[PATCH 14/17] memremap: simplify duplicate region handling in devm_memremap_pages

[Christoph Hellwig]

__radix_tree_insert already checks for duplicates and returns -EEXIST in
that case, so remove the duplicate (and racy) duplicates check.

Signed-off-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Logan Gunthorpe <log...@deltatee.com>
---
 kernel/memremap.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 891491ddccdb..901404094df1 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -395,17 +395,6 @@ void *devm_memremap_pages(struct device *dev, struct 
resource *res,
        align_end = align_start + align_size - 1;
 
        foreach_order_pgoff(res, order, pgoff) {
-               struct dev_pagemap *dup;
-
-               rcu_read_lock();
-               dup = find_dev_pagemap(res->start + PFN_PHYS(pgoff));
-               rcu_read_unlock();
-               if (dup) {
-                       dev_err(dev, "%s: %pr collides with mapping for %s\n",
-                                       __func__, res, dev_name(dup->dev));
-                       error = -EBUSY;
-                       break;
-               }
                error = __radix_tree_insert(&pgmap_radix,
                                PHYS_PFN(res->start) + pgoff, order, page_map);
                if (error) {
-- 
2.14.2