diff options
Diffstat (limited to 'arch/s390/pci/pci_bus.c')
| -rw-r--r-- | arch/s390/pci/pci_bus.c | 123 |
1 files changed, 89 insertions, 34 deletions
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c index 45a1c36c5a54..42a13e451f64 100644 --- a/arch/s390/pci/pci_bus.c +++ b/arch/s390/pci/pci_bus.c @@ -7,14 +7,14 @@ * */ -#define KMSG_COMPONENT "zpci" -#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt +#define pr_fmt(fmt) "zpci: " fmt #include <linux/kernel.h> #include <linux/slab.h> #include <linux/err.h> #include <linux/delay.h> #include <linux/seq_file.h> +#include <linux/irqdomain.h> #include <linux/jump_label.h> #include <linux/pci.h> #include <linux/printk.h> @@ -45,8 +45,10 @@ static int zpci_bus_prepare_device(struct zpci_dev *zdev) if (!zdev_enabled(zdev)) { rc = zpci_enable_device(zdev); - if (rc) + if (rc) { + pr_err("Enabling PCI function %08x failed\n", zdev->fid); return rc; + } } if (!zdev->has_resources) { @@ -151,23 +153,6 @@ int zpci_bus_scan_bus(struct zpci_bus *zbus) return ret; } -/* zpci_bus_scan_busses - Scan all registered busses - * - * Scan all available zbusses - * - */ -void zpci_bus_scan_busses(void) -{ - struct zpci_bus *zbus = NULL; - - mutex_lock(&zbus_list_lock); - list_for_each_entry(zbus, &zbus_list, bus_next) { - zpci_bus_scan_bus(zbus); - cond_resched(); - } - mutex_unlock(&zbus_list_lock); -} - static bool zpci_bus_is_multifunction_root(struct zpci_dev *zdev) { return !s390_pci_no_rid && zdev->rid_available && @@ -197,25 +182,52 @@ static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, s zbus->multifunction = zpci_bus_is_multifunction_root(fr); zbus->max_bus_speed = fr->max_bus_speed; + if (zpci_create_parent_msi_domain(zbus)) + goto out_free_domain; + /* * Note that the zbus->resources are taken over and zbus->resources * is empty after a successful call */ bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); - if (!bus) { - zpci_free_domain(zbus->domain_nr); - return -EFAULT; - } + if (!bus) + goto out_remove_msi_domain; zbus->bus = bus; + dev_set_msi_domain(&zbus->bus->dev, zbus->msi_parent_domain); return 0; + +out_remove_msi_domain: + zpci_remove_parent_msi_domain(zbus); +out_free_domain: + zpci_free_domain(zbus->domain_nr); + return -ENOMEM; } -static void zpci_bus_release(struct kref *kref) +/** + * zpci_bus_release - Un-initialize resources associated with the zbus and + * free memory + * @kref: refcount * that is part of struct zpci_bus + * + * MUST be called with `zbus_list_lock` held, but the lock is released during + * run of the function. + */ +static inline void zpci_bus_release(struct kref *kref) + __releases(&zbus_list_lock) { struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); + lockdep_assert_held(&zbus_list_lock); + + list_del(&zbus->bus_next); + mutex_unlock(&zbus_list_lock); + + /* + * At this point no-one should see this object, or be able to get a new + * reference to it. + */ + if (zbus->bus) { pci_lock_rescan_remove(); pci_stop_root_bus(zbus->bus); @@ -227,15 +239,19 @@ static void zpci_bus_release(struct kref *kref) pci_unlock_rescan_remove(); } - mutex_lock(&zbus_list_lock); - list_del(&zbus->bus_next); - mutex_unlock(&zbus_list_lock); + zpci_remove_parent_msi_domain(zbus); kfree(zbus); } -static void zpci_bus_put(struct zpci_bus *zbus) +static inline void __zpci_bus_get(struct zpci_bus *zbus) { - kref_put(&zbus->kref, zpci_bus_release); + lockdep_assert_held(&zbus_list_lock); + kref_get(&zbus->kref); +} + +static inline void zpci_bus_put(struct zpci_bus *zbus) +{ + kref_put_mutex(&zbus->kref, zpci_bus_release, &zbus_list_lock); } static struct zpci_bus *zpci_bus_get(int topo, bool topo_is_tid) @@ -247,7 +263,7 @@ static struct zpci_bus *zpci_bus_get(int topo, bool topo_is_tid) if (!zbus->multifunction) continue; if (topo_is_tid == zbus->topo_is_tid && topo == zbus->topo) { - kref_get(&zbus->kref); + __zpci_bus_get(zbus); goto out_unlock; } } @@ -257,6 +273,44 @@ out_unlock: return zbus; } +/** + * zpci_bus_get_next - get the next zbus object from given position in the list + * @pos: current position/cursor in the global zbus list + * + * Acquires and releases references as the cursor iterates (might also free/ + * release the cursor). Is tolerant of concurrent operations on the list. + * + * To begin the iteration, set *@pos to %NULL before calling the function. + * + * *@pos is set to %NULL in cases where either the list is empty, or *@pos is + * the last element in the list. + * + * Context: Process context. May sleep. + */ +void zpci_bus_get_next(struct zpci_bus **pos) +{ + struct zpci_bus *curp = *pos, *next = NULL; + + mutex_lock(&zbus_list_lock); + if (curp) + next = list_next_entry(curp, bus_next); + else + next = list_first_entry(&zbus_list, typeof(*curp), bus_next); + + if (list_entry_is_head(next, &zbus_list, bus_next)) + next = NULL; + + if (next) + __zpci_bus_get(next); + + *pos = next; + mutex_unlock(&zbus_list_lock); + + /* zpci_bus_put() might drop refcount to 0 and locks zbus_list_lock */ + if (curp) + zpci_bus_put(curp); +} + static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid) { struct zpci_bus *zbus; @@ -268,9 +322,6 @@ static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid) zbus->topo = topo; zbus->topo_is_tid = topo_is_tid; INIT_LIST_HEAD(&zbus->bus_next); - mutex_lock(&zbus_list_lock); - list_add_tail(&zbus->bus_next, &zbus_list); - mutex_unlock(&zbus_list_lock); kref_init(&zbus->kref); INIT_LIST_HEAD(&zbus->resources); @@ -280,6 +331,10 @@ static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid) zbus->bus_resource.flags = IORESOURCE_BUS; pci_add_resource(&zbus->resources, &zbus->bus_resource); + mutex_lock(&zbus_list_lock); + list_add_tail(&zbus->bus_next, &zbus_list); + mutex_unlock(&zbus_list_lock); + return zbus; } |