Merge "msm: mhi_dev: Handle wrap-around case for event ring updates" (c750f235) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/platform/msm/mhi_dev/mhi_ring.c

+52 −19

Original line number	Diff line number	Diff line
		@@ -278,11 +278,12 @@ EXPORT_SYMBOL(mhi_dev_process_ring);

		int mhi_dev_add_element(struct mhi_dev_ring *ring,
		union mhi_dev_ring_element_type *element,
		struct event_req *ereq, int evt_offset)
		struct event_req *ereq, int size)
		{
		uint32_t old_offset = 0;
		struct mhi_addr host_addr;
		uint32_t num_elem = 0;
		uint32_t num_elem = 1;
		uint32_t num_free_elem;

		if (!ring \|\| !element) {
		pr_err("%s: Invalid context\n", __func__);
		@@ -291,16 +292,24 @@ int mhi_dev_add_element(struct mhi_dev_ring *ring,

		mhi_dev_update_wr_offset(ring);

		if ((ring->rd_offset + 1) % ring->ring_size == ring->wr_offset) {
		mhi_log(MHI_MSG_VERBOSE, "ring full to insert element\n");
		if (ereq)
		num_elem = size / (sizeof(union mhi_dev_ring_element_type));

		if (ring->rd_offset < ring->wr_offset)
		num_free_elem = ring->wr_offset - ring->rd_offset - 1;
		else
		num_free_elem = ring->ring_size - ring->rd_offset +
		ring->wr_offset - 1;

		if (num_free_elem < num_elem) {
		mhi_log(MHI_MSG_ERROR, "No space to add %d elem in ring (%d)\n",
		num_elem, ring->id);
		return -EINVAL;
		}

		old_offset = ring->rd_offset;

		if (evt_offset) {
		num_elem = evt_offset /
		(sizeof(union mhi_dev_ring_element_type));
		if (ereq) {
		ring->rd_offset += num_elem;
		if (ring->rd_offset >= ring->ring_size)
		ring->rd_offset -= ring->ring_size;
		@@ -322,23 +331,47 @@ int mhi_dev_add_element(struct mhi_dev_ring *ring,
		host_addr.device_va = ring->ring_shadow.device_va +
		sizeof(union mhi_dev_ring_element_type) * old_offset;

		if (!ereq) {
		/* We're adding only a single ring element */
		host_addr.virt_addr = element;

		if (evt_offset)
		host_addr.size = evt_offset;
		else
		host_addr.size = sizeof(union mhi_dev_ring_element_type);

		mhi_log(MHI_MSG_VERBOSE, "adding element to ring (%d)\n", ring->id);
		mhi_log(MHI_MSG_VERBOSE, "adding element to ring (%d)\n",
		ring->id);
		mhi_log(MHI_MSG_VERBOSE, "rd_ofset %d\n", ring->rd_offset);
		mhi_log(MHI_MSG_VERBOSE, "type %d\n", element->generic.type);

		if (ereq)
		mhi_dev_write_to_host(ring->mhi_dev, &host_addr,
		NULL, MHI_DEV_DMA_SYNC);
		return 0;
		}

		/* Adding multiple ring elements */
		if (ring->rd_offset == 0 \|\| (ring->rd_offset > old_offset)) {
		/* No wrap-around case */
		host_addr.virt_addr = element;
		host_addr.size = size;
		mhi_dev_write_to_host(ring->mhi_dev, &host_addr,
		ereq, MHI_DEV_DMA_ASYNC);
		else
		} else {
		/* Wrap-around case - first chunk uses dma sync */
		host_addr.virt_addr = element;
		host_addr.size = (ring->ring_size - old_offset) *
		sizeof(union mhi_dev_ring_element_type);
		mhi_dev_write_to_host(ring->mhi_dev, &host_addr,
		NULL, MHI_DEV_DMA_SYNC);

		/* Copy remaining elements */
		if (ring->mhi_dev->use_ipa)
		host_addr.host_pa = ring->ring_shadow.host_pa;
		else
		host_addr.device_va = ring->ring_shadow.device_va;
		host_addr.virt_addr = element + (ring->ring_size - old_offset);
		host_addr.size = ring->rd_offset *
		sizeof(union mhi_dev_ring_element_type);
		mhi_dev_write_to_host(ring->mhi_dev, &host_addr,
		ereq, MHI_DEV_DMA_ASYNC);
		}
		return 0;
		}
		EXPORT_SYMBOL(mhi_dev_add_element);