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-rw-r--r--drivers/base/core.c90
-rw-r--r--drivers/net/phy/mdio_bus.c4
-rw-r--r--fs/debugfs/inode.c2
-rw-r--r--fs/kernfs/dir.c9
-rw-r--r--include/linux/cpumask.h7
-rw-r--r--include/linux/fwnode.h11
6 files changed, 87 insertions, 36 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index e65dd803a453..15986cc2fe5e 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -95,6 +95,8 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
list_add(&link->s_hook, &sup->consumers);
list_add(&link->c_hook, &con->suppliers);
+ pr_debug("%pfwP Linked as a fwnode consumer to %pfwP\n",
+ con, sup);
out:
mutex_unlock(&fwnode_link_lock);
@@ -102,6 +104,21 @@ out:
}
/**
+ * __fwnode_link_del - Delete a link between two fwnode_handles.
+ * @link: the fwnode_link to be deleted
+ *
+ * The fwnode_link_lock needs to be held when this function is called.
+ */
+static void __fwnode_link_del(struct fwnode_link *link)
+{
+ pr_debug("%pfwP Dropping the fwnode link to %pfwP\n",
+ link->consumer, link->supplier);
+ list_del(&link->s_hook);
+ list_del(&link->c_hook);
+ kfree(link);
+}
+
+/**
* fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
* @fwnode: fwnode whose supplier links need to be deleted
*
@@ -112,11 +129,8 @@ static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode)
struct fwnode_link *link, *tmp;
mutex_lock(&fwnode_link_lock);
- list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
- list_del(&link->s_hook);
- list_del(&link->c_hook);
- kfree(link);
- }
+ list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook)
+ __fwnode_link_del(link);
mutex_unlock(&fwnode_link_lock);
}
@@ -131,11 +145,8 @@ static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode)
struct fwnode_link *link, *tmp;
mutex_lock(&fwnode_link_lock);
- list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
- list_del(&link->s_hook);
- list_del(&link->c_hook);
- kfree(link);
- }
+ list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook)
+ __fwnode_link_del(link);
mutex_unlock(&fwnode_link_lock);
}
@@ -975,6 +986,7 @@ int device_links_check_suppliers(struct device *dev)
{
struct device_link *link;
int ret = 0;
+ struct fwnode_handle *sup_fw;
/*
* Device waiting for supplier to become available is not allowed to
@@ -983,10 +995,11 @@ int device_links_check_suppliers(struct device *dev)
mutex_lock(&fwnode_link_lock);
if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
!fw_devlink_is_permissive()) {
- dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
- list_first_entry(&dev->fwnode->suppliers,
- struct fwnode_link,
- c_hook)->supplier);
+ sup_fw = list_first_entry(&dev->fwnode->suppliers,
+ struct fwnode_link,
+ c_hook)->supplier;
+ dev_err_probe(dev, -EPROBE_DEFER, "wait for supplier %pfwP\n",
+ sup_fw);
mutex_unlock(&fwnode_link_lock);
return -EPROBE_DEFER;
}
@@ -1001,8 +1014,9 @@ int device_links_check_suppliers(struct device *dev)
if (link->status != DL_STATE_AVAILABLE &&
!(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
device_links_missing_supplier(dev);
- dev_dbg(dev, "probe deferral - supplier %s not ready\n",
- dev_name(link->supplier));
+ dev_err_probe(dev, -EPROBE_DEFER,
+ "supplier %s not ready\n",
+ dev_name(link->supplier));
ret = -EPROBE_DEFER;
break;
}
@@ -1722,6 +1736,25 @@ static int fw_devlink_create_devlink(struct device *con,
struct device *sup_dev;
int ret = 0;
+ /*
+ * 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
+ * completes successfully. This is perfectly fine in the device driver
+ * model. device_add() doesn't guarantee probe completion of the device
+ * by the time it returns.
+ *
+ * However, there are a few drivers that assume C will finish probing
+ * as soon as it's added and before P finishes probing. So, we provide
+ * a flag to let fw_devlink know not to delay the probe of C until the
+ * probe of P completes successfully.
+ *
+ * When such a flag is set, we can't create device links where P is the
+ * supplier of C as that would delay the probe of C.
+ */
+ if (sup_handle->flags & FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD &&
+ fwnode_is_ancestor_of(sup_handle, con->fwnode))
+ return -EINVAL;
+
sup_dev = get_dev_from_fwnode(sup_handle);
if (sup_dev) {
/*
@@ -1772,14 +1805,21 @@ static int fw_devlink_create_devlink(struct device *con,
* be broken by applying logic. Check for these types of cycles and
* break them so that devices in the cycle probe properly.
*
- * If the supplier's parent is dependent on the consumer, then
- * the consumer-supplier dependency is a false dependency. So,
- * treat it as an invalid link.
+ * If the supplier's parent is dependent on the consumer, then the
+ * consumer and supplier have a cyclic dependency. Since fw_devlink
+ * can't tell which of the inferred dependencies are incorrect, don't
+ * enforce probe ordering between any of the devices in this cyclic
+ * dependency. Do this by relaxing all the fw_devlink device links in
+ * this cycle and by treating the fwnode link between the consumer and
+ * the supplier as an invalid dependency.
*/
sup_dev = fwnode_get_next_parent_dev(sup_handle);
if (sup_dev && device_is_dependent(con, sup_dev)) {
- dev_dbg(con, "Not linking to %pfwP - False link\n",
- sup_handle);
+ dev_info(con, "Fixing up cyclic dependency with %pfwP (%s)\n",
+ sup_handle, dev_name(sup_dev));
+ device_links_write_lock();
+ fw_devlink_relax_cycle(con, sup_dev);
+ device_links_write_unlock();
ret = -EINVAL;
} else {
/*
@@ -1858,9 +1898,7 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
if (!own_link || ret == -EAGAIN)
continue;
- list_del(&link->s_hook);
- list_del(&link->c_hook);
- kfree(link);
+ __fwnode_link_del(link);
}
}
@@ -1912,9 +1950,7 @@ static void __fw_devlink_link_to_suppliers(struct device *dev,
if (!own_link || ret == -EAGAIN)
continue;
- list_del(&link->s_hook);
- list_del(&link->c_hook);
- kfree(link);
+ __fwnode_link_del(link);
/* If no device link was created, nothing more to do. */
if (ret)
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 6f4b4e5df639..e37edf70f2f8 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -525,6 +525,10 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
NULL == bus->read || NULL == bus->write)
return -EINVAL;
+ if (bus->parent && bus->parent->of_node)
+ bus->parent->of_node->fwnode.flags |=
+ FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
+
BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
bus->state != MDIOBUS_UNREGISTERED);
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 8129a430d789..2f117c57160d 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -528,7 +528,7 @@ void debugfs_create_file_size(const char *name, umode_t mode,
{
struct dentry *de = debugfs_create_file(name, mode, parent, data, fops);
- if (de)
+ if (!IS_ERR(de))
d_inode(de)->i_size = file_size;
}
EXPORT_SYMBOL_GPL(debugfs_create_file_size);
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index ba581429bf7b..cfc3ce8b815a 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1116,8 +1116,13 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
if (!inode)
inode = ERR_PTR(-ENOMEM);
}
- /* Needed only for negative dentry validation */
- if (!inode)
+ /*
+ * Needed for negative dentry validation.
+ * The negative dentry can be created in kernfs_iop_lookup()
+ * or transforms from positive dentry in dentry_unlink_inode()
+ * called from vfs_rmdir().
+ */
+ if (!IS_ERR(inode))
kernfs_set_rev(parent, dentry);
up_read(&kernfs_rwsem);
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 5d4d07a9e1ed..1e7399fc69c0 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -996,14 +996,15 @@ cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
* cpumask; Typically used by bin_attribute to export cpumask bitmask
* ABI.
*
- * Returns the length of how many bytes have been copied.
+ * Returns the length of how many bytes have been copied, excluding
+ * terminating '\0'.
*/
static inline ssize_t
cpumap_print_bitmask_to_buf(char *buf, const struct cpumask *mask,
loff_t off, size_t count)
{
return bitmap_print_bitmask_to_buf(buf, cpumask_bits(mask),
- nr_cpu_ids, off, count);
+ nr_cpu_ids, off, count) - 1;
}
/**
@@ -1018,7 +1019,7 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
loff_t off, size_t count)
{
return bitmap_print_list_to_buf(buf, cpumask_bits(mask),
- nr_cpu_ids, off, count);
+ nr_cpu_ids, off, count) - 1;
}
#if NR_CPUS <= BITS_PER_LONG
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 59828516ebaf..9f4ad719bfe3 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -22,10 +22,15 @@ struct device;
* LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
* NOT_DEVICE: The fwnode will never be populated as a struct device.
* INITIALIZED: The hardware corresponding to fwnode has been initialized.
+ * NEEDS_CHILD_BOUND_ON_ADD: For this fwnode/device to probe successfully, its
+ * driver needs its child devices to be bound with
+ * their respective drivers as soon as they are
+ * added.
*/
-#define FWNODE_FLAG_LINKS_ADDED BIT(0)
-#define FWNODE_FLAG_NOT_DEVICE BIT(1)
-#define FWNODE_FLAG_INITIALIZED BIT(2)
+#define FWNODE_FLAG_LINKS_ADDED BIT(0)
+#define FWNODE_FLAG_NOT_DEVICE BIT(1)
+#define FWNODE_FLAG_INITIALIZED BIT(2)
+#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD BIT(3)
struct fwnode_handle {
struct fwnode_handle *secondary;
generated by cgit (git 2.34.1) at 2024-05-26 10:32:22 +0000