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diff --git a/mm/zbud.c b/mm/zbud.c
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index e9836fff9438..000000000000
--- a/mm/zbud.c
+++ /dev/null
@@ -1,455 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * zbud.c
- *
- * Copyright (C) 2013, Seth Jennings, IBM
- *
- * Concepts based on zcache internal zbud allocator by Dan Magenheimer.
- *
- * zbud is an special purpose allocator for storing compressed pages.  Contrary
- * to what its name may suggest, zbud is not a buddy allocator, but rather an
- * allocator that "buddies" two compressed pages together in a single memory
- * page.
- *
- * While this design limits storage density, it has simple and deterministic
- * reclaim properties that make it preferable to a higher density approach when
- * reclaim will be used.
- *
- * zbud works by storing compressed pages, or "zpages", together in pairs in a
- * single memory page called a "zbud page".  The first buddy is "left
- * justified" at the beginning of the zbud page, and the last buddy is "right
- * justified" at the end of the zbud page.  The benefit is that if either
- * buddy is freed, the freed buddy space, coalesced with whatever slack space
- * that existed between the buddies, results in the largest possible free region
- * within the zbud page.
- *
- * zbud also provides an attractive lower bound on density. The ratio of zpages
- * to zbud pages can not be less than 1.  This ensures that zbud can never "do
- * harm" by using more pages to store zpages than the uncompressed zpages would
- * have used on their own.
- *
- * zbud pages are divided into "chunks".  The size of the chunks is fixed at
- * compile time and determined by NCHUNKS_ORDER below.  Dividing zbud pages
- * into chunks allows organizing unbuddied zbud pages into a manageable number
- * of unbuddied lists according to the number of free chunks available in the
- * zbud page.
- *
- * The zbud API differs from that of conventional allocators in that the
- * allocation function, zbud_alloc(), returns an opaque handle to the user,
- * not a dereferenceable pointer.  The user must map the handle using
- * zbud_map() in order to get a usable pointer by which to access the
- * allocation data and unmap the handle with zbud_unmap() when operations
- * on the allocation data are complete.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/atomic.h>
-#include <linux/list.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/preempt.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/zpool.h>
-
-/*****************
- * Structures
-*****************/
-/*
- * NCHUNKS_ORDER determines the internal allocation granularity, effectively
- * adjusting internal fragmentation.  It also determines the number of
- * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the
- * allocation granularity will be in chunks of size PAGE_SIZE/64. As one chunk
- * in allocated page is occupied by zbud header, NCHUNKS will be calculated to
- * 63 which shows the max number of free chunks in zbud page, also there will be
- * 63 freelists per pool.
- */
-#define NCHUNKS_ORDER	6
-
-#define CHUNK_SHIFT	(PAGE_SHIFT - NCHUNKS_ORDER)
-#define CHUNK_SIZE	(1 << CHUNK_SHIFT)
-#define ZHDR_SIZE_ALIGNED CHUNK_SIZE
-#define NCHUNKS		((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT)
-
-struct zbud_pool;
-
-/**
- * struct zbud_pool - stores metadata for each zbud pool
- * @lock:	protects all pool fields and first|last_chunk fields of any
- *		zbud page in the pool
- * @unbuddied:	array of lists tracking zbud pages that only contain one buddy;
- *		the lists each zbud page is added to depends on the size of
- *		its free region.
- * @buddied:	list tracking the zbud pages that contain two buddies;
- *		these zbud pages are full
- * @pages_nr:	number of zbud pages in the pool.
- *
- * This structure is allocated at pool creation time and maintains metadata
- * pertaining to a particular zbud pool.
- */
-struct zbud_pool {
-	spinlock_t lock;
-	union {
-		/*
-		 * Reuse unbuddied[0] as buddied on the ground that
-		 * unbuddied[0] is unused.
-		 */
-		struct list_head buddied;
-		struct list_head unbuddied[NCHUNKS];
-	};
-	u64 pages_nr;
-};
-
-/*
- * struct zbud_header - zbud page metadata occupying the first chunk of each
- *			zbud page.
- * @buddy:	links the zbud page into the unbuddied/buddied lists in the pool
- * @first_chunks:	the size of the first buddy in chunks, 0 if free
- * @last_chunks:	the size of the last buddy in chunks, 0 if free
- */
-struct zbud_header {
-	struct list_head buddy;
-	unsigned int first_chunks;
-	unsigned int last_chunks;
-};
-
-/*****************
- * Helpers
-*****************/
-/* Just to make the code easier to read */
-enum buddy {
-	FIRST,
-	LAST
-};
-
-/* Converts an allocation size in bytes to size in zbud chunks */
-static int size_to_chunks(size_t size)
-{
-	return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
-}
-
-#define for_each_unbuddied_list(_iter, _begin) \
-	for ((_iter) = (_begin); (_iter) < NCHUNKS; (_iter)++)
-
-/* Initializes the zbud header of a newly allocated zbud page */
-static struct zbud_header *init_zbud_page(struct page *page)
-{
-	struct zbud_header *zhdr = page_address(page);
-	zhdr->first_chunks = 0;
-	zhdr->last_chunks = 0;
-	INIT_LIST_HEAD(&zhdr->buddy);
-	return zhdr;
-}
-
-/* Resets the struct page fields and frees the page */
-static void free_zbud_page(struct zbud_header *zhdr)
-{
-	__free_page(virt_to_page(zhdr));
-}
-
-/*
- * Encodes the handle of a particular buddy within a zbud page
- * Pool lock should be held as this function accesses first|last_chunks
- */
-static unsigned long encode_handle(struct zbud_header *zhdr, enum buddy bud)
-{
-	unsigned long handle;
-
-	/*
-	 * For now, the encoded handle is actually just the pointer to the data
-	 * but this might not always be the case.  A little information hiding.
-	 * Add CHUNK_SIZE to the handle if it is the first allocation to jump
-	 * over the zbud header in the first chunk.
-	 */
-	handle = (unsigned long)zhdr;
-	if (bud == FIRST)
-		/* skip over zbud header */
-		handle += ZHDR_SIZE_ALIGNED;
-	else /* bud == LAST */
-		handle += PAGE_SIZE - (zhdr->last_chunks  << CHUNK_SHIFT);
-	return handle;
-}
-
-/* Returns the zbud page where a given handle is stored */
-static struct zbud_header *handle_to_zbud_header(unsigned long handle)
-{
-	return (struct zbud_header *)(handle & PAGE_MASK);
-}
-
-/* Returns the number of free chunks in a zbud page */
-static int num_free_chunks(struct zbud_header *zhdr)
-{
-	/*
-	 * Rather than branch for different situations, just use the fact that
-	 * free buddies have a length of zero to simplify everything.
-	 */
-	return NCHUNKS - zhdr->first_chunks - zhdr->last_chunks;
-}
-
-/*****************
- * API Functions
-*****************/
-/**
- * zbud_create_pool() - create a new zbud pool
- * @gfp:	gfp flags when allocating the zbud pool structure
- *
- * Return: pointer to the new zbud pool or NULL if the metadata allocation
- * failed.
- */
-static struct zbud_pool *zbud_create_pool(gfp_t gfp)
-{
-	struct zbud_pool *pool;
-	int i;
-
-	pool = kzalloc(sizeof(struct zbud_pool), gfp);
-	if (!pool)
-		return NULL;
-	spin_lock_init(&pool->lock);
-	for_each_unbuddied_list(i, 0)
-		INIT_LIST_HEAD(&pool->unbuddied[i]);
-	INIT_LIST_HEAD(&pool->buddied);
-	pool->pages_nr = 0;
-	return pool;
-}
-
-/**
- * zbud_destroy_pool() - destroys an existing zbud pool
- * @pool:	the zbud pool to be destroyed
- *
- * The pool should be emptied before this function is called.
- */
-static void zbud_destroy_pool(struct zbud_pool *pool)
-{
-	kfree(pool);
-}
-
-/**
- * zbud_alloc() - allocates a region of a given size
- * @pool:	zbud pool from which to allocate
- * @size:	size in bytes of the desired allocation
- * @gfp:	gfp flags used if the pool needs to grow
- * @handle:	handle of the new allocation
- *
- * This function will attempt to find a free region in the pool large enough to
- * satisfy the allocation request.  A search of the unbuddied lists is
- * performed first. If no suitable free region is found, then a new page is
- * allocated and added to the pool to satisfy the request.
- *
- * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
- * as zbud pool pages.
- *
- * Return: 0 if success and handle is set, otherwise -EINVAL if the size or
- * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
- * a new page.
- */
-static int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
-			unsigned long *handle)
-{
-	int chunks, i, freechunks;
-	struct zbud_header *zhdr = NULL;
-	enum buddy bud;
-	struct page *page;
-
-	if (!size || (gfp & __GFP_HIGHMEM))
-		return -EINVAL;
-	if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE)
-		return -ENOSPC;
-	chunks = size_to_chunks(size);
-	spin_lock(&pool->lock);
-
-	/* First, try to find an unbuddied zbud page. */
-	for_each_unbuddied_list(i, chunks) {
-		if (!list_empty(&pool->unbuddied[i])) {
-			zhdr = list_first_entry(&pool->unbuddied[i],
-					struct zbud_header, buddy);
-			list_del(&zhdr->buddy);
-			if (zhdr->first_chunks == 0)
-				bud = FIRST;
-			else
-				bud = LAST;
-			goto found;
-		}
-	}
-
-	/* Couldn't find unbuddied zbud page, create new one */
-	spin_unlock(&pool->lock);
-	page = alloc_page(gfp);
-	if (!page)
-		return -ENOMEM;
-	spin_lock(&pool->lock);
-	pool->pages_nr++;
-	zhdr = init_zbud_page(page);
-	bud = FIRST;
-
-found:
-	if (bud == FIRST)
-		zhdr->first_chunks = chunks;
-	else
-		zhdr->last_chunks = chunks;
-
-	if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0) {
-		/* Add to unbuddied list */
-		freechunks = num_free_chunks(zhdr);
-		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
-	} else {
-		/* Add to buddied list */
-		list_add(&zhdr->buddy, &pool->buddied);
-	}
-
-	*handle = encode_handle(zhdr, bud);
-	spin_unlock(&pool->lock);
-
-	return 0;
-}
-
-/**
- * zbud_free() - frees the allocation associated with the given handle
- * @pool:	pool in which the allocation resided
- * @handle:	handle associated with the allocation returned by zbud_alloc()
- */
-static void zbud_free(struct zbud_pool *pool, unsigned long handle)
-{
-	struct zbud_header *zhdr;
-	int freechunks;
-
-	spin_lock(&pool->lock);
-	zhdr = handle_to_zbud_header(handle);
-
-	/* If first buddy, handle will be page aligned */
-	if ((handle - ZHDR_SIZE_ALIGNED) & ~PAGE_MASK)
-		zhdr->last_chunks = 0;
-	else
-		zhdr->first_chunks = 0;
-
-	/* Remove from existing buddy list */
-	list_del(&zhdr->buddy);
-
-	if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
-		/* zbud page is empty, free */
-		free_zbud_page(zhdr);
-		pool->pages_nr--;
-	} else {
-		/* Add to unbuddied list */
-		freechunks = num_free_chunks(zhdr);
-		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
-	}
-
-	spin_unlock(&pool->lock);
-}
-
-/**
- * zbud_map() - maps the allocation associated with the given handle
- * @pool:	pool in which the allocation resides
- * @handle:	handle associated with the allocation to be mapped
- *
- * While trivial for zbud, the mapping functions for others allocators
- * implementing this allocation API could have more complex information encoded
- * in the handle and could create temporary mappings to make the data
- * accessible to the user.
- *
- * Returns: a pointer to the mapped allocation
- */
-static void *zbud_map(struct zbud_pool *pool, unsigned long handle)
-{
-	return (void *)(handle);
-}
-
-/**
- * zbud_unmap() - maps the allocation associated with the given handle
- * @pool:	pool in which the allocation resides
- * @handle:	handle associated with the allocation to be unmapped
- */
-static void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
-{
-}
-
-/**
- * zbud_get_pool_pages() - gets the zbud pool size in pages
- * @pool:	pool whose size is being queried
- *
- * Returns: size in pages of the given pool.  The pool lock need not be
- * taken to access pages_nr.
- */
-static u64 zbud_get_pool_pages(struct zbud_pool *pool)
-{
-	return pool->pages_nr;
-}
-
-/*****************
- * zpool
- ****************/
-
-static void *zbud_zpool_create(const char *name, gfp_t gfp)
-{
-	return zbud_create_pool(gfp);
-}
-
-static void zbud_zpool_destroy(void *pool)
-{
-	zbud_destroy_pool(pool);
-}
-
-static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,
-			unsigned long *handle)
-{
-	return zbud_alloc(pool, size, gfp, handle);
-}
-static void zbud_zpool_free(void *pool, unsigned long handle)
-{
-	zbud_free(pool, handle);
-}
-
-static void *zbud_zpool_map(void *pool, unsigned long handle,
-			enum zpool_mapmode mm)
-{
-	return zbud_map(pool, handle);
-}
-static void zbud_zpool_unmap(void *pool, unsigned long handle)
-{
-	zbud_unmap(pool, handle);
-}
-
-static u64 zbud_zpool_total_pages(void *pool)
-{
-	return zbud_get_pool_pages(pool);
-}
-
-static struct zpool_driver zbud_zpool_driver = {
-	.type =		"zbud",
-	.sleep_mapped = true,
-	.owner =	THIS_MODULE,
-	.create =	zbud_zpool_create,
-	.destroy =	zbud_zpool_destroy,
-	.malloc =	zbud_zpool_malloc,
-	.free =		zbud_zpool_free,
-	.map =		zbud_zpool_map,
-	.unmap =	zbud_zpool_unmap,
-	.total_pages =	zbud_zpool_total_pages,
-};
-
-MODULE_ALIAS("zpool-zbud");
-
-static int __init init_zbud(void)
-{
-	/* Make sure the zbud header will fit in one chunk */
-	BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED);
-	pr_info("loaded\n");
-
-	zpool_register_driver(&zbud_zpool_driver);
-
-	return 0;
-}
-
-static void __exit exit_zbud(void)
-{
-	zpool_unregister_driver(&zbud_zpool_driver);
-	pr_info("unloaded\n");
-}
-
-module_init(init_zbud);
-module_exit(exit_zbud);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Seth Jennings <sjennings@variantweb.net>");
-MODULE_DESCRIPTION("Buddy Allocator for Compressed Pages");