dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC

stable inclusion
from stable-v5.10.121
commit 1ecd01d77c9bf5517617862d87b817804b67c771
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1ecd01d77c9bf5517617862d87b817804b67c771

--------------------------------

[ Upstream commit 84bc4f1d ]

We observed the error "cacheline tracking ENOMEM, dma-debug disabled"
during a light system load (copying some files). The reason for this error
is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation -
so it can't access the emergency memory reserves and it fails as soon as
anybody reaches the watermark.

This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the
emergency memory reserves.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

kernel/dma/debug.c

@@ -448,7 +448,7 @@ void debug_dma_dump_mappings(struct device *dev)
  * other hand, consumes a single dma_debug_entry, but inserts 'nents'
  * entries into the tree.
  */
-static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
+static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC);
 static DEFINE_SPINLOCK(radix_lock);
 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)