It turns out that if you want to mmap GEM buffers fully cached, then they should be allocated as such as well. Who would have known?

Introduce a custom .dumb_create callback, that will behave just like drm_gem_cma_dumb_create(), except that it will allocate the GEM buffer using dma_alloc_noncoherent() if non-coherent memory is what we want.

Signed-off-by: Paul Cercueil paul@crapouillou.net --- drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 48 ++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index 07a1da7266e4..8ece269c040f 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -794,6 +794,52 @@ static int ingenic_drm_gem_cma_mmap(struct file *filp, return ingenic_drm_gem_mmap(vma->vm_private_data, vma); }

+static int ingenic_drm_gem_cma_dumb_create(struct drm_file *file_priv, + struct drm_device *drm, + struct drm_mode_create_dumb *args) +{ + /* + * This is basically a copy of drm_gem_cma_dumb_create, which supports + * creating fully cached GEM buffers. + */ + struct drm_gem_cma_object *cma_obj; + struct drm_gem_object *gem_obj; + size_t size; + int ret; + + args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); + args->size = args->pitch * args->height; + + size = PAGE_ALIGN(args->size); + + cma_obj = drm_gem_cma_create_noalloc(drm, size); + if (IS_ERR(cma_obj)) + return PTR_ERR(cma_obj); + + if (ingenic_drm_cached_gem_buf) { + cma_obj->vaddr = dma_alloc_noncoherent(drm->dev, size, + &cma_obj->paddr, + DMA_TO_DEVICE, + GFP_KERNEL | __GFP_NOWARN); + } else { + cma_obj->vaddr = dma_alloc_wc(drm->dev, size, &cma_obj->paddr, + GFP_KERNEL | __GFP_NOWARN); + } + if (!cma_obj->vaddr) { + dev_err(drm->dev, "Failed to allocate buffer with size %zu\n", size); + ret = -ENOMEM; + goto out_gem_object_put; + } + + gem_obj = &cma_obj->base; + + ret = drm_gem_handle_create(file_priv, gem_obj, &args->handle); + +out_gem_object_put: + drm_gem_object_put(gem_obj); + return ret; +} + static const struct file_operations ingenic_drm_fops = { .owner = THIS_MODULE, .open = drm_open, @@ -816,7 +862,7 @@ static struct drm_driver ingenic_drm_driver_data = { .patchlevel = 0,

.fops = &ingenic_drm_fops, - DRM_GEM_CMA_DRIVER_OPS, + DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE(ingenic_drm_gem_cma_dumb_create),

.irq_handler = ingenic_drm_irq_handler, };