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unicore32: make dma_cache_sync a no-op

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unicore32 does not implement DMA_ATTR_NON_CONSISTENT allocations, so it
doesn't make any sense to do any work in dma_cache_sync given that it
must be a no-op when dma_alloc_attrs returns coherent memory.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
This commit is contained in:
Christoph Hellwig 2017-08-27 10:22:48 +02:00
parent 87f626348a
commit a535bb8010
3 changed files with 0 additions and 29 deletions
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9
arch/unicore32/include/asm/cacheflush.h
View file

@ -101,15 +101,6 @@ extern void __cpuc_coherent_user_range(unsigned long, unsigned long);
extern void __cpuc_flush_dcache_area(void *, size_t);
extern void __cpuc_flush_kern_dcache_area(void *addr, size_t size);
/*
* These are private to the dma-mapping API. Do not use directly.
* Their sole purpose is to ensure that data held in the cache
* is visible to DMA, or data written by DMA to system memory is
* visible to the CPU.
*/
extern void __cpuc_dma_clean_range(unsigned long, unsigned long);
extern void __cpuc_dma_flush_range(unsigned long, unsigned long);
/*
* Copy user data from/to a page which is mapped into a different
* processes address space. Really, we want to allow our "user

17
arch/unicore32/include/asm/dma-mapping.h
View file

@ -18,9 +18,6 @@
#include <linux/scatterlist.h>
#include <linux/swiotlb.h>
#include <asm/memory.h>
#include <asm/cacheflush.h>
extern const struct dma_map_ops swiotlb_dma_map_ops;
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
@ -51,20 +48,6 @@ static inline void dma_mark_clean(void *addr, size_t size) {}
static inline void dma_cache_sync(struct device *dev, void *vaddr,
size_t size, enum dma_data_direction direction)
{
unsigned long start = (unsigned long)vaddr;
unsigned long end = start + size;
switch (direction) {
case DMA_NONE:
BUG();
case DMA_FROM_DEVICE:
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
__cpuc_dma_flush_range(start, end);
break;
case DMA_TO_DEVICE: /* writeback only */
__cpuc_dma_clean_range(start, end);
break;
}
}
#endif /* __KERNEL__ */

3
arch/unicore32/mm/proc-syms.c
View file

@ -20,6 +20,3 @@ EXPORT_SYMBOL(cpu_dcache_clean_area);
EXPORT_SYMBOL(cpu_set_pte);
EXPORT_SYMBOL(__cpuc_coherent_kern_range);
EXPORT_SYMBOL(__cpuc_dma_flush_range);
EXPORT_SYMBOL(__cpuc_dma_clean_range);