v4.19.13 snapshot.
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h
new file mode 100644
index 0000000..b1739dc
--- /dev/null
+++ b/mm/percpu-internal.h
@@ -0,0 +1,225 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _MM_PERCPU_INTERNAL_H
+#define _MM_PERCPU_INTERNAL_H
+
+#include <linux/types.h>
+#include <linux/percpu.h>
+
+/*
+ * 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.
+ */
+struct pcpu_block_md {
+ int contig_hint; /* contig hint for block */
+ int contig_hint_start; /* block relative starting
+ position of the contig hint */
+ int left_free; /* size of free space along
+ the left side of the block */
+ int right_free; /* size of free space along
+ the right side of the block */
+ int first_free; /* block position of first free */
+};
+
+struct pcpu_chunk {
+#ifdef CONFIG_PERCPU_STATS
+ int nr_alloc; /* # of allocations */
+ size_t max_alloc_size; /* largest allocation size */
+#endif
+
+ struct list_head list; /* linked to pcpu_slot lists */
+ int free_bytes; /* free bytes in the chunk */
+ int contig_bits; /* max contiguous size hint */
+ int contig_bits_start; /* contig_bits starting
+ offset */
+ void *base_addr; /* base address of this chunk */
+
+ unsigned long *alloc_map; /* allocation map */
+ unsigned long *bound_map; /* boundary map */
+ struct pcpu_block_md *md_blocks; /* metadata blocks */
+
+ void *data; /* chunk data */
+ int first_bit; /* no free below this */
+ bool immutable; /* no [de]population allowed */
+ int start_offset; /* the overlap with the previous
+ region to have a page aligned
+ base_addr */
+ int end_offset; /* additional area required to
+ have the region end page
+ aligned */
+
+ int nr_pages; /* # of pages served by this chunk */
+ int nr_populated; /* # of populated pages */
+ int nr_empty_pop_pages; /* # of empty populated pages */
+ unsigned long populated[]; /* populated bitmap */
+};
+
+extern spinlock_t pcpu_lock;
+
+extern struct list_head *pcpu_slot;
+extern int pcpu_nr_slots;
+extern int pcpu_nr_empty_pop_pages;
+
+extern struct pcpu_chunk *pcpu_first_chunk;
+extern struct pcpu_chunk *pcpu_reserved_chunk;
+
+/**
+ * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
+ * @chunk: chunk of interest
+ *
+ * This conversion is from the number of physical pages that the chunk
+ * serves to the number of bitmap blocks used.
+ */
+static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
+{
+ return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
+}
+
+/**
+ * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
+ * @pages: number of physical pages
+ *
+ * This conversion is from physical pages to the number of bits
+ * required in the bitmap.
+ */
+static inline int pcpu_nr_pages_to_map_bits(int pages)
+{
+ return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
+}
+
+/**
+ * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
+ * @chunk: chunk of interest
+ *
+ * This conversion is from the number of physical pages that the chunk
+ * serves to the number of bits in the bitmap.
+ */
+static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
+{
+ return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
+}
+
+#ifdef CONFIG_PERCPU_STATS
+
+#include <linux/spinlock.h>
+
+struct percpu_stats {
+ u64 nr_alloc; /* lifetime # of allocations */
+ u64 nr_dealloc; /* lifetime # of deallocations */
+ u64 nr_cur_alloc; /* current # of allocations */
+ u64 nr_max_alloc; /* max # of live allocations */
+ u32 nr_chunks; /* current # of live chunks */
+ u32 nr_max_chunks; /* max # of live chunks */
+ size_t min_alloc_size; /* min allocaiton size */
+ size_t max_alloc_size; /* max allocation size */
+};
+
+extern struct percpu_stats pcpu_stats;
+extern struct pcpu_alloc_info pcpu_stats_ai;
+
+/*
+ * For debug purposes. We don't care about the flexible array.
+ */
+static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
+{
+ memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
+
+ /* initialize min_alloc_size to unit_size */
+ pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
+}
+
+/*
+ * pcpu_stats_area_alloc - increment area allocation stats
+ * @chunk: the location of the area being allocated
+ * @size: size of area to allocate in bytes
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ */
+static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
+{
+ lockdep_assert_held(&pcpu_lock);
+
+ pcpu_stats.nr_alloc++;
+ pcpu_stats.nr_cur_alloc++;
+ pcpu_stats.nr_max_alloc =
+ max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
+ pcpu_stats.min_alloc_size =
+ min(pcpu_stats.min_alloc_size, size);
+ pcpu_stats.max_alloc_size =
+ max(pcpu_stats.max_alloc_size, size);
+
+ chunk->nr_alloc++;
+ chunk->max_alloc_size = max(chunk->max_alloc_size, size);
+}
+
+/*
+ * pcpu_stats_area_dealloc - decrement allocation stats
+ * @chunk: the location of the area being deallocated
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ */
+static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
+{
+ lockdep_assert_held(&pcpu_lock);
+
+ pcpu_stats.nr_dealloc++;
+ pcpu_stats.nr_cur_alloc--;
+
+ chunk->nr_alloc--;
+}
+
+/*
+ * pcpu_stats_chunk_alloc - increment chunk stats
+ */
+static inline void pcpu_stats_chunk_alloc(void)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ pcpu_stats.nr_chunks++;
+ pcpu_stats.nr_max_chunks =
+ max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
+
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+}
+
+/*
+ * pcpu_stats_chunk_dealloc - decrement chunk stats
+ */
+static inline void pcpu_stats_chunk_dealloc(void)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ pcpu_stats.nr_chunks--;
+
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+}
+
+#else
+
+static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
+{
+}
+
+static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
+{
+}
+
+static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
+{
+}
+
+static inline void pcpu_stats_chunk_alloc(void)
+{
+}
+
+static inline void pcpu_stats_chunk_dealloc(void)
+{
+}
+
+#endif /* !CONFIG_PERCPU_STATS */
+
+#endif