[PATCH 3/8] ACPI: CPPC: Refactor resource cleanup into free_reg_resource()

[Lifeng Zheng]

Both the error path of acpi_cppc_processor_probe() and the normal
cleanup in acpi_cppc_processor_exit() iterate over the cpc_regs[]
array and iounmap() any SystemMemory virtual addresses that were
set up during probe.

CPPC v4 adds Package-type entries that own dynamically allocated
sub-elements which also need to be freed.  Inlining this recursive
cleanup at every call-site would be error-prone and repetitive.

Extract the per-register cleanup logic into free_reg_resource(),
which releases any iomapped address and, for Package-type entries,
recursively frees all child elements and the elements array itself.
Convert both the probe error path and _exit() to use the new helper.

No functional change for existing Integer / Buffer entries.

Signed-off-by: Lifeng Zheng <zhenglifeng1@xxxxxxxxxx>
---
 drivers/acpi/cppc_acpi.c | 41 ++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index ac4d4d002d40..bad959f46f90 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -759,6 +759,30 @@ static int parse_cpc_element(union acpi_object *cpc_obj,
 	return 0;
 }
 
+/**
+ * free_reg_resource - Free resources held by a CPC register resource.
+ * @cpc_reg: Pointer to the CPC register resource to clean up.
+ *
+ * Releases any iomapped SystemMemory address and, for Package-type
+ * resources, recursively frees all nested elements before freeing the
+ * elements array itself.
+ */
+static void free_reg_resource(struct cpc_register_resource *cpc_reg)
+{
+	void __iomem *addr = cpc_reg->sys_mem_vaddr;
+	int i;
+
+	if (addr)
+		iounmap(addr);
+
+	if (cpc_reg->type == ACPI_TYPE_PACKAGE) {
+		for (i = 0; i < cpc_reg->cpc_entry.package.count; i++)
+			free_reg_resource(&cpc_reg->cpc_entry.package.elements[i]);
+
+		kfree(cpc_reg->cpc_entry.package.elements);
+	}
+}
+
 /*
  * An example CPC table looks like the following.
  *
@@ -972,12 +996,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 
 out_free:
 	/* Free all the mapped sys mem areas for this CPU */
-	for (i = 2; i < cpc_ptr->num_entries; i++) {
-		void __iomem *addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr;
+	for (i = 2; i < cpc_ptr->num_entries; i++)
+		free_reg_resource(&cpc_ptr->cpc_regs[i-2]);
 
-		if (addr)
-			iounmap(addr);
-	}
 	kfree(cpc_ptr);
 
 out_buf_free:
@@ -996,7 +1017,6 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
 {
 	struct cpc_desc *cpc_ptr;
 	unsigned int i;
-	void __iomem *addr;
 	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id);
 
 	if (pcc_ss_id >= 0 && pcc_data[pcc_ss_id]) {
@@ -1014,12 +1034,9 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
 	if (!cpc_ptr)
 		return;
 
-	/* Free all the mapped sys mem areas for this CPU */
-	for (i = 2; i < cpc_ptr->num_entries; i++) {
-		addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr;
-		if (addr)
-			iounmap(addr);
-	}
+	/* Free all the mapped sys mem areas and nested package resources for this CPU */
+	for (i = 2; i < cpc_ptr->num_entries; i++)
+		free_reg_resource(&cpc_ptr->cpc_regs[i-2]);
 
 	kobject_put(&cpc_ptr->kobj);
 	kfree(cpc_ptr);
-- 
2.33.0