On 6/2/2021 5:39 PM, Keith Busch wrote:

On Wed, Jun 02, 2021 at 02:10:55PM +0300, Max Gurtovoy wrote:

quoted

P2PMEM is using mhp framework to connect to the memory subsystem. In
case the CMB size is not compatible to mhp alignment, the CMB mapping
will fail. Use pci_p2pdma_align_size to align CMB size in order to
successfully map non-aligned original CMB.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
---
  drivers/nvme/host/pci.c | 7 +++++++
  1 file changed, 7 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index a29b170701fc..1197263b4cd0 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c

@@ -1817,6 +1817,7 @@ static void nvme_map_cmb(struct nvme_dev *dev)
  	u64 size, offset;
  	resource_size_t bar_size;
  	struct pci_dev *pdev = to_pci_dev(dev->dev);
+	unsigned long nr_pages, min_align;

These new variables don't appear to be used anywhere.

oh, I have some leftovers..

Sorry.

quoted

  	int bar;
  
  	if (dev->cmb_size)

@@ -1856,6 +1857,12 @@ static void nvme_map_cmb(struct nvme_dev *dev)
  	if (size > bar_size - offset)
  		size = bar_size - offset;
  
+	size = pci_p2pdma_align_size(size);
+	if (!size) {
+		dev_warn(dev->ctrl.device, "CMB size is 0 after alignment\n");
+		return;
+	}
+
  	if (pci_p2pdma_add_resource(pdev, bar, size, offset)) {
  		dev_warn(dev->ctrl.device,
  			 "failed to register the CMB\n");

--