRE Not Freed\n");

	buf_info->p_addr = mhi_buf->dma_addr;

	buf_info->pre_mapped = true;

	buf_info->cb_buf = mhi_buf;

	buf_info->wp = tre_ring->wp;

	buf_info->dir = mhi_chan->dir;

	buf_info->len = len;



	mhi_tre = tre_ring->wp;



	if (mhi_chan->xfer_type == MHI_XFER_RSC_DMA) {

		buf_info->used = true;

		mhi_tre->ptr =

			MHI_RSCTRE_DATA_PTR(buf_info->p_addr, buf_info->len);
@@ -425,13 +513,6 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, 
	read_unlock_bh(&mhi_cntrl->pm_lock);



	return 0;



map_error:

	if (assert_wake)

		mhi_cntrl->wake_put(mhi_cntrl, false);

	read_unlock_bh(&mhi_cntrl->pm_lock);



	return ret;

}



int mhi_gen_tre(struct mhi_controller *mhi_cntrl,
@@ -856,6 +937,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, 
			else

				xfer_len = buf_info->len;



			/* unmap if it's not premapped by client */

			if (likely(!buf_info->pre_mapped))

				mhi_cntrl->unmap_single(mhi_cntrl, buf_info);



			result.buf_addr = buf_info->cb_buf;
@@ -960,8 +1043,6 @@ static int parse_rsc_event(struct mhi_controller *mhi_cntrl, 


	MHI_ASSERT(!buf_info->used, "TRE already Freed\n");



	mhi_cntrl->unmap_single(mhi_cntrl, buf_info);



	/* notify the client */

	mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
@@ -1651,7 +1732,7 @@ static void mhi_reset_data_chan(struct mhi_controller *mhi_cntrl, 


		if (mhi_chan->dir == DMA_TO_DEVICE)

			mhi_cntrl->wake_put(mhi_cntrl, false);



		if (!buf_info->pre_mapped)

			mhi_cntrl->unmap_single(mhi_cntrl, buf_info);

		mhi_del_ring_element(mhi_cntrl, buf_ring);

		mhi_del_ring_element(mhi_cntrl, tre_ring);
@@ -1682,7 +1763,6 @@ static void mhi_reset_rsc_chan(struct mhi_controller *mhi_cntrl, 
	for (; (void *)buf_info < buf_ring->base + buf_ring->len; buf_info++) {

		if (!buf_info->used)

			continue;

		mhi_cntrl->unmap_single(mhi_cntrl, buf_info);



		result.buf_addr = buf_info->cb_buf;

		mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
@@ -1707,7 +1787,7 @@ void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan) 


	mhi_mark_stale_events(mhi_cntrl, mhi_event, er_ctxt, chan);



	if (mhi_chan->xfer_type == MHI_XFER_RSC_SKB)

	if (mhi_chan->xfer_type == MHI_XFER_RSC_DMA)

		mhi_reset_rsc_chan(mhi_cntrl, mhi_chan);

	else

		mhi_reset_data_chan(mhi_cntrl, mhi_chan);