Re: [PATCH 3/3] nvme-pci: align CMB size according to P2PMEM alignment

[Max Gurtovoy]

On 6/2/2021 5:39 PM, Keith Busch wrote:
> On Wed, Jun 02, 2021 at 02:10:55PM +0300, Max Gurtovoy wrote:
> > 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@xxxxxxxxxx>
> > ---
> >   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.


> >   	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");
> > --