Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git

author: Stephen Rothwell <sfr@canb.auug.org.au> 2022-06-28 14:02:49 +1000
committer: Stephen Rothwell <sfr@canb.auug.org.au> 2022-06-28 14:02:49 +1000
commit: f3c284343a174fc50f5401dffa718aa3e257da1f (patch)
tree: f787d2a6d49b059bc1fb9cfb7391aed7302f47b1
parent: c2fefa46d1a046cac65a28c3a4ce71d7f0973dbf (diff)
parent: 38a523a2946d3a0961d141d477a1ee2b1f3bdbb1 (diff)
download: linux-next-f3c284343a174fc50f5401dffa718aa3e257da1f.tar.gz
11 files changed, 150 insertions, 56 deletions
diff --git a/drivers/base/base.h b/drivers/base/base.h
index ab71403d102fc..b3a43a164dcd1 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -160,6 +160,7 @@ extern int devres_release_all(struct device *dev);
 extern void device_block_probing(void);
 extern void device_unblock_probing(void);
 extern void deferred_probe_extend_timeout(void);
+extern void driver_deferred_probe_trigger(void);
 
 /* /sys/devices directory */
 extern struct kset *devices_kset;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7cd789c4985d4..839f64485a555 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -54,6 +54,7 @@ static unsigned int defer_sync_state_count = 1;
 static DEFINE_MUTEX(fwnode_link_lock);
 static bool fw_devlink_is_permissive(void);
 static bool fw_devlink_drv_reg_done;
+static bool fw_devlink_best_effort;
 
 /**
  * fwnode_link_add - Create a link between two fwnode_handles.
@@ -965,6 +966,11 @@ static void device_links_missing_supplier(struct device *dev)
 	}
 }
 
+static bool dev_is_best_effort(struct device *dev)
+{
+	return fw_devlink_best_effort && dev->can_match;
+}
+
 /**
  * device_links_check_suppliers - Check presence of supplier drivers.
  * @dev: Consumer device.
@@ -984,7 +990,7 @@ static void device_links_missing_supplier(struct device *dev)
 int device_links_check_suppliers(struct device *dev)
 {
 	struct device_link *link;
-	int ret = 0;
+	int ret = 0, fwnode_ret = 0;
 	struct fwnode_handle *sup_fw;
 
 	/*
@@ -997,12 +1003,17 @@ int device_links_check_suppliers(struct device *dev)
 		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;
+		if (!dev_is_best_effort(dev)) {
+			fwnode_ret = -EPROBE_DEFER;
+			dev_err_probe(dev, -EPROBE_DEFER,
+				    "wait for supplier %pfwP\n", sup_fw);
+		} else {
+			fwnode_ret = -EAGAIN;
+		}
 	}
 	mutex_unlock(&fwnode_link_lock);
+	if (fwnode_ret == -EPROBE_DEFER)
+		return fwnode_ret;
 
 	device_links_write_lock();
 
@@ -1012,6 +1023,14 @@ int device_links_check_suppliers(struct device *dev)
 
 		if (link->status != DL_STATE_AVAILABLE &&
 		    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
+
+			if (dev_is_best_effort(dev) &&
+			    link->flags & 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",
@@ -1024,7 +1043,8 @@ int device_links_check_suppliers(struct device *dev)
 	dev->links.status = DL_DEV_PROBING;
 
 	device_links_write_unlock();
-	return ret;
+
+	return ret ? ret : fwnode_ret;
 }
 
 /**
@@ -1289,6 +1309,18 @@ void device_links_driver_bound(struct device *dev)
 			 * save to drop the managed link completely.
 			 */
 			device_link_drop_managed(link);
+		} else if (dev_is_best_effort(dev) &&
+			   link->flags & DL_FLAG_INFERRED &&
+			   link->status != DL_STATE_CONSUMER_PROBE &&
+			   !link->supplier->can_match) {
+			/*
+			 * When dev_is_best_effort() is true, we ignore device
+			 * links to suppliers that don't have a driver.  If the
+			 * consumer device still managed to probe, there's no
+			 * point in maintaining a device link in a weird state
+			 * (consumer probed before supplier). So delete it.
+			 */
+			device_link_drop_managed(link);
 		} else {
 			WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
 			WRITE_ONCE(link->status, DL_STATE_ACTIVE);
@@ -1581,7 +1613,7 @@ static int __init fw_devlink_setup(char *arg)
 }
 early_param("fw_devlink", fw_devlink_setup);
 
-static bool fw_devlink_strict;
+static bool fw_devlink_strict = true;
 static int __init fw_devlink_strict_setup(char *arg)
 {
 	return strtobool(arg, &fw_devlink_strict);
@@ -1655,6 +1687,62 @@ void fw_devlink_drivers_done(void)
 	device_links_write_unlock();
 }
 
+/**
+ * wait_for_init_devices_probe - Try to probe any device needed for init
+ *
+ * Some devices might need to be probed and bound successfully before the kernel
+ * boot sequence can finish and move on to init/userspace. For example, a
+ * network interface might need to be bound to be able to mount a NFS rootfs.
+ *
+ * With fw_devlink=on by default, some of these devices might be blocked from
+ * probing because they are waiting on a optional supplier that doesn't have a
+ * driver. While fw_devlink will eventually identify such devices and unblock
+ * the probing automatically, it might be too late by the time it unblocks the
+ * probing of devices. For example, the IP4 autoconfig might timeout before
+ * fw_devlink unblocks probing of the network interface.
+ *
+ * This function is available to temporarily try and probe all devices that have
+ * a driver even if some of their suppliers haven't been added or don't have
+ * drivers.
+ *
+ * The drivers can then decide which of the suppliers are optional vs mandatory
+ * and probe the device if possible. By the time this function returns, all such
+ * "best effort" probes are guaranteed to be completed. If a device successfully
+ * probes in this mode, we delete all fw_devlink discovered dependencies of that
+ * device where the supplier hasn't yet probed successfully because they have to
+ * be optional dependencies.
+ *
+ * Any devices that didn't successfully probe go back to being treated as if
+ * this function was never called.
+ *
+ * This also means that some devices that aren't needed for init and could have
+ * waited for their optional supplier to probe (when the supplier's module is
+ * loaded later on) would end up probing prematurely with limited functionality.
+ * So call this function only when boot would fail without it.
+ */
+void __init wait_for_init_devices_probe(void)
+{
+	if (!fw_devlink_flags || fw_devlink_is_permissive())
+		return;
+
+	/*
+	 * Wait for all ongoing probes to finish so that the "best effort" is
+	 * only applied to devices that can't probe otherwise.
+	 */
+	wait_for_device_probe();
+
+	pr_info("Trying to probe devices needed for running init ...\n");
+	fw_devlink_best_effort = true;
+	driver_deferred_probe_trigger();
+
+	/*
+	 * Wait for all "best effort" probes to finish before going back to
+	 * normal enforcement.
+	 */
+	wait_for_device_probe();
+	fw_devlink_best_effort = false;
+}
+
 static void fw_devlink_unblock_consumers(struct device *dev)
 {
 	struct device_link *link;
@@ -3832,6 +3920,26 @@ struct device *device_find_child_by_name(struct device *parent,
 }
 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);
+
 int __init devices_init(void)
 {
 	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 11b0fb6414d37..e600dd2afc35e 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -172,7 +172,7 @@ static bool driver_deferred_probe_enable;
  * changes in the midst of a probe, then deferred processing should be triggered
  * again.
  */
-static void driver_deferred_probe_trigger(void)
+void driver_deferred_probe_trigger(void)
 {
 	if (!driver_deferred_probe_enable)
 		return;
@@ -256,7 +256,12 @@ static int deferred_devs_show(struct seq_file *s, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(deferred_devs);
 
+#ifdef CONFIG_MODULES
+int driver_deferred_probe_timeout = 10;
+#else
 int driver_deferred_probe_timeout;
+#endif
+
 EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout);
 
 static int __init deferred_probe_timeout_setup(char *str)
@@ -269,42 +274,12 @@ static int __init deferred_probe_timeout_setup(char *str)
 }
 __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
 
-/**
- * driver_deferred_probe_check_state() - Check deferred probe state
- * @dev: device to check
- *
- * Return:
- * * -ENODEV if initcalls have completed and modules are disabled.
- * * -ETIMEDOUT if the deferred probe timeout was set and has expired
- *   and modules are enabled.
- * * -EPROBE_DEFER in other cases.
- *
- * Drivers or subsystems can opt-in to calling this function instead of directly
- * returning -EPROBE_DEFER.
- */
-int driver_deferred_probe_check_state(struct device *dev)
-{
-	if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
-		dev_warn(dev, "ignoring dependency for device, assuming no driver\n");
-		return -ENODEV;
-	}
-
-	if (!driver_deferred_probe_timeout && initcalls_done) {
-		dev_warn(dev, "deferred probe timeout, ignoring dependency\n");
-		return -ETIMEDOUT;
-	}
-
-	return -EPROBE_DEFER;
-}
-EXPORT_SYMBOL_GPL(driver_deferred_probe_check_state);
-
 static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
 	struct device_private *p;
 
 	fw_devlink_drivers_done();
 
-	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
@@ -580,7 +555,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 {
 	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
 			   !drv->suppress_bind_attrs;
-	int ret;
+	int ret, link_ret;
 
 	if (defer_all_probes) {
 		/*
@@ -592,9 +567,9 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		return -EPROBE_DEFER;
 	}
 
-	ret = device_links_check_suppliers(dev);
-	if (ret)
-		return ret;
+	link_ret = device_links_check_suppliers(dev);
+	if (link_ret == -EPROBE_DEFER)
+		return link_ret;
 
 	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
 		 drv->bus->name, __func__, drv->name, dev_name(dev));
@@ -634,6 +609,15 @@ re_probe:
 	ret = call_driver_probe(dev, drv);
 	if (ret) {
 		/*
+		 * If fw_devlink_best_effort is active (denoted by -EAGAIN), the
+		 * device might actually probe properly once some of its missing
+		 * suppliers have probed. So, treat this as if the driver
+		 * returned -EPROBE_DEFER.
+		 */
+		if (link_ret == -EAGAIN)
+			ret = -EPROBE_DEFER;
+
+		/*
 		 * Return probe errors as positive values so that the callers
 		 * can distinguish them from other errors.
 		 */
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 739e52cd4aba5..3e86772d5fac5 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2730,7 +2730,7 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 		mutex_unlock(&gpd_list_lock);
 		dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
 			__func__, PTR_ERR(pd));
-		return driver_deferred_probe_check_state(base_dev);
+		return -ENODEV;
 	}
 
 	dev_dbg(dev, "adding to PM domain %s\n", pd->name);
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 5696314ae69e7..41f4eb0052192 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -40,7 +40,7 @@ static int of_iommu_xlate(struct device *dev,
 	 * a proper probe-ordering dependency mechanism in future.
 	 */
 	if (!ops)
-		return driver_deferred_probe_check_state(dev);
+		return -ENODEV;
 
 	if (!try_module_get(ops->owner))
 		return -ENODEV;
diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index 1c1584fca6327..3e79c2c519298 100644
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -47,9 +47,7 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
 	 * just fall back to poll mode
 	 */
 	if (rc == -EPROBE_DEFER)
-		rc = driver_deferred_probe_check_state(&phy->mdio.dev);
-	if (rc == -EPROBE_DEFER)
-		return rc;
+		rc = -ENODEV;
 
 	if (rc > 0) {
 		phy->irq = rc;
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index 3fb2387147189..ef898ee8ca6bd 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -129,7 +129,7 @@ static int dt_to_map_one_config(struct pinctrl *p,
 		np_pctldev = of_get_next_parent(np_pctldev);
 		if (!np_pctldev || of_node_is_root(np_pctldev)) {
 			of_node_put(np_pctldev);
-			ret = driver_deferred_probe_check_state(p->dev);
+			ret = -ENODEV;
 			/* keep deferring if modules are enabled */
 			if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
 				ret = -EPROBE_DEFER;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c78d1ceeaa422..77a0d4fde3897 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2663,11 +2663,6 @@ int spi_slave_abort(struct spi_device *spi)
 }
 EXPORT_SYMBOL_GPL(spi_slave_abort);
 
-static int match_true(struct device *dev, void *data)
-{
-	return 1;
-}
-
 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
@@ -2675,7 +2670,7 @@ static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
 						   dev);
 	struct device *child;
 
-	child = device_find_child(&ctlr->dev, NULL, match_true);
+	child = device_find_any_child(&ctlr->dev);
 	return sprintf(buf, "%s\n",
 		       child ? to_spi_device(child)->modalias : NULL);
 }
@@ -2694,7 +2689,7 @@ static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
 	if (rc != 1 || !name[0])
 		return -EINVAL;
 
-	child = device_find_child(&ctlr->dev, NULL, match_true);
+	child = device_find_any_child(&ctlr->dev);
 	if (child) {
 		/* Remove registered slave */
 		device_unregister(child);
diff --git a/include/linux/device.h b/include/linux/device.h
index dc941997795cf..424b55df02727 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -905,6 +905,8 @@ struct device *device_find_child(struct device *dev, void *data,
 				 int (*match)(struct device *dev, void *data));
 struct device *device_find_child_by_name(struct device *parent,
 					 const char *name);
+struct device *device_find_any_child(struct device *parent);
+
 int device_rename(struct device *dev, const char *new_name);
 int device_move(struct device *dev, struct device *new_parent,
 		enum dpm_order dpm_order);
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index 700453017e1c7..7acaabde5396d 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -129,6 +129,7 @@ extern struct device_driver *driver_find(const char *name,
 					 struct bus_type *bus);
 extern int driver_probe_done(void);
 extern void wait_for_device_probe(void);
+void __init wait_for_init_devices_probe(void);
 
 /* sysfs interface for exporting driver attributes */
 
@@ -241,7 +242,6 @@ driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
 
 extern int driver_deferred_probe_timeout;
 void driver_deferred_probe_add(struct device *dev);
-int driver_deferred_probe_check_state(struct device *dev);
 void driver_init(void);
 
 /**
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index 9d41d5d5cd1e5..2342debd70660 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -1434,6 +1434,7 @@ __be32 __init root_nfs_parse_addr(char *name)
 static int __init wait_for_devices(void)
 {
 	int i;
+	bool try_init_devs = true;
 
 	for (i = 0; i < DEVICE_WAIT_MAX; i++) {
 		struct net_device *dev;
@@ -1452,6 +1453,11 @@ static int __init wait_for_devices(void)
 		rtnl_unlock();
 		if (found)
 			return 0;
+		if (try_init_devs &&
+		    (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) {
+			try_init_devs = false;
+			wait_for_init_devices_probe();
+		}
 		ssleep(1);
 	}
 	return -ENODEV;
author	Stephen Rothwell <sfr@canb.auug.org.au>	2022-06-28 14:02:49 +1000
committer	Stephen Rothwell <sfr@canb.auug.org.au>	2022-06-28 14:02:49 +1000
commit	f3c284343a174fc50f5401dffa718aa3e257da1f (patch)
tree	f787d2a6d49b059bc1fb9cfb7391aed7302f47b1
parent	c2fefa46d1a046cac65a28c3a4ce71d7f0973dbf (diff)
parent	38a523a2946d3a0961d141d477a1ee2b1f3bdbb1 (diff)
download	linux-next-f3c284343a174fc50f5401dffa718aa3e257da1f.tar.gz