[PATCH 4.13 005/110] nvme-pci: use appropriate initial chunk size for HMB allocation

[Greg Kroah-Hartman]

4.13-stable review patch.  If anyone has any objections, please let me know.

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

From: Akinobu Mita <akinobu.mita@xxxxxxxxx>

commit 30f92d62e5b41a94de2d0bbd677a6ea2fcfed74f upstream.

The initial chunk size for host memory buffer allocation is currently
PAGE_SIZE << MAX_ORDER.  MAX_ORDER order allocation is usually failed
without CONFIG_DMA_CMA.  So the HMB allocation is retried with chunk size
PAGE_SIZE << (MAX_ORDER - 1) in general, but there is no problem if the
retry allocation works correctly.

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
[hch: rebased]
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/nvme/host/pci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1677,7 +1677,7 @@ static int nvme_alloc_host_mem(struct nv
 	u32 chunk_size;
 
 	/* start big and work our way down */
-	for (chunk_size = min_t(u64, preferred, PAGE_SIZE << MAX_ORDER);
+	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);
 	     chunk_size >= PAGE_SIZE * 2;
 	     chunk_size /= 2) {
 		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {