NVReadVgaGr
gr4 = NVReadVgaGr(dev, 0, NV_VIO_GX_READ_MAP_INDEX);
gr5 = NVReadVgaGr(dev, 0, NV_VIO_GX_MODE_INDEX);
gr6 = NVReadVgaGr(dev, 0, NV_VIO_GX_MISC_INDEX);
regp->Graphics[i] = NVReadVgaGr(dev, head, i);
uint8_t NVReadVgaGr(struct drm_device *, int head, uint8_t index);