Merge "msm: mhi_dev: Avoid race in event ring updates" (687c08a4) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/platform/msm/mhi_dev/mhi.c

+44 −10

Original line number	Diff line number	Diff line
		@@ -323,6 +323,7 @@ static int mhi_dev_send_multiple_tr_events(struct mhi_dev *mhi, int evnt_ring,
		return -EINVAL;
		}

		mutex_lock(&ring->event_lock);
		mhi_log(MHI_MSG_VERBOSE, "Flushing %d cmpl events of ch %d\n",
		ereq->num_events, ch->ch_id);
		/* add the events */
		@@ -331,6 +332,7 @@ static int mhi_dev_send_multiple_tr_events(struct mhi_dev *mhi, int evnt_ring,
		rc = mhi_dev_add_element(ring, ereq->tr_events, ereq, evt_len);
		if (rc) {
		pr_err("%s(): error in adding element rc %d\n", __func__, rc);
		mutex_unlock(&ring->event_lock);
		return rc;
		}
		ring->ring_ctx_shadow->ev.rp = (ring->rd_offset *
		@@ -366,6 +368,7 @@ static int mhi_dev_send_multiple_tr_events(struct mhi_dev *mhi, int evnt_ring,
		ereq->client_cb = mhi_dev_event_rd_offset_completion_cb;
		ereq->event_ring = evnt_ring;
		mhi_ctx->write_to_host(mhi, &transfer_addr, ereq, MHI_DEV_DMA_ASYNC);
		mutex_unlock(&ring->event_lock);
		return rc;
		}

		@@ -1393,6 +1396,37 @@ int mhi_dev_send_event(struct mhi_dev *mhi, int evnt_ring,
		return ep_pcie_trigger_msi(mhi_ctx->phandle, ctx->ev.msivec);
		}

		static int mhi_dev_send_completion_event_async(struct mhi_dev_channel *ch,
		size_t rd_ofst, uint32_t len,
		enum mhi_dev_cmd_completion_code code,
		struct mhi_req *mreq)
		{
		int rc;
		struct mhi_dev *mhi = ch->ring->mhi_dev;

		mhi_log(MHI_MSG_VERBOSE, "Ch %d\n", ch->ch_id);

		/* Queue the completion event for the current transfer */
		mreq->snd_cmpl = 1;
		rc = mhi_dev_queue_transfer_completion(mreq, NULL);
		if (rc) {
		mhi_log(MHI_MSG_ERROR,
		"Failed to queue completion for ch %d, rc %d\n",
		ch->ch_id, rc);
		return rc;
		}

		mhi_log(MHI_MSG_VERBOSE, "Calling flush for ch %d\n", ch->ch_id);
		rc = mhi_dev_flush_transfer_completion_events(mhi, ch);
		if (rc) {
		mhi_log(MHI_MSG_ERROR,
		"Failed to flush read completions to host\n");
		return rc;
		}

		return 0;
		}

		static int mhi_dev_send_completion_event(struct mhi_dev_channel *ch,
		size_t rd_ofst, uint32_t len,
		enum mhi_dev_cmd_completion_code code)
		@@ -2699,7 +2733,7 @@ EXPORT_SYMBOL(mhi_dev_close_channel);

		static int mhi_dev_check_tre_bytes_left(struct mhi_dev_channel *ch,
		struct mhi_dev_ring ring, union mhi_dev_ring_element_type el,
		uint32_t *chain)
		struct mhi_req *mreq)
		{
		uint32_t td_done = 0;

		@@ -2710,17 +2744,17 @@ static int mhi_dev_check_tre_bytes_left(struct mhi_dev_channel *ch,
		if (ch->tre_bytes_left == 0) {
		if (el->tre.chain) {
		if (el->tre.ieob)
		mhi_dev_send_completion_event(ch,
		mhi_dev_send_completion_event_async(ch,
		ring->rd_offset, el->tre.len,
		MHI_CMD_COMPL_CODE_EOB);
		*chain = 1;
		MHI_CMD_COMPL_CODE_EOB, mreq);
		mreq->chain = 1;
		} else {
		if (el->tre.ieot)
		mhi_dev_send_completion_event(
		mhi_dev_send_completion_event_async(
		ch, ring->rd_offset, el->tre.len,
		MHI_CMD_COMPL_CODE_EOT);
		MHI_CMD_COMPL_CODE_EOT, mreq);
		td_done = 1;
		*chain = 0;
		mreq->chain = 0;
		}
		mhi_dev_ring_inc_index(ring, ring->rd_offset);
		ch->tre_bytes_left = 0;
		@@ -2831,7 +2865,7 @@ int mhi_dev_read_channel(struct mhi_req *mreq)
		goto exit;
		} else {
		td_done = mhi_dev_check_tre_bytes_left(ch, ring,
		el, &mreq->chain);
		el, mreq);
		}
		} while (usr_buf_remaining && !td_done);
		if (td_done && ch->state == MHI_DEV_CH_PENDING_STOP) {

drivers/platform/msm/mhi_dev/mhi.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -382,7 +382,11 @@ struct mhi_dev_ring {

		enum mhi_dev_ring_type type;
		enum mhi_dev_ring_state state;

		/*
		* Lock to prevent race in updating event ring
		* which is shared by multiple channels
		*/
		struct mutex event_lock;
		/* device virtual address location of the cached host ring ctx data */
		union mhi_dev_ring_element_type *ring_cache;
		/* Physical address of the cached ring copy on the device side */

drivers/platform/msm/mhi_dev/mhi_ring.c

+2 −1

Original line number	Diff line number	Diff line
		/* Copyright (c) 2015-2019, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2015-2020, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -453,6 +453,7 @@ void mhi_ring_init(struct mhi_dev_ring *ring, enum mhi_dev_ring_type type,
		ring->state = RING_STATE_UINT;
		ring->ring_cb = NULL;
		ring->type = type;
		mutex_init(&ring->event_lock);
		}
		EXPORT_SYMBOL(mhi_ring_init);