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Merge branch 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

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Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "Two tiny implementations of the DMA API for callback in ARM (for Xen)"

* 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb-xen: implement xen_swiotlb_get_sgtable callback
  swiotlb-xen: implement xen_swiotlb_dma_mmap callback
This commit is contained in:
Linus Torvalds
2017-03-07 10:23:17 -08:00
parent 304362a8bc 69369f52d2
commit 8c2c8ed8b8
3 changed files with 60 additions and 0 deletions
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47
drivers/xen/swiotlb-xen.c
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@@ -681,3 +681,50 @@ xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask)
return 0;
}
EXPORT_SYMBOL_GPL(xen_swiotlb_set_dma_mask);
/*
* Create userspace mapping for the DMA-coherent memory.
* This function should be called with the pages from the current domain only,
* passing pages mapped from other domains would lead to memory corruption.
*/
int
xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
if (__generic_dma_ops(dev)->mmap)
return __generic_dma_ops(dev)->mmap(dev, vma, cpu_addr,
dma_addr, size, attrs);
#endif
return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mmap);
/*
* This function should be called with the pages from the current domain only,
* passing pages mapped from other domains would lead to memory corruption.
*/
int
xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
{
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
if (__generic_dma_ops(dev)->get_sgtable) {
#if 0
/*
* This check verifies that the page belongs to the current domain and
* is not one mapped from another domain.
* This check is for debug only, and should not go to production build
*/
unsigned long bfn = PHYS_PFN(dma_to_phys(dev, handle));
BUG_ON (!page_is_ram(bfn));
#endif
return __generic_dma_ops(dev)->get_sgtable(dev, sgt, cpu_addr,
handle, size, attrs);
}
#endif
return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
}
EXPORT_SYMBOL_GPL(xen_swiotlb_get_sgtable);