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Commit ef3be547 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Greg Kroah-Hartman
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[PATCH] shpchp - bugfix: add missing serialization 



Current shpchp driver might cause system panic because of lack of
serialization. It can be reproduced very easily by the following
operation.

	# cd /sys/bus/pci/slots/<slot#>
	# while true; do echo 0 > power ; echo 1 > power ; done &
	# while true; do echo 0 > power ; echo 1 > power ; done &

This patch fixes this issue by changing shpchp to get appropreate
semaphore for hot-plug operation.

Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d29aadda

drivers/pci/hotplug/shpchp_ctrl.c

+24 −42
Original line number Diff line number Diff line
@@ -307,15 +307,10 @@ static int board_added(struct slot *p_slot) 
			__FUNCTION__, p_slot->device,

			ctrl->slot_device_offset, hp_slot);



	/* Wait for exclusive access to hardware */

	mutex_lock(&ctrl->crit_sect);



	/* Power on slot without connecting to bus */

	rc = p_slot->hpc_ops->power_on_slot(p_slot);

	if (rc) {

		err("%s: Failed to power on slot\n", __FUNCTION__);

		/* Done with exclusive hardware access */

		mutex_unlock(&ctrl->crit_sect);

		return -1;

	}
@@ -325,14 +320,12 @@ static int board_added(struct slot *p_slot) 
		

		if ((rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, PCI_SPEED_33MHz))) {

			err("%s: Issue of set bus speed mode command failed\n", __FUNCTION__);

			mutex_unlock(&ctrl->crit_sect);

			return WRONG_BUS_FREQUENCY;

		}

		

		/* turn on board, blink green LED, turn off Amber LED */

		if ((rc = p_slot->hpc_ops->slot_enable(p_slot))) {

			err("%s: Issue of Slot Enable command failed\n", __FUNCTION__);

			mutex_unlock(&ctrl->crit_sect);

			return rc;

		}

	}
@@ -346,16 +339,12 @@ static int board_added(struct slot *p_slot) 


	if (rc  || adapter_speed == PCI_SPEED_UNKNOWN) {

		err("%s: Can't get adapter speed or bus mode mismatch\n", __FUNCTION__);

		/* Done with exclusive hardware access */

		mutex_unlock(&ctrl->crit_sect);

		return WRONG_BUS_FREQUENCY;

	}



	rc = p_slot->hpc_ops->get_cur_bus_speed(p_slot, &bus_speed);

	if (rc || bus_speed == PCI_SPEED_UNKNOWN) {

		err("%s: Can't get bus operation speed\n", __FUNCTION__);

		/* Done with exclusive hardware access */

		mutex_unlock(&ctrl->crit_sect);

		return WRONG_BUS_FREQUENCY;

	}
@@ -365,9 +354,6 @@ static int board_added(struct slot *p_slot) 
		max_bus_speed = bus_speed;

	}



	/* Done with exclusive hardware access */

	mutex_unlock(&ctrl->crit_sect);



	if ((rc  = p_slot->hpc_ops->get_prog_int(p_slot, &pi))) {

		err("%s: Can't get controller programming interface, set it to 1\n", __FUNCTION__);

		pi = 1;
@@ -744,29 +730,25 @@ static void interrupt_event_handler(struct controller *ctrl) 
int shpchp_enable_slot (struct slot *p_slot)

{

	u8 getstatus = 0;

	int rc;

	int rc, retval = -ENODEV;



	/* Check to see if (latch closed, card present, power off) */

	mutex_lock(&p_slot->ctrl->crit_sect);

	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);

	if (rc || !getstatus) {

		info("%s: no adapter on slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

	if (rc || getstatus) {

		info("%s: latch open on slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);

	if (rc || getstatus) {

		info("%s: already enabled on slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	mutex_unlock(&p_slot->ctrl->crit_sect);



	p_slot->is_a_board = 1;
@@ -781,27 +763,29 @@ int shpchp_enable_slot (struct slot *p_slot) 
	     && p_slot->ctrl->num_slots == 1) {

		/* handle amd pogo errata; this must be done before enable  */

		amd_pogo_errata_save_misc_reg(p_slot);

		rc = board_added(p_slot);

		retval = board_added(p_slot);

		/* handle amd pogo errata; this must be done after enable  */

		amd_pogo_errata_restore_misc_reg(p_slot);

	} else

		rc = board_added(p_slot);

		retval = board_added(p_slot);



	if (rc) {

	if (retval) {

		p_slot->hpc_ops->get_adapter_status(p_slot,

				&(p_slot->presence_save));

		p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

	}



	update_slot_info(p_slot);

	return rc;

 out:

	mutex_unlock(&p_slot->ctrl->crit_sect);

	return retval;

}





int shpchp_disable_slot (struct slot *p_slot)

{

	u8 getstatus = 0;

	int ret = 0;

	int rc, retval = -ENODEV;



	if (!p_slot->ctrl)

		return -ENODEV;
@@ -809,28 +793,26 @@ int shpchp_disable_slot (struct slot *p_slot) 
	/* Check to see if (latch closed, card present, power on) */

	mutex_lock(&p_slot->ctrl->crit_sect);



	ret = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);

	if (ret || !getstatus) {

	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);

	if (rc || !getstatus) {

		info("%s: no adapter on slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	ret = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

	if (ret || getstatus) {

	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

	if (rc || getstatus) {

		info("%s: latch open on slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	ret = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);

	if (ret || !getstatus) {

	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);

	if (rc || !getstatus) {

		info("%s: already disabled slot(%x)\n", __FUNCTION__, p_slot->number);

		mutex_unlock(&p_slot->ctrl->crit_sect);

		return -ENODEV;

		goto out;

	}

	mutex_unlock(&p_slot->ctrl->crit_sect);



	ret = remove_board(p_slot);

	retval = remove_board(p_slot);

	update_slot_info(p_slot);

	return ret;

 out:

	mutex_unlock(&p_slot->ctrl->crit_sect);

	return retval;

}