Re: [PATCH 2/2] ARM: Samsung: update/rewrite Samsung SYSMMU (IOMMU) driver

[KyongHo Cho <pullip.cho@samsung.com>]

Hi.

On Fri, Sep 2, 2011 at 10:56 PM, Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
> + *
> + * iova must be aligned on a 4kB, 64kB, 1MB and 16MB boundaries, respectively.
> + */

Actually, iova is just needed to be aligned by 4KiB because it is
minimum requirement.
I think IOMMU driver is capable of mapping a group of page frames that
is aligned
by 1MiB with an iova that is aligned by 4KB
if the iova is large enough to map the given page frames.

> +static int s5p_sysmmu_map(struct iommu_domain *domain, unsigned long iova,
> +                         phys_addr_t paddr, int gfp_order, int prot)
> +{
> +       struct s5p_sysmmu_domain *s5p_domain = domain->priv;
> +       int flpt_idx = flpt_index(iova);
> +       size_t len = 0x1000UL << gfp_order;
> +       void *flpt_va, *slpt_va;
> +
> +       if (len != SZ_16M && len != SZ_1M && len != SZ_64K && len != SZ_4K) {
> +               sysmmu_debug(3, "bad order: %d\n", gfp_order);
> +               return -EINVAL;
> +       }

Likewise, I think this driver need to support mapping 128KiB aligned,
128KiB physical memory, for example.

Otherwise, it is somewhat restrictive than we expect.

Thank you.

Cho KyongHo.

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