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

Christoph Hellwig
2017-12-29T07:50:21Z

__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>
---
kernel/memremap.c | 11 -----------
1 file changed, 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) {