Messages in this thread | | | Date | Thu, 11 Mar 2021 12:32:27 +0000 | From | Paul Cercueil <> | Subject | Re: [PATCH v2 3/5] drm: Add and export function drm_gem_cma_mmap_noncoherent |
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Hi Christoph,
Le jeu. 11 mars 2021 à 12:26, Christoph Hellwig <hch@infradead.org> a écrit : >> +int drm_gem_cma_mmap_noncoherent(struct drm_gem_object *obj, >> + struct vm_area_struct *vma) >> +{ >> + struct drm_gem_cma_object *cma_obj; >> + unsigned long pfn; >> + int ret; >> + >> + /* >> + * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and >> set the >> + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want >> to map >> + * the whole buffer. >> + */ >> + vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node); >> + vma->vm_flags &= ~VM_PFNMAP; >> + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); >> + >> + cma_obj = to_drm_gem_cma_obj(obj); >> + >> + pfn = PHYS_PFN(dma_to_phys(cma_obj->base.dev->dev, >> cma_obj->paddr)); >> + >> + ret = remap_pfn_range(vma, vma->vm_start, pfn, >> + vma->vm_end - vma->vm_start, >> + vma->vm_page_prot); > > dma_to_phys must not be used by drivers. > > I have a proper helper for this waiting for users: > > http://git.infradead.org/users/hch/misc.git/commitdiff/96a546e7229ec53aadbdb7936d1e5e6cb5958952 > > If you can confirm the helpers works for you I can try to still sneak > it to Linus for 5.12 to ease the merge pain.
I can try. How do I get a page pointer from a dma_addr_t?
-Paul
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