| Message ID | 20120810151417.031666ce.izumi.taku@jp.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Aug 9, 2012 at 11:14 PM, Taku Izumi <izumi.taku@jp.fujitsu.com> wrote: > From: Jiang Liu <jiang.liu@huawei.com> > > ACPI, PCI: Protect global lists in drivers/acpi/pci_root.c > > There are two global lists inf file drivers/acpi/pci_root.c. > One is for registered acpi_pci_drivers, the other is for > enumerated ACPI PCI root bridge objects. These two global > lists may change dynamically when registering/deregistering > acpi_pci_drivers or adding/removing ACPI PCI root bridge > objects. So protect them by mutex lock and RCU list. Is it possible to split this into two patches, one to add acpi_pci_drivers protection and another to add acpi_pci_roots protection? That would make this easier to review. > Signed-off-by: Jiang Liu <jiang.liu@huawei.com> > Signed-off-by: Yinghai Lu <yinghai@kernel.org> > [izumi.taku@jp.fujitsu.com: a bit change at acpi_pci_root_remove()] > Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> > > --- > drivers/acpi/pci_root.c | 86 +++++++++++++++++++++++++++++------------------- > 1 file changed, 53 insertions(+), 33 deletions(-) > > Index: Bjorn-next/drivers/acpi/pci_root.c > =================================================================== > --- Bjorn-next.orig/drivers/acpi/pci_root.c > +++ Bjorn-next/drivers/acpi/pci_root.c > @@ -27,7 +27,8 @@ > #include <linux/module.h> > #include <linux/init.h> > #include <linux/types.h> > -#include <linux/spinlock.h> > +#include <linux/mutex.h> > +#include <linux/rculist.h> > #include <linux/pm.h> > #include <linux/pm_runtime.h> > #include <linux/pci.h> > @@ -71,6 +72,8 @@ static struct acpi_driver acpi_pci_root_ > }, > }; > > +/* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */ > +static DEFINE_MUTEX(acpi_pci_root_lock); > static LIST_HEAD(acpi_pci_roots); > static LIST_HEAD(acpi_pci_drivers); > > @@ -81,47 +84,48 @@ int acpi_pci_register_driver(struct acpi > int n = 0; > struct acpi_pci_root *root; > > + mutex_lock(&acpi_pci_root_lock); > list_add_tail(&driver->node, &acpi_pci_drivers); > - > - if (!driver->add) > - return 0; > - > - list_for_each_entry(root, &acpi_pci_roots, node) { > - driver->add(root->device->handle); > - n++; > - } > + if (driver->add) > + list_for_each_entry_rcu(root, &acpi_pci_roots, node) { > + driver->add(root->device->handle); > + n++; > + } > + mutex_unlock(&acpi_pci_root_lock); > > return n; > } > - > EXPORT_SYMBOL(acpi_pci_register_driver); > > void acpi_pci_unregister_driver(struct acpi_pci_driver *driver) > { > struct acpi_pci_root *root; > > + mutex_lock(&acpi_pci_root_lock); > list_del(&driver->node); > - > - if (!driver->remove) > - return; > - > - list_for_each_entry(root, &acpi_pci_roots, node) > - driver->remove(root->device->handle); > + if (driver->remove) > + list_for_each_entry_rcu(root, &acpi_pci_roots, node) > + driver->remove(root->device->handle); > + mutex_unlock(&acpi_pci_root_lock); > } > - > EXPORT_SYMBOL(acpi_pci_unregister_driver); > > acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus) > { > struct acpi_pci_root *root; > + struct acpi_handle *handle = NULL; > > - list_for_each_entry(root, &acpi_pci_roots, node) > + rcu_read_lock(); > + list_for_each_entry_rcu(root, &acpi_pci_roots, node) > if ((root->segment == (u16) seg) && > - (root->secondary.start == (u16) bus)) > - return root->device->handle; > - return NULL; > -} > + (root->secondary.start == (u16) bus)) { > + handle = root->device->handle; > + break; > + } > + rcu_read_unlock(); > > + return handle; > +} > EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle); > > /** > @@ -268,10 +272,15 @@ struct acpi_pci_root *acpi_pci_find_root > { > struct acpi_pci_root *root; > > - list_for_each_entry(root, &acpi_pci_roots, node) { > - if (root->device->handle == handle) > + rcu_read_lock(); > + list_for_each_entry_rcu(root, &acpi_pci_roots, node) { > + if (root->device->handle == handle) { > + rcu_read_unlock(); > return root; > + } > } > + rcu_read_unlock(); > + > return NULL; > } > EXPORT_SYMBOL_GPL(acpi_pci_find_root); > @@ -459,7 +468,7 @@ static int __devinit acpi_pci_root_add(s > if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { > printk(KERN_ERR PREFIX "can't evaluate _SEG\n"); > result = -ENODEV; > - goto end; > + goto out_free; > } > > /* Check _CRS first, then _BBN. If no _BBN, default to zero. */ > @@ -484,7 +493,7 @@ static int __devinit acpi_pci_root_add(s > else { > printk(KERN_ERR PREFIX "can't evaluate _BBN\n"); > result = -ENODEV; > - goto end; > + goto out_free; > } > } > > @@ -508,8 +517,8 @@ static int __devinit acpi_pci_root_add(s > * TBD: Need PCI interface for enumeration/configuration of roots. > */ > > - /* TBD: Locking */ > - list_add_tail(&root->node, &acpi_pci_roots); > + mutex_lock(&acpi_pci_root_lock); > + list_add_tail_rcu(&root->node, &acpi_pci_roots); > > printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n", > acpi_device_name(device), acpi_device_bid(device), > @@ -528,7 +537,7 @@ static int __devinit acpi_pci_root_add(s > "Bus %04x:%02x not present in PCI namespace\n", > root->segment, (unsigned int)root->secondary.start); > result = -ENODEV; > - goto end; > + goto out_del_root; > } > > /* > @@ -538,7 +547,7 @@ static int __devinit acpi_pci_root_add(s > */ > result = acpi_pci_bind_root(device); > if (result) > - goto end; > + goto out_del_root; > > /* > * PCI Routing Table > @@ -614,11 +623,15 @@ static int __devinit acpi_pci_root_add(s > if (device->wakeup.flags.run_wake) > device_set_run_wake(root->bus->bridge, true); > > + mutex_unlock(&acpi_pci_root_lock); > + > return 0; > > -end: > - if (!list_empty(&root->node)) > - list_del(&root->node); > +out_del_root: > + list_del_rcu(&root->node); > + mutex_unlock(&acpi_pci_root_lock); > + synchronize_rcu(); > +out_free: > kfree(root); > return result; > } > @@ -628,11 +641,13 @@ static int acpi_pci_root_start(struct ac > struct acpi_pci_root *root = acpi_driver_data(device); > struct acpi_pci_driver *driver; > > + mutex_lock(&acpi_pci_root_lock); > list_for_each_entry(driver, &acpi_pci_drivers, node) > if (driver->add) > driver->add(device->handle); > > pci_bus_add_devices(root->bus); > + mutex_unlock(&acpi_pci_root_lock); > > return 0; > } > @@ -642,6 +657,8 @@ static int acpi_pci_root_remove(struct a > struct acpi_pci_root *root = acpi_driver_data(device); > struct acpi_pci_driver *driver; > > + mutex_lock(&acpi_pci_root_lock); > + > list_for_each_entry(driver, &acpi_pci_drivers, node) > if (driver->remove) > driver->remove(root->device->handle); > @@ -649,6 +666,9 @@ static int acpi_pci_root_remove(struct a > device_set_run_wake(root->bus->bridge, false); > pci_acpi_remove_bus_pm_notifier(device); > > + list_del_rcu(&root->node); > + mutex_unlock(&acpi_pci_root_lock); > + synchronize_rcu(); > kfree(root); > return 0; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: Bjorn-next/drivers/acpi/pci_root.c =================================================================== --- Bjorn-next.orig/drivers/acpi/pci_root.c +++ Bjorn-next/drivers/acpi/pci_root.c @@ -27,7 +27,8 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/types.h> -#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/rculist.h> #include <linux/pm.h> #include <linux/pm_runtime.h> #include <linux/pci.h> @@ -71,6 +72,8 @@ static struct acpi_driver acpi_pci_root_ }, }; +/* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */ +static DEFINE_MUTEX(acpi_pci_root_lock); static LIST_HEAD(acpi_pci_roots); static LIST_HEAD(acpi_pci_drivers); @@ -81,47 +84,48 @@ int acpi_pci_register_driver(struct acpi int n = 0; struct acpi_pci_root *root; + mutex_lock(&acpi_pci_root_lock); list_add_tail(&driver->node, &acpi_pci_drivers); - - if (!driver->add) - return 0; - - list_for_each_entry(root, &acpi_pci_roots, node) { - driver->add(root->device->handle); - n++; - } + if (driver->add) + list_for_each_entry_rcu(root, &acpi_pci_roots, node) { + driver->add(root->device->handle); + n++; + } + mutex_unlock(&acpi_pci_root_lock); return n; } - EXPORT_SYMBOL(acpi_pci_register_driver); void acpi_pci_unregister_driver(struct acpi_pci_driver *driver) { struct acpi_pci_root *root; + mutex_lock(&acpi_pci_root_lock); list_del(&driver->node); - - if (!driver->remove) - return; - - list_for_each_entry(root, &acpi_pci_roots, node) - driver->remove(root->device->handle); + if (driver->remove) + list_for_each_entry_rcu(root, &acpi_pci_roots, node) + driver->remove(root->device->handle); + mutex_unlock(&acpi_pci_root_lock); } - EXPORT_SYMBOL(acpi_pci_unregister_driver); acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus) { struct acpi_pci_root *root; + struct acpi_handle *handle = NULL; - list_for_each_entry(root, &acpi_pci_roots, node) + rcu_read_lock(); + list_for_each_entry_rcu(root, &acpi_pci_roots, node) if ((root->segment == (u16) seg) && - (root->secondary.start == (u16) bus)) - return root->device->handle; - return NULL; -} + (root->secondary.start == (u16) bus)) { + handle = root->device->handle; + break; + } + rcu_read_unlock(); + return handle; +} EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle); /** @@ -268,10 +272,15 @@ struct acpi_pci_root *acpi_pci_find_root { struct acpi_pci_root *root; - list_for_each_entry(root, &acpi_pci_roots, node) { - if (root->device->handle == handle) + rcu_read_lock(); + list_for_each_entry_rcu(root, &acpi_pci_roots, node) { + if (root->device->handle == handle) { + rcu_read_unlock(); return root; + } } + rcu_read_unlock(); + return NULL; } EXPORT_SYMBOL_GPL(acpi_pci_find_root); @@ -459,7 +468,7 @@ static int __devinit acpi_pci_root_add(s if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { printk(KERN_ERR PREFIX "can't evaluate _SEG\n"); result = -ENODEV; - goto end; + goto out_free; } /* Check _CRS first, then _BBN. If no _BBN, default to zero. */ @@ -484,7 +493,7 @@ static int __devinit acpi_pci_root_add(s else { printk(KERN_ERR PREFIX "can't evaluate _BBN\n"); result = -ENODEV; - goto end; + goto out_free; } } @@ -508,8 +517,8 @@ static int __devinit acpi_pci_root_add(s * TBD: Need PCI interface for enumeration/configuration of roots. */ - /* TBD: Locking */ - list_add_tail(&root->node, &acpi_pci_roots); + mutex_lock(&acpi_pci_root_lock); + list_add_tail_rcu(&root->node, &acpi_pci_roots); printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n", acpi_device_name(device), acpi_device_bid(device), @@ -528,7 +537,7 @@ static int __devinit acpi_pci_root_add(s "Bus %04x:%02x not present in PCI namespace\n", root->segment, (unsigned int)root->secondary.start); result = -ENODEV; - goto end; + goto out_del_root; } /* @@ -538,7 +547,7 @@ static int __devinit acpi_pci_root_add(s */ result = acpi_pci_bind_root(device); if (result) - goto end; + goto out_del_root; /* * PCI Routing Table @@ -614,11 +623,15 @@ static int __devinit acpi_pci_root_add(s if (device->wakeup.flags.run_wake) device_set_run_wake(root->bus->bridge, true); + mutex_unlock(&acpi_pci_root_lock); + return 0; -end: - if (!list_empty(&root->node)) - list_del(&root->node); +out_del_root: + list_del_rcu(&root->node); + mutex_unlock(&acpi_pci_root_lock); + synchronize_rcu(); +out_free: kfree(root); return result; } @@ -628,11 +641,13 @@ static int acpi_pci_root_start(struct ac struct acpi_pci_root *root = acpi_driver_data(device); struct acpi_pci_driver *driver; + mutex_lock(&acpi_pci_root_lock); list_for_each_entry(driver, &acpi_pci_drivers, node) if (driver->add) driver->add(device->handle); pci_bus_add_devices(root->bus); + mutex_unlock(&acpi_pci_root_lock); return 0; } @@ -642,6 +657,8 @@ static int acpi_pci_root_remove(struct a struct acpi_pci_root *root = acpi_driver_data(device); struct acpi_pci_driver *driver; + mutex_lock(&acpi_pci_root_lock); + list_for_each_entry(driver, &acpi_pci_drivers, node) if (driver->remove) driver->remove(root->device->handle); @@ -649,6 +666,9 @@ static int acpi_pci_root_remove(struct a device_set_run_wake(root->bus->bridge, false); pci_acpi_remove_bus_pm_notifier(device); + list_del_rcu(&root->node); + mutex_unlock(&acpi_pci_root_lock); + synchronize_rcu(); kfree(root); return 0; }