commit 0e64123141f3854e695eb4924d82b52856691466
author Olivier Deprez <olivier.deprez@arm.com> Thu Sep 23 10:07:05 2021 +0200
committer Olivier Deprez <olivier.deprez@arm.com> Tue Oct 26 16:50:53 2021 +0100
tree 9f79e140db584f9b107f4e33373a0075983df1f4
parent 98854e9675dc7d951fa9c4e10d9c9d230c54bde6

Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>

drivers/acpi/osl.c

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index a2e844a..41168c0 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -374,19 +374,21 @@
 }
 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
 
-static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
+/* Must be called with mutex_lock(&acpi_ioremap_lock) */
+static unsigned long acpi_os_drop_map_ref(struct acpi_ioremap *map)
 {
-	if (!--map->refcount)
+	unsigned long refcount = --map->refcount;
+
+	if (!refcount)
 		list_del_rcu(&map->list);
+	return refcount;
 }
 
 static void acpi_os_map_cleanup(struct acpi_ioremap *map)
 {
-	if (!map->refcount) {
-		synchronize_rcu_expedited();
-		acpi_unmap(map->phys, map->virt);
-		kfree(map);
-	}
+	synchronize_rcu_expedited();
+	acpi_unmap(map->phys, map->virt);
+	kfree(map);
 }
 
 /**
@@ -406,6 +408,7 @@
 void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
 {
 	struct acpi_ioremap *map;
+	unsigned long refcount;
 
 	if (!acpi_permanent_mmap) {
 		__acpi_unmap_table(virt, size);
@@ -419,10 +422,11 @@
 		WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
 		return;
 	}
-	acpi_os_drop_map_ref(map);
+	refcount = acpi_os_drop_map_ref(map);
 	mutex_unlock(&acpi_ioremap_lock);
 
-	acpi_os_map_cleanup(map);
+	if (!refcount)
+		acpi_os_map_cleanup(map);
 }
 EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem);
 
@@ -457,6 +461,7 @@
 {
 	u64 addr;
 	struct acpi_ioremap *map;
+	unsigned long refcount;
 
 	if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		return;
@@ -472,10 +477,11 @@
 		mutex_unlock(&acpi_ioremap_lock);
 		return;
 	}
-	acpi_os_drop_map_ref(map);
+	refcount = acpi_os_drop_map_ref(map);
 	mutex_unlock(&acpi_ioremap_lock);
 
-	acpi_os_map_cleanup(map);
+	if (!refcount)
+		acpi_os_map_cleanup(map);
 }
 EXPORT_SYMBOL(acpi_os_unmap_generic_address);