Commit 5d756f3f authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/locking' 

- Make pci_stop_dev() and pci_destroy_dev() concurrent safe (Keith Busch)

- Move __pci_walk_bus() mutex up into the caller, which avoids the need for
  a parameter to control locking (Keith Busch)

- Simplify __pci_walk_bus() by making it recursive (Keith Busch)

- Unexport pci_walk_bus_locked(), which is only used internally by the PCI
  core (Keith Busch)

* pci/locking:
  PCI: Unexport pci_walk_bus_locked()
  PCI: Convert __pci_walk_bus() to be recursive
  PCI: Move __pci_walk_bus() mutex to where we need it
  PCI: Make pci_destroy_dev() concurrent safe
  PCI: Make pci_stop_dev() concurrent safe
parents 665e4a34 38a18dfe

drivers/pci/bus.c

+16 −33
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ void pci_bus_add_device(struct pci_dev *dev) 
	if (retval < 0 && retval != -EPROBE_DEFER)

		pci_warn(dev, "device attach failed (%d)\n", retval);



	pci_dev_assign_added(dev, true);

	pci_dev_assign_added(dev);



	if (dev_of_node(&dev->dev) && pci_is_bridge(dev)) {

		retval = of_platform_populate(dev_of_node(&dev->dev), NULL, NULL,
@@ -399,41 +399,23 @@ void pci_bus_add_devices(const struct pci_bus *bus) 
}

EXPORT_SYMBOL(pci_bus_add_devices);



static void __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),

			   void *userdata, bool locked)

static int __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),

			  void *userdata)

{

	struct pci_dev *dev;

	struct pci_bus *bus;

	struct list_head *next;

	int retval;

	int ret = 0;



	bus = top;

	if (!locked)

		down_read(&pci_bus_sem);

	next = top->devices.next;

	for (;;) {

		if (next == &bus->devices) {

			/* end of this bus, go up or finish */

			if (bus == top)

	list_for_each_entry(dev, &top->devices, bus_list) {

		ret = cb(dev, userdata);

		if (ret)

			break;

			next = bus->self->bus_list.next;

			bus = bus->self->bus;

			continue;

		}

		dev = list_entry(next, struct pci_dev, bus_list);

		if (dev->subordinate) {

			/* this is a pci-pci bridge, do its devices next */

			next = dev->subordinate->devices.next;

			bus = dev->subordinate;

		} else

			next = dev->bus_list.next;



		retval = cb(dev, userdata);

		if (retval)

			ret = __pci_walk_bus(dev->subordinate, cb, userdata);

			if (ret)

				break;

		}

	if (!locked)

		up_read(&pci_bus_sem);

	}

	return ret;

}



/**
@@ -451,7 +433,9 @@ static void __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void 
 */

void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), void *userdata)

{

	__pci_walk_bus(top, cb, userdata, false);

	down_read(&pci_bus_sem);

	__pci_walk_bus(top, cb, userdata);

	up_read(&pci_bus_sem);

}

EXPORT_SYMBOL_GPL(pci_walk_bus);
@@ -459,9 +443,8 @@ void pci_walk_bus_locked(struct pci_bus *top, int (*cb)(struct pci_dev *, void * 
{

	lockdep_assert_held(&pci_bus_sem);



	__pci_walk_bus(top, cb, userdata, true);

	__pci_walk_bus(top, cb, userdata);

}

EXPORT_SYMBOL_GPL(pci_walk_bus_locked);



struct pci_bus *pci_bus_get(struct pci_bus *bus)

{

drivers/pci/pci.h

+18 −2
Original line number Diff line number Diff line
@@ -323,6 +323,9 @@ void __pci_bus_assign_resources(const struct pci_bus *bus, 
				struct list_head *realloc_head,

				struct list_head *fail_head);

bool pci_bus_clip_resource(struct pci_dev *dev, int idx);

void pci_walk_bus_locked(struct pci_bus *top,

			 int (*cb)(struct pci_dev *, void *),

			 void *userdata);



const char *pci_resource_name(struct pci_dev *dev, unsigned int i);
@@ -493,10 +496,18 @@ static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused) 
#define PCI_DEV_ADDED 0

#define PCI_DPC_RECOVERED 1

#define PCI_DPC_RECOVERING 2

#define PCI_DEV_REMOVED 3



static inline void pci_dev_assign_added(struct pci_dev *dev)

{

	smp_mb__before_atomic();

	set_bit(PCI_DEV_ADDED, &dev->priv_flags);

	smp_mb__after_atomic();

}



static inline void pci_dev_assign_added(struct pci_dev *dev, bool added)

static inline bool pci_dev_test_and_clear_added(struct pci_dev *dev)

{

	assign_bit(PCI_DEV_ADDED, &dev->priv_flags, added);

	return test_and_clear_bit(PCI_DEV_ADDED, &dev->priv_flags);

}



static inline bool pci_dev_is_added(const struct pci_dev *dev)
@@ -504,6 +515,11 @@ static inline bool pci_dev_is_added(const struct pci_dev *dev) 
	return test_bit(PCI_DEV_ADDED, &dev->priv_flags);

}



static inline bool pci_dev_test_and_set_removed(struct pci_dev *dev)

{

	return test_and_set_bit(PCI_DEV_REMOVED, &dev->priv_flags);

}



#ifdef CONFIG_PCIEAER

#include <linux/aer.h>

drivers/pci/remove.c

+10 −11
Original line number Diff line number Diff line
@@ -33,21 +33,20 @@ static void pci_stop_dev(struct pci_dev *dev) 
{

	pci_pme_active(dev, false);



	if (pci_dev_is_added(dev)) {

	if (!pci_dev_test_and_clear_added(dev))

		return;



	device_for_each_child(dev->dev.parent, dev_of_node(&dev->dev),

			      pci_pwrctl_unregister);

	device_release_driver(&dev->dev);

	pci_proc_detach_device(dev);

	pci_remove_sysfs_dev_files(dev);

	of_pci_remove_node(dev);



		pci_dev_assign_added(dev, false);

	}

}



static void pci_destroy_dev(struct pci_dev *dev)

{

	if (!dev->dev.kobj.parent)

	if (pci_dev_test_and_set_removed(dev))

		return;



	pci_npem_remove(dev);

include/linux/pci.h

+0 −2
Original line number Diff line number Diff line
@@ -1612,8 +1612,6 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, 


void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),

		  void *userdata);

void pci_walk_bus_locked(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),

			 void *userdata);

int pci_cfg_space_size(struct pci_dev *dev);

unsigned char pci_bus_max_busnr(struct pci_bus *bus);

void pci_setup_bridge(struct pci_bus *bus);