PCI: hotplug: Use global PCI rescan-remove locking
Multiple race conditions are possible between PCI hotplug and the generic
PCI bus rescan and device removal that can be triggered via sysfs.
To avoid those race conditions make PCI hotplug use global PCI
rescan-remove locking.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/cpci_hotplug_pci.c b/drivers/pci/hotplug/cpci_hotplug_pci.c
index d3add98..8c14648 100644
--- a/drivers/pci/hotplug/cpci_hotplug_pci.c
+++ b/drivers/pci/hotplug/cpci_hotplug_pci.c
@@ -254,9 +254,12 @@
{
struct pci_dev *dev;
struct pci_bus *parent;
+ int ret = 0;
dbg("%s - enter", __func__);
+ pci_lock_rescan_remove();
+
if (slot->dev == NULL) {
dbg("pci_dev null, finding %02x:%02x:%x",
slot->bus->number, PCI_SLOT(slot->devfn), PCI_FUNC(slot->devfn));
@@ -277,7 +280,8 @@
slot->dev = pci_get_slot(slot->bus, slot->devfn);
if (slot->dev == NULL) {
err("Could not find PCI device for slot %02x", slot->number);
- return -ENODEV;
+ ret = -ENODEV;
+ goto out;
}
}
parent = slot->dev->bus;
@@ -294,8 +298,10 @@
pci_bus_add_devices(parent);
+ out:
+ pci_unlock_rescan_remove();
dbg("%s - exit", __func__);
- return 0;
+ return ret;
}
int cpci_unconfigure_slot(struct slot* slot)
@@ -308,6 +314,8 @@
return -ENODEV;
}
+ pci_lock_rescan_remove();
+
list_for_each_entry_safe(dev, temp, &slot->bus->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != PCI_SLOT(slot->devfn))
continue;
@@ -318,6 +326,8 @@
pci_dev_put(slot->dev);
slot->dev = NULL;
+ pci_unlock_rescan_remove();
+
dbg("%s - exit", __func__);
return 0;
}
diff --git a/drivers/pci/hotplug/cpqphp_pci.c b/drivers/pci/hotplug/cpqphp_pci.c
index 6e4a12c..a3e3c20 100644
--- a/drivers/pci/hotplug/cpqphp_pci.c
+++ b/drivers/pci/hotplug/cpqphp_pci.c
@@ -86,6 +86,8 @@
struct pci_bus *child;
int num;
+ pci_lock_rescan_remove();
+
if (func->pci_dev == NULL)
func->pci_dev = pci_get_bus_and_slot(func->bus,PCI_DEVFN(func->device, func->function));
@@ -100,7 +102,7 @@
func->pci_dev = pci_get_bus_and_slot(func->bus, PCI_DEVFN(func->device, func->function));
if (func->pci_dev == NULL) {
dbg("ERROR: pci_dev still null\n");
- return 0;
+ goto out;
}
}
@@ -113,6 +115,8 @@
pci_dev_put(func->pci_dev);
+ out:
+ pci_unlock_rescan_remove();
return 0;
}
@@ -123,6 +127,7 @@
dbg("%s: bus/dev/func = %x/%x/%x\n", __func__, func->bus, func->device, func->function);
+ pci_lock_rescan_remove();
for (j=0; j<8 ; j++) {
struct pci_dev* temp = pci_get_bus_and_slot(func->bus, PCI_DEVFN(func->device, j));
if (temp) {
@@ -130,6 +135,7 @@
pci_stop_and_remove_bus_device(temp);
}
}
+ pci_unlock_rescan_remove();
return 0;
}
diff --git a/drivers/pci/hotplug/ibmphp_core.c b/drivers/pci/hotplug/ibmphp_core.c
index efdc13a..cf3ac1e 100644
--- a/drivers/pci/hotplug/ibmphp_core.c
+++ b/drivers/pci/hotplug/ibmphp_core.c
@@ -718,6 +718,8 @@
func->device, func->function);
debug("func->device << 3 | 0x0 = %x\n", func->device << 3 | 0x0);
+ pci_lock_rescan_remove();
+
for (j = 0; j < 0x08; j++) {
temp = pci_get_bus_and_slot(func->busno, (func->device << 3) | j);
if (temp) {
@@ -725,7 +727,10 @@
pci_dev_put(temp);
}
}
+
pci_dev_put(func->dev);
+
+ pci_unlock_rescan_remove();
}
/*
@@ -780,6 +785,8 @@
int flag = 0; /* this is to make sure we don't double scan the bus,
for bridged devices primarily */
+ pci_lock_rescan_remove();
+
if (!(bus_structure_fixup(func->busno)))
flag = 1;
if (func->dev == NULL)
@@ -789,7 +796,7 @@
if (func->dev == NULL) {
struct pci_bus *bus = pci_find_bus(0, func->busno);
if (!bus)
- return 0;
+ goto out;
num = pci_scan_slot(bus,
PCI_DEVFN(func->device, func->function));
@@ -800,7 +807,7 @@
PCI_DEVFN(func->device, func->function));
if (func->dev == NULL) {
err("ERROR... : pci_dev still NULL\n");
- return 0;
+ goto out;
}
}
if (!(flag) && (func->dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
@@ -810,6 +817,8 @@
pci_bus_add_devices(child);
}
+ out:
+ pci_unlock_rescan_remove();
return 0;
}
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 1983551..b07d7cc 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -39,22 +39,26 @@
struct pci_dev *dev;
struct pci_dev *bridge = p_slot->ctrl->pcie->port;
struct pci_bus *parent = bridge->subordinate;
- int num;
+ int num, ret = 0;
struct controller *ctrl = p_slot->ctrl;
+ pci_lock_rescan_remove();
+
dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
if (dev) {
ctrl_err(ctrl, "Device %s already exists "
"at %04x:%02x:00, cannot hot-add\n", pci_name(dev),
pci_domain_nr(parent), parent->number);
pci_dev_put(dev);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto out;
}
list_for_each_entry(dev, &parent->devices, bus_list)
@@ -73,7 +77,9 @@
pci_bus_add_devices(parent);
- return 0;
+ out:
+ pci_unlock_rescan_remove();
+ return ret;
}
int pciehp_unconfigure_device(struct slot *p_slot)
@@ -90,6 +96,8 @@
__func__, pci_domain_nr(parent), parent->number);
pciehp_get_adapter_status(p_slot, &presence);
+ pci_lock_rescan_remove();
+
/*
* Stopping an SR-IOV PF device removes all the associated VFs,
* which will update the bus->devices list and confuse the
@@ -124,5 +132,6 @@
pci_dev_put(dev);
}
+ pci_unlock_rescan_remove();
return rc;
}
diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index e9c044d..4fcdeed 100644
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -354,10 +354,15 @@
{
struct pci_bus *bus;
struct slot *slot;
+ int ret = 0;
+
+ pci_lock_rescan_remove();
bus = pcibios_find_pci_bus(dn);
- if (!bus)
- return -EINVAL;
+ if (!bus) {
+ ret = -EINVAL;
+ goto out;
+ }
pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
bus->self ? pci_name(bus->self) : "<!PHB!>");
@@ -371,7 +376,8 @@
printk(KERN_ERR
"%s: unable to remove hotplug slot %s\n",
__func__, drc_name);
- return -EIO;
+ ret = -EIO;
+ goto out;
}
}
@@ -382,7 +388,8 @@
if (pcibios_unmap_io_space(bus)) {
printk(KERN_ERR "%s: failed to unmap bus range\n",
__func__);
- return -ERANGE;
+ ret = -ERANGE;
+ goto out;
}
/* Remove the EADS bridge device itself */
@@ -390,7 +397,9 @@
pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
pci_stop_and_remove_bus_device(bus->self);
- return 0;
+ out:
+ pci_unlock_rescan_remove();
+ return ret;
}
/**
diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
index b7fc5c9..4796c15 100644
--- a/drivers/pci/hotplug/rpaphp_core.c
+++ b/drivers/pci/hotplug/rpaphp_core.c
@@ -398,7 +398,9 @@
return retval;
if (state == PRESENT) {
+ pci_lock_rescan_remove();
pcibios_add_pci_devices(slot->bus);
+ pci_unlock_rescan_remove();
slot->state = CONFIGURED;
} else if (state == EMPTY) {
slot->state = EMPTY;
@@ -418,7 +420,9 @@
if (slot->state == NOT_CONFIGURED)
return -EINVAL;
+ pci_lock_rescan_remove();
pcibios_remove_pci_devices(slot->bus);
+ pci_unlock_rescan_remove();
vm_unmap_aliases();
slot->state = NOT_CONFIGURED;
diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c
index 3c7eb5d..8d2ce22 100644
--- a/drivers/pci/hotplug/s390_pci_hpc.c
+++ b/drivers/pci/hotplug/s390_pci_hpc.c
@@ -80,7 +80,9 @@
goto out_deconfigure;
pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
+ pci_lock_rescan_remove();
pci_bus_add_devices(slot->zdev->bus);
+ pci_unlock_rescan_remove();
return rc;
@@ -98,7 +100,7 @@
return -EIO;
if (slot->zdev->pdev)
- pci_stop_and_remove_bus_device(slot->zdev->pdev);
+ pci_stop_and_remove_bus_device_locked(slot->zdev->pdev);
rc = zpci_disable_device(slot->zdev);
if (rc)
diff --git a/drivers/pci/hotplug/sgi_hotplug.c b/drivers/pci/hotplug/sgi_hotplug.c
index 5b05a68..613043f 100644
--- a/drivers/pci/hotplug/sgi_hotplug.c
+++ b/drivers/pci/hotplug/sgi_hotplug.c
@@ -459,12 +459,15 @@
acpi_scan_lock_release();
}
+ pci_lock_rescan_remove();
+
/* Call the driver for the new device */
pci_bus_add_devices(slot->pci_bus);
/* Call the drivers for the new devices subordinate to PPB */
if (new_ppb)
pci_bus_add_devices(new_bus);
+ pci_unlock_rescan_remove();
mutex_unlock(&sn_hotplug_mutex);
if (rc == 0)
@@ -540,6 +543,7 @@
acpi_scan_lock_release();
}
+ pci_lock_rescan_remove();
/* Free the SN resources assigned to the Linux device.*/
list_for_each_entry_safe(dev, temp, &slot->pci_bus->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
@@ -550,6 +554,7 @@
pci_stop_and_remove_bus_device(dev);
pci_dev_put(dev);
}
+ pci_unlock_rescan_remove();
/* Remove the SSDT for the slot from the ACPI namespace */
if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
diff --git a/drivers/pci/hotplug/shpchp_pci.c b/drivers/pci/hotplug/shpchp_pci.c
index b0e8313..2bf69fe 100644
--- a/drivers/pci/hotplug/shpchp_pci.c
+++ b/drivers/pci/hotplug/shpchp_pci.c
@@ -40,7 +40,9 @@
struct controller *ctrl = p_slot->ctrl;
struct pci_dev *bridge = ctrl->pci_dev;
struct pci_bus *parent = bridge->subordinate;
- int num;
+ int num, ret = 0;
+
+ pci_lock_rescan_remove();
dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, 0));
if (dev) {
@@ -48,13 +50,15 @@
"at %04x:%02x:%02x, cannot hot-add\n", pci_name(dev),
pci_domain_nr(parent), p_slot->bus, p_slot->device);
pci_dev_put(dev);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
num = pci_scan_slot(parent, PCI_DEVFN(p_slot->device, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto out;
}
list_for_each_entry(dev, &parent->devices, bus_list) {
@@ -75,7 +79,9 @@
pci_bus_add_devices(parent);
- return 0;
+ out:
+ pci_unlock_rescan_remove();
+ return ret;
}
int shpchp_unconfigure_device(struct slot *p_slot)
@@ -89,6 +95,8 @@
ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:%02x\n",
__func__, pci_domain_nr(parent), p_slot->bus, p_slot->device);
+ pci_lock_rescan_remove();
+
list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != p_slot->device)
continue;
@@ -108,6 +116,8 @@
pci_stop_and_remove_bus_device(dev);
pci_dev_put(dev);
}
+
+ pci_unlock_rescan_remove();
return rc;
}