[PATCH v8 07/24] dma-mapping: Implement link/unlink ranges API

[ALOK TIWARI]

Since we're touching this code, it might be a good opportunity to fix 
the old typo

> + * dma_iova_link - Link a range of IOVA space
> + * @dev: DMA device
> + * @state: IOVA state
> + * @phys: physical address to link
> + * @offset: offset into the IOVA state to map into
> + * @size: size of the buffer
> + * @dir: DMA direction
> + * @attrs: attributes of mapping properties
> + *
> + * Link a range of IOVA space for the given IOVA state without IOTLB sync.
> + * This function is used to link multiple physical addresses in contigueous

old typo contigueous -> contiguous

> + * IOVA space without performing costly IOTLB sync.
> + *
> + * The caller is responsible to call to dma_iova_sync() to sync IOTLB at
> + * the end of linkage.
> + */
> +int dma_iova_link(struct device *dev, struct dma_iova_state *state,
> +		phys_addr_t phys, size_t offset, size_t size,
> +		enum dma_data_direction dir, unsigned long attrs)
> +{
> +	struct iommu_domain *domain = iommu_get_dma_domain(dev);
> +	struct iommu_dma_cookie *cookie = domain->iova_cookie;
> +	struct iova_domain *iovad = &cookie->iovad;
> +	size_t iova_start_pad = iova_offset(iovad, phys);
> +
> +	if (WARN_ON_ONCE(iova_start_pad && offset > 0))
> +		return -EIO;
> +
> +	if (dev_use_swiotlb(dev, size, dir) && iova_offset(iovad, phys | size))
> +		return iommu_dma_iova_link_swiotlb(dev, state, phys, offset,
> +				size, dir, attrs);
> +
> +	return __dma_iova_link(dev, state->addr + offset - iova_start_pad,
> +			phys - iova_start_pad,
> +			iova_align(iovad, size + iova_start_pad), dir, attrs);
> +}
> +EXPORT_SYMBOL_GPL(dma_iova_link);
> +
> +/**
> + * dma_iova_sync - Sync IOTLB
> + * @dev: DMA device
> + * @state: IOVA state
> + * @offset: offset into the IOVA state to sync
> + * @size: size of the buffer
> + *
> + * Sync IOTLB for the given IOVA state. This function should be called on
> + * the IOVA-contigous range created by one ore more dma_iova_link() calls

old typo IOVA-contigous -> IOVA-contiguous

> + * to sync the IOTLB.
> + */
> +int dma_iova_sync(struct device *dev, struct dma_iova_state *state,
> +		size_t offset, size_t size)
> +{
> +	struct iommu_domain *domain = iommu_get_dma_domain(dev);
> +	struct iommu_dma_cookie *cookie = domain->iova_cookie;
> +	struct iova_domain *iovad = &cookie->iovad;
> +	dma_addr_t addr = state->addr + offset;
> +	size_t iova_start_pad = iova_offset(iovad, addr);
> +
> +	return iommu_sync_map(domain, addr - iova_start_pad,
> +		      iova_align(iovad, size + iova_start_pad));
> +}


Thanks,
Alok