Revert commit 
f1549cb5ab2b ("mm/z3fold.c: allow __GFP_HIGHMEM in
z3fold_alloc").
z3fold can't support GFP_HIGHMEM page now.  page_address is used directly
at all places.  Moreover, z3fold_header is on per cpu unbuddied list which
could be accessed anytime.  So we should remove the support of GFP_HIGHMEM
allocation for z3fold.
Link: https://lkml.kernel.org/r/20220429064051.61552-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
                                                        gfp_t gfp)
 {
-       struct z3fold_buddy_slots *slots;
-
-       slots = kmem_cache_zalloc(pool->c_handle,
-                                (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE)));
+       struct z3fold_buddy_slots *slots = kmem_cache_zalloc(pool->c_handle,
+                                                            gfp);
 
        if (slots) {
                /* It will be freed separately in free_handle(). */
        enum buddy bud;
        bool can_sleep = gfpflags_allow_blocking(gfp);
 
-       if (!size)
+       if (!size || (gfp & __GFP_HIGHMEM))
                return -EINVAL;
 
        if (size > PAGE_SIZE)