Adding Robin for review.
On Thu, Aug 31, 2017 at 03:08:21PM -0700, Krishna Reddy wrote:
> Limit the IOVA allocated to dma-ranges specified for the device.
> This is necessary to ensure that IOVA allocated is addressable
> by device.
>
> Signed-off-by: Krishna Reddy <vdu...@nvidia.com>
> ---
> drivers/iommu/dma-iommu.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 9d1cebe7f6cb..e8a8320b571b 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -364,6 +364,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct
> iommu_domain *domain,
> struct iommu_dma_cookie *cookie = domain->iova_cookie;
> struct iova_domain *iovad = &cookie->iovad;
> unsigned long shift, iova_len, iova = 0;
> + dma_addr_t dma_end_addr;
>
> if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
> cookie->msi_iova += size;
> @@ -381,6 +382,10 @@ static dma_addr_t iommu_dma_alloc_iova(struct
> iommu_domain *domain,
> if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
> iova_len = roundup_pow_of_two(iova_len);
>
> + /* Limit IOVA allocated to device addressable dma-ranges region. */
> + dma_end_addr = (dma_addr_t)iovad->dma_32bit_pfn << shift;
> + dma_limit = dma_limit > dma_end_addr ? dma_end_addr : dma_limit;
This looks like a good use-case for min().
> +
> if (domain->geometry.force_aperture)
> dma_limit = min(dma_limit, domain->geometry.aperture_end);
>
> --
> 2.1.4
