ASoC: nau8822: add support for supply regulators

Alexey Charkov <alchark@flipper.net> says:

The Nuvoton NAU8822 codec has four power supply pins: VDDA, VDDB, VDDC
and VDDSPK, which must be online and stable before the device can be
accessed over I2C. On boards where these rails are software-controlled,
probing the codec before the regulators are up results in -ENXIO errors
during register access.

This short series adds optional regulator support to both the device
tree binding and the driver, so platforms that need explicit power
sequencing can describe and enforce it:

Link: https://patch.msgid.link/20260525-nau8822-reg-v2-0-7d37ae393e46@flipper.net

2 files changed, 37 insertions, 30 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 5f3fdfdb14c7..8ac38beae360 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2664,8 +2664,6 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
  *
  * It copies the process, and if successful kick-starts
  * it and waits for it to finish using the VM if required.
- *
- * args->exit_signal is expected to be checked for sanity by the caller.
  */
 pid_t kernel_clone(struct kernel_clone_args *args)
 {
@@ -2700,6 +2698,9 @@ pid_t kernel_clone(struct kernel_clone_args *args)
 	    (args->pidfd == args->parent_tid))
 		return -EINVAL;
 
+	if (!valid_signal(args->exit_signal))
+		return -EINVAL;
+
 	/*
 	 * Determine whether and which event to report to ptracer.  When
 	 * called from kernel_thread or CLONE_UNTRACED is explicitly
@@ -2898,11 +2899,9 @@ static noinline int copy_clone_args_from_user(struct kernel_clone_args *kargs,
 		return -EINVAL;
 
 	/*
-	 * Verify that higher 32bits of exit_signal are unset and that
-	 * it is a valid signal
+	 * Verify that higher 32bits of exit_signal are unset
 	 */
-	if (unlikely((args.exit_signal & ~((u64)CSIGNAL)) ||
-		     !valid_signal(args.exit_signal)))
+	if (unlikely(args.exit_signal & ~((u64)CSIGNAL)))
 		return -EINVAL;
 
 	if ((args.flags & CLONE_INTO_CGROUP) &&
diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index 2592f7ca16e2..1b592d86dc48 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -357,20 +357,6 @@ int kho_radix_walk_tree(struct kho_radix_tree *tree,
 }
 EXPORT_SYMBOL_GPL(kho_radix_walk_tree);
 
-static void __kho_unpreserve(struct kho_radix_tree *tree,
-			     unsigned long pfn, unsigned long end_pfn)
-{
-	unsigned int order;
-
-	while (pfn < end_pfn) {
-		order = min(count_trailing_zeros(pfn), ilog2(end_pfn - pfn));
-
-		kho_radix_del_page(tree, pfn, order);
-
-		pfn += 1 << order;
-	}
-}
-
 /* For physically contiguous 0-order pages. */
 static void kho_init_pages(struct page *page, unsigned long nr_pages)
 {
@@ -860,6 +846,37 @@ void kho_unpreserve_folio(struct folio *folio)
 }
 EXPORT_SYMBOL_GPL(kho_unpreserve_folio);
 
+static unsigned int __kho_preserve_pages_order(unsigned long start_pfn,
+					       unsigned long end_pfn)
+{
+	unsigned int order = min(count_trailing_zeros(start_pfn),
+				 ilog2(end_pfn - start_pfn));
+
+	/*
+	 * Make sure all the pages in a single preservation are in the same NUMA
+	 * node. The restore machinery can not cope with a preservation spanning
+	 * multiple NUMA nodes.
+	 */
+	while (pfn_to_nid(start_pfn) != pfn_to_nid(start_pfn + (1UL << order) - 1))
+		order--;
+
+	return order;
+}
+
+static void __kho_unpreserve(struct kho_radix_tree *tree,
+			     unsigned long pfn, unsigned long end_pfn)
+{
+	unsigned int order;
+
+	while (pfn < end_pfn) {
+		order = __kho_preserve_pages_order(pfn, end_pfn);
+
+		kho_radix_del_page(tree, pfn, order);
+
+		pfn += 1 << order;
+	}
+}
+
 /**
  * kho_preserve_pages - preserve contiguous pages across kexec
  * @page: first page in the list.
@@ -885,16 +902,7 @@ int kho_preserve_pages(struct page *page, unsigned long nr_pages)
 	}
 
 	while (pfn < end_pfn) {
-		unsigned int order =
-			min(count_trailing_zeros(pfn), ilog2(end_pfn - pfn));
-
-		/*
-		 * Make sure all the pages in a single preservation are in the
-		 * same NUMA node. The restore machinery can not cope with a
-		 * preservation spanning multiple NUMA nodes.
-		 */
-		while (pfn_to_nid(pfn) != pfn_to_nid(pfn + (1UL << order) - 1))
-			order--;
+		unsigned int order = __kho_preserve_pages_order(pfn, end_pfn);
 
 		err = kho_radix_add_page(tree, pfn, order);
 		if (err) {