From: Rajat Jain <rajatxjain@xxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit 50b52fdee050745935d92e7026373edea2647e60 upstream.
Today it is there is no protection around pciehp_enable_slot() and
pciehp_disable_slot() to ensure that they complete before another
hot-plug operation can be done on that particular slot.
This patch introduces the slot->hotplug_lock to ensure that any hotplug
operations (add / remove) complete before another hotplug event can begin
processing on that particular slot.
Signed-off-by: Rajat Jain <rajatxjain@xxxxxxxxx>
Signed-off-by: Rajat Jain <rajatjain@xxxxxxxxxxx>
Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
[backported for SLE12]
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxxx>
---
drivers/pci/hotplug/pciehp.h | 1 +
drivers/pci/hotplug/pciehp_core.c | 7 ++++++-
drivers/pci/hotplug/pciehp_ctrl.c | 17 +++++++++++++++--
drivers/pci/hotplug/pciehp_hpc.c | 1 +
4 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 541bbe6d5343..b7f1ba33c4c1 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -77,6 +77,7 @@ struct slot {
struct hotplug_slot *hotplug_slot;
struct delayed_work work; /* work for button event */
struct mutex lock;
+ struct mutex hotplug_lock;
struct workqueue_struct *wq;
};
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index f4a18f51a29c..3904483ef12b 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -278,8 +278,11 @@ static int pciehp_probe(struct pcie_device *dev)
slot = ctrl->slot;
pciehp_get_adapter_status(slot, &occupied);
pciehp_get_power_status(slot, &poweron);
- if (occupied && pciehp_force)
+ if (occupied && pciehp_force) {
+ mutex_lock(&slot->hotplug_lock);
pciehp_enable_slot(slot);
+ mutex_unlock(&slot->hotplug_lock);
+ }
/* If empty slot's power status is on, turn power off */
if (!occupied && poweron && POWER_CTRL(ctrl))
pciehp_power_off_slot(slot);
@@ -323,10 +326,12 @@ static int pciehp_resume (struct pcie_device *dev)
/* Check if slot is occupied */
pciehp_get_adapter_status(slot, &status);
+ mutex_lock(&slot->hotplug_lock);
if (status)
pciehp_enable_slot(slot);
else
pciehp_disable_slot(slot);
+ mutex_unlock(&slot->hotplug_lock);
return 0;
}
#endif /* PM */
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index 38f018679175..62bfb528b4ff 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -290,6 +290,7 @@ static void pciehp_power_thread(struct work_struct *work)
struct power_work_info *info =
container_of(work, struct power_work_info, work);
struct slot *p_slot = info->p_slot;
+ int ret;
mutex_lock(&p_slot->lock);
switch (p_slot->state) {
@@ -299,13 +300,18 @@ static void pciehp_power_thread(struct work_struct *work)
"Disabling domain:bus:device=%04x:%02x:00\n",
pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
p_slot->ctrl->pcie->port->subordinate->number);
+ mutex_lock(&p_slot->hotplug_lock);
pciehp_disable_slot(p_slot);
+ mutex_unlock(&p_slot->hotplug_lock);
mutex_lock(&p_slot->lock);
p_slot->state = STATIC_STATE;
break;
case POWERON_STATE:
mutex_unlock(&p_slot->lock);
- if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl))
+ mutex_lock(&p_slot->hotplug_lock);
+ ret = pciehp_enable_slot(p_slot);
+ mutex_unlock(&p_slot->hotplug_lock);
+ if (ret && PWR_LED(p_slot->ctrl))
pciehp_green_led_off(p_slot);
mutex_lock(&p_slot->lock);
p_slot->state = STATIC_STATE;
@@ -476,6 +482,9 @@ static void interrupt_event_handler(struct work_struct *work)
kfree(info);
}
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
int pciehp_enable_slot(struct slot *p_slot)
{
u8 getstatus = 0;
@@ -514,7 +523,9 @@ int pciehp_enable_slot(struct slot *p_slot)
return rc;
}
-
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
int pciehp_disable_slot(struct slot *p_slot)
{
u8 getstatus = 0;
@@ -566,7 +577,9 @@ int pciehp_sysfs_enable_slot(struct slot *p_slot)
case STATIC_STATE:
p_slot->state = POWERON_STATE;
mutex_unlock(&p_slot->lock);
+ mutex_lock(&p_slot->hotplug_lock);
retval = pciehp_enable_slot(p_slot);
+ mutex_unlock(&p_slot->hotplug_lock);
mutex_lock(&p_slot->lock);
p_slot->state = STATIC_STATE;
break;
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 51f56ef4ab6f..f49e74239aed 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -815,6 +815,7 @@ static int pcie_init_slot(struct controller *ctrl)
slot->ctrl = ctrl;
mutex_init(&slot->lock);
+ mutex_init(&slot->hotplug_lock);
INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
ctrl->slot = slot;
return 0;
--
2.4.6
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