kernel_optimize_test/arch/mips/include/asm/device.h
Paul Burton 20d330645c MIPS: Support per-device DMA coherence
On some MIPS systems, a subset of devices may have DMA coherent with CPU
caches. For example in systems including a MIPS I/O Coherence Unit
(IOCU), some devices may be connected to that IOCU whilst others are
not.

Prior to this patch, we have a plat_device_is_coherent() function but no
implementation which does anything besides return a global true or
false, optionally chosen at runtime. For devices such as those described
above this is insufficient.

Fix this by tracking DMA coherence on a per-device basis with a
dma_coherent field in struct dev_archdata. Setting this from
arch_setup_dma_ops() takes care of devices which set the dma-coherent
property via device tree, and any PCI devices beneath a bridge described
in DT, automatically.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14349/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06 18:02:01 +02:00

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C

/*
* Arch specific extensions to struct device
*
* This file is released under the GPLv2
*/
#ifndef _ASM_MIPS_DEVICE_H
#define _ASM_MIPS_DEVICE_H
struct dma_map_ops;
struct dev_archdata {
/* DMA operations on that device */
struct dma_map_ops *dma_ops;
#ifdef CONFIG_DMA_PERDEV_COHERENT
/* Non-zero if DMA is coherent with CPU caches */
bool dma_coherent;
#endif
};
struct pdev_archdata {
};
#endif /* _ASM_MIPS_DEVICE_H*/