Index: sys/external/bsd/drm2/dist/drm/radeon/radeon_bios.c
===================================================================
RCS file: /cvsroot/src/sys/external/bsd/drm2/dist/drm/radeon/radeon_bios.c,v
retrieving revision 1.3
diff -p -u -r1.3 radeon_bios.c
--- sys/external/bsd/drm2/dist/drm/radeon/radeon_bios.c	13 Jun 2015 18:18:18 -0000	1.3
+++ sys/external/bsd/drm2/dist/drm/radeon/radeon_bios.c	22 Jun 2015 21:45:34 -0000
@@ -116,6 +124,31 @@ static bool radeon_read_bios(struct rade
 		return false;
 	}
 
+#ifdef __NetBSD__
+	/*
+	 * Using kmemdup results in >4-byte memory access on 64-bit
+	 * systems, which yields bogus answers on some devices.  So we
+	 * use bus_space(9) to do guaranteed byte access with
+	 * bus_space_read_region_1 which seems to work better.
+	 */
+    {
+	const bus_space_tag_t bst = rdev->pdev->pd_rom_bst;
+	const bus_space_handle_t bsh = rdev->pdev->pd_rom_found_bsh;
+
+	if (size == 0 ||
+	    bus_space_read_1(bst, bsh, 0) != 0x55 ||
+	    bus_space_read_1(bst, bsh, 1) != 0xaa) {
+		pci_unmap_rom(rdev->pdev, bios);
+		return false;
+	}
+	rdev->bios = kmalloc(size, GFP_KERNEL);
+	if (rdev->bios == NULL) {
+		pci_unmap_rom(rdev->pdev, bios);
+		return false;
+	}
+	bus_space_read_region_1(bst, bsh, 0, rdev->bios, size);
+    }
+#else
 	if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
 		pci_unmap_rom(rdev->pdev, bios);
 		return false;
@@ -125,6 +158,7 @@ static bool radeon_read_bios(struct rade
 		pci_unmap_rom(rdev->pdev, bios);
 		return false;
 	}
+#endif
 	pci_unmap_rom(rdev->pdev, bios);
 	return true;
 }
Index: sys/external/bsd/drm2/include/linux/pci.h
===================================================================
RCS file: /cvsroot/src/sys/external/bsd/drm2/include/linux/pci.h,v
retrieving revision 1.17
diff -p -u -r1.17 pci.h
--- sys/external/bsd/drm2/include/linux/pci.h	6 Apr 2015 02:29:18 -0000	1.17
+++ sys/external/bsd/drm2/include/linux/pci.h	22 Jun 2015 21:45:34 -0000
@@ -126,6 +126,8 @@ struct pci_dev {
 	bus_space_tag_t		pd_rom_bst;
 	bus_space_handle_t	pd_rom_bsh;
 	bus_size_t		pd_rom_size;
+	bus_space_handle_t	pd_rom_found_bsh;
+	bus_space_handle_t	pd_rom_found_size;
 	void			*pd_rom_vaddr;
 	device_t		pd_dev;
 	struct drm_device	*pd_drm_dev; /* XXX Nouveau kludge!  */
@@ -504,8 +506,6 @@ pci_map_rom_md(struct pci_dev *pdev)
 static inline void __pci_rom_iomem *
 pci_map_rom(struct pci_dev *pdev, size_t *sizep)
 {
-	bus_space_handle_t bsh;
-	bus_size_t size;
 
 	KASSERT(!ISSET(pdev->pd_kludges, NBPCI_KLUDGE_MAP_ROM));
 
@@ -519,14 +519,16 @@ pci_map_rom(struct pci_dev *pdev, size_t
 
 	/* XXX This type is obviously wrong in general...  */
 	if (pci_find_rom(&pdev->pd_pa, pdev->pd_rom_bst, pdev->pd_rom_bsh,
-		pdev->pd_rom_size, PCI_ROM_CODE_TYPE_X86, &bsh, &size)) {
+		pdev->pd_rom_size, PCI_ROM_CODE_TYPE_X86,
+		&pdev->pd_rom_found_bsh, &pdev->pd_rom_found_size)) {
 		pci_unmap_rom(pdev, NULL);
 		return NULL;
 	}
 
-	KASSERT(size <= SIZE_T_MAX);
-	*sizep = size;
-	pdev->pd_rom_vaddr = bus_space_vaddr(pdev->pd_rom_bst, bsh);
+	KASSERT(pdev->pd_rom_found_size <= SIZE_T_MAX);
+	*sizep = pdev->pd_rom_found_size;
+	pdev->pd_rom_vaddr = bus_space_vaddr(pdev->pd_rom_bst,
+	    pdev->pd_rom_found_bsh);
 	return pdev->pd_rom_vaddr;
 }