memremap: simplify duplicate region handling in devm_memremap_pages

__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 <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 0 insertions, 11 deletions

diff --git a/kernel/memremap.c b/kernel/memremap.c
index b09517439dec..12e78528fea4 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -396,17 +396,6 @@ 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) {