linux-stable/include/linux/dma-direct.h
Robin Murphy b34087157d dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB
With the overflow buffer removed, we no longer have a unique address
which is guaranteed not to be a valid DMA target to use as an error
token. The DIRECT_MAPPING_ERROR value of 0 tries to at least represent
an unlikely DMA target, but unfortunately there are already SWIOTLB
users with DMA-able memory at physical address 0 which now gets falsely
treated as a mapping failure and leads to all manner of misbehaviour.

The best we can do to mitigate that is flip DIRECT_MAPPING_ERROR to the
other commonly-used error value of all-bits-set, since the last single
byte of memory is by far the least-likely-valid DMA target.

Fixes: dff8d6c1ed ("swiotlb: remove the overflow buffer")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-11-21 18:47:52 +01:00

77 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DMA_DIRECT_H
#define _LINUX_DMA_DIRECT_H 1
#include <linux/dma-mapping.h>
#include <linux/mem_encrypt.h>
#define DIRECT_MAPPING_ERROR (~(dma_addr_t)0)
#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
#include <asm/dma-direct.h>
#else
static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
dma_addr_t dev_addr = (dma_addr_t)paddr;
return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
}
static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
{
phys_addr_t paddr = (phys_addr_t)dev_addr;
return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
}
static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
if (!dev->dma_mask)
return false;
return addr + size - 1 <=
min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
}
#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
/*
* If memory encryption is supported, phys_to_dma will set the memory encryption
* bit in the DMA address, and dma_to_phys will clear it. The raw __phys_to_dma
* and __dma_to_phys versions should only be used on non-encrypted memory for
* special occasions like DMA coherent buffers.
*/
static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
return __sme_set(__phys_to_dma(dev, paddr));
}
static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
{
return __sme_clr(__dma_to_phys(dev, daddr));
}
#ifdef CONFIG_ARCH_HAS_DMA_MARK_CLEAN
void dma_mark_clean(void *addr, size_t size);
#else
static inline void dma_mark_clean(void *addr, size_t size)
{
}
#endif /* CONFIG_ARCH_HAS_DMA_MARK_CLEAN */
u64 dma_direct_get_required_mask(struct device *dev);
void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs);
void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs);
void *dma_direct_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs);
void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs);
dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs);
int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
enum dma_data_direction dir, unsigned long attrs);
int dma_direct_supported(struct device *dev, u64 mask);
int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr);
#endif /* _LINUX_DMA_DIRECT_H */