The current mmap page-fault handler requires some changes before it can track folio access.
Call to folio_test_pmd_mappable() into the mmap page-fault handler before calling drm_gem_shmem_try_map_pmd(). The folio will become useful for tracking the access status. Also rename drm_gem_shmem_try_map_pmd() to _try_insert_pfn_pmd() and only pass the page fault and page-frame number. The new name and parameters make it similar to vmf_insert_pfn_pmd(). No functional changes. If PMD mapping fails or is not supported, insert a regular PFN as before. Signed-off-by: Thomas Zimmermann <[email protected]> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index ab8e331005f9..c3a054899ba3 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -550,17 +550,14 @@ int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, } EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); -static vm_fault_t drm_gem_shmem_try_map_pmd(struct vm_fault *vmf, unsigned long addr, - struct page *page) +static vm_fault_t drm_gem_shmem_try_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn) { #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP - unsigned long pfn = page_to_pfn(page); unsigned long paddr = pfn << PAGE_SHIFT; - bool aligned = (addr & ~PMD_MASK) == (paddr & ~PMD_MASK); + bool aligned = (vmf->address & ~PMD_MASK) == (paddr & ~PMD_MASK); - if (aligned && - pmd_none(*vmf->pmd) && - folio_test_pmd_mappable(page_folio(page))) { + if (aligned && pmd_none(*vmf->pmd)) { + /* Read-only mapping; split upon write fault */ pfn &= PMD_MASK >> PAGE_SHIFT; return vmf_insert_pfn_pmd(vmf, pfn, false); } @@ -580,6 +577,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) struct page **pages = shmem->pages; pgoff_t page_offset = vmf->pgoff - vma->vm_pgoff; /* page offset within VMA */ struct page *page; + struct folio *folio; unsigned long pfn; dma_resv_lock(obj->resv, NULL); @@ -591,15 +589,16 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) page = pages[page_offset]; if (drm_WARN_ON_ONCE(dev, !page)) goto out; - - ret = drm_gem_shmem_try_map_pmd(vmf, vmf->address, page); - if (ret == VM_FAULT_NOPAGE) - goto out; + folio = page_folio(page); pfn = page_to_pfn(page); - ret = vmf_insert_pfn(vma, vmf->address, pfn); - out: + if (folio_test_pmd_mappable(folio)) + ret = drm_gem_shmem_try_insert_pfn_pmd(vmf, pfn); + if (ret != VM_FAULT_NOPAGE) + ret = vmf_insert_pfn(vma, vmf->address, pfn); + +out: dma_resv_unlock(obj->resv); return ret; -- 2.52.0
