Messages in this thread | | | Date | Tue, 29 Sep 2020 11:28:33 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH V2 4/4] misc: vop: mapping kernel memory to user space as noncached |
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On Tue, Sep 29, 2020 at 04:44:25PM +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 <qiangqing.zhang@nxp.com> > Signed-off-by: Sherry Sun <sherry.sun@nxp.com> > --- > 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 4d5feb39aeb7..6e193bd64ef1 100644 > --- a/drivers/misc/mic/vop/vop_vringh.c > +++ b/drivers/misc/mic/vop/vop_vringh.c > @@ -1057,7 +1057,7 @@ 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));
You can't call remap_pfn_range on memory returned from dma_alloc_coherent (which btw is not marked uncached on many platforms).
You need to use the dma_mmap_coherent helper instead. And this also needs to go into the first patch.
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