Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h
index 0468ba5..095d7ea 100644
--- a/mm/percpu-internal.h
+++ b/mm/percpu-internal.h
@@ -6,6 +6,25 @@
 #include <linux/percpu.h>
 
 /*
+ * There are two chunk types: root and memcg-aware.
+ * Chunks of each type have separate slots list.
+ *
+ * Memcg-aware chunks have an attached vector of obj_cgroup pointers, which is
+ * used to store memcg membership data of a percpu object.  Obj_cgroups are
+ * ref-counted pointers to a memory cgroup with an ability to switch dynamically
+ * to the parent memory cgroup.  This allows to reclaim a deleted memory cgroup
+ * without reclaiming of all outstanding objects, which hold a reference at it.
+ */
+enum pcpu_chunk_type {
+	PCPU_CHUNK_ROOT,
+#ifdef CONFIG_MEMCG_KMEM
+	PCPU_CHUNK_MEMCG,
+#endif
+	PCPU_NR_CHUNK_TYPES,
+	PCPU_FAIL_ALLOC = PCPU_NR_CHUNK_TYPES
+};
+
+/*
  * pcpu_block_md is the metadata block struct.
  * Each chunk's bitmap is split into a number of full blocks.
  * All units are in terms of bits.
@@ -54,6 +73,9 @@
 	int			end_offset;	/* additional area required to
 						   have the region end page
 						   aligned */
+#ifdef CONFIG_MEMCG_KMEM
+	struct obj_cgroup	**obj_cgroups;	/* vector of object cgroups */
+#endif
 
 	int			nr_pages;	/* # of pages served by this chunk */
 	int			nr_populated;	/* # of populated pages */
@@ -63,9 +85,9 @@
 
 extern spinlock_t pcpu_lock;
 
-extern struct list_head *pcpu_slot;
+extern struct list_head *pcpu_chunk_lists;
 extern int pcpu_nr_slots;
-extern int pcpu_nr_empty_pop_pages;
+extern int pcpu_nr_empty_pop_pages[];
 
 extern struct pcpu_chunk *pcpu_first_chunk;
 extern struct pcpu_chunk *pcpu_reserved_chunk;
@@ -106,6 +128,37 @@
 	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
 }
 
+#ifdef CONFIG_MEMCG_KMEM
+static inline enum pcpu_chunk_type pcpu_chunk_type(struct pcpu_chunk *chunk)
+{
+	if (chunk->obj_cgroups)
+		return PCPU_CHUNK_MEMCG;
+	return PCPU_CHUNK_ROOT;
+}
+
+static inline bool pcpu_is_memcg_chunk(enum pcpu_chunk_type chunk_type)
+{
+	return chunk_type == PCPU_CHUNK_MEMCG;
+}
+
+#else
+static inline enum pcpu_chunk_type pcpu_chunk_type(struct pcpu_chunk *chunk)
+{
+	return PCPU_CHUNK_ROOT;
+}
+
+static inline bool pcpu_is_memcg_chunk(enum pcpu_chunk_type chunk_type)
+{
+	return false;
+}
+#endif
+
+static inline struct list_head *pcpu_chunk_list(enum pcpu_chunk_type chunk_type)
+{
+	return &pcpu_chunk_lists[pcpu_nr_slots *
+				 pcpu_is_memcg_chunk(chunk_type)];
+}
+
 #ifdef CONFIG_PERCPU_STATS
 
 #include <linux/spinlock.h>