17 files changed, 298 insertions, 102 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index c07815d230bc..a2e862e10a25 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1354,6 +1354,24 @@
 			can be changed at run time by the max_graph_depth file
 			in the tracefs tracing directory. default: 0 (no limit)
 
+	fw_devlink=	[KNL] Create device links between consumer and supplier
+			devices by scanning the firmware to infer the
+			consumer/supplier relationships. This feature is
+			especially useful when drivers are loaded as modules as
+			it ensures proper ordering of tasks like device probing
+			(suppliers first, then consumers), supplier boot state
+			clean up (only after all consumers have probed),
+			suspend/resume & runtime PM (consumers first, then
+			suppliers).
+			Format: { off | permissive | on | rpm }
+			off --	Don't create device links from firmware info.
+			permissive -- Create device links from firmware info
+				but use it only for ordering boot state clean
+				up (sync_state() calls).
+			on -- 	Create device links from firmware info and use it
+				to enforce probe and suspend/resume ordering.
+			rpm --	Like "on", but also use to order runtime PM.
+
 	gamecon.map[2|3]=
 			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 			support via parallel port (up to 5 devices per port)
@@ -3285,12 +3303,6 @@
 			This can be set from sysctl after boot.
 			See Documentation/admin-guide/sysctl/vm.rst for details.
 
-	of_devlink	[OF, KNL] Create device links between consumer and
-			supplier devices by scanning the devictree to infer the
-			consumer/supplier relationships.  A consumer device
-			will not be probed until all the supplier devices have
-			probed successfully.
-
 	ohci1394_dma=early	[HW] enable debugging via the ohci1394 driver.
 			See Documentation/debugging-via-ohci1394.txt for more
 			info.
diff --git a/drivers/base/core.c b/drivers/base/core.c
index dbb0f9130f42..fc6a60998cd6 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -64,12 +64,12 @@ static inline void device_links_write_unlock(void)
 	mutex_unlock(&device_links_lock);
 }
 
-int device_links_read_lock(void)
+int device_links_read_lock(void) __acquires(&device_links_srcu)
 {
 	return srcu_read_lock(&device_links_srcu);
 }
 
-void device_links_read_unlock(int idx)
+void device_links_read_unlock(int idx) __releases(&device_links_srcu)
 {
 	srcu_read_unlock(&device_links_srcu, idx);
 }
@@ -523,9 +523,13 @@ static void device_link_add_missing_supplier_links(void)
 
 	mutex_lock(&wfs_lock);
 	list_for_each_entry_safe(dev, tmp, &wait_for_suppliers,
-				 links.needs_suppliers)
-		if (!fwnode_call_int_op(dev->fwnode, add_links, dev))
+				 links.needs_suppliers) {
+		int ret = fwnode_call_int_op(dev->fwnode, add_links, dev);
+		if (!ret)
 			list_del_init(&dev->links.needs_suppliers);
+		else if (ret != -ENODEV)
+			dev->links.need_for_probe = false;
+	}
 	mutex_unlock(&wfs_lock);
 }
 
@@ -2341,6 +2345,31 @@ static int device_private_init(struct device *dev)
 	return 0;
 }
 
+static u32 fw_devlink_flags;
+static int __init fw_devlink_setup(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (strcmp(arg, "off") == 0) {
+		fw_devlink_flags = 0;
+	} else if (strcmp(arg, "permissive") == 0) {
+		fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY;
+	} else if (strcmp(arg, "on") == 0) {
+		fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER;
+	} else if (strcmp(arg, "rpm") == 0) {
+		fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER |
+				   DL_FLAG_PM_RUNTIME;
+	}
+	return 0;
+}
+early_param("fw_devlink", fw_devlink_setup);
+
+u32 fw_devlink_get_flags(void)
+{
+	return fw_devlink_flags;
+}
+
 /**
  * device_add - add device to device hierarchy.
  * @dev: device.
@@ -2489,7 +2518,7 @@ int device_add(struct device *dev)
 	 */
 	device_link_add_missing_supplier_links();
 
-	if (fwnode_has_op(dev->fwnode, add_links)) {
+	if (fw_devlink_flags && fwnode_has_op(dev->fwnode, add_links)) {
 		fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev);
 		if (fw_ret == -ENODEV)
 			device_link_wait_for_mandatory_supplier(dev);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b25bcab2a26b..76888a7459d8 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -224,76 +224,52 @@ static int deferred_devs_show(struct seq_file *s, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(deferred_devs);
 
-static int deferred_probe_timeout = -1;
+#ifdef CONFIG_MODULES
+/*
+ * In the case of modules, set the default probe timeout to
+ * 30 seconds to give userland some time to load needed modules
+ */
+int driver_deferred_probe_timeout = 30;
+#else
+/* In the case of !modules, no probe timeout needed */
+int driver_deferred_probe_timeout = -1;
+#endif
+EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout);
+
 static int __init deferred_probe_timeout_setup(char *str)
 {
 	int timeout;
 
 	if (!kstrtoint(str, 10, &timeout))
-		deferred_probe_timeout = timeout;
+		driver_deferred_probe_timeout = timeout;
 	return 1;
 }
 __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
 
-static int __driver_deferred_probe_check_state(struct device *dev)
-{
-	if (!initcalls_done)
-		return -EPROBE_DEFER;
-
-	if (!deferred_probe_timeout) {
-		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
-		return -ETIMEDOUT;
-	}
-
-	return 0;
-}
-
 /**
  * driver_deferred_probe_check_state() - Check deferred probe state
  * @dev: device to check
  *
- * Returns -ENODEV if init is done and all built-in drivers have had a chance
- * to probe (i.e. initcalls are done), -ETIMEDOUT if deferred probe debug
- * timeout has expired, or -EPROBE_DEFER if none of those conditions are met.
+ * 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)
 {
-	int ret;
-
-	ret = __driver_deferred_probe_check_state(dev);
-	if (ret < 0)
-		return ret;
-
-	dev_warn(dev, "ignoring dependency for device, assuming no driver");
-
-	return -ENODEV;
-}
-
-/**
- * driver_deferred_probe_check_state_continue() - check deferred probe state
- * @dev: device to check
- *
- * Returns -ETIMEDOUT if deferred probe debug timeout has expired, or
- * -EPROBE_DEFER otherwise.
- *
- * Drivers or subsystems can opt-in to calling this function instead of
- * directly returning -EPROBE_DEFER.
- *
- * This is similar to driver_deferred_probe_check_state(), but it allows the
- * subsystem to keep deferring probe after built-in drivers have had a chance
- * to probe. One scenario where that is useful is if built-in drivers rely on
- * resources that are provided by modular drivers.
- */
-int driver_deferred_probe_check_state_continue(struct device *dev)
-{
-	int ret;
+	if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
+		dev_warn(dev, "ignoring dependency for device, assuming no driver");
+		return -ENODEV;
+	}
 
-	ret = __driver_deferred_probe_check_state(dev);
-	if (ret < 0)
-		return ret;
+	if (!driver_deferred_probe_timeout) {
+		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
+		return -ETIMEDOUT;
+	}
 
 	return -EPROBE_DEFER;
 }
@@ -302,7 +278,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
 	struct device_private *private, *p;
 
-	deferred_probe_timeout = 0;
+	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
@@ -336,9 +312,9 @@ static int deferred_probe_initcall(void)
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
-	if (deferred_probe_timeout > 0) {
+	if (driver_deferred_probe_timeout > 0) {
 		schedule_delayed_work(&deferred_probe_timeout_work,
-			deferred_probe_timeout * HZ);
+			driver_deferred_probe_timeout * HZ);
 	}
 	return 0;
 }
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 57133a9dad09..59d1dc322080 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -493,8 +493,10 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 		}
 
 		fw_priv->size = 0;
-		rc = kernel_read_file_from_path(path, &buffer, &size,
-						msize, id);
+
+		/* load firmware files from the mount namespace of init */
+		rc = kernel_read_file_from_path_initns(path, &buffer,
+						       &size, msize, id);
 		if (rc) {
 			if (rc != -ENOENT)
 				dev_warn(device, "loading %s failed with error %d\n",
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index d99f5b0c8a09..6703bedfa9e1 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -349,7 +349,7 @@ static int efifb_add_links(const struct fwnode_handle *fwnode,
 	 * If this fails, retrying this function at a later point won't
 	 * change anything. So, don't return an error after this.
 	 */
-	if (!device_link_add(dev, sup_dev, 0))
+	if (!device_link_add(dev, sup_dev, fw_devlink_get_flags()))
 		dev_warn(dev, "device_link_add() failed\n");
 
 	put_device(sup_dev);
diff --git a/drivers/of/property.c b/drivers/of/property.c
index e851c57a15b0..f104f15b57fb 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1262,7 +1262,7 @@ static int of_link_property(struct device *dev, struct device_node *con_np,
 	u32 dl_flags;
 
 	if (dev->of_node == con_np)
-		dl_flags = DL_FLAG_AUTOPROBE_CONSUMER;
+		dl_flags = fw_devlink_get_flags();
 	else
 		dl_flags = DL_FLAG_SYNC_STATE_ONLY;
 
@@ -1299,15 +1299,9 @@ static int of_link_to_suppliers(struct device *dev,
 	return ret;
 }
 
-static bool of_devlink;
-core_param(of_devlink, of_devlink, bool, 0);
-
 static int of_fwnode_add_links(const struct fwnode_handle *fwnode,
 			       struct device *dev)
 {
-	if (!of_devlink)
-		return 0;
-
 	if (unlikely(!is_of_node(fwnode)))
 		return 0;
 
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index 9357f7c46cf3..1ed20ac2243f 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -127,11 +127,12 @@ 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);
 			/* keep deferring if modules are enabled unless we've timed out */
-			if (IS_ENABLED(CONFIG_MODULES) && !allow_default)
-				return driver_deferred_probe_check_state_continue(p->dev);
-
-			return driver_deferred_probe_check_state(p->dev);
+			if (IS_ENABLED(CONFIG_MODULES) && !allow_default &&
+			    (ret == -ENODEV))
+				ret = -EPROBE_DEFER;
+			return ret;
 		}
 		/* If we're creating a hog we can use the passed pctldev */
 		if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index d015d99cb59d..51b6a2dea717 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5757,6 +5757,10 @@ static DECLARE_DELAYED_WORK(regulator_init_complete_work,
 
 static int __init regulator_init_complete(void)
 {
+	int delay = driver_deferred_probe_timeout;
+
+	if (delay < 0)
+		delay = 0;
 	/*
 	 * Since DT doesn't provide an idiomatic mechanism for
 	 * enabling full constraints and since it's much more natural
@@ -5767,18 +5771,17 @@ static int __init regulator_init_complete(void)
 		has_full_constraints = true;
 
 	/*
-	 * We punt completion for an arbitrary amount of time since
-	 * systems like distros will load many drivers from userspace
-	 * so consumers might not always be ready yet, this is
-	 * particularly an issue with laptops where this might bounce
-	 * the display off then on.  Ideally we'd get a notification
-	 * from userspace when this happens but we don't so just wait
-	 * a bit and hope we waited long enough.  It'd be better if
-	 * we'd only do this on systems that need it, and a kernel
-	 * command line option might be useful.
+	 * If driver_deferred_probe_timeout is set, we punt
+	 * completion for that many seconds since systems like
+	 * distros will load many drivers from userspace so consumers
+	 * might not always be ready yet, this is particularly an
+	 * issue with laptops where this might bounce the display off
+	 * then on.  Ideally we'd get a notification from userspace
+	 * when this happens but we don't so just wait a bit and hope
+	 * we waited long enough.  It'd be better if we'd only do
+	 * this on systems that need it.
 	 */
-	schedule_delayed_work(&regulator_init_complete_work,
-			      msecs_to_jiffies(30000));
+	schedule_delayed_work(&regulator_init_complete_work, delay * HZ);
 
 	return 0;
 }
diff --git a/fs/exec.c b/fs/exec.c
index db17be51b112..688c824cdac8 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -985,6 +985,32 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
 }
 EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
 
+int kernel_read_file_from_path_initns(const char *path, void **buf,
+				      loff_t *size, loff_t max_size,
+				      enum kernel_read_file_id id)
+{
+	struct file *file;
+	struct path root;
+	int ret;
+
+	if (!path || !*path)
+		return -EINVAL;
+
+	task_lock(&init_task);
+	get_fs_root(init_task.fs, &root);
+	task_unlock(&init_task);
+
+	file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
+	path_put(&root);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	ret = kernel_read_file(file, buf, size, max_size, id);
+	fput(file);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
+
 int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
 			     enum kernel_read_file_id id)
 {
diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h
index 3015ecbb90b1..c507e9ddd909 100644
--- a/include/linux/arch_topology.h
+++ b/include/linux/arch_topology.h
@@ -16,9 +16,7 @@ bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu);
 
 DECLARE_PER_CPU(unsigned long, cpu_scale);
 
-struct sched_domain;
-static inline
-unsigned long topology_get_cpu_scale(int cpu)
+static inline unsigned long topology_get_cpu_scale(int cpu)
 {
 	return per_cpu(cpu_scale, cpu);
 }
@@ -27,8 +25,7 @@ void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity);
 
 DECLARE_PER_CPU(unsigned long, freq_scale);
 
-static inline
-unsigned long topology_get_freq_scale(int cpu)
+static inline unsigned long topology_get_freq_scale(int cpu)
 {
 	return per_cpu(freq_scale, cpu);
 }
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index 1188260f9a02..ee7ba5b5417e 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -236,9 +236,9 @@ driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
 }
 #endif
 
+extern int driver_deferred_probe_timeout;
 void driver_deferred_probe_add(struct device *dev);
 int driver_deferred_probe_check_state(struct device *dev);
-int driver_deferred_probe_check_state_continue(struct device *dev);
 void driver_init(void);
 
 /**
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3cd4fe6b845e..f814ccd8d929 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3012,6 +3012,8 @@ extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
 			    enum kernel_read_file_id);
 extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t,
 				      enum kernel_read_file_id);
+extern int kernel_read_file_from_path_initns(const char *, void **, loff_t *, loff_t,
+					     enum kernel_read_file_id);
 extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
 				    enum kernel_read_file_id);
 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 8feeb94b8acc..e0abafbb17f8 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -170,4 +170,6 @@ struct fwnode_operations {
 	} while (false)
 #define get_dev_from_fwnode(fwnode)	get_device((fwnode)->dev)
 
+extern u32 fw_devlink_get_flags(void);
+
 #endif
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 276a03c24691..8e83c6ff140d 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -89,7 +89,7 @@ struct platform_device_info {
 		size_t size_data;
 		u64 dma_mask;
 
-		struct property_entry *properties;
+		const struct property_entry *properties;
 };
 extern struct platform_device *platform_device_register_full(
 		const struct platform_device_info *pdevinfo);
diff --git a/tools/testing/selftests/firmware/Makefile b/tools/testing/selftests/firmware/Makefile
index 012b2cf69c11..40211cd8f0e6 100644
--- a/tools/testing/selftests/firmware/Makefile
+++ b/tools/testing/selftests/firmware/Makefile
@@ -1,13 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0-only
 # Makefile for firmware loading selftests
-
-# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
-all:
+CFLAGS = -Wall \
+         -O2
 
 TEST_PROGS := fw_run_tests.sh
 TEST_FILES := fw_fallback.sh fw_filesystem.sh fw_lib.sh
+TEST_GEN_FILES := fw_namespace
 
 include ../lib.mk
-
-# Nothing to clean up.
-clean:
diff --git a/tools/testing/selftests/firmware/fw_namespace.c b/tools/testing/selftests/firmware/fw_namespace.c
new file mode 100644
index 000000000000..5ebc1aec7923
--- /dev/null
+++ b/tools/testing/selftests/firmware/fw_namespace.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Test triggering of loading of firmware from different mount
+ * namespaces. Expect firmware to be always loaded from the mount
+ * namespace of PID 1. */
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#ifndef CLONE_NEWNS
+# define CLONE_NEWNS 0x00020000
+#endif
+
+static char *fw_path = NULL;
+
+static void die(char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	if (fw_path)
+		unlink(fw_path);
+	umount("/lib/firmware");
+	exit(EXIT_FAILURE);
+}
+
+static void trigger_fw(const char *fw_name, const char *sys_path)
+{
+	int fd;
+
+	fd = open(sys_path, O_WRONLY);
+	if (fd < 0)
+		die("open failed: %s\n",
+		    strerror(errno));
+	if (write(fd, fw_name, strlen(fw_name)) != strlen(fw_name))
+		exit(EXIT_FAILURE);
+	close(fd);
+}
+
+static void setup_fw(const char *fw_path)
+{
+	int fd;
+	const char fw[] = "ABCD0123";
+
+	fd = open(fw_path, O_WRONLY | O_CREAT, 0600);
+	if (fd < 0)
+		die("open failed: %s\n",
+		    strerror(errno));
+	if (write(fd, fw, sizeof(fw) -1) != sizeof(fw) -1)
+		die("write failed: %s\n",
+		    strerror(errno));
+	close(fd);
+}
+
+static bool test_fw_in_ns(const char *fw_name, const char *sys_path, bool block_fw_in_parent_ns)
+{
+	pid_t child;
+
+	if (block_fw_in_parent_ns)
+		if (mount("test", "/lib/firmware", "tmpfs", MS_RDONLY, NULL) == -1)
+			die("blocking firmware in parent ns failed\n");
+
+	child = fork();
+	if (child == -1) {
+		die("fork failed: %s\n",
+			strerror(errno));
+	}
+	if (child != 0) { /* parent */
+		pid_t pid;
+		int status;
+
+		pid = waitpid(child, &status, 0);
+		if (pid == -1) {
+			die("waitpid failed: %s\n",
+				strerror(errno));
+		}
+		if (pid != child) {
+			die("waited for %d got %d\n",
+				child, pid);
+		}
+		if (!WIFEXITED(status)) {
+			die("child did not terminate cleanly\n");
+		}
+		if (block_fw_in_parent_ns)
+			umount("/lib/firmware");
+		return WEXITSTATUS(status) == EXIT_SUCCESS ? true : false;
+	}
+
+	if (unshare(CLONE_NEWNS) != 0) {
+		die("unshare(CLONE_NEWNS) failed: %s\n",
+			strerror(errno));
+	}
+	if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) == -1)
+		die("remount root in child ns failed\n");
+
+	if (!block_fw_in_parent_ns) {
+		if (mount("test", "/lib/firmware", "tmpfs", MS_RDONLY, NULL) == -1)
+			die("blocking firmware in child ns failed\n");
+	} else
+		umount("/lib/firmware");
+
+	trigger_fw(fw_name, sys_path);
+
+	exit(EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+	const char *fw_name = "test-firmware.bin";
+	char *sys_path;
+	if (argc != 2)
+		die("usage: %s sys_path\n", argv[0]);
+
+	/* Mount tmpfs to /lib/firmware so we don't have to assume
+	   that it is writable for us.*/
+	if (mount("test", "/lib/firmware", "tmpfs", 0, NULL) == -1)
+		die("mounting tmpfs to /lib/firmware failed\n");
+
+	sys_path = argv[1];
+	asprintf(&fw_path, "/lib/firmware/%s", fw_name);
+
+	setup_fw(fw_path);
+
+	setvbuf(stdout, NULL, _IONBF, 0);
+	/* Positive case: firmware in PID1 mount namespace */
+	printf("Testing with firmware in parent namespace (assumed to be same file system as PID1)\n");
+	if (!test_fw_in_ns(fw_name, sys_path, false))
+		die("error: failed to access firmware\n");
+
+	/* Negative case: firmware in child mount namespace, expected to fail */
+	printf("Testing with firmware in child namespace\n");
+	if (test_fw_in_ns(fw_name, sys_path, true))
+		die("error: firmware access did not fail\n");
+
+	unlink(fw_path);
+	free(fw_path);
+	umount("/lib/firmware");
+	exit(EXIT_SUCCESS);
+}
diff --git a/tools/testing/selftests/firmware/fw_run_tests.sh b/tools/testing/selftests/firmware/fw_run_tests.sh
index 8e14d555c197..777377078d5e 100755
--- a/tools/testing/selftests/firmware/fw_run_tests.sh
+++ b/tools/testing/selftests/firmware/fw_run_tests.sh
@@ -61,6 +61,10 @@ run_test_config_0003()
 check_mods
 check_setup
 
+echo "Running namespace test: "
+$TEST_DIR/fw_namespace $DIR/trigger_request
+echo "OK"
+
 if [ -f $FW_FORCE_SYSFS_FALLBACK ]; then
 	run_test_config_0001
 	run_test_config_0002