Merge tag 'driver-core-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the "big" set of driver core patches for 5.5-rc1

  There's a few minor cleanups and fixes in here, but the majority of
  the patches in here fall into two buckets:

   - debugfs api cleanups and fixes

   - driver core device link support for boot dependancy issues

  The debugfs api cleanups are working to slowly refactor the debugfs
  apis so that it is even harder to use incorrectly. That work has been
  happening for the past few kernel releases and will continue over
  time, it's a long-term project/goal

  The driver core device link support missed 5.4 by just a bit, so it's
  been sitting and baking for many months now. It's from Saravana Kannan
  to help resolve the problems that DT-based systems have at boot time
  with dependancy graphs and kernel modules. Turns out that no one has
  actually tried to build a generic arm64 kernel with loads of modules
  and have it "just work" for a variety of platforms (like a distro
  kernel). The big problem turned out to be a lack of dependency
  information between different areas of DT entries, and the work here
  resolves that problem and now allows devices to boot properly, and
  quicker than a monolith kernel.

  All of these patches have been in linux-next for a long time with no
  reported issues"

* tag 'driver-core-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (68 commits)
  tracing: Remove unnecessary DEBUG_FS dependency
  of: property: Add device link support for interrupt-parent, dmas and -gpio(s)
  debugfs: Fix !DEBUG_FS debugfs_create_automount
  of: property: Add device link support for "iommu-map"
  of: property: Fix the semantics of of_is_ancestor_of()
  i2c: of: Populate fwnode in of_i2c_get_board_info()
  drivers: base: Fix Kconfig indentation
  firmware_loader: Fix labels with comma for builtin firmware
  driver core: Allow device link operations inside sync_state()
  driver core: platform: Declare ret variable only once
  cpu-topology: declare parse_acpi_topology in <linux/arch_topology.h>
  crypto: hisilicon: no need to check return value of debugfs_create functions
  driver core: platform: use the correct callback type for bus_find_device
  firmware_class: make firmware caching configurable
  driver core: Clarify documentation for fwnode_operations.add_links()
  mailbox: tegra: Fix superfluous IRQ error message
  net: caif: Fix debugfs on 64-bit platforms
  mac80211: Use debugfs_create_xul() helper
  media: c8sectpfe: no need to check return value of debugfs_create functions
  of: property: Add device link support for iommus, mboxes and io-channels
  ...

3 files changed, 10 insertions, 55 deletions

diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index 2b87480f2837..eab8aa293743 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -19,7 +19,6 @@
 
 struct dtl {
 	struct dtl_entry	*buf;
-	struct dentry		*file;
 	int			cpu;
 	int			buf_entries;
 	u64			last_idx;
@@ -320,46 +319,28 @@ static const struct file_operations dtl_fops = {
 
 static struct dentry *dtl_dir;
 
-static int dtl_setup_file(struct dtl *dtl)
+static void dtl_setup_file(struct dtl *dtl)
 {
 	char name[10];
 
 	sprintf(name, "cpu-%d", dtl->cpu);
 
-	dtl->file = debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
-	if (!dtl->file)
-		return -ENOMEM;
-
-	return 0;
+	debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
 }
 
 static int dtl_init(void)
 {
-	struct dentry *event_mask_file, *buf_entries_file;
-	int rc, i;
+	int i;
 
 	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
 		return -ENODEV;
 
 	/* set up common debugfs structure */
 
-	rc = -ENOMEM;
 	dtl_dir = debugfs_create_dir("dtl", powerpc_debugfs_root);
-	if (!dtl_dir) {
-		printk(KERN_WARNING "%s: can't create dtl root dir\n",
-				__func__);
-		goto err;
-	}
 
-	event_mask_file = debugfs_create_x8("dtl_event_mask", 0600,
-				dtl_dir, &dtl_event_mask);
-	buf_entries_file = debugfs_create_u32("dtl_buf_entries", 0400,
-				dtl_dir, &dtl_buf_entries);
-
-	if (!event_mask_file || !buf_entries_file) {
-		printk(KERN_WARNING "%s: can't create dtl files\n", __func__);
-		goto err_remove_dir;
-	}
+	debugfs_create_x8("dtl_event_mask", 0600, dtl_dir, &dtl_event_mask);
+	debugfs_create_u32("dtl_buf_entries", 0400, dtl_dir, &dtl_buf_entries);
 
 	/* set up the per-cpu log structures */
 	for_each_possible_cpu(i) {
@@ -367,16 +348,9 @@ static int dtl_init(void)
 		spin_lock_init(&dtl->lock);
 		dtl->cpu = i;
 
-		rc = dtl_setup_file(dtl);
-		if (rc)
-			goto err_remove_dir;
+		dtl_setup_file(dtl);
 	}
 
 	return 0;
-
-err_remove_dir:
-	debugfs_remove_recursive(dtl_dir);
-err:
-	return rc;
 }
 machine_arch_initcall(pseries, dtl_init);
diff --git a/arch/powerpc/platforms/pseries/hvCall_inst.c b/arch/powerpc/platforms/pseries/hvCall_inst.c
index bcc1b67417a8..c40c62ec432e 100644
--- a/arch/powerpc/platforms/pseries/hvCall_inst.c
+++ b/arch/powerpc/platforms/pseries/hvCall_inst.c
@@ -129,7 +129,6 @@ static void probe_hcall_exit(void *ignored, unsigned long opcode, long retval,
 static int __init hcall_inst_init(void)
 {
 	struct dentry *hcall_root;
-	struct dentry *hcall_file;
 	char cpu_name_buf[CPU_NAME_BUF_SIZE];
 	int cpu;
 
@@ -145,17 +144,12 @@ static int __init hcall_inst_init(void)
 	}
 
 	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
-	if (!hcall_root)
-		return -ENOMEM;
 
 	for_each_possible_cpu(cpu) {
 		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
-		hcall_file = debugfs_create_file(cpu_name_buf, 0444,
-						 hcall_root,
-						 per_cpu(hcall_stats, cpu),
-						 &hcall_inst_seq_fops);
-		if (!hcall_file)
-			return -ENOMEM;
+		debugfs_create_file(cpu_name_buf, 0444, hcall_root,
+				    per_cpu(hcall_stats, cpu),
+				    &hcall_inst_seq_fops);
 	}
 
 	return 0;
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index f87a5c64e24d..f9f57c55655e 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -1998,24 +1998,11 @@ static int __init vpa_debugfs_init(void)
 		return 0;
 
 	vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);
-	if (!vpa_dir) {
-		pr_warn("%s: can't create vpa root dir\n", __func__);
-		return -ENOMEM;
-	}
 
 	/* set up the per-cpu vpa file*/
 	for_each_possible_cpu(i) {
-		struct dentry *d;
-
 		sprintf(name, "cpu-%ld", i);
-
-		d = debugfs_create_file(name, 0400, vpa_dir, (void *)i,
-					&vpa_fops);
-		if (!d) {
-			pr_warn("%s: can't create per-cpu vpa file\n",
-					__func__);
-			return -ENOMEM;
-		}
+		debugfs_create_file(name, 0400, vpa_dir, (void *)i, &vpa_fops);
 	}
 
 	return 0;