Hi Dominic, Thanks a lot for this patch. Please see my comments inline. On Wed, Mar 04, 2020 at 01:14:06AM -0500, Dominic Chen wrote: > Allow debug access to memory-mapped regions using e.g. gdb. Do you mind improving the title to something like "fpga: dfl: afu: ...." > > Signed-off-by: Dominic Chen <d.c.ddcc@xxxxxxxxx> > --- > drivers/fpga/dfl-afu-main.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c > index 02baa6a227c0..38983f9dde98 100644 > --- a/drivers/fpga/dfl-afu-main.c > +++ b/drivers/fpga/dfl-afu-main.c > @@ -459,6 +459,12 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return -EINVAL; > } > > +#ifdef CONFIG_HAVE_IOREMAP_PROT > +const struct vm_operations_struct afu_vma_ops = { let's add "static" for afu_vma_ops here. > + .access = generic_access_phys, > +}; > +#endif /* CONFIG_HAVE_IOREMAP_PROT */ > + What about static const struct vm_operations_struct afu_vma_ops = { #ifdef CONFIG_HAVE_IOREMAP_PROT .access = generic_access_phys, #endif }; Then we just need one line below. vma->vm_ops = &afu_vma_ops; Thanks Hao > static int afu_mmap(struct file *filp, struct vm_area_struct *vma) > { > struct platform_device *pdev = filp->private_data; > @@ -488,6 +494,11 @@ static int afu_mmap(struct file *filp, struct vm_area_struct *vma) > !(region.flags & DFL_PORT_REGION_WRITE)) > return -EPERM; > > + // Support debug access to the mapping > +#ifdef CONFIG_HAVE_IOREMAP_PROT > + vma->vm_ops = &afu_vma_ops; > +#endif /* CONFIG_HAVE_IOREMAP_PROT */ > + > vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > > return remap_pfn_range(vma, vma->vm_start, > -- > 2.17.1