From 2820a708d5a321342bef34e459fdc8679c30e20f Mon Sep 17 00:00:00 2001 From: Eugeniy Paltsev Date: Mon, 30 Jul 2018 19:26:34 +0300 Subject: ARC: dma [IOC] Enable per device io coherency So far the IOC treatment was global on ARC, being turned on (or off) for all devices in the system. With this patch, this can now be done per device using the "dma-coherent" DT property; IOW with this patch we can use both HW-coherent and regular DMA peripherals simultaneously. The changes involved are too many so enlisting the summary below: 1. common code calls ARC arch_setup_dma_ops() per device. 2. For coherent dma (IOC) it plugs in generic @dma_direct_ops which doesn't need any arch specific backend: No need for any explicit cache flushes or MMU mappings to provide for uncached access - dma_(map|sync)_single* return early as corresponding dma ops callbacks are NULL in generic code. So arch_sync_dma_*() -> dma_cache_*() need not handle the coherent dma case, hence drop ARC __dma_cache_*_ioc() which were no-op anyways 3. For noncoherent dma (non IOC) generic @dma_noncoherent_ops is used which in turns calls ARC specific routines - arch_dma_alloc() no longer checks for @ioc_enable since this is called only for !IOC case. Reviewed-by: Christoph Hellwig Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta [vgupta: rewrote changelog] --- arch/arc/include/asm/dma-mapping.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 arch/arc/include/asm/dma-mapping.h (limited to 'arch/arc/include') diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h new file mode 100644 index 000000000000..c946c0a83e76 --- /dev/null +++ b/arch/arc/include/asm/dma-mapping.h @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +// (C) 2018 Synopsys, Inc. (www.synopsys.com) + +#ifndef ASM_ARC_DMA_MAPPING_H +#define ASM_ARC_DMA_MAPPING_H + +#include + +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent); +#define arch_setup_dma_ops arch_setup_dma_ops + +#endif -- cgit v1.2.3