Re: [PATCH v1 2/4] iommu/tegra: gart: Check whether page is already mapped

2017-09-26 Thread Dmitry Osipenko
On 26.09.2017 19:07, Thierry Reding wrote: > On Tue, Sep 26, 2017 at 04:49:52PM +0300, Dmitry Osipenko wrote: >> On 26.09.2017 14:06, Thierry Reding wrote: >>> On Wed, Jul 05, 2017 at 07:29:46PM +0300, Dmitry Osipenko wrote: Due to a bug, multiple devices may try to map the same IOVA region.

Re: [PATCH v1 2/4] iommu/tegra: gart: Check whether page is already mapped

2017-09-26 Thread Thierry Reding
On Tue, Sep 26, 2017 at 04:49:52PM +0300, Dmitry Osipenko wrote: > On 26.09.2017 14:06, Thierry Reding wrote: > > On Wed, Jul 05, 2017 at 07:29:46PM +0300, Dmitry Osipenko wrote: > >> Due to a bug, multiple devices may try to map the same IOVA region. We can > >> catch that case by checking that

Re: [PATCH v1 2/4] iommu/tegra: gart: Check whether page is already mapped

2017-09-26 Thread Dmitry Osipenko
On 26.09.2017 14:06, Thierry Reding wrote: > On Wed, Jul 05, 2017 at 07:29:46PM +0300, Dmitry Osipenko wrote: >> Due to a bug, multiple devices may try to map the same IOVA region. We can >> catch that case by checking that 'VALID' bit of the GART's page entry is >> unset prior to mapping of the

Re: [PATCH v1 2/4] iommu/tegra: gart: Check whether page is already mapped

2017-09-26 Thread Thierry Reding
On Wed, Jul 05, 2017 at 07:29:46PM +0300, Dmitry Osipenko wrote: > Due to a bug, multiple devices may try to map the same IOVA region. We can > catch that case by checking that 'VALID' bit of the GART's page entry is > unset prior to mapping of the page. Due to what bug? Sounds to me like access

[PATCH v1 2/4] iommu/tegra: gart: Check whether page is already mapped

2017-07-05 Thread Dmitry Osipenko
Due to a bug, multiple devices may try to map the same IOVA region. We can catch that case by checking that 'VALID' bit of the GART's page entry is unset prior to mapping of the page. Signed-off-by: Dmitry Osipenko --- drivers/iommu/tegra-gart.c | 7 +++ 1 file changed, 7