On 04.05.2018 13:54, Thierry Reding wrote:
> On Fri, May 04, 2018 at 02:47:20AM +0300, Dmitry Osipenko wrote:
>> Attach GR2D to the display IOMMU group in order to provide GR2D access
>> to BO's IOVA.
>>
>> Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
>> ---
>> drivers/gpu/drm/tegra/gr2d.c | 31 +++++++++++++++++++++++++++++--
>> 1 file changed, 29 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
>> index 9a8ea93016a9..8eb530a85dd0 100644
>> --- a/drivers/gpu/drm/tegra/gr2d.c
>> +++ b/drivers/gpu/drm/tegra/gr2d.c
>> @@ -7,12 +7,14 @@
>> */
>>
>> #include <linux/clk.h>
>> +#include <linux/iommu.h>
>>
>> #include "drm.h"
>> #include "gem.h"
>> #include "gr2d.h"
>>
>> struct gr2d {
>> + struct iommu_group *group;
>> struct tegra_drm_client client;
>> struct host1x_channel *channel;
>> struct clk *clk;
>> @@ -30,7 +32,9 @@ static int gr2d_init(struct host1x_client *client)
>> struct tegra_drm_client *drm = host1x_to_drm_client(client);
>> struct drm_device *dev = dev_get_drvdata(client->parent);
>> unsigned long flags = HOST1X_SYNCPT_HAS_BASE;
>> + struct tegra_drm *tegra = dev->dev_private;
>> struct gr2d *gr2d = to_gr2d(drm);
>> + int err;
>>
>> gr2d->channel = host1x_channel_request(client->dev);
>> if (!gr2d->channel)
>> @@ -42,23 +46,46 @@ static int gr2d_init(struct host1x_client *client)
>> return -ENOMEM;
>> }
>>
>> - return tegra_drm_register_client(dev->dev_private, drm);
>> + if (tegra->domain) {
>> + gr2d->group = iommu_group_get(client->dev);
>> +
>> + if (gr2d->group) {
>> + err = iommu_attach_group(tegra->domain, gr2d->group);
>> + if (err < 0) {
>> + dev_err(client->dev,
>> + "failed to attach to domain: %d\n",
>> + err);
>> + host1x_syncpt_free(client->syncpts[0]);
>> + host1x_channel_put(gr2d->channel);
>> + iommu_group_put(gr2d->group);
>> + return err;
>> + }
>> + }
>> + }
>
> This is almost identical to the code in DC, perhaps we should factor
> this out into a separate helper? Nothing that needs to be done right
> now, I'll take a look at it and see if I can come up with something
> good in a follow-up patch.
Sounds good.
