diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 673 |
1 files changed, 427 insertions, 246 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 2b4c0624b704..40de2f51a1b1 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -9,28 +9,29 @@ */ #include <linux/acpi.h> +#include <linux/blkdev.h> +#include <linux/cleanup.h> #include <linux/cpufreq.h> #include <linux/device.h> +#include <linux/dma-map-ops.h> /* for dma_default_coherent */ #include <linux/err.h> #include <linux/fwnode.h> #include <linux/init.h> +#include <linux/kdev_t.h> #include <linux/kstrtox.h> #include <linux/module.h> -#include <linux/slab.h> -#include <linux/kdev_t.h> +#include <linux/mutex.h> +#include <linux/netdevice.h> #include <linux/notifier.h> #include <linux/of.h> #include <linux/of_device.h> -#include <linux/blkdev.h> -#include <linux/mutex.h> #include <linux/pm_runtime.h> -#include <linux/netdevice.h> -#include <linux/sched/signal.h> #include <linux/sched/mm.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> #include <linux/string_helpers.h> #include <linux/swiotlb.h> #include <linux/sysfs.h> -#include <linux/dma-map-ops.h> /* for dma_default_coherent */ #include "base.h" #include "physical_location.h" @@ -96,12 +97,9 @@ static int __fwnode_link_add(struct fwnode_handle *con, int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup, u8 flags) { - int ret; + guard(mutex)(&fwnode_link_lock); - mutex_lock(&fwnode_link_lock); - ret = __fwnode_link_add(con, sup, flags); - mutex_unlock(&fwnode_link_lock); - return ret; + return __fwnode_link_add(con, sup, flags); } /** @@ -142,10 +140,10 @@ static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode) { struct fwnode_link *link, *tmp; - mutex_lock(&fwnode_link_lock); + guard(mutex)(&fwnode_link_lock); + list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) __fwnode_link_del(link); - mutex_unlock(&fwnode_link_lock); } /** @@ -158,10 +156,10 @@ static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode) { struct fwnode_link *link, *tmp; - mutex_lock(&fwnode_link_lock); + guard(mutex)(&fwnode_link_lock); + list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) __fwnode_link_del(link); - mutex_unlock(&fwnode_link_lock); } /** @@ -289,7 +287,7 @@ static bool device_is_ancestor(struct device *dev, struct device *target) #define DL_MARKER_FLAGS (DL_FLAG_INFERRED | \ DL_FLAG_CYCLE | \ DL_FLAG_MANAGED) -static inline bool device_link_flag_is_sync_state_only(u32 flags) +bool device_link_flag_is_sync_state_only(u32 flags) { return (flags & ~DL_MARKER_FLAGS) == DL_FLAG_SYNC_STATE_ONLY; } @@ -462,9 +460,9 @@ static ssize_t auto_remove_on_show(struct device *dev, struct device_link *link = to_devlink(dev); const char *output; - if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER) + if (device_link_test(link, DL_FLAG_AUTOREMOVE_SUPPLIER)) output = "supplier unbind"; - else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) + else if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)) output = "consumer unbind"; else output = "never"; @@ -478,7 +476,7 @@ static ssize_t runtime_pm_show(struct device *dev, { struct device_link *link = to_devlink(dev); - return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME)); + return sysfs_emit(buf, "%d\n", device_link_test(link, DL_FLAG_PM_RUNTIME)); } static DEVICE_ATTR_RO(runtime_pm); @@ -487,8 +485,7 @@ static ssize_t sync_state_only_show(struct device *dev, { struct device_link *link = to_devlink(dev); - return sysfs_emit(buf, "%d\n", - !!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); + return sysfs_emit(buf, "%d\n", device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)); } static DEVICE_ATTR_RO(sync_state_only); @@ -554,7 +551,7 @@ void device_link_wait_removal(void) } EXPORT_SYMBOL_GPL(device_link_wait_removal); -static struct class devlink_class = { +static const struct class devlink_class = { .name = "devlink", .dev_groups = devlink_groups, .dev_release = devlink_dev_release, @@ -562,20 +559,11 @@ static struct class devlink_class = { static int devlink_add_symlinks(struct device *dev) { + char *buf_con __free(kfree) = NULL, *buf_sup __free(kfree) = NULL; int ret; - size_t len; struct device_link *link = to_devlink(dev); struct device *sup = link->supplier; struct device *con = link->consumer; - char *buf; - - len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), - strlen(dev_bus_name(con)) + strlen(dev_name(con))); - len += strlen(":"); - len += strlen("supplier:") + 1; - buf = kzalloc(len, GFP_KERNEL); - if (!buf) - return -ENOMEM; ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier"); if (ret) @@ -585,58 +573,64 @@ static int devlink_add_symlinks(struct device *dev) if (ret) goto err_con; - snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); - ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf); + buf_con = kasprintf(GFP_KERNEL, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); + if (!buf_con) { + ret = -ENOMEM; + goto err_con_dev; + } + + ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf_con); if (ret) goto err_con_dev; - snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); - ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf); + buf_sup = kasprintf(GFP_KERNEL, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); + if (!buf_sup) { + ret = -ENOMEM; + goto err_sup_dev; + } + + ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf_sup); if (ret) goto err_sup_dev; goto out; err_sup_dev: - snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); - sysfs_remove_link(&sup->kobj, buf); + sysfs_remove_link(&sup->kobj, buf_con); err_con_dev: sysfs_remove_link(&link->link_dev.kobj, "consumer"); err_con: sysfs_remove_link(&link->link_dev.kobj, "supplier"); out: - kfree(buf); return ret; } static void devlink_remove_symlinks(struct device *dev) { + char *buf_con __free(kfree) = NULL, *buf_sup __free(kfree) = NULL; struct device_link *link = to_devlink(dev); - size_t len; struct device *sup = link->supplier; struct device *con = link->consumer; - char *buf; sysfs_remove_link(&link->link_dev.kobj, "consumer"); sysfs_remove_link(&link->link_dev.kobj, "supplier"); - len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), - strlen(dev_bus_name(con)) + strlen(dev_name(con))); - len += strlen(":"); - len += strlen("supplier:") + 1; - buf = kzalloc(len, GFP_KERNEL); - if (!buf) { - WARN(1, "Unable to properly free device link symlinks!\n"); - return; - } - if (device_is_registered(con)) { - snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); - sysfs_remove_link(&con->kobj, buf); + buf_sup = kasprintf(GFP_KERNEL, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); + if (!buf_sup) + goto out; + sysfs_remove_link(&con->kobj, buf_sup); } - snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); - sysfs_remove_link(&sup->kobj, buf); - kfree(buf); + + buf_con = kasprintf(GFP_KERNEL, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); + if (!buf_con) + goto out; + sysfs_remove_link(&sup->kobj, buf_con); + + return; + +out: + WARN(1, "Unable to properly free device link symlinks!\n"); } static struct class_interface devlink_class_intf = { @@ -677,6 +671,9 @@ postcore_initcall(devlink_class_init); * @supplier: Supplier end of the link. * @flags: Link flags. * + * Return: On success, a device_link struct will be returned. + * On error or invalid flag settings, NULL will be returned. + * * The caller is responsible for the proper synchronization of the link creation * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the * runtime PM framework to take the link into account. Second, if the @@ -794,12 +791,12 @@ struct device_link *device_link_add(struct device *consumer, if (link->consumer != consumer) continue; - if (link->flags & DL_FLAG_INFERRED && + if (device_link_test(link, DL_FLAG_INFERRED) && !(flags & DL_FLAG_INFERRED)) link->flags &= ~DL_FLAG_INFERRED; if (flags & DL_FLAG_PM_RUNTIME) { - if (!(link->flags & DL_FLAG_PM_RUNTIME)) { + if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) { pm_runtime_new_link(consumer); link->flags |= DL_FLAG_PM_RUNTIME; } @@ -809,8 +806,8 @@ struct device_link *device_link_add(struct device *consumer, if (flags & DL_FLAG_STATELESS) { kref_get(&link->kref); - if (link->flags & DL_FLAG_SYNC_STATE_ONLY && - !(link->flags & DL_FLAG_STATELESS)) { + if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY) && + !device_link_test(link, DL_FLAG_STATELESS)) { link->flags |= DL_FLAG_STATELESS; goto reorder; } else { @@ -825,7 +822,7 @@ struct device_link *device_link_add(struct device *consumer, * update the existing link to stay around longer. */ if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) { - if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) { + if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)) { link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER; link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER; } @@ -833,12 +830,12 @@ struct device_link *device_link_add(struct device *consumer, link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOREMOVE_SUPPLIER); } - if (!(link->flags & DL_FLAG_MANAGED)) { + if (!device_link_test(link, DL_FLAG_MANAGED)) { kref_get(&link->kref); link->flags |= DL_FLAG_MANAGED; device_link_init_status(link, consumer, supplier); } - if (link->flags & DL_FLAG_SYNC_STATE_ONLY && + if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY) && !(flags & DL_FLAG_SYNC_STATE_ONLY)) { link->flags &= ~DL_FLAG_SYNC_STATE_ONLY; goto reorder; @@ -942,7 +939,7 @@ static void __device_link_del(struct kref *kref) static void device_link_put_kref(struct device_link *link) { - if (link->flags & DL_FLAG_STATELESS) + if (device_link_test(link, DL_FLAG_STATELESS)) kref_put(&link->kref, __device_link_del); else if (!device_is_registered(link->consumer)) __device_link_del(&link->kref); @@ -1006,7 +1003,7 @@ static void device_links_missing_supplier(struct device *dev) if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { WRITE_ONCE(link->status, DL_STATE_AVAILABLE); } else { - WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); + WARN_ON(!device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)); WRITE_ONCE(link->status, DL_STATE_DORMANT); } } @@ -1060,42 +1057,36 @@ int device_links_check_suppliers(struct device *dev) * Device waiting for supplier to become available is not allowed to * probe. */ - mutex_lock(&fwnode_link_lock); - sup_fw = fwnode_links_check_suppliers(dev->fwnode); - if (sup_fw) { - if (!dev_is_best_effort(dev)) { - fwnode_ret = -EPROBE_DEFER; - dev_err_probe(dev, -EPROBE_DEFER, - "wait for supplier %pfwf\n", sup_fw); - } else { - fwnode_ret = -EAGAIN; + scoped_guard(mutex, &fwnode_link_lock) { + sup_fw = fwnode_links_check_suppliers(dev->fwnode); + if (sup_fw) { + if (dev_is_best_effort(dev)) + fwnode_ret = -EAGAIN; + else + return dev_err_probe(dev, -EPROBE_DEFER, + "wait for supplier %pfwf\n", sup_fw); } } - mutex_unlock(&fwnode_link_lock); - if (fwnode_ret == -EPROBE_DEFER) - return fwnode_ret; device_links_write_lock(); list_for_each_entry(link, &dev->links.suppliers, c_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; if (link->status != DL_STATE_AVAILABLE && - !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) { + !device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)) { if (dev_is_best_effort(dev) && - link->flags & DL_FLAG_INFERRED && + device_link_test(link, DL_FLAG_INFERRED) && !link->supplier->can_match) { ret = -EAGAIN; continue; } device_links_missing_supplier(dev); - dev_err_probe(dev, -EPROBE_DEFER, - "supplier %s not ready\n", - dev_name(link->supplier)); - ret = -EPROBE_DEFER; + ret = dev_err_probe(dev, -EPROBE_DEFER, + "supplier %s not ready\n", dev_name(link->supplier)); break; } WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); @@ -1136,7 +1127,7 @@ static void __device_links_queue_sync_state(struct device *dev, return; list_for_each_entry(link, &dev->links.consumers, s_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; if (link->status != DL_STATE_ACTIVE) return; @@ -1248,9 +1239,8 @@ static ssize_t waiting_for_supplier_show(struct device *dev, bool val; device_lock(dev); - mutex_lock(&fwnode_link_lock); - val = !!fwnode_links_check_suppliers(dev->fwnode); - mutex_unlock(&fwnode_link_lock); + scoped_guard(mutex, &fwnode_link_lock) + val = !!fwnode_links_check_suppliers(dev->fwnode); device_unlock(dev); return sysfs_emit(buf, "%u\n", val); } @@ -1277,7 +1267,7 @@ void device_links_force_bind(struct device *dev) device_links_write_lock(); list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; if (link->status != DL_STATE_AVAILABLE) { @@ -1323,20 +1313,22 @@ void device_links_driver_bound(struct device *dev) */ if (dev->fwnode && dev->fwnode->dev == dev) { struct fwnode_handle *child; + fwnode_links_purge_suppliers(dev->fwnode); - mutex_lock(&fwnode_link_lock); + + guard(mutex)(&fwnode_link_lock); + fwnode_for_each_available_child_node(dev->fwnode, child) __fw_devlink_pickup_dangling_consumers(child, dev->fwnode); __fw_devlink_link_to_consumers(dev); - mutex_unlock(&fwnode_link_lock); } device_remove_file(dev, &dev_attr_waiting_for_supplier); device_links_write_lock(); list_for_each_entry(link, &dev->links.consumers, s_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; /* @@ -1352,7 +1344,7 @@ void device_links_driver_bound(struct device *dev) WARN_ON(link->status != DL_STATE_DORMANT); WRITE_ONCE(link->status, DL_STATE_AVAILABLE); - if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER) + if (device_link_test(link, DL_FLAG_AUTOPROBE_CONSUMER)) driver_deferred_probe_add(link->consumer); } @@ -1364,11 +1356,11 @@ void device_links_driver_bound(struct device *dev) list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { struct device *supplier; - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; supplier = link->supplier; - if (link->flags & DL_FLAG_SYNC_STATE_ONLY) { + if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)) { /* * When DL_FLAG_SYNC_STATE_ONLY is set, it means no * other DL_MANAGED_LINK_FLAGS have been set. So, it's @@ -1376,7 +1368,7 @@ void device_links_driver_bound(struct device *dev) */ device_link_drop_managed(link); } else if (dev_is_best_effort(dev) && - link->flags & DL_FLAG_INFERRED && + device_link_test(link, DL_FLAG_INFERRED) && link->status != DL_STATE_CONSUMER_PROBE && !link->supplier->can_match) { /* @@ -1428,10 +1420,10 @@ static void __device_links_no_driver(struct device *dev) struct device_link *link, *ln; list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; - if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) { + if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)) { device_link_drop_managed(link); continue; } @@ -1443,7 +1435,7 @@ static void __device_links_no_driver(struct device *dev) if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { WRITE_ONCE(link->status, DL_STATE_AVAILABLE); } else { - WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); + WARN_ON(!device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)); WRITE_ONCE(link->status, DL_STATE_DORMANT); } } @@ -1468,7 +1460,7 @@ void device_links_no_driver(struct device *dev) device_links_write_lock(); list_for_each_entry(link, &dev->links.consumers, s_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; /* @@ -1505,10 +1497,10 @@ void device_links_driver_cleanup(struct device *dev) device_links_write_lock(); list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; - WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER); + WARN_ON(device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)); WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND); /* @@ -1517,7 +1509,7 @@ void device_links_driver_cleanup(struct device *dev) * has moved to DL_STATE_SUPPLIER_UNBIND. */ if (link->status == DL_STATE_SUPPLIER_UNBIND && - link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER) + device_link_test(link, DL_FLAG_AUTOREMOVE_SUPPLIER)) device_link_drop_managed(link); WRITE_ONCE(link->status, DL_STATE_DORMANT); @@ -1551,7 +1543,7 @@ bool device_links_busy(struct device *dev) device_links_write_lock(); list_for_each_entry(link, &dev->links.consumers, s_node) { - if (!(link->flags & DL_FLAG_MANAGED)) + if (!device_link_test(link, DL_FLAG_MANAGED)) continue; if (link->status == DL_STATE_CONSUMER_PROBE @@ -1593,8 +1585,8 @@ void device_links_unbind_consumers(struct device *dev) list_for_each_entry(link, &dev->links.consumers, s_node) { enum device_link_state status; - if (!(link->flags & DL_FLAG_MANAGED) || - link->flags & DL_FLAG_SYNC_STATE_ONLY) + if (!device_link_test(link, DL_FLAG_MANAGED) || + device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)) continue; status = link->status; @@ -1750,7 +1742,7 @@ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode) static void fw_devlink_relax_link(struct device_link *link) { - if (!(link->flags & DL_FLAG_INFERRED)) + if (!device_link_test(link, DL_FLAG_INFERRED)) return; if (device_link_flag_is_sync_state_only(link->flags)) @@ -1786,13 +1778,13 @@ static int fw_devlink_dev_sync_state(struct device *dev, void *data) struct device_link *link = to_devlink(dev); struct device *sup = link->supplier; - if (!(link->flags & DL_FLAG_MANAGED) || + if (!device_link_test(link, DL_FLAG_MANAGED) || link->status == DL_STATE_ACTIVE || sup->state_synced || !dev_has_sync_state(sup)) return 0; if (fw_devlink_sync_state == FW_DEVLINK_SYNC_STATE_STRICT) { - dev_warn(sup, "sync_state() pending due to %s\n", + dev_info(sup, "sync_state() pending due to %s\n", dev_name(link->consumer)); return 0; } @@ -1888,8 +1880,6 @@ static void fw_devlink_unblock_consumers(struct device *dev) device_links_write_unlock(); } -#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev) - static bool fwnode_init_without_drv(struct fwnode_handle *fwnode) { struct device *dev; @@ -1978,7 +1968,7 @@ static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwn /** * __fw_devlink_relax_cycles - Relax and mark dependency cycles. - * @con: Potential consumer device. + * @con_handle: Potential consumer device fwnode. * @sup_handle: Potential supplier's fwnode. * * Needs to be called with fwnode_lock and device link lock held. @@ -1996,10 +1986,10 @@ static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwn * * Return true if one or more cycles were found. Otherwise, return false. */ -static bool __fw_devlink_relax_cycles(struct device *con, +static bool __fw_devlink_relax_cycles(struct fwnode_handle *con_handle, struct fwnode_handle *sup_handle) { - struct device *sup_dev = NULL, *par_dev = NULL; + struct device *sup_dev = NULL, *par_dev = NULL, *con_dev = NULL; struct fwnode_link *link; struct device_link *dev_link; bool ret = false; @@ -2016,22 +2006,22 @@ static bool __fw_devlink_relax_cycles(struct device *con, sup_handle->flags |= FWNODE_FLAG_VISITED; - sup_dev = get_dev_from_fwnode(sup_handle); - /* Termination condition. */ - if (sup_dev == con) { + if (sup_handle == con_handle) { pr_debug("----- cycle: start -----\n"); ret = true; goto out; } + sup_dev = get_dev_from_fwnode(sup_handle); + con_dev = get_dev_from_fwnode(con_handle); /* * If sup_dev is bound to a driver and @con hasn't started binding to a * driver, sup_dev can't be a consumer of @con. So, no need to check * further. */ if (sup_dev && sup_dev->links.status == DL_DEV_DRIVER_BOUND && - con->links.status == DL_DEV_NO_DRIVER) { + con_dev && con_dev->links.status == DL_DEV_NO_DRIVER) { ret = false; goto out; } @@ -2040,7 +2030,7 @@ static bool __fw_devlink_relax_cycles(struct device *con, if (link->flags & FWLINK_FLAG_IGNORE) continue; - if (__fw_devlink_relax_cycles(con, link->supplier)) { + if (__fw_devlink_relax_cycles(con_handle, link->supplier)) { __fwnode_link_cycle(link); ret = true; } @@ -2055,7 +2045,7 @@ static bool __fw_devlink_relax_cycles(struct device *con, else par_dev = fwnode_get_next_parent_dev(sup_handle); - if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode)) { + if (par_dev && __fw_devlink_relax_cycles(con_handle, par_dev->fwnode)) { pr_debug("%pfwf: cycle: child of %pfwf\n", sup_handle, par_dev->fwnode); ret = true; @@ -2070,10 +2060,10 @@ static bool __fw_devlink_relax_cycles(struct device *con, * such due to a cycle. */ if (device_link_flag_is_sync_state_only(dev_link->flags) && - !(dev_link->flags & DL_FLAG_CYCLE)) + !device_link_test(dev_link, DL_FLAG_CYCLE)) continue; - if (__fw_devlink_relax_cycles(con, + if (__fw_devlink_relax_cycles(con_handle, dev_link->supplier->fwnode)) { pr_debug("%pfwf: cycle: depends on %pfwf\n", sup_handle, dev_link->supplier->fwnode); @@ -2086,6 +2076,7 @@ static bool __fw_devlink_relax_cycles(struct device *con, out: sup_handle->flags &= ~FWNODE_FLAG_VISITED; put_device(sup_dev); + put_device(con_dev); put_device(par_dev); return ret; } @@ -2121,11 +2112,6 @@ static int fw_devlink_create_devlink(struct device *con, if (link->flags & FWLINK_FLAG_IGNORE) return 0; - if (con->fwnode == link->consumer) - flags = fw_devlink_get_flags(link->flags); - else - flags = FW_DEVLINK_FLAGS_PERMISSIVE; - /* * In some cases, a device P might also be a supplier to its child node * C. However, this would defer the probe of C until the probe of P @@ -2146,25 +2132,23 @@ static int fw_devlink_create_devlink(struct device *con, return -EINVAL; /* - * SYNC_STATE_ONLY device links don't block probing and supports cycles. - * So, one might expect that cycle detection isn't necessary for them. - * However, if the device link was marked as SYNC_STATE_ONLY because - * it's part of a cycle, then we still need to do cycle detection. This - * is because the consumer and supplier might be part of multiple cycles - * and we need to detect all those cycles. + * Don't try to optimize by not calling the cycle detection logic under + * certain conditions. There's always some corner case that won't get + * detected. */ - if (!device_link_flag_is_sync_state_only(flags) || - flags & DL_FLAG_CYCLE) { - device_links_write_lock(); - if (__fw_devlink_relax_cycles(con, sup_handle)) { - __fwnode_link_cycle(link); - flags = fw_devlink_get_flags(link->flags); - pr_debug("----- cycle: end -----\n"); - dev_info(con, "Fixed dependency cycle(s) with %pfwf\n", - sup_handle); - } - device_links_write_unlock(); + device_links_write_lock(); + if (__fw_devlink_relax_cycles(link->consumer, sup_handle)) { + __fwnode_link_cycle(link); + pr_debug("----- cycle: end -----\n"); + pr_info("%pfwf: Fixed dependency cycle(s) with %pfwf\n", + link->consumer, sup_handle); } + device_links_write_unlock(); + + if (con->fwnode == link->consumer) + flags = fw_devlink_get_flags(link->flags); + else + flags = FW_DEVLINK_FLAGS_PERMISSIVE; if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE) sup_dev = fwnode_get_next_parent_dev(sup_handle); @@ -2187,8 +2171,8 @@ static int fw_devlink_create_devlink(struct device *con, } if (con != sup_dev && !device_link_add(con, sup_dev, flags)) { - dev_err(con, "Failed to create device link (0x%x) with %s\n", - flags, dev_name(sup_dev)); + dev_err(con, "Failed to create device link (0x%x) with supplier %s for %pfwf\n", + flags, dev_name(sup_dev), link->consumer); ret = -EINVAL; } @@ -2338,10 +2322,10 @@ static void fw_devlink_link_device(struct device *dev) fw_devlink_parse_fwtree(fwnode); - mutex_lock(&fwnode_link_lock); + guard(mutex)(&fwnode_link_lock); + __fw_devlink_link_to_consumers(dev); __fw_devlink_link_to_suppliers(dev, fwnode); - mutex_unlock(&fwnode_link_lock); } /* Device links support end. */ @@ -2590,7 +2574,7 @@ static const void *device_namespace(const struct kobject *kobj) const struct device *dev = kobj_to_dev(kobj); const void *ns = NULL; - if (dev->class && dev->class->ns_type) + if (dev->class && dev->class->namespace) ns = dev->class->namespace(dev); return ns; @@ -2637,6 +2621,35 @@ static const char *dev_uevent_name(const struct kobject *kobj) return NULL; } +/* + * Try filling "DRIVER=<name>" uevent variable for a device. Because this + * function may race with binding and unbinding the device from a driver, + * we need to be careful. Binding is generally safe, at worst we miss the + * fact that the device is already bound to a driver (but the driver + * information that is delivered through uevents is best-effort, it may + * become obsolete as soon as it is generated anyways). Unbinding is more + * risky as driver pointer is transitioning to NULL, so READ_ONCE() should + * be used to make sure we are dealing with the same pointer, and to + * ensure that driver structure is not going to disappear from under us + * we take bus' drivers klist lock. The assumption that only registered + * driver can be bound to a device, and to unregister a driver bus code + * will take the same lock. + */ +static void dev_driver_uevent(const struct device *dev, struct kobj_uevent_env *env) +{ + struct subsys_private *sp = bus_to_subsys(dev->bus); + + if (sp) { + scoped_guard(spinlock, &sp->klist_drivers.k_lock) { + struct device_driver *drv = READ_ONCE(dev->driver); + if (drv) + add_uevent_var(env, "DRIVER=%s", drv->name); + } + + subsys_put(sp); + } +} + static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env) { const struct device *dev = kobj_to_dev(kobj); @@ -2668,8 +2681,8 @@ static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env) if (dev->type && dev->type->name) add_uevent_var(env, "DEVTYPE=%s", dev->type->name); - if (dev->driver) - add_uevent_var(env, "DRIVER=%s", dev->driver->name); + /* Add "DRIVER=%s" variable if the device is bound to a driver */ + dev_driver_uevent(dev, env); /* Add common DT information about the device */ of_device_uevent(dev, env); @@ -2739,11 +2752,8 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr, if (!env) return -ENOMEM; - /* Synchronize with really_probe() */ - device_lock(dev); /* let the kset specific function add its keys */ retval = kset->uevent_ops->uevent(&dev->kobj, env); - device_unlock(dev); if (retval) goto out; @@ -3167,7 +3177,7 @@ void device_initialize(struct device *dev) } EXPORT_SYMBOL_GPL(device_initialize); -struct kobject *virtual_device_parent(struct device *dev) +struct kobject *virtual_device_parent(void) { static struct kobject *virtual_dir = NULL; @@ -3245,7 +3255,7 @@ static struct kobject *get_device_parent(struct device *dev, * in a "glue" directory to prevent namespace collisions. */ if (parent == NULL) - parent_kobj = virtual_device_parent(dev); + parent_kobj = virtual_device_parent(); else if (parent->class && !dev->class->ns_type) { subsys_put(sp); return &parent->kobj; @@ -3713,7 +3723,7 @@ done: device_pm_remove(dev); dpm_sysfs_remove(dev); DPMError: - dev->driver = NULL; + device_set_driver(dev, NULL); bus_remove_device(dev); BusError: device_remove_attrs(dev); @@ -3984,8 +3994,8 @@ const char *device_get_devnode(const struct device *dev, /** * device_for_each_child - device child iterator. * @parent: parent struct device. - * @fn: function to be called for each device. * @data: data for the callback. + * @fn: function to be called for each device. * * Iterate over @parent's child devices, and call @fn for each, * passing it @data. @@ -3994,13 +4004,13 @@ const char *device_get_devnode(const struct device *dev, * other than 0, we break out and return that value. */ int device_for_each_child(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)) + device_iter_t fn) { struct klist_iter i; struct device *child; int error = 0; - if (!parent->p) + if (!parent || !parent->p) return 0; klist_iter_init(&parent->p->klist_children, &i); @@ -4014,8 +4024,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child); /** * device_for_each_child_reverse - device child iterator in reversed order. * @parent: parent struct device. - * @fn: function to be called for each device. * @data: data for the callback. + * @fn: function to be called for each device. * * Iterate over @parent's child devices, and call @fn for each, * passing it @data. @@ -4024,13 +4034,13 @@ EXPORT_SYMBOL_GPL(device_for_each_child); * other than 0, we break out and return that value. */ int device_for_each_child_reverse(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)) + device_iter_t fn) { struct klist_iter i; struct device *child; int error = 0; - if (!parent->p) + if (!parent || !parent->p) return 0; klist_iter_init(&parent->p->klist_children, &i); @@ -4042,87 +4052,77 @@ int device_for_each_child_reverse(struct device *parent, void *data, EXPORT_SYMBOL_GPL(device_for_each_child_reverse); /** - * device_find_child - device iterator for locating a particular device. - * @parent: parent struct device - * @match: Callback function to check device - * @data: Data to pass to match function - * - * This is similar to the device_for_each_child() function above, but it - * returns a reference to a device that is 'found' for later use, as - * determined by the @match callback. + * device_for_each_child_reverse_from - device child iterator in reversed order. + * @parent: parent struct device. + * @from: optional starting point in child list + * @data: data for the callback. + * @fn: function to be called for each device. * - * The callback should return 0 if the device doesn't match and non-zero - * if it does. If the callback returns non-zero and a reference to the - * current device can be obtained, this function will return to the caller - * and not iterate over any more devices. + * Iterate over @parent's child devices, starting at @from, and call @fn + * for each, passing it @data. This helper is identical to + * device_for_each_child_reverse() when @from is NULL. * - * NOTE: you will need to drop the reference with put_device() after use. + * @fn is checked each iteration. If it returns anything other than 0, + * iteration stop and that value is returned to the caller of + * device_for_each_child_reverse_from(); */ -struct device *device_find_child(struct device *parent, void *data, - int (*match)(struct device *dev, void *data)) +int device_for_each_child_reverse_from(struct device *parent, + struct device *from, void *data, + device_iter_t fn) { struct klist_iter i; struct device *child; + int error = 0; - if (!parent) - return NULL; + if (!parent || !parent->p) + return 0; - klist_iter_init(&parent->p->klist_children, &i); - while ((child = next_device(&i))) - if (match(child, data) && get_device(child)) - break; + klist_iter_init_node(&parent->p->klist_children, &i, + (from ? &from->p->knode_parent : NULL)); + while ((child = prev_device(&i)) && !error) + error = fn(child, data); klist_iter_exit(&i); - return child; + return error; } -EXPORT_SYMBOL_GPL(device_find_child); +EXPORT_SYMBOL_GPL(device_for_each_child_reverse_from); /** - * device_find_child_by_name - device iterator for locating a child device. + * device_find_child - device iterator for locating a particular device. * @parent: parent struct device - * @name: name of the child device + * @data: Data to pass to match function + * @match: Callback function to check device * - * This is similar to the device_find_child() function above, but it - * returns a reference to a device that has the name @name. + * This is similar to the device_for_each_child() function above, but it + * returns a reference to a device that is 'found' for later use, as + * determined by the @match callback. + * + * The callback should return 0 if the device doesn't match and non-zero + * if it does. If the callback returns non-zero and a reference to the + * current device can be obtained, this function will return to the caller + * and not iterate over any more devices. * * NOTE: you will need to drop the reference with put_device() after use. */ -struct device *device_find_child_by_name(struct device *parent, - const char *name) +struct device *device_find_child(struct device *parent, const void *data, + device_match_t match) { struct klist_iter i; struct device *child; - if (!parent) + if (!parent || !parent->p) return NULL; klist_iter_init(&parent->p->klist_children, &i); - while ((child = next_device(&i))) - if (sysfs_streq(dev_name(child), name) && get_device(child)) + while ((child = next_device(&i))) { + if (match(child, data)) { + get_device(child); break; + } + } klist_iter_exit(&i); return child; } -EXPORT_SYMBOL_GPL(device_find_child_by_name); - -static int match_any(struct device *dev, void *unused) -{ - return 1; -} - -/** - * device_find_any_child - device iterator for locating a child device, if any. - * @parent: parent struct device - * - * This is similar to the device_find_child() function above, but it - * returns a reference to a child device, if any. - * - * NOTE: you will need to drop the reference with put_device() after use. - */ -struct device *device_find_any_child(struct device *parent) -{ - return device_find_child(parent, NULL, match_any); -} -EXPORT_SYMBOL_GPL(device_find_any_child); +EXPORT_SYMBOL_GPL(device_find_child); int __init devices_init(void) { @@ -4138,7 +4138,7 @@ int __init devices_init(void) sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj); if (!sysfs_dev_char_kobj) goto char_kobj_err; - device_link_wq = alloc_workqueue("device_link_wq", 0, 0); + device_link_wq = alloc_workqueue("device_link_wq", WQ_PERCPU, 0); if (!device_link_wq) goto wq_err; @@ -4512,9 +4512,11 @@ EXPORT_SYMBOL_GPL(device_destroy); */ int device_rename(struct device *dev, const char *new_name) { + struct subsys_private *sp = NULL; struct kobject *kobj = &dev->kobj; char *old_device_name = NULL; int error; + bool is_link_renamed = false; dev = get_device(dev); if (!dev) @@ -4529,7 +4531,7 @@ int device_rename(struct device *dev, const char *new_name) } if (dev->class) { - struct subsys_private *sp = class_to_subsys(dev->class); + sp = class_to_subsys(dev->class); if (!sp) { error = -EINVAL; @@ -4538,16 +4540,19 @@ int device_rename(struct device *dev, const char *new_name) error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name, new_name, kobject_namespace(kobj)); - subsys_put(sp); if (error) goto out; + + is_link_renamed = true; } error = kobject_rename(kobj, new_name); - if (error) - goto out; - out: + if (error && is_link_renamed) + sysfs_rename_link_ns(&sp->subsys.kobj, kobj, new_name, + old_device_name, kobject_namespace(kobj)); + subsys_put(sp); + put_device(dev); kfree(old_device_name); @@ -4869,7 +4874,7 @@ set_dev_info(const struct device *dev, struct dev_printk_info *dev_info) else return; - strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem)); + strscpy(dev_info->subsystem, subsys); /* * Add device identifier DEVICE=: @@ -4979,6 +4984,49 @@ define_dev_printk_level(_dev_info, KERN_INFO); #endif +static void __dev_probe_failed(const struct device *dev, int err, bool fatal, + const char *fmt, va_list vargsp) +{ + struct va_format vaf; + va_list vargs; + + /* + * On x86_64 and possibly on other architectures, va_list is actually a + * size-1 array containing a structure. As a result, function parameter + * vargsp decays from T[1] to T*, and &vargsp has type T** rather than + * T(*)[1], which is expected by its assignment to vaf.va below. + * + * One standard way to solve this mess is by creating a copy in a local + * variable of type va_list and then using a pointer to that local copy + * instead, which is the approach employed here. + */ + va_copy(vargs, vargsp); + + vaf.fmt = fmt; + vaf.va = &vargs; + + switch (err) { + case -EPROBE_DEFER: + device_set_deferred_probe_reason(dev, &vaf); + dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + break; + + case -ENOMEM: + /* Don't print anything on -ENOMEM, there's already enough output */ + break; + + default: + /* Log fatal final failures as errors, otherwise produce warnings */ + if (fatal) + dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + else + dev_warn(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + break; + } + + va_end(vargs); +} + /** * dev_err_probe - probe error check and log helper * @dev: the pointer to the struct device @@ -4991,7 +5039,7 @@ define_dev_printk_level(_dev_info, KERN_INFO); * -EPROBE_DEFER and propagate error upwards. * In case of -EPROBE_DEFER it sets also defer probe reason, which can be * checked later by reading devices_deferred debugfs attribute. - * It replaces code sequence:: + * It replaces the following code sequence:: * * if (err != -EPROBE_DEFER) * dev_err(dev, ...); @@ -5003,37 +5051,78 @@ define_dev_printk_level(_dev_info, KERN_INFO); * * return dev_err_probe(dev, err, ...); * - * Using this helper in your probe function is totally fine even if @err is - * known to never be -EPROBE_DEFER. + * Using this helper in your probe function is totally fine even if @err + * is known to never be -EPROBE_DEFER. * The benefit compared to a normal dev_err() is the standardized format - * of the error code, it being emitted symbolically (i.e. you get "EAGAIN" - * instead of "-35") and the fact that the error code is returned which allows - * more compact error paths. + * of the error code, which is emitted symbolically (i.e. you get "EAGAIN" + * instead of "-35"), and having the error code returned allows more + * compact error paths. * * Returns @err. */ int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) { - struct va_format vaf; - va_list args; + va_list vargs; - va_start(args, fmt); - vaf.fmt = fmt; - vaf.va = &args; + va_start(vargs, fmt); - if (err != -EPROBE_DEFER) { - dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf); - } else { - device_set_deferred_probe_reason(dev, &vaf); - dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf); - } + /* Use dev_err() for logging when err doesn't equal -EPROBE_DEFER */ + __dev_probe_failed(dev, err, true, fmt, vargs); - va_end(args); + va_end(vargs); return err; } EXPORT_SYMBOL_GPL(dev_err_probe); +/** + * dev_warn_probe - probe error check and log helper + * @dev: the pointer to the struct device + * @err: error value to test + * @fmt: printf-style format string + * @...: arguments as specified in the format string + * + * This helper implements common pattern present in probe functions for error + * checking: print debug or warning message depending if the error value is + * -EPROBE_DEFER and propagate error upwards. + * In case of -EPROBE_DEFER it sets also defer probe reason, which can be + * checked later by reading devices_deferred debugfs attribute. + * It replaces the following code sequence:: + * + * if (err != -EPROBE_DEFER) + * dev_warn(dev, ...); + * else + * dev_dbg(dev, ...); + * return err; + * + * with:: + * + * return dev_warn_probe(dev, err, ...); + * + * Using this helper in your probe function is totally fine even if @err + * is known to never be -EPROBE_DEFER. + * The benefit compared to a normal dev_warn() is the standardized format + * of the error code, which is emitted symbolically (i.e. you get "EAGAIN" + * instead of "-35"), and having the error code returned allows more + * compact error paths. + * + * Returns @err. + */ +int dev_warn_probe(const struct device *dev, int err, const char *fmt, ...) +{ + va_list vargs; + + va_start(vargs, fmt); + + /* Use dev_warn() for logging when err doesn't equal -EPROBE_DEFER */ + __dev_probe_failed(dev, err, false, fmt, vargs); + + va_end(vargs); + + return err; +} +EXPORT_SYMBOL_GPL(dev_warn_probe); + static inline bool fwnode_is_primary(struct fwnode_handle *fwnode) { return fwnode && !IS_ERR(fwnode->secondary); @@ -5106,6 +5195,67 @@ void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) EXPORT_SYMBOL_GPL(set_secondary_fwnode); /** + * device_remove_of_node - Remove an of_node from a device + * @dev: device whose device tree node is being removed + */ +void device_remove_of_node(struct device *dev) +{ + dev = get_device(dev); + if (!dev) + return; + + if (!dev->of_node) + goto end; + + if (dev->fwnode == of_fwnode_handle(dev->of_node)) + dev->fwnode = NULL; + + of_node_put(dev->of_node); + dev->of_node = NULL; + +end: + put_device(dev); +} +EXPORT_SYMBOL_GPL(device_remove_of_node); + +/** + * device_add_of_node - Add an of_node to an existing device + * @dev: device whose device tree node is being added + * @of_node: of_node to add + * + * Return: 0 on success or error code on failure. + */ +int device_add_of_node(struct device *dev, struct device_node *of_node) +{ + int ret; + + if (!of_node) + return -EINVAL; + + dev = get_device(dev); + if (!dev) + return -EINVAL; + + if (dev->of_node) { + dev_err(dev, "Cannot replace node %pOF with %pOF\n", + dev->of_node, of_node); + ret = -EBUSY; + goto end; + } + + dev->of_node = of_node_get(of_node); + + if (!dev->fwnode) + dev->fwnode = of_fwnode_handle(of_node); + + ret = 0; +end: + put_device(dev); + return ret; +} +EXPORT_SYMBOL_GPL(device_add_of_node); + +/** * device_set_of_node_from_dev - reuse device-tree node of another device * @dev: device whose device-tree node is being set * @dev2: device whose device-tree node is being reused @@ -5128,21 +5278,52 @@ void device_set_node(struct device *dev, struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(device_set_node); +/** + * get_dev_from_fwnode - Obtain a reference count of the struct device the + * struct fwnode_handle is associated with. + * @fwnode: The pointer to the struct fwnode_handle to obtain the struct device + * reference count of. + * + * This function obtains a reference count of the device the device pointer + * embedded in the struct fwnode_handle points to. + * + * Note that the struct device pointer embedded in struct fwnode_handle does + * *not* have a reference count of the struct device itself. + * + * Hence, it is a UAF (and thus a bug) to call this function if the caller can't + * guarantee that the last reference count of the corresponding struct device is + * not dropped concurrently. + * + * This is possible since struct fwnode_handle has its own reference count and + * hence can out-live the struct device it is associated with. + */ +struct device *get_dev_from_fwnode(struct fwnode_handle *fwnode) +{ + return get_device((fwnode)->dev); +} +EXPORT_SYMBOL_GPL(get_dev_from_fwnode); + int device_match_name(struct device *dev, const void *name) { return sysfs_streq(dev_name(dev), name); } EXPORT_SYMBOL_GPL(device_match_name); +int device_match_type(struct device *dev, const void *type) +{ + return dev->type == type; +} +EXPORT_SYMBOL_GPL(device_match_type); + int device_match_of_node(struct device *dev, const void *np) { - return dev->of_node == np; + return np && dev->of_node == np; } EXPORT_SYMBOL_GPL(device_match_of_node); int device_match_fwnode(struct device *dev, const void *fwnode) { - return dev_fwnode(dev) == fwnode; + return fwnode && dev_fwnode(dev) == fwnode; } EXPORT_SYMBOL_GPL(device_match_fwnode); @@ -5154,13 +5335,13 @@ EXPORT_SYMBOL_GPL(device_match_devt); int device_match_acpi_dev(struct device *dev, const void *adev) { - return ACPI_COMPANION(dev) == adev; + return adev && ACPI_COMPANION(dev) == adev; } EXPORT_SYMBOL(device_match_acpi_dev); int device_match_acpi_handle(struct device *dev, const void *handle) { - return ACPI_HANDLE(dev) == handle; + return handle && ACPI_HANDLE(dev) == handle; } EXPORT_SYMBOL(device_match_acpi_handle); |