linux/arch/mips/include/asm/dma-mapping.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

46 lines
1.1 KiB
C

#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
#include <linux/scatterlist.h>
#include <asm/dma-coherence.h>
#include <asm/cache.h>
#ifndef CONFIG_SGI_IP27 /* Kludge to fix 2.6.39 build for IP27 */
#include <dma-coherence.h>
#endif
extern struct dma_map_ops *mips_dma_map_ops;
static inline struct dma_map_ops *get_dma_ops(struct device *dev)
{
if (dev && dev->archdata.dma_ops)
return dev->archdata.dma_ops;
else
return mips_dma_map_ops;
}
static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
if (!dev->dma_mask)
return false;
return addr + size <= *dev->dma_mask;
}
static inline void dma_mark_clean(void *addr, size_t size) {}
extern void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction);
#define arch_setup_dma_ops arch_setup_dma_ops
static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
u64 size, const struct iommu_ops *iommu,
bool coherent)
{
#ifdef CONFIG_DMA_PERDEV_COHERENT
dev->archdata.dma_coherent = coherent;
#endif
}
#endif /* _ASM_DMA_MAPPING_H */