Default IO_TLB_SEGSIZE (128) slabs may be not enough for some use cases. This series adds support to customize io_tlb_segsize for each restricted-dma-pool. Example use case: mtk-isp drivers[1] are controlled by mtk-scp[2] and allocate memory through mtk-scp. In order to use the noncontiguous DMA API[3], we need to use the swiotlb pool. mtk-scp needs to allocate memory with 2560 slabs. mtk-isp drivers also needs to allocate memory with 200+ slabs. Both are larger than the default IO_TLB_SEGSIZE (128) slabs. [1] (not in upstream) https://patchwork.kernel.org/project/linux-media/cover/20190611035344.29814-1-jungo.lin@xxxxxxxxxxxx/ [2] https://elixir.bootlin.com/linux/latest/source/drivers/remoteproc/mtk_scp.c [3] https://patchwork.kernel.org/project/linux-media/cover/20210909112430.61243-1-senozhatsky@xxxxxxxxxxxx/ Hsin-Yi Wang (3): dma: swiotlb: Allow restricted-dma-pool to customize IO_TLB_SEGSIZE dt-bindings: Add io-tlb-segsize property for restricted-dma-pool arm64: dts: mt8183: use restricted swiotlb for scp mem .../reserved-memory/shared-dma-pool.yaml | 8 +++++ .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 4 +-- include/linux/swiotlb.h | 1 + kernel/dma/swiotlb.c | 34 ++++++++++++++----- 4 files changed, 37 insertions(+), 10 deletions(-) -- 2.34.0.rc2.393.gf8c9666880-goog
