pciehp - add missing locking
This patch fixes the problem that system will panic if multiple power
on/off operations are issued to the same slot in parallel. This
problem can be easily reproduced by commands below.
# while true; do echo 1 > power; echo 0 > power; done &
# while true; do echo 1 > power; echo 0 > power; done &
The cause is lack of locking for enable/disable operations. This patch
fixes this problem.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index b71f774..30f021c 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -92,6 +92,7 @@
struct controller {
struct controller *next;
struct mutex crit_sect; /* critical section mutex */
+ struct mutex ctrl_lock; /* controller lock */
struct php_ctlr_state_s *hpc_ctlr_handle; /* HPC controller handle */
int num_slots; /* Number of slots on ctlr */
int slot_num_inc; /* 1 or -1 */
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index c67b7c3..f93e81e 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -448,7 +448,7 @@
}
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
t_slot->hpc_ops->get_adapter_status(t_slot, &value); /* Check if slot is occupied */
@@ -456,7 +456,7 @@
rc = t_slot->hpc_ops->power_off_slot(t_slot); /* Power off slot if not occupied*/
if (rc) {
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
goto err_out_free_ctrl_slot;
} else
/* Wait for the command to complete */
@@ -464,7 +464,7 @@
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return 0;
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index f602b04..c206a3d 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -234,13 +234,13 @@
static void set_slot_off(struct controller *ctrl, struct slot * pslot)
{
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
if (POWER_CTRL(ctrl->ctrlcap)) {
if (pslot->hpc_ops->power_off_slot(pslot)) {
err("%s: Issue of Slot Power Off command failed\n", __FUNCTION__);
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return;
}
wait_for_ctrl_irq (ctrl);
@@ -254,14 +254,14 @@
if (ATTN_LED(ctrl->ctrlcap)) {
if (pslot->hpc_ops->set_attention_status(pslot, 1)) {
err("%s: Issue of Set Attention Led command failed\n", __FUNCTION__);
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return;
}
wait_for_ctrl_irq (ctrl);
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
}
/**
@@ -284,13 +284,13 @@
ctrl->slot_device_offset, hp_slot);
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
if (POWER_CTRL(ctrl->ctrlcap)) {
/* Power on slot */
rc = p_slot->hpc_ops->power_on_slot(p_slot);
if (rc) {
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return -1;
}
@@ -306,7 +306,7 @@
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
/* Wait for ~1 second */
wait_for_ctrl_irq (ctrl);
@@ -340,7 +340,7 @@
pci_fixup_device(pci_fixup_final, ctrl->pci_dev);
if (PWR_LED(ctrl->ctrlcap)) {
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
p_slot->hpc_ops->green_led_on(p_slot);
@@ -348,7 +348,7 @@
wait_for_ctrl_irq (ctrl);
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
}
return 0;
@@ -380,14 +380,14 @@
dbg("In %s, hp_slot = %d\n", __FUNCTION__, hp_slot);
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
if (POWER_CTRL(ctrl->ctrlcap)) {
/* power off slot */
rc = p_slot->hpc_ops->power_off_slot(p_slot);
if (rc) {
err("%s: Issue of Slot Disable command failed\n", __FUNCTION__);
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return rc;
}
/* Wait for the command to complete */
@@ -403,7 +403,7 @@
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
return 0;
}
@@ -450,7 +450,7 @@
if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl->ctrlcap)) {
/* Wait for exclusive access to hardware */
- mutex_lock(&p_slot->ctrl->crit_sect);
+ mutex_lock(&p_slot->ctrl->ctrl_lock);
p_slot->hpc_ops->green_led_off(p_slot);
@@ -458,7 +458,7 @@
wait_for_ctrl_irq (p_slot->ctrl);
/* Done with exclusive hardware access */
- mutex_unlock(&p_slot->ctrl->crit_sect);
+ mutex_unlock(&p_slot->ctrl->ctrl_lock);
}
p_slot->state = STATIC_STATE;
}
@@ -500,7 +500,7 @@
if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl->ctrlcap)) {
/* Wait for exclusive access to hardware */
- mutex_lock(&p_slot->ctrl->crit_sect);
+ mutex_lock(&p_slot->ctrl->ctrl_lock);
p_slot->hpc_ops->green_led_off(p_slot);
@@ -508,7 +508,7 @@
wait_for_ctrl_irq (p_slot->ctrl);
/* Done with exclusive hardware access */
- mutex_unlock(&p_slot->ctrl->crit_sect);
+ mutex_unlock(&p_slot->ctrl->ctrl_lock);
}
p_slot->state = STATIC_STATE;
}
@@ -621,7 +621,7 @@
switch (p_slot->state) {
case BLINKINGOFF_STATE:
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
if (PWR_LED(ctrl->ctrlcap)) {
p_slot->hpc_ops->green_led_on(p_slot);
@@ -635,11 +635,11 @@
wait_for_ctrl_irq (ctrl);
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
break;
case BLINKINGON_STATE:
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
if (PWR_LED(ctrl->ctrlcap)) {
p_slot->hpc_ops->green_led_off(p_slot);
@@ -652,7 +652,7 @@
wait_for_ctrl_irq (ctrl);
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
break;
default:
@@ -681,7 +681,7 @@
}
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
/* blink green LED and turn off amber */
if (PWR_LED(ctrl->ctrlcap)) {
@@ -698,7 +698,7 @@
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
init_timer(&p_slot->task_event);
p_slot->task_event.expires = jiffies + 5 * HZ; /* 5 second delay */
@@ -713,7 +713,7 @@
if (POWER_CTRL(ctrl->ctrlcap)) {
dbg("power fault\n");
/* Wait for exclusive access to hardware */
- mutex_lock(&ctrl->crit_sect);
+ mutex_lock(&ctrl->ctrl_lock);
if (ATTN_LED(ctrl->ctrlcap)) {
p_slot->hpc_ops->set_attention_status(p_slot, 1);
@@ -726,7 +726,7 @@
}
/* Done with exclusive hardware access */
- mutex_unlock(&ctrl->crit_sect);
+ mutex_unlock(&ctrl->ctrl_lock);
}
}
/***********SURPRISE REMOVAL********************/
@@ -789,7 +789,6 @@
return -EINVAL;
}
}
- mutex_unlock(&p_slot->ctrl->crit_sect);
p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
@@ -801,6 +800,7 @@
if (p_slot)
update_slot_info(p_slot);
+ mutex_unlock(&p_slot->ctrl->crit_sect);
return rc;
}
@@ -846,10 +846,10 @@
}
}
- mutex_unlock(&p_slot->ctrl->crit_sect);
-
ret = remove_board(p_slot);
update_slot_info(p_slot);
+
+ mutex_unlock(&p_slot->ctrl->crit_sect);
return ret;
}
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 703a64a..1c551c6 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -1402,6 +1402,8 @@
pdev->subsystem_vendor, pdev->subsystem_device);
mutex_init(&ctrl->crit_sect);
+ mutex_init(&ctrl->ctrl_lock);
+
/* setup wait queue */
init_waitqueue_head(&ctrl->queue);