linux_dsm_epyc7002/arch/mips/include/asm/mach-generic/dma-coherence.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

86 lines
1.8 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2006 Ralf Baechle <ralf@linux-mips.org>
*
*/
#ifndef __ASM_MACH_GENERIC_DMA_COHERENCE_H
#define __ASM_MACH_GENERIC_DMA_COHERENCE_H
struct device;
static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
size_t size)
{
return virt_to_phys(addr);
}
static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
struct page *page)
{
return page_to_phys(page);
}
static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
dma_addr_t dma_addr)
{
return dma_addr;
}
static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction)
{
}
static inline int plat_dma_supported(struct device *dev, u64 mask)
{
/*
* we fall back to GFP_DMA when the mask isn't all 1s,
* so we can't guarantee allocations that must be
* within a tighter range than GFP_DMA..
*/
if (mask < DMA_BIT_MASK(24))
return 0;
return 1;
}
static inline int plat_device_is_coherent(struct device *dev)
{
#ifdef CONFIG_DMA_PERDEV_COHERENT
return dev->archdata.dma_coherent;
#else
switch (coherentio) {
default:
case IO_COHERENCE_DEFAULT:
return hw_coherentio;
case IO_COHERENCE_ENABLED:
return 1;
case IO_COHERENCE_DISABLED:
return 0;
}
#endif
}
#ifndef plat_post_dma_flush
static inline void plat_post_dma_flush(struct device *dev)
{
}
#endif
#ifdef CONFIG_SWIOTLB
static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
return paddr;
}
static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
{
return daddr;
}
#endif
#endif /* __ASM_MACH_GENERIC_DMA_COHERENCE_H */