From bd65c1c8966a6b0cda102ff660579926ac893ab7 Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Sun, 15 Oct 2023 17:41:32 +0200 Subject: [PATCH] drm/simpledrm: Set DMA and coherency mask Simpledrm is "DMA" access is not limited. All CPU addressible memory can be used via direct DMA mappings. Fixes following warning on Apple silicon systems. Physical memory on those systems starts at (1 << 35) or (1 << 40) so 32-bit direct DMA mappings are not possible. ------------[ cut here ]------------ simple-framebuffer 9e5064000.framebuffer: swiotlb addr 0x00000009de654000+16384 overflow (mask ffffffff, bus limit 0). WARNING: CPU: 3 PID: 961 at kernel/dma/swiotlb.c:928 swiotlb_map+0x1f4/0x2a0 Modules linked in: ... CPU: 3 PID: 961 Comm: kwin_wayland Not tainted 6.5.0-asahi+ #1 Hardware name: Apple Mac mini (M2, 2023) (DT) ... Call trace: swiotlb_map+0x1f4/0x2a0 dma_direct_map_sg+0x8c/0x2a8 dma_map_sgtable+0x5c/0xd0 drm_gem_map_dma_buf+0x64/0xb8 dma_buf_map_attachment+0xac/0x158 dma_buf_map_attachment_unlocked+0x48/0x80 drm_gem_prime_import_dev+0xa0/0x1a0 drm_gem_prime_fd_to_handle+0xc8/0x218 drm_prime_fd_to_handle_ioctl+0x34/0x50 drm_ioctl_kernel+0xe4/0x160 drm_ioctl+0x23c/0x3e0 ... ---[ end trace 0000000000000000 ]--- Avoids using swiotbl bounce buffers on other platforms when the mapped memory is above 4GB. Fixes: 11e8f5fd223b ("drm: Add simpledrm driver") Signed-off-by: Janne Grunau --- drivers/gpu/drm/tiny/simpledrm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c index d19e102894282f..fad21ec6071f03 100644 --- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -1029,6 +1029,12 @@ static int simpledrm_probe(struct platform_device *pdev) unsigned int color_mode; int ret; + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + if (ret) + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + if (ret) + return dev_err_probe(&pdev->dev, ret, "Failed to set dma mask\n"); + sdev = simpledrm_device_create(&simpledrm_driver, pdev); if (IS_ERR(sdev)) return PTR_ERR(sdev);