unsigned int is_g33 : 1;
        unsigned int is_pineview : 1;
        unsigned int is_ironlake : 1;
+       unsigned int dma_mask_size : 8;
        /* Chipset specific GTT setup */
        int (*setup)(void);
        void (*write_entry)(dma_addr_t addr, unsigned int entry, unsigned int flags);
 
 static const struct intel_gtt_driver i81x_gtt_driver = {
        .gen = 1,
+       .dma_mask_size = 32,
 };
 static const struct intel_gtt_driver i8xx_gtt_driver = {
        .gen = 2,
        .setup = i830_setup,
        .write_entry = i830_write_entry,
+       .dma_mask_size = 32,
        .check_flags = i830_check_flags,
        .chipset_flush = i830_chipset_flush,
 };
        .setup = i9xx_setup,
        /* i945 is the last gpu to need phys mem (for overlay and cursors). */
        .write_entry = i830_write_entry, 
+       .dma_mask_size = 32,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .is_g33 = 1,
        .setup = i9xx_setup,
        .write_entry = i965_write_entry,
+       .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .is_pineview = 1, .is_g33 = 1,
        .setup = i9xx_setup,
        .write_entry = i965_write_entry,
+       .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .gen = 4,
        .setup = i9xx_setup,
        .write_entry = i965_write_entry,
+       .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .gen = 5,
        .setup = i9xx_setup,
        .write_entry = i965_write_entry,
+       .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .is_ironlake = 1,
        .setup = i9xx_setup,
        .write_entry = i965_write_entry,
+       .dma_mask_size = 36,
        .check_flags = i830_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
        .gen = 6,
        .setup = i9xx_setup,
        .write_entry = gen6_write_entry,
+       .dma_mask_size = 40,
        .check_flags = gen6_check_flags,
        .chipset_flush = i9xx_chipset_flush,
 };
 
        dev_info(&pdev->dev, "Intel %s Chipset\n", intel_gtt_chipsets[i].name);
 
-       if (intel_private.driver->write_entry == gen6_write_entry)
-               mask = 40;
-       else if (intel_private.driver->write_entry == i965_write_entry)
-               mask = 36;
-       else
-               mask = 32;
-
+       mask = intel_private.driver->dma_mask_size;
        if (pci_set_dma_mask(intel_private.pcidev, DMA_BIT_MASK(mask)))
                dev_err(&intel_private.pcidev->dev,
                        "set gfx device dma mask %d-bit failed!\n", mask);