Re: [PATCH] gpu: host1x: Acquire a reference to the IOVA cache

[Dmitry Osipenko]

On 14.05.2018 13:13, Thierry Reding wrote:
> From: Thierry Reding 
> 
> The IOVA API uses a memory cache to allocate IOVA nodes from. To make
> sure that this cache is available, obtain a reference to it and release
> the reference when the cache is no longer needed.
> 
> On 64-bit ARM this is hidden by the fact that the DMA mapping API gets
> that reference and never releases it. On 32-bit ARM, this is papered
> over by the Tegra DRM driver (the sole user of the host1x API requiring
> the cache) acquiring a reference to the IOVA cache for its own purposes.
> However, there may be additional users of this API in the future, so fix
> this upfront to avoid surprises.
> 
> Fixes: 404bfb78daf3 ("gpu: host1x: Add IOMMU support")
> Signed-off-by: Thierry Reding 
> ---
>  drivers/gpu/host1x/dev.c | 11 ++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
> index 03db71173f5d..f1d5f76e9c33 100644
> --- a/drivers/gpu/host1x/dev.c
> +++ b/drivers/gpu/host1x/dev.c
> @@ -223,10 +223,14 @@ static int host1x_probe(struct platform_device *pdev)
>   struct iommu_domain_geometry *geometry;
>   unsigned long order;
>  
> + err = iova_cache_get();
> + if (err < 0)
> + goto put_group;
> +
>   host->domain = iommu_domain_alloc(_bus_type);
>   if (!host->domain) {
>   err = -ENOMEM;
> - goto put_group;
> + goto put_cache;
>   }
>  
>   err = iommu_attach_group(host->domain, host->group);
> @@ -234,6 +238,7 @@ static int host1x_probe(struct platform_device *pdev)
>   if (err == -ENODEV) {
>   iommu_domain_free(host->domain);
>   host->domain = NULL;
> + iova_cache_put();
>   iommu_group_put(host->group);
>   host->group = NULL;
>   goto skip_iommu;
> @@ -308,6 +313,9 @@ static int host1x_probe(struct platform_device *pdev)
>  fail_free_domain:
>   if (host->domain)
>   iommu_domain_free(host->domain);
> +put_cache:
> + if (host->group)
> + iova_cache_put();
>  put_group:
>   iommu_group_put(host->group);
>  
> @@ -328,6 +336,7 @@ static int host1x_remove(struct platform_device *pdev)
>   put_iova_domain(>iova);
>   iommu_detach_group(host->domain, host->group);
>   iommu_domain_free(host->domain);
> + iova_cache_put();
>   iommu_group_put(host->group);
>   }
>  
> 

Reviewed-by: Dmitry Osipenko 
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH] gpu: host1x: Acquire a reference to the IOVA cache

[Thierry Reding]

On Mon, May 14, 2018 at 01:34:27PM +0300, Dmitry Osipenko wrote:
> On 14.05.2018 13:13, Thierry Reding wrote:
> > From: Thierry Reding 
> > 
> > The IOVA API uses a memory cache to allocate IOVA nodes from. To make
> > sure that this cache is available, obtain a reference to it and release
> > the reference when the cache is no longer needed.
> > 
> > On 64-bit ARM this is hidden by the fact that the DMA mapping API gets
> > that reference and never releases it. On 32-bit ARM, this is papered
> > over by the Tegra DRM driver (the sole user of the host1x API requiring
> > the cache) acquiring a reference to the IOVA cache for its own purposes.
> > However, there may be additional users of this API in the future, so fix
> > this upfront to avoid surprises.
> > 
> > Fixes: 404bfb78daf3 ("gpu: host1x: Add IOMMU support")
> > Signed-off-by: Thierry Reding 
> > ---
> >  drivers/gpu/host1x/dev.c | 11 ++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)

Applied, thanks.

Thierry


signature.asc
Description: PGP signature
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH] gpu: host1x: Acquire a reference to the IOVA cache

[Thierry Reding]

From: Thierry Reding 

The IOVA API uses a memory cache to allocate IOVA nodes from. To make
sure that this cache is available, obtain a reference to it and release
the reference when the cache is no longer needed.

On 64-bit ARM this is hidden by the fact that the DMA mapping API gets
that reference and never releases it. On 32-bit ARM, this is papered
over by the Tegra DRM driver (the sole user of the host1x API requiring
the cache) acquiring a reference to the IOVA cache for its own purposes.
However, there may be additional users of this API in the future, so fix
this upfront to avoid surprises.

Fixes: 404bfb78daf3 ("gpu: host1x: Add IOMMU support")
Signed-off-by: Thierry Reding 
---
 drivers/gpu/host1x/dev.c | 11 ++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 03db71173f5d..f1d5f76e9c33 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -223,10 +223,14 @@ static int host1x_probe(struct platform_device *pdev)
struct iommu_domain_geometry *geometry;
unsigned long order;
 
+   err = iova_cache_get();
+   if (err < 0)
+   goto put_group;
+
host->domain = iommu_domain_alloc(_bus_type);
if (!host->domain) {
err = -ENOMEM;
-   goto put_group;
+   goto put_cache;
}
 
err = iommu_attach_group(host->domain, host->group);
@@ -234,6 +238,7 @@ static int host1x_probe(struct platform_device *pdev)
if (err == -ENODEV) {
iommu_domain_free(host->domain);
host->domain = NULL;
+   iova_cache_put();
iommu_group_put(host->group);
host->group = NULL;
goto skip_iommu;
@@ -308,6 +313,9 @@ static int host1x_probe(struct platform_device *pdev)
 fail_free_domain:
if (host->domain)
iommu_domain_free(host->domain);
+put_cache:
+   if (host->group)
+   iova_cache_put();
 put_group:
iommu_group_put(host->group);
 
@@ -328,6 +336,7 @@ static int host1x_remove(struct platform_device *pdev)
put_iova_domain(>iova);
iommu_detach_group(host->domain, host->group);
iommu_domain_free(host->domain);
+   iova_cache_put();
iommu_group_put(host->group);
}
 
-- 
2.17.0

___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel