Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...

1 files changed, 49 insertions, 3 deletions

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 1637b65ba07a..0b2340a79b65 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -280,6 +280,45 @@ static const struct file_operations sched_dynamic_fops = {
 
 __read_mostly bool sched_debug_verbose;
 
+#ifdef CONFIG_SMP
+static struct dentry           *sd_dentry;
+
+
+static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
+				  size_t cnt, loff_t *ppos)
+{
+	ssize_t result;
+	bool orig;
+
+	cpus_read_lock();
+	mutex_lock(&sched_domains_mutex);
+
+	orig = sched_debug_verbose;
+	result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
+
+	if (sched_debug_verbose && !orig)
+		update_sched_domain_debugfs();
+	else if (!sched_debug_verbose && orig) {
+		debugfs_remove(sd_dentry);
+		sd_dentry = NULL;
+	}
+
+	mutex_unlock(&sched_domains_mutex);
+	cpus_read_unlock();
+
+	return result;
+}
+#else
+#define sched_verbose_write debugfs_write_file_bool
+#endif
+
+static const struct file_operations sched_verbose_fops = {
+	.read =         debugfs_read_file_bool,
+	.write =        sched_verbose_write,
+	.open =         simple_open,
+	.llseek =       default_llseek,
+};
+
 static const struct seq_operations sched_debug_sops;
 
 static int sched_debug_open(struct inode *inode, struct file *filp)
@@ -303,7 +342,7 @@ static __init int sched_init_debug(void)
 	debugfs_sched = debugfs_create_dir("sched", NULL);
 
 	debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
-	debugfs_create_bool("verbose", 0644, debugfs_sched, &sched_debug_verbose);
+	debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops);
 #ifdef CONFIG_PREEMPT_DYNAMIC
 	debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
 #endif
@@ -345,7 +384,6 @@ late_initcall(sched_init_debug);
 #ifdef CONFIG_SMP
 
 static cpumask_var_t		sd_sysctl_cpus;
-static struct dentry		*sd_dentry;
 
 static int sd_flags_show(struct seq_file *m, void *v)
 {
@@ -402,15 +440,23 @@ void update_sched_domain_debugfs(void)
 	if (!debugfs_sched)
 		return;
 
+	if (!sched_debug_verbose)
+		return;
+
 	if (!cpumask_available(sd_sysctl_cpus)) {
 		if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
 			return;
 		cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
 	}
 
-	if (!sd_dentry)
+	if (!sd_dentry) {
 		sd_dentry = debugfs_create_dir("domains", debugfs_sched);
 
+		/* rebuild sd_sysctl_cpus if empty since it gets cleared below */
+		if (cpumask_empty(sd_sysctl_cpus))
+			cpumask_copy(sd_sysctl_cpus, cpu_online_mask);
+	}
+
 	for_each_cpu(cpu, sd_sysctl_cpus) {
 		struct sched_domain *sd;
 		struct dentry *d_cpu;