From 3417f33e762bf7d4277031a655e3ad07e73ce0be Mon Sep 17 00:00:00 2001 From: George Sapountzis Date: Tue, 24 Oct 2006 12:03:04 -0700 Subject: drm: add flag for mapping PCI DMA buffers read-only. Add DRM_PCI_BUFFER_RO flag for mapping PCI DMA buffer read-only. An additional flag is needed, since PCI DMA buffers do not have an associated map. Signed-off-by: Dave Airlie --- drivers/char/drm/drm_vm.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/char/drm/drm_vm.c') diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c index b40ae438f531..74686e9a2d34 100644 --- a/drivers/char/drm/drm_vm.c +++ b/drivers/char/drm/drm_vm.c @@ -473,6 +473,22 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) } unlock_kernel(); + if (!capable(CAP_SYS_ADMIN) && + (dma->flags & _DRM_DMA_USE_PCI_RO)) { + vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); +#if defined(__i386__) || defined(__x86_64__) + pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; +#else + /* Ye gads this is ugly. With more thought + we could move this up higher and use + `protection_map' instead. */ + vma->vm_page_prot = + __pgprot(pte_val + (pte_wrprotect + (__pte(pgprot_val(vma->vm_page_prot))))); +#endif + } + vma->vm_ops = &drm_vm_dma_ops; vma->vm_flags |= VM_RESERVED; /* Don't swap */ -- cgit v1.2.3