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Commit 2ece1caf authored by Alexandre Bounine's avatar Alexandre Bounine Committed by Linus Torvalds
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rapidio/tsi721: fix locking in OB_MSG processing 



- Add spinlock protection into outbound message queuing routine.

- Change outbound message interrupt handler to avoid deadlock when
  calling registered callback routine.

- Allow infinite retries for outbound messages to avoid retry threshold
  error signaling in systems with nodes that have slow message receive
  queue processing.

Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9a0b0627

drivers/rapidio/devices/tsi721.c

+30 −12
Original line number Diff line number Diff line
@@ -1453,11 +1453,14 @@ tsi721_add_outb_message(struct rio_mport *mport, struct rio_dev *rdev, int mbox, 
	struct tsi721_device *priv = mport->priv;

	struct tsi721_omsg_desc *desc;

	u32 tx_slot;

	unsigned long flags;



	if (!priv->omsg_init[mbox] ||

	    len > TSI721_MSG_MAX_SIZE || len < 8)

		return -EINVAL;



	spin_lock_irqsave(&priv->omsg_ring[mbox].lock, flags);



	tx_slot = priv->omsg_ring[mbox].tx_slot;



	/* Copy copy message into transfer buffer */
@@ -1469,9 +1472,11 @@ tsi721_add_outb_message(struct rio_mport *mport, struct rio_dev *rdev, int mbox, 
	/* Build descriptor associated with buffer */

	desc = priv->omsg_ring[mbox].omd_base;

	desc[tx_slot].type_id = cpu_to_le32((DTYPE4 << 29) | rdev->destid);

#ifdef TSI721_OMSG_DESC_INT

	/* Request IOF_DONE interrupt generation for each N-th frame in queue */

	if (tx_slot % 4 == 0)

		desc[tx_slot].type_id |= cpu_to_le32(TSI721_OMD_IOF);



#endif

	desc[tx_slot].msg_info =

		cpu_to_le32((mport->sys_size << 26) | (mbox << 22) |

			    (0xe << 12) | (len & 0xff8));
@@ -1497,6 +1502,8 @@ tsi721_add_outb_message(struct rio_mport *mport, struct rio_dev *rdev, int mbox, 
		priv->regs + TSI721_OBDMAC_DWRCNT(mbox));

	ioread32(priv->regs + TSI721_OBDMAC_DWRCNT(mbox));



	spin_unlock_irqrestore(&priv->omsg_ring[mbox].lock, flags);



	return 0;

}
@@ -1511,6 +1518,9 @@ static void tsi721_omsg_handler(struct tsi721_device *priv, int ch) 
{

	u32 omsg_int;

	struct rio_mport *mport = &priv->mport;

	void *dev_id = NULL;

	u32 tx_slot = 0xffffffff;

	int do_callback = 0;



	spin_lock(&priv->omsg_ring[ch].lock);
@@ -1524,7 +1534,6 @@ static void tsi721_omsg_handler(struct tsi721_device *priv, int ch) 
		u32 srd_ptr;

		u64 *sts_ptr, last_ptr = 0, prev_ptr = 0;

		int i, j;

		u32 tx_slot;



		/*

		 * Find last successfully processed descriptor
@@ -1574,14 +1583,19 @@ static void tsi721_omsg_handler(struct tsi721_device *priv, int ch) 
				goto no_sts_update;

		}



		if (tx_slot >= priv->omsg_ring[ch].size)

			dev_dbg(&priv->pdev->dev,

				  "OB_MSG tx_slot=%x > size=%x",

				  tx_slot, priv->omsg_ring[ch].size);

		WARN_ON(tx_slot >= priv->omsg_ring[ch].size);



		/* Move slot index to the next message to be sent */

		++tx_slot;

		if (tx_slot == priv->omsg_ring[ch].size)

			tx_slot = 0;

		BUG_ON(tx_slot >= priv->omsg_ring[ch].size);

		mport->outb_msg[ch].mcback(mport,

				priv->omsg_ring[ch].dev_id, ch,

				tx_slot);



		dev_id = priv->omsg_ring[ch].dev_id;

		do_callback = 1;

	}



no_sts_update:
@@ -1597,15 +1611,15 @@ static void tsi721_omsg_handler(struct tsi721_device *priv, int ch) 


		iowrite32(TSI721_OBDMAC_INT_ERROR,

				priv->regs + TSI721_OBDMAC_INT(ch));

		iowrite32(TSI721_OBDMAC_CTL_INIT,

		iowrite32(TSI721_OBDMAC_CTL_RETRY_THR | TSI721_OBDMAC_CTL_INIT,

				priv->regs + TSI721_OBDMAC_CTL(ch));

		ioread32(priv->regs + TSI721_OBDMAC_CTL(ch));



		/* Inform upper level to clear all pending tx slots */

		if (mport->outb_msg[ch].mcback)

			mport->outb_msg[ch].mcback(mport,

					priv->omsg_ring[ch].dev_id, ch,

					priv->omsg_ring[ch].tx_slot);

		dev_id = priv->omsg_ring[ch].dev_id;

		tx_slot = priv->omsg_ring[ch].tx_slot;

		do_callback = 1;



		/* Synch tx_slot tracking */

		iowrite32(priv->omsg_ring[ch].tx_slot,

			priv->regs + TSI721_OBDMAC_DRDCNT(ch));
@@ -1627,6 +1641,9 @@ static void tsi721_omsg_handler(struct tsi721_device *priv, int ch) 
	}



	spin_unlock(&priv->omsg_ring[ch].lock);



	if (mport->outb_msg[ch].mcback && do_callback)

		mport->outb_msg[ch].mcback(mport, dev_id, ch, tx_slot);

}



/**
@@ -1768,7 +1785,8 @@ static int tsi721_open_outb_mbox(struct rio_mport *mport, void *dev_id, 
	mb();



	/* Initialize Outbound Message engine */

	iowrite32(TSI721_OBDMAC_CTL_INIT, priv->regs + TSI721_OBDMAC_CTL(mbox));

	iowrite32(TSI721_OBDMAC_CTL_RETRY_THR | TSI721_OBDMAC_CTL_INIT,

		  priv->regs + TSI721_OBDMAC_CTL(mbox));

	ioread32(priv->regs + TSI721_OBDMAC_DWRCNT(mbox));

	udelay(10);