On Fri, Nov 06, 2020 at 10:00:35AM -0700, Logan Gunthorpe wrote: > Introduce pci_mmap_p2pmem() which is a helper to allocate and mmap > a hunk of p2pmem into userspace. > > Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > drivers/pci/p2pdma.c | 104 +++++++++++++++++++++++++++++++++++++ > include/linux/pci-p2pdma.h | 6 +++ > 2 files changed, 110 insertions(+) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index 9961e779f430..8eab53ac59ae 100644 > +++ b/drivers/pci/p2pdma.c > @@ -16,6 +16,7 @@ > #include <linux/genalloc.h> > #include <linux/memremap.h> > #include <linux/percpu-refcount.h> > +#include <linux/pfn_t.h> > #include <linux/random.h> > #include <linux/seq_buf.h> > #include <linux/xarray.h> > @@ -1055,3 +1056,106 @@ ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, > return sprintf(page, "%s\n", pci_name(p2p_dev)); > } > EXPORT_SYMBOL_GPL(pci_p2pdma_enable_show); > + > +struct pci_p2pdma_map { > + struct kref ref; > + struct pci_dev *pdev; > + void *kaddr; > + size_t len; > +}; Why have this at all? Nothing uses it and no vm_operations ops are implemented? This is very inflexable, it would be better if this is designed like io_remap_pfn where it just preps and fills the VMA, doesn't take ownership of the entire VMA Jason