On Thu, Oct 22, 2020 at 01:06:38PM +0800, Sherry Sun wrote: > Mapping kernel space memory to user space as noncached, since user space > need check the updates of avail_idx and device page flags timely. > > Signed-off-by: Joakim Zhang <[email protected]> > Signed-off-by: Sherry Sun <[email protected]> > --- > drivers/misc/mic/vop/vop_vringh.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/misc/mic/vop/vop_vringh.c > b/drivers/misc/mic/vop/vop_vringh.c > index b5612183dcb8..b75c2b713a3b 100644 > --- a/drivers/misc/mic/vop/vop_vringh.c > +++ b/drivers/misc/mic/vop/vop_vringh.c > @@ -1058,7 +1058,7 @@ static int vop_mmap(struct file *f, struct > vm_area_struct *vma) > } > err = remap_pfn_range(vma, vma->vm_start + offset, > pa >> PAGE_SHIFT, size, > - vma->vm_page_prot); > + pgprot_noncached(vma->vm_page_prot));
Again, memory allocated using dma_alloc_coherent can only be mapped using dma_mmap_coherent, which will use the right attributes for the mapping, which often are cached.
