Re: [PATCH 10/18] iommu/msm: Add IOMMU_DOMAIN_DMA support

From: Rob Clark
Date: Thu Aug 20 2020 - 11:55:19 EST


Side note, I suspect we'll end up needing something like
0e764a01015dfebff8a8ffd297d74663772e248a .. if someone can dig a 32b
device out of the closet and dust it off, the fix is easy enough.
Just wanted to mention that here so anyone with a 32b device could
find what is needed.

BR,
-R

On Thu, Aug 20, 2020 at 8:09 AM Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> Now that arch/arm is wired up for default domains and iommu-dma,
> implement the corresponding driver-side support for DMA domains.
>
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
> drivers/iommu/msm_iommu.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3615cd6241c4..f34efcbb0b2b 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -8,6 +8,7 @@
> #include <linux/kernel.h>
> #include <linux/init.h>
> #include <linux/platform_device.h>
> +#include <linux/dma-iommu.h>
> #include <linux/errno.h>
> #include <linux/io.h>
> #include <linux/io-pgtable.h>
> @@ -314,13 +315,16 @@ static struct iommu_domain *msm_iommu_domain_alloc(unsigned type)
> {
> struct msm_priv *priv;
>
> - if (type != IOMMU_DOMAIN_UNMANAGED)
> + if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
> return NULL;
>
> priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> if (!priv)
> goto fail_nomem;
>
> + if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(&priv->domain))
> + goto fail_nomem;
> +
> INIT_LIST_HEAD(&priv->list_attached);
>
> priv->domain.geometry.aperture_start = 0;
> @@ -339,6 +343,7 @@ static void msm_iommu_domain_free(struct iommu_domain *domain)
> struct msm_priv *priv;
> unsigned long flags;
>
> + iommu_put_dma_cookie(domain);
> spin_lock_irqsave(&msm_iommu_lock, flags);
> priv = to_msm_priv(domain);
> kfree(priv);
> --
> 2.28.0.dirty
>
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