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Commit 3b2b7d4d authored by Hemant Kumar's avatar Hemant Kumar
Browse files

mhi: core: Add support to create uncached event ring 



This helps to selectively mark an event ring as uncached
to debug cache-coherency issue.

Change-Id: I25a1310df0576496af9e1fb624ec8c54c670dfe8
Signed-off-by: default avatarHemant Kumar <hemantk@codeaurora.org>
parent 6063f4e4

drivers/bus/mhi/core/mhi_init.c

+35 −3
Original line number Diff line number Diff line
@@ -234,6 +234,21 @@ static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl, 
	return 0;

}



/* MHI protocol require transfer ring to be aligned to ring length */

static int mhi_alloc_aligned_ring_uncached(

	struct mhi_controller *mhi_cntrl, struct mhi_ring *ring, u64 len)

{

	ring->alloc_size = len + (len - 1);

	ring->pre_aligned = mhi_alloc_uncached(mhi_cntrl, ring->alloc_size,

					       &ring->dma_handle, GFP_KERNEL);

	if (!ring->pre_aligned)

		return -ENOMEM;



	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);

	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);

	return 0;

}



void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)

{

	int i;
@@ -318,6 +333,10 @@ void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl) 
			continue;



		ring = &mhi_event->ring;

		if (mhi_event->force_uncached)

			mhi_free_uncached(mhi_cntrl, ring->alloc_size,

					  ring->pre_aligned, ring->dma_handle);

		else

			mhi_free_coherent(mhi_cntrl, ring->alloc_size,

				  ring->pre_aligned, ring->dma_handle);

		ring->base = NULL;
@@ -487,7 +506,12 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl) 


		ring->el_size = sizeof(struct mhi_tre);

		ring->len = ring->el_size * ring->elements;

		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);

		if (mhi_event->force_uncached)

			ret = mhi_alloc_aligned_ring_uncached(mhi_cntrl, ring,

				ring->len);

		else

			ret = mhi_alloc_aligned_ring(mhi_cntrl, ring,

				ring->len);

		if (ret)

			goto error_alloc_er;
@@ -548,6 +572,10 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl) 
		if (mhi_event->offload_ev)

			continue;



		if (mhi_event->force_uncached)

			mhi_free_uncached(mhi_cntrl, ring->alloc_size,

				  ring->pre_aligned, ring->dma_handle);

		else

			mhi_free_coherent(mhi_cntrl, ring->alloc_size,

				  ring->pre_aligned, ring->dma_handle);

	}
@@ -1041,6 +1069,10 @@ static int of_parse_ev_cfg(struct mhi_controller *mhi_cntrl, 
			continue;



		mhi_event->er_index = i++;



		mhi_event->force_uncached = of_property_read_bool(child,

				"mhi,force-uncached");



		ret = of_property_read_u32(child, "mhi,num-elements",

					   (u32 *)&mhi_event->ring.elements);

		if (ret)

drivers/bus/mhi/core/mhi_internal.h

+24 −0
Original line number Diff line number Diff line
@@ -667,6 +667,7 @@ struct mhi_event { 
	struct mhi_controller *mhi_cntrl;

	struct mhi_tre last_cached_tre;

	u64 last_dev_rp;

	bool force_uncached;

};



struct mhi_chan {
@@ -882,6 +883,29 @@ static inline void mhi_free_coherent(struct mhi_controller *mhi_cntrl, 
	dma_free_coherent(mhi_cntrl->dev, size, vaddr, dma_handle);

}



static inline void *mhi_alloc_uncached(struct mhi_controller *mhi_cntrl,

				       size_t size,

				       dma_addr_t *dma_handle,

				       gfp_t gfp)

{

	void *buf = dma_alloc_attrs(mhi_cntrl->dev, size, dma_handle, gfp,

			DMA_ATTR_FORCE_NON_COHERENT);



	if (buf)

		atomic_add(size, &mhi_cntrl->alloc_size);



	return buf;

}

static inline void mhi_free_uncached(struct mhi_controller *mhi_cntrl,

				     size_t size,

				     void *vaddr,

				     dma_addr_t dma_handle)

{

	atomic_sub(size, &mhi_cntrl->alloc_size);

	dma_free_attrs(mhi_cntrl->dev, size, vaddr, dma_handle,

			DMA_ATTR_FORCE_NON_COHERENT);

}



static inline void *mhi_alloc_contig_coherent(

					struct mhi_controller *mhi_cntrl,

					size_t size, dma_addr_t *dma_handle,