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Commit e342c119 authored by John Gregor's avatar John Gregor Committed by Roland Dreier
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IB/ipath: Fix sendctrl locking 



Code review pointed out that the locking around uses of ipath_sendctrl 
and kr_sendctrl were, in several places, incorrect and/or inconsistent.

Signed-off-by: default avatarJohn Gregor <john.gregor@qlogic.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 9ab4295d

drivers/infiniband/hw/ipath/ipath_driver.c

+26 −14
Original line number Diff line number Diff line
@@ -803,31 +803,37 @@ void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first, 
			  unsigned cnt)

{

	unsigned i, last = first + cnt;

	u64 sendctrl, sendorig;

	unsigned long flags;



	ipath_cdbg(PKT, "disarm %u PIObufs first=%u\n", cnt, first);

	sendorig = dd->ipath_sendctrl;

	for (i = first; i < last; i++) {

		sendctrl = sendorig  | INFINIPATH_S_DISARM |

			(i << INFINIPATH_S_DISARMPIOBUF_SHIFT);

		spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

		/*

		 * The disarm-related bits are write-only, so it

		 * is ok to OR them in with our copy of sendctrl

		 * while we hold the lock.

		 */

		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

				 sendctrl);

			dd->ipath_sendctrl | INFINIPATH_S_DISARM |

			(i << INFINIPATH_S_DISARMPIOBUF_SHIFT));

		/* can't disarm bufs back-to-back per iba7220 spec */

		ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

		spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);

	}



	/*

	 * Write it again with current value, in case ipath_sendctrl changed

	 * while we were looping; no critical bits that would require

	 * locking.

	 *

	 * disable PIOAVAILUPD, then re-enable, reading scratch in

	 * Disable PIOAVAILUPD, then re-enable, reading scratch in

	 * between.  This seems to avoid a chip timing race that causes

	 * pioavail updates to memory to stop.

	 * pioavail updates to memory to stop.  We xor as we don't

	 * know the state of the bit when we're called.

	 */

	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 sendorig & ~INFINIPATH_S_PIOBUFAVAILUPD);

	sendorig = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

		dd->ipath_sendctrl ^ INFINIPATH_S_PIOBUFAVAILUPD);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 dd->ipath_sendctrl);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);

}



/**
@@ -2056,6 +2062,8 @@ void ipath_set_led_override(struct ipath_devdata *dd, unsigned int val) 
 */

void ipath_shutdown_device(struct ipath_devdata *dd)

{

	unsigned long flags;



	ipath_dbg("Shutting down the device\n");



	dd->ipath_flags |= IPATH_LINKUNK;
@@ -2076,9 +2084,13 @@ void ipath_shutdown_device(struct ipath_devdata *dd) 
	 * gracefully stop all sends allowing any in progress to trickle out

	 * first.

	 */

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, 0ULL);

	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	dd->ipath_sendctrl = 0;

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);

	/* flush it */

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	/*

	 * enough for anything that's going to trickle out to have actually

	 * done so.

drivers/infiniband/hw/ipath/ipath_file_ops.c

+7 −3
Original line number Diff line number Diff line
@@ -2149,11 +2149,15 @@ static int ipath_get_slave_info(struct ipath_portdata *pd, 


static int ipath_force_pio_avail_update(struct ipath_devdata *dd)

{

	u64 reg = dd->ipath_sendctrl;

	unsigned long flags;



	clear_bit(IPATH_S_PIOBUFAVAILUPD, &reg);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, reg);

	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

		dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	return 0;

}

drivers/infiniband/hw/ipath/ipath_init_chip.c

+16 −8
Original line number Diff line number Diff line
@@ -345,7 +345,7 @@ static int init_chip_first(struct ipath_devdata *dd, 
		       dd->ipath_piobcnt2k, dd->ipath_pio2kbase);



	spin_lock_init(&dd->ipath_tid_lock);



	spin_lock_init(&dd->ipath_sendctrl_lock);

	spin_lock_init(&dd->ipath_gpio_lock);

	spin_lock_init(&dd->ipath_eep_st_lock);

	mutex_init(&dd->ipath_eep_lock);
@@ -372,9 +372,9 @@ static int init_chip_reset(struct ipath_devdata *dd, 
	*pdp = dd->ipath_pd[0];

	/* ensure chip does no sends or receives while we re-initialize */

	dd->ipath_control = dd->ipath_sendctrl = dd->ipath_rcvctrl = 0U;

	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl, 0);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, 0);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl, dd->ipath_rcvctrl);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_control, dd->ipath_control);



	rtmp = ipath_read_kreg32(dd, dd->ipath_kregs->kr_portcnt);

	if (dd->ipath_portcnt != rtmp)
@@ -487,6 +487,7 @@ static void enable_chip(struct ipath_devdata *dd, 
			struct ipath_portdata *pd, int reinit)

{

	u32 val;

	unsigned long flags;

	int i;



	if (!reinit)
@@ -495,11 +496,13 @@ static void enable_chip(struct ipath_devdata *dd, 
	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,

			 dd->ipath_rcvctrl);



	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	/* Enable PIO send, and update of PIOavail regs to memory. */

	dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE |

		INFINIPATH_S_PIOBUFAVAILUPD;

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 dd->ipath_sendctrl);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	/*

	 * enable port 0 receive, and receive interrupt.  other ports
@@ -696,6 +699,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit) 
	u64 val;

	struct ipath_portdata *pd = NULL; /* keep gcc4 happy */

	gfp_t gfp_flags = GFP_USER | __GFP_COMP;

	unsigned long flags;



	ret = init_housekeeping(dd, &pd, reinit);

	if (ret)
@@ -827,8 +831,12 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit) 
	ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear,

			 ~0ULL&~INFINIPATH_HWE_MEMBISTFAILED);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0ULL);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 INFINIPATH_S_PIOENABLE);



	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE;

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	/*

	 * before error clears, since we expect serdes pll errors during

drivers/infiniband/hw/ipath/ipath_intr.c

+16 −3
Original line number Diff line number Diff line
@@ -795,6 +795,7 @@ void ipath_clear_freeze(struct ipath_devdata *dd) 
{

	int i, im;

	__le64 val;

	unsigned long flags;



	/* disable error interrupts, to avoid confusion */

	ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask, 0ULL);
@@ -813,11 +814,14 @@ void ipath_clear_freeze(struct ipath_devdata *dd) 
			 dd->ipath_control);



	/* ensure pio avail updates continue */

	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

		 dd->ipath_sendctrl & ~INFINIPATH_S_PIOBUFAVAILUPD);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 dd->ipath_sendctrl);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	/*

	 * We just enabled pioavailupdate, so dma copy is almost certainly
@@ -922,6 +926,7 @@ static noinline void ipath_bad_regread(struct ipath_devdata *dd) 


static void handle_layer_pioavail(struct ipath_devdata *dd)

{

	unsigned long flags;

	int ret;



	ret = ipath_ib_piobufavail(dd->verbs_dev);
@@ -930,9 +935,12 @@ static void handle_layer_pioavail(struct ipath_devdata *dd) 


	return;

set:

	set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);

	spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

	dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;

	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

			 dd->ipath_sendctrl);

	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);

}



/*
@@ -1168,9 +1176,14 @@ irqreturn_t ipath_intr(int irq, void *data) 
		handle_urcv(dd, istat);



	if (istat & INFINIPATH_I_SPIOBUFAVAIL) {

		clear_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);

		unsigned long flags;



		spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

		dd->ipath_sendctrl &= ~INFINIPATH_S_PIOINTBUFAVAIL;

		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,

				 dd->ipath_sendctrl);

		ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

		spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



		handle_layer_pioavail(dd);

	}

drivers/infiniband/hw/ipath/ipath_kernel.h

+1 −0
Original line number Diff line number Diff line
@@ -376,6 +376,7 @@ struct ipath_devdata { 
	dma_addr_t *ipath_physshadow;

	/* lock to workaround chip bug 9437 */

	spinlock_t ipath_tid_lock;

	spinlock_t ipath_sendctrl_lock;



	/*

	 * IPATH_STATUS_*,