diff mbox series

[RFC,v2,17/17] WIP: drm/tegra: Implement new UAPI

Message ID 20200905103420.3021852-18-mperttunen@nvidia.com
State Changes Requested
Headers show
Series Host1x/TegraDRM UAPI | expand

Commit Message

Mikko Perttunen Sept. 5, 2020, 10:34 a.m. UTC 
Implement the new UAPI, and bump the TegraDRM major version.

WIP:
- Wait DMA reservations
- Implement firewall on TegraDRM side

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/gpu/drm/tegra/Makefile      |   2 +
 drivers/gpu/drm/tegra/drm.c         |  46 +-
 drivers/gpu/drm/tegra/drm.h         |   5 +
 drivers/gpu/drm/tegra/uapi.h        |  59 +++
 drivers/gpu/drm/tegra/uapi/submit.c | 687 ++++++++++++++++++++++++++++
 drivers/gpu/drm/tegra/uapi/uapi.c   | 328 +++++++++++++
 6 files changed, 1109 insertions(+), 18 deletions(-)
 create mode 100644 drivers/gpu/drm/tegra/uapi.h
 create mode 100644 drivers/gpu/drm/tegra/uapi/submit.c
 create mode 100644 drivers/gpu/drm/tegra/uapi/uapi.c

Comments

Dmitry Osipenko Sept. 9, 2020, 12:47 a.m. UTC | #1 
05.09.2020 13:34, Mikko Perttunen пишет:
> +static int submit_process_bufs(struct drm_device *drm, struct gather_bo *bo,
> +			       struct tegra_drm_job_data *job_data,
> +			       struct tegra_drm_channel_ctx *ctx,
> +			       struct drm_tegra_channel_submit *args,
> +			       struct ww_acquire_ctx *acquire_ctx)
> +{
> +	struct drm_tegra_submit_buf __user *user_bufs_ptr =
> +		u64_to_user_ptr(args->bufs_ptr);

If assignment makes line too long, then factor it out.

  struct drm_tegra_submit_buf __user *user_bufs_ptr;

  user_bufs_ptr = u64_to_user_ptr(args->bufs_ptr);

> +	struct tegra_drm_mapping *mapping;
> +	struct drm_tegra_submit_buf buf;
> +	unsigned long copy_err;
> +	int err;
> +	u32 i;
> +
> +	job_data->used_mappings =
> +		kcalloc(args->num_bufs, sizeof(*job_data->used_mappings), GFP_KERNEL);

The checkpatch should disallow this coding style. I'd write it as:

size_t size;

size = sizeof(*job_data->used_mappings);
job_data->used_mappings = kcalloc(args->num_bufs, size..);

> +	if (!job_data->used_mappings)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < args->num_bufs; i++) {
> +		copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));

Whole array always should be copied at once. Please keep in mind that
each copy_from_user() has a cpu-time cost, there should maximum up to 2
copyings per job.
Dmitry Osipenko Sept. 9, 2020, 1:13 a.m. UTC | #2 
05.09.2020 13:34, Mikko Perttunen пишет:
> +int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
> +				   struct drm_file *file)
> +{
> +	struct tegra_drm_file *fpriv = file->driver_priv;
> +	struct drm_tegra_channel_submit *args = data;
> +	struct drm_tegra_submit_syncpt_incr incr;
> +	struct tegra_drm_job_data *job_data;
> +	struct ww_acquire_ctx acquire_ctx;
> +	struct tegra_drm_channel_ctx *ctx;
> +	struct host1x_job *job;
> +	struct gather_bo *bo;
> +	u32 i;
> +	int err;
> +
> +	if (args->reserved[0] || args->reserved[1] || args->reserved[2] ||
> +	    args->reserved[3])
> +		return -EINVAL;
> +
> +	ctx = tegra_drm_channel_ctx_lock(fpriv, args->channel_ctx);
> +	if (!ctx)
> +		return -EINVAL;
> +
> +	err = submit_copy_gather_data(drm, &bo, args);
> +	if (err)
> +		goto unlock;
> +
> +	job_data = kzalloc(sizeof(*job_data), GFP_KERNEL);
> +	if (!job_data) {
> +		err = -ENOMEM;
> +		goto put_bo;
> +	}
> +
> +	err = submit_process_bufs(drm, bo, job_data, ctx, args, &acquire_ctx);
> +	if (err)
> +		goto free_job_data;
> +
> +	err = submit_create_job(drm, &job, bo, ctx, args, file);
> +	if (err)
> +		goto free_job_data;
> +
> +	err = submit_handle_syncpts(drm, job, &incr, args);
> +	if (err)
> +		goto put_job;

How many sync points would use an average job? Maybe it should be better
to have the predefined array of sync points within the struct
drm_tegra_channel_submit?
Dmitry Osipenko Sept. 9, 2020, 1:24 a.m. UTC | #3 
09.09.2020 04:13, Dmitry Osipenko пишет:
...
> How many sync points would use an average job? Maybe it should be better
> to have the predefined array of sync points within the struct
> drm_tegra_channel_submit?
> 

The same question regarding the commands.

Wouldn't it be a good idea to make both usrptr arrays of sync points and
commands optional by having a small fixed-size buffers within
drm_tegra_channel_submit? Then a majority of jobs would only need to
copy the gather data from userspace.
Dmitry Osipenko Sept. 9, 2020, 2:06 a.m. UTC | #4 
05.09.2020 13:34, Mikko Perttunen пишет:
> +int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data,
> +				 struct drm_file *file)
> +{
> +	struct tegra_drm_file *fpriv = file->driver_priv;
> +	struct tegra_drm *tegra = drm->dev_private;
> +	struct drm_tegra_channel_open *args = data;
> +	struct tegra_drm_client *client = NULL;
> +	struct tegra_drm_channel_ctx *ctx;
> +	int err;
> +
> +	if (args->flags || args->reserved[0] || args->reserved[1])
> +		return -EINVAL;
> +
> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	err = -ENODEV;
> +	list_for_each_entry(client, &tegra->clients, list) {
> +		if (client->base.class == args->host1x_class) {
> +			err = 0;
> +			break;
> +		}
> +	}
> +	if (err)
> +		goto free_ctx;
> +
> +	if (client->shared_channel) {
> +		ctx->channel = host1x_channel_get(client->shared_channel);
> +	} else {
> +		ctx->channel = host1x_channel_request(&client->base);
> +		if (!ctx->channel) {
> +			err = -EBUSY;
> +			goto free_ctx;
> +		}
> +	}
> +
> +	err = xa_alloc(&fpriv->contexts, &args->channel_ctx, ctx,
> +		       XA_LIMIT(1, U32_MAX), GFP_KERNEL);
> +	if (err < 0) {
> +		mutex_unlock(&fpriv->lock);

Looks like the lock was never taken.

> +		goto put_channel;
> +	}
> +
> +	ctx->client = client;
> +	xa_init_flags(&ctx->mappings, XA_FLAGS_ALLOC);

Why not XA_FLAGS_ALLOC1?
Dmitry Osipenko Sept. 9, 2020, 2:10 a.m. UTC | #5 
05.09.2020 13:34, Mikko Perttunen пишет:
> +	job->timeout = min(args->timeout_us / 1000, 10000U);
> +	if (job->timeout == 0)
> +		job->timeout = 1;

clamp()
Dmitry Osipenko Sept. 9, 2020, 2:34 a.m. UTC | #6 
09.09.2020 05:10, Dmitry Osipenko пишет:
> 05.09.2020 13:34, Mikko Perttunen пишет:
>> +	job->timeout = min(args->timeout_us / 1000, 10000U);
>> +	if (job->timeout == 0)
>> +		job->timeout = 1;
> 
> clamp()
> 

Does it make sense to have timeout in microseconds?
Mikko Perttunen Sept. 9, 2020, 8:19 a.m. UTC | #7 
On 9/9/20 3:47 AM, Dmitry Osipenko wrote:
> 05.09.2020 13:34, Mikko Perttunen пишет:
>> +static int submit_process_bufs(struct drm_device *drm, struct gather_bo *bo,
>> +			       struct tegra_drm_job_data *job_data,
>> +			       struct tegra_drm_channel_ctx *ctx,
>> +			       struct drm_tegra_channel_submit *args,
>> +			       struct ww_acquire_ctx *acquire_ctx)
>> +{
>> +	struct drm_tegra_submit_buf __user *user_bufs_ptr =
>> +		u64_to_user_ptr(args->bufs_ptr);
> 
> If assignment makes line too long, then factor it out.
> 
>    struct drm_tegra_submit_buf __user *user_bufs_ptr;
> 
>    user_bufs_ptr = u64_to_user_ptr(args->bufs_ptr);
> 
>> +	struct tegra_drm_mapping *mapping;
>> +	struct drm_tegra_submit_buf buf;
>> +	unsigned long copy_err;
>> +	int err;
>> +	u32 i;
>> +
>> +	job_data->used_mappings =
>> +		kcalloc(args->num_bufs, sizeof(*job_data->used_mappings), GFP_KERNEL);
> 
> The checkpatch should disallow this coding style. I'd write it as:
> 
> size_t size;
> 
> size = sizeof(*job_data->used_mappings);
> job_data->used_mappings = kcalloc(args->num_bufs, size..);

I'll make these cleaner for next version.

> 
>> +	if (!job_data->used_mappings)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < args->num_bufs; i++) {
>> +		copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));
> 
> Whole array always should be copied at once. Please keep in mind that
> each copy_from_user() has a cpu-time cost, there should maximum up to 2
> copyings per job.
> 

OK. BTW, do you have some reference/numbers for this or is it based on 
grate-driver experience?

Mikko
Mikko Perttunen Sept. 9, 2020, 8:26 a.m. UTC | #8 
On 9/9/20 4:24 AM, Dmitry Osipenko wrote:
> 09.09.2020 04:13, Dmitry Osipenko пишет:
> ...
>> How many sync points would use an average job? Maybe it should be better
>> to have the predefined array of sync points within the struct
>> drm_tegra_channel_submit?
>>
> 
> The same question regarding the commands.
> 
> Wouldn't it be a good idea to make both usrptr arrays of sync points and
> commands optional by having a small fixed-size buffers within
> drm_tegra_channel_submit? Then a majority of jobs would only need to
> copy the gather data from userspace.
> 

Sure, I'll look into it. For syncpoints, it would be usually 1 but 
sometimes 2, so maybe make it 2. For commands, at least for downstream 
it would typically be 2 (one wait and one gather). Any opinion from 
grate-driver's point of view? Not sure if there is any recommendation 
regarding the max size of IOCTL data.

Mikko
Mikko Perttunen Sept. 9, 2020, 8:26 a.m. UTC | #9 
On 9/9/20 5:06 AM, Dmitry Osipenko wrote:
> 05.09.2020 13:34, Mikko Perttunen пишет:
>> +int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data,
>> +				 struct drm_file *file)
>> +{
>> +	struct tegra_drm_file *fpriv = file->driver_priv;
>> +	struct tegra_drm *tegra = drm->dev_private;
>> +	struct drm_tegra_channel_open *args = data;
>> +	struct tegra_drm_client *client = NULL;
>> +	struct tegra_drm_channel_ctx *ctx;
>> +	int err;
>> +
>> +	if (args->flags || args->reserved[0] || args->reserved[1])
>> +		return -EINVAL;
>> +
>> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
>> +	if (!ctx)
>> +		return -ENOMEM;
>> +
>> +	err = -ENODEV;
>> +	list_for_each_entry(client, &tegra->clients, list) {
>> +		if (client->base.class == args->host1x_class) {
>> +			err = 0;
>> +			break;
>> +		}
>> +	}
>> +	if (err)
>> +		goto free_ctx;
>> +
>> +	if (client->shared_channel) {
>> +		ctx->channel = host1x_channel_get(client->shared_channel);
>> +	} else {
>> +		ctx->channel = host1x_channel_request(&client->base);
>> +		if (!ctx->channel) {
>> +			err = -EBUSY;
>> +			goto free_ctx;
>> +		}
>> +	}
>> +
>> +	err = xa_alloc(&fpriv->contexts, &args->channel_ctx, ctx,
>> +		       XA_LIMIT(1, U32_MAX), GFP_KERNEL);
>> +	if (err < 0) {
>> +		mutex_unlock(&fpriv->lock);
> 
> Looks like the lock was never taken.

Thanks, will fix.

> 
>> +		goto put_channel;
>> +	}
>> +
>> +	ctx->client = client;
>> +	xa_init_flags(&ctx->mappings, XA_FLAGS_ALLOC);
> 
> Why not XA_FLAGS_ALLOC1?
> 

Will fix as well.

Mikko
Mikko Perttunen Sept. 9, 2020, 8:36 a.m. UTC | #10 
On 9/9/20 5:34 AM, Dmitry Osipenko wrote:
> 09.09.2020 05:10, Dmitry Osipenko пишет:
>> 05.09.2020 13:34, Mikko Perttunen пишет:
>>> +	job->timeout = min(args->timeout_us / 1000, 10000U);
>>> +	if (job->timeout == 0)
>>> +		job->timeout = 1;
>>
>> clamp()
>>

Will fix.

> 
> Does it make sense to have timeout in microseconds?
> 

Not sure, but better have it a bit more fine-grained rather than 
coarse-grained. This still gives a maximum timeout of 71 minutes so I 
don't think it has any negatives compared to milliseconds.

Mikko
Dmitry Osipenko Sept. 10, 2020, 9:57 p.m. UTC | #11 
09.09.2020 11:36, Mikko Perttunen пишет:
...
>>
>> Does it make sense to have timeout in microseconds?
>>
> 
> Not sure, but better have it a bit more fine-grained rather than
> coarse-grained. This still gives a maximum timeout of 71 minutes so I
> don't think it has any negatives compared to milliseconds.

If there is no good reason to use microseconds right now, then should be
better to default to milliseconds, IMO. It shouldn't be a problem to
extend the IOCLT with a microseconds entry, if ever be needed.

{
	__u32 timeout_ms;
...
	__u32 timeout_us;
}

timeout = timeout_ms + 1000 * timeout_us;

There shouldn't be a need for a long timeouts, since a job that takes
over 100ms is probably too unpractical. It also should be possible to
detect a progressing job and then defer timeout in the driver. At least
this is what other drivers do, like etnaviv driver for example:

https://elixir.bootlin.com/linux/v5.9-rc4/source/drivers/gpu/drm/etnaviv/etnaviv_sched.c#L107
Dmitry Osipenko Sept. 10, 2020, 9:58 p.m. UTC | #12 
09.09.2020 11:26, Mikko Perttunen пишет:
> On 9/9/20 4:24 AM, Dmitry Osipenko wrote:
>> 09.09.2020 04:13, Dmitry Osipenko пишет:
>> ...
>>> How many sync points would use an average job? Maybe it should be better
>>> to have the predefined array of sync points within the struct
>>> drm_tegra_channel_submit?
>>>
>>
>> The same question regarding the commands.
>>
>> Wouldn't it be a good idea to make both usrptr arrays of sync points and
>> commands optional by having a small fixed-size buffers within
>> drm_tegra_channel_submit? Then a majority of jobs would only need to
>> copy the gather data from userspace.
>>
> 
> Sure, I'll look into it. For syncpoints, it would be usually 1 but
> sometimes 2, so maybe make it 2. For commands, at least for downstream
> it would typically be 2 (one wait and one gather). Any opinion from
> grate-driver's point of view? Not sure if there is any recommendation
> regarding the max size of IOCTL data.

The Opentegra will need more than 2 commands. We'll need to take a look
at what are the min/max/average numbers of commands are used by
Opentegra since it combines multiple jobs into one and each job may have
several wait commands.
Dmitry Osipenko Sept. 10, 2020, 9:59 p.m. UTC | #13 
09.09.2020 11:19, Mikko Perttunen пишет:
...
>>> +    if (!job_data->used_mappings)
>>> +        return -ENOMEM;
>>> +
>>> +    for (i = 0; i < args->num_bufs; i++) {
>>> +        copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));
>>
>> Whole array always should be copied at once. Please keep in mind that
>> each copy_from_user() has a cpu-time cost, there should maximum up to 2
>> copyings per job.
>>
> 
> OK. BTW, do you have some reference/numbers for this or is it based on
> grate-driver experience?

I had numbers about 2 years ago while was profiling job submission
latency using host1x-tests and for a simple jobs there was a visible
difference caused by each copy_from_user(), kmalloc() and having
firewall functions uninlined.

Of course it wasn't critical, but it's also not difficult to optimize
such things.
Mikko Perttunen Sept. 11, 2020, 9:59 a.m. UTC | #14 
On 9/11/20 12:57 AM, Dmitry Osipenko wrote:
> 09.09.2020 11:36, Mikko Perttunen пишет:
> ...
>>>
>>> Does it make sense to have timeout in microseconds?
>>>
>>
>> Not sure, but better have it a bit more fine-grained rather than
>> coarse-grained. This still gives a maximum timeout of 71 minutes so I
>> don't think it has any negatives compared to milliseconds.
> 
> If there is no good reason to use microseconds right now, then should be
> better to default to milliseconds, IMO. It shouldn't be a problem to
> extend the IOCLT with a microseconds entry, if ever be needed.
> 
> {
> 	__u32 timeout_ms;
> ...
> 	__u32 timeout_us;
> }
> 
> timeout = timeout_ms + 1000 * timeout_us;
> 
> There shouldn't be a need for a long timeouts, since a job that takes
> over 100ms is probably too unpractical. It also should be possible to
> detect a progressing job and then defer timeout in the driver. At least
> this is what other drivers do, like etnaviv driver for example:
> 
> https://elixir.bootlin.com/linux/v5.9-rc4/source/drivers/gpu/drm/etnaviv/etnaviv_sched.c#L107
> 

I still don't quite understand why it's better to default to 
milliseconds? As you say, there is no need to have a long timeout, and 
if we go microseconds now, then there wouldn't be a need to extend in 
the future.

Mikko
Dmitry Osipenko Sept. 11, 2020, 4:30 p.m. UTC | #15 
11.09.2020 12:59, Mikko Perttunen пишет:
> On 9/11/20 12:57 AM, Dmitry Osipenko wrote:
>> 09.09.2020 11:36, Mikko Perttunen пишет:
>> ...
>>>>
>>>> Does it make sense to have timeout in microseconds?
>>>>
>>>
>>> Not sure, but better have it a bit more fine-grained rather than
>>> coarse-grained. This still gives a maximum timeout of 71 minutes so I
>>> don't think it has any negatives compared to milliseconds.
>>
>> If there is no good reason to use microseconds right now, then should be
>> better to default to milliseconds, IMO. It shouldn't be a problem to
>> extend the IOCLT with a microseconds entry, if ever be needed.
>>
>> {
>>     __u32 timeout_ms;
>> ...
>>     __u32 timeout_us;
>> }
>>
>> timeout = timeout_ms + 1000 * timeout_us;
>>
>> There shouldn't be a need for a long timeouts, since a job that takes
>> over 100ms is probably too unpractical. It also should be possible to
>> detect a progressing job and then defer timeout in the driver. At least
>> this is what other drivers do, like etnaviv driver for example:
>>
>> https://elixir.bootlin.com/linux/v5.9-rc4/source/drivers/gpu/drm/etnaviv/etnaviv_sched.c#L107
>>
>>
> 
> I still don't quite understand why it's better to default to
> milliseconds? As you say, there is no need to have a long timeout, and
> if we go microseconds now, then there wouldn't be a need to extend in
> the future.

It will nicer to avoid unnecessary unit-conversions in the code in order
to keep it cleaner.

I'm now also a bit dubious about that the timeout field of the submit
IOCTL will be in the final UAPI version because it should become
obsolete once drm-scheduler will be hooked up, since the hung-check
timeout will be specified per-hardware engine within the kernel driver
and there won't be much use for the user-defined timeout.
Mikko Perttunen Sept. 15, 2020, 11:08 a.m. UTC | #16 
On 9/11/20 7:30 PM, Dmitry Osipenko wrote:
> 11.09.2020 12:59, Mikko Perttunen пишет:
>> On 9/11/20 12:57 AM, Dmitry Osipenko wrote:
>>> 09.09.2020 11:36, Mikko Perttunen пишет:
>>> ...
>>>>>
>>>>> Does it make sense to have timeout in microseconds?
>>>>>
>>>>
>>>> Not sure, but better have it a bit more fine-grained rather than
>>>> coarse-grained. This still gives a maximum timeout of 71 minutes so I
>>>> don't think it has any negatives compared to milliseconds.
>>>
>>> If there is no good reason to use microseconds right now, then should be
>>> better to default to milliseconds, IMO. It shouldn't be a problem to
>>> extend the IOCLT with a microseconds entry, if ever be needed.
>>>
>>> {
>>>      __u32 timeout_ms;
>>> ...
>>>      __u32 timeout_us;
>>> }
>>>
>>> timeout = timeout_ms + 1000 * timeout_us;
>>>
>>> There shouldn't be a need for a long timeouts, since a job that takes
>>> over 100ms is probably too unpractical. It also should be possible to
>>> detect a progressing job and then defer timeout in the driver. At least
>>> this is what other drivers do, like etnaviv driver for example:
>>>
>>> https://elixir.bootlin.com/linux/v5.9-rc4/source/drivers/gpu/drm/etnaviv/etnaviv_sched.c#L107
>>>
>>>
>>
>> I still don't quite understand why it's better to default to
>> milliseconds? As you say, there is no need to have a long timeout, and
>> if we go microseconds now, then there wouldn't be a need to extend in
>> the future.
> 
> It will nicer to avoid unnecessary unit-conversions in the code in order
> to keep it cleaner.

We can change all the internals to use microseconds as well. We 
eventually have to convert it to jiffies anyway, so the unit before that 
shouldn't matter much.

> 
> I'm now also a bit dubious about that the timeout field of the submit
> IOCTL will be in the final UAPI version because it should become
> obsolete once drm-scheduler will be hooked up, since the hung-check
> timeout will be specified per-hardware engine within the kernel driver
> and there won't be much use for the user-defined timeout.
> 

Perhaps we can omit this field for now. Looking at it, it's primarily 
used for tests, and for that we could add a debugfs knob to adjust the 
timeout if needed.

Mikko
diff mbox series

Patch

diff --git a/drivers/gpu/drm/tegra/Makefile b/drivers/gpu/drm/tegra/Makefile
index d6cf202414f0..d480491564b7 100644
--- a/drivers/gpu/drm/tegra/Makefile
+++ b/drivers/gpu/drm/tegra/Makefile
@@ -3,6 +3,8 @@  ccflags-$(CONFIG_DRM_TEGRA_DEBUG) += -DDEBUG
 
 tegra-drm-y := \
 	drm.o \
+	uapi/uapi.o \
+	uapi/submit.o \
 	gem.o \
 	fb.o \
 	dp.o \
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 7124b0b0154b..acd734104c9a 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -20,24 +20,20 @@ 
 #include <drm/drm_prime.h>
 #include <drm/drm_vblank.h>
 
+#include "uapi.h"
 #include "drm.h"
 #include "gem.h"
 
 #define DRIVER_NAME "tegra"
 #define DRIVER_DESC "NVIDIA Tegra graphics"
 #define DRIVER_DATE "20120330"
-#define DRIVER_MAJOR 0
+#define DRIVER_MAJOR 1
 #define DRIVER_MINOR 0
 #define DRIVER_PATCHLEVEL 0
 
 #define CARVEOUT_SZ SZ_64M
 #define CDMA_GATHER_FETCHES_MAX_NB 16383
 
-struct tegra_drm_file {
-	struct idr contexts;
-	struct mutex lock;
-};
-
 static int tegra_atomic_check(struct drm_device *drm,
 			      struct drm_atomic_state *state)
 {
@@ -90,7 +86,8 @@  static int tegra_drm_open(struct drm_device *drm, struct drm_file *filp)
 	if (!fpriv)
 		return -ENOMEM;
 
-	idr_init(&fpriv->contexts);
+	idr_init(&fpriv->legacy_contexts);
+	xa_init_flags(&fpriv->contexts, XA_FLAGS_ALLOC);
 	mutex_init(&fpriv->lock);
 	filp->driver_priv = fpriv;
 
@@ -432,7 +429,7 @@  static int tegra_client_open(struct tegra_drm_file *fpriv,
 	if (err < 0)
 		return err;
 
-	err = idr_alloc(&fpriv->contexts, context, 1, 0, GFP_KERNEL);
+	err = idr_alloc(&fpriv->legacy_contexts, context, 1, 0, GFP_KERNEL);
 	if (err < 0) {
 		client->ops->close_channel(context);
 		return err;
@@ -487,13 +484,13 @@  static int tegra_close_channel(struct drm_device *drm, void *data,
 
 	mutex_lock(&fpriv->lock);
 
-	context = idr_find(&fpriv->contexts, args->context);
+	context = idr_find(&fpriv->legacy_contexts, args->context);
 	if (!context) {
 		err = -EINVAL;
 		goto unlock;
 	}
 
-	idr_remove(&fpriv->contexts, context->id);
+	idr_remove(&fpriv->legacy_contexts, context->id);
 	tegra_drm_context_free(context);
 
 unlock:
@@ -512,7 +509,7 @@  static int tegra_get_syncpt(struct drm_device *drm, void *data,
 
 	mutex_lock(&fpriv->lock);
 
-	context = idr_find(&fpriv->contexts, args->context);
+	context = idr_find(&fpriv->legacy_contexts, args->context);
 	if (!context) {
 		err = -ENODEV;
 		goto unlock;
@@ -541,7 +538,7 @@  static int tegra_submit(struct drm_device *drm, void *data,
 
 	mutex_lock(&fpriv->lock);
 
-	context = idr_find(&fpriv->contexts, args->context);
+	context = idr_find(&fpriv->legacy_contexts, args->context);
 	if (!context) {
 		err = -ENODEV;
 		goto unlock;
@@ -566,7 +563,7 @@  static int tegra_get_syncpt_base(struct drm_device *drm, void *data,
 
 	mutex_lock(&fpriv->lock);
 
-	context = idr_find(&fpriv->contexts, args->context);
+	context = idr_find(&fpriv->legacy_contexts, args->context);
 	if (!context) {
 		err = -ENODEV;
 		goto unlock;
@@ -734,11 +731,23 @@  static int tegra_gem_get_flags(struct drm_device *drm, void *data,
 #endif
 
 static const struct drm_ioctl_desc tegra_drm_ioctls[] = {
-#ifdef CONFIG_DRM_TEGRA_STAGING
-	DRM_IOCTL_DEF_DRV(TEGRA_GEM_CREATE, tegra_gem_create,
+	DRM_IOCTL_DEF_DRV(TEGRA_CHANNEL_OPEN, tegra_drm_ioctl_channel_open,
+			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_CHANNEL_CLOSE, tegra_drm_ioctl_channel_close,
+			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_CHANNEL_MAP, tegra_drm_ioctl_channel_map,
 			  DRM_RENDER_ALLOW),
-	DRM_IOCTL_DEF_DRV(TEGRA_GEM_MMAP, tegra_gem_mmap,
+	DRM_IOCTL_DEF_DRV(TEGRA_CHANNEL_UNMAP, tegra_drm_ioctl_channel_unmap,
 			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_CHANNEL_SUBMIT, tegra_drm_ioctl_channel_submit,
+			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_GEM_CREATE, tegra_drm_ioctl_gem_create,
+			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_GEM_MMAP, tegra_drm_ioctl_gem_mmap,
+			  DRM_RENDER_ALLOW),
+#ifdef CONFIG_DRM_TEGRA_STAGING
+	DRM_IOCTL_DEF_DRV(TEGRA_GEM_CREATE_LEGACY, tegra_gem_create, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(TEGRA_GEM_MMAP_LEGACY, tegra_gem_mmap, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(TEGRA_SYNCPT_READ, tegra_syncpt_read,
 			  DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(TEGRA_SYNCPT_INCR, tegra_syncpt_incr,
@@ -792,10 +801,11 @@  static void tegra_drm_postclose(struct drm_device *drm, struct drm_file *file)
 	struct tegra_drm_file *fpriv = file->driver_priv;
 
 	mutex_lock(&fpriv->lock);
-	idr_for_each(&fpriv->contexts, tegra_drm_context_cleanup, NULL);
+	idr_for_each(&fpriv->legacy_contexts, tegra_drm_context_cleanup, NULL);
+	tegra_drm_uapi_close_file(fpriv);
 	mutex_unlock(&fpriv->lock);
 
-	idr_destroy(&fpriv->contexts);
+	idr_destroy(&fpriv->legacy_contexts);
 	mutex_destroy(&fpriv->lock);
 	kfree(fpriv);
 }
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 984925d0ad3e..fbacb0b35189 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -58,6 +58,11 @@  struct tegra_drm {
 	struct tegra_display_hub *hub;
 };
 
+static inline struct host1x *tegra_drm_to_host1x(struct tegra_drm *tegra)
+{
+	return dev_get_drvdata(tegra->drm->dev->parent);
+}
+
 struct tegra_drm_client;
 
 struct tegra_drm_context {
diff --git a/drivers/gpu/drm/tegra/uapi.h b/drivers/gpu/drm/tegra/uapi.h
new file mode 100644
index 000000000000..4867646670c6
--- /dev/null
+++ b/drivers/gpu/drm/tegra/uapi.h
@@ -0,0 +1,59 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2020 NVIDIA Corporation */
+
+#ifndef _TEGRA_DRM_CHANNEL_UAPI_H
+#define _TEGRA_DRM_CHANNEL_UAPI_H
+
+#include <linux/dma-mapping.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+#include <linux/xarray.h>
+
+#include <drm/drm.h>
+
+struct tegra_drm_file {
+	/* Legacy UAPI state */
+	struct idr legacy_contexts;
+	struct mutex lock;
+
+	/* New UAPI state */
+	struct xarray contexts;
+};
+
+struct tegra_drm_channel_ctx {
+	struct tegra_drm_client *client;
+	struct host1x_channel *channel;
+	struct xarray mappings;
+};
+
+struct tegra_drm_mapping {
+	struct kref ref;
+
+	struct device *dev;
+	struct host1x_bo *bo;
+	struct sg_table *sgt;
+	enum dma_data_direction direction;
+	dma_addr_t iova;
+};
+
+int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data,
+				 struct drm_file *file);
+int tegra_drm_ioctl_channel_close(struct drm_device *drm, void *data,
+				  struct drm_file *file);
+int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data,
+				struct drm_file *file);
+int tegra_drm_ioctl_channel_unmap(struct drm_device *drm, void *data,
+				struct drm_file *file);
+int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
+				   struct drm_file *file);
+int tegra_drm_ioctl_gem_create(struct drm_device *drm, void *data,
+				struct drm_file *file);
+int tegra_drm_ioctl_gem_mmap(struct drm_device *drm, void *data,
+				struct drm_file *file);
+
+void tegra_drm_uapi_close_file(struct tegra_drm_file *file);
+void tegra_drm_mapping_put(struct tegra_drm_mapping *mapping);
+struct tegra_drm_channel_ctx *
+tegra_drm_channel_ctx_lock(struct tegra_drm_file *file, u32 id);
+
+#endif
diff --git a/drivers/gpu/drm/tegra/uapi/submit.c b/drivers/gpu/drm/tegra/uapi/submit.c
new file mode 100644
index 000000000000..84e1c602db3e
--- /dev/null
+++ b/drivers/gpu/drm/tegra/uapi/submit.c
@@ -0,0 +1,687 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 NVIDIA Corporation */
+
+#include <linux/dma-fence-array.h>
+#include <linux/file.h>
+#include <linux/host1x.h>
+#include <linux/iommu.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/nospec.h>
+#include <linux/sync_file.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+
+#include "../uapi.h"
+#include "../drm.h"
+#include "../gem.h"
+
+static struct tegra_drm_mapping *
+tegra_drm_mapping_get(struct tegra_drm_channel_ctx *ctx, u32 id)
+{
+	struct tegra_drm_mapping *mapping;
+
+	xa_lock(&ctx->mappings);
+	mapping = xa_load(&ctx->mappings, id);
+	if (mapping)
+		kref_get(&mapping->ref);
+	xa_unlock(&ctx->mappings);
+
+	return mapping;
+}
+
+struct gather_bo {
+	struct host1x_bo base;
+
+	struct kref ref;
+
+	u32 *gather_data;
+	size_t gather_data_len;
+};
+
+static struct host1x_bo *gather_bo_get(struct host1x_bo *host_bo)
+{
+	struct gather_bo *bo = container_of(host_bo, struct gather_bo, base);
+
+	kref_get(&bo->ref);
+
+	return host_bo;
+}
+
+static void gather_bo_release(struct kref *ref)
+{
+	struct gather_bo *bo = container_of(ref, struct gather_bo, ref);
+
+	kfree(bo->gather_data);
+	kfree(bo);
+}
+
+static void gather_bo_put(struct host1x_bo *host_bo)
+{
+	struct gather_bo *bo = container_of(host_bo, struct gather_bo, base);
+
+	kref_put(&bo->ref, gather_bo_release);
+}
+
+static struct sg_table *
+gather_bo_pin(struct device *dev, struct host1x_bo *host_bo, dma_addr_t *phys)
+{
+	struct gather_bo *bo = container_of(host_bo, struct gather_bo, base);
+	struct sg_table *sgt;
+	int err;
+
+	if (phys) {
+		*phys = virt_to_phys(bo->gather_data);
+		return NULL;
+	}
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	err = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (err) {
+		kfree(sgt);
+		return ERR_PTR(err);
+	}
+
+	sg_init_one(sgt->sgl, bo->gather_data, bo->gather_data_len);
+
+	return sgt;
+}
+
+static void gather_bo_unpin(struct device *dev, struct sg_table *sgt)
+{
+	if (sgt) {
+		sg_free_table(sgt);
+		kfree(sgt);
+	}
+}
+
+static void *gather_bo_mmap(struct host1x_bo *host_bo)
+{
+	struct gather_bo *bo = container_of(host_bo, struct gather_bo, base);
+
+	return bo->gather_data;
+}
+
+static void gather_bo_munmap(struct host1x_bo *host_bo, void *addr)
+{
+}
+
+static const struct host1x_bo_ops gather_bo_ops = {
+	.get = gather_bo_get,
+	.put = gather_bo_put,
+	.pin = gather_bo_pin,
+	.unpin = gather_bo_unpin,
+	.mmap = gather_bo_mmap,
+	.munmap = gather_bo_munmap,
+};
+
+struct tegra_drm_used_mapping {
+	struct tegra_drm_mapping *mapping;
+	u32 flags;
+};
+
+struct tegra_drm_job_data {
+	struct tegra_drm_used_mapping *used_mappings;
+	u32 num_used_mappings;
+};
+
+static int submit_copy_gather_data(struct drm_device *drm,
+				   struct gather_bo **pbo,
+				   struct drm_tegra_channel_submit *args)
+{
+	unsigned long copy_err;
+	struct gather_bo *bo;
+
+	if (args->gather_data_words == 0) {
+		drm_info(drm, "gather_data_words can't be 0");
+		return -EINVAL;
+	}
+	if (args->gather_data_words > 1024) {
+		drm_info(drm, "gather_data_words can't be over 1024");
+		return -E2BIG;
+	}
+
+	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+	if (!bo)
+		return -ENOMEM;
+
+	kref_init(&bo->ref);
+	host1x_bo_init(&bo->base, &gather_bo_ops);
+
+	bo->gather_data =
+		kmalloc(args->gather_data_words*4, GFP_KERNEL | __GFP_NOWARN);
+	if (!bo->gather_data) {
+		kfree(bo);
+		return -ENOMEM;
+	}
+
+	copy_err = copy_from_user(bo->gather_data,
+				  u64_to_user_ptr(args->gather_data_ptr),
+				  args->gather_data_words*4);
+	if (copy_err) {
+		kfree(bo->gather_data);
+		kfree(bo);
+		return -EFAULT;
+	}
+
+	bo->gather_data_len = args->gather_data_words;
+
+	*pbo = bo;
+
+	return 0;
+}
+
+static int submit_write_reloc(struct gather_bo *bo,
+			      struct drm_tegra_submit_buf *buf,
+			      struct tegra_drm_mapping *mapping)
+{
+	/* TODO check that target_offset is within bounds */
+	dma_addr_t iova = mapping->iova + buf->reloc.target_offset;
+	u32 written_ptr = (u32)(iova >> buf->reloc.shift);
+
+	if (buf->flags & DRM_TEGRA_SUBMIT_BUF_RELOC_BLOCKLINEAR)
+		written_ptr |= BIT(39);
+
+	if (buf->reloc.gather_offset_words >= bo->gather_data_len)
+		return -EINVAL;
+
+	buf->reloc.gather_offset_words = array_index_nospec(
+		buf->reloc.gather_offset_words, bo->gather_data_len);
+
+	bo->gather_data[buf->reloc.gather_offset_words] = written_ptr;
+
+	return 0;
+}
+
+static void submit_unlock_resv(struct tegra_drm_job_data *job_data,
+			       struct ww_acquire_ctx *acquire_ctx)
+{
+	u32 i;
+
+	for (i = 0; i < job_data->num_used_mappings; i++) {
+		struct tegra_bo *bo = host1x_to_tegra_bo(
+			job_data->used_mappings[i].mapping->bo);
+
+		dma_resv_unlock(bo->gem.resv);
+	}
+
+	ww_acquire_fini(acquire_ctx);
+}
+
+static int submit_handle_resv(struct tegra_drm_job_data *job_data,
+			      struct ww_acquire_ctx *acquire_ctx)
+{
+	int contended = -1;
+	int err;
+	u32 i;
+
+	/* Based on drm_gem_lock_reservations */
+
+	ww_acquire_init(acquire_ctx, &reservation_ww_class);
+
+retry:
+	if (contended != -1) {
+		struct tegra_bo *bo = host1x_to_tegra_bo(
+			job_data->used_mappings[contended].mapping->bo);
+
+		err = dma_resv_lock_slow_interruptible(bo->gem.resv,
+						       acquire_ctx);
+		if (err) {
+			ww_acquire_done(acquire_ctx);
+			return err;
+		}
+	}
+
+	for (i = 0; i < job_data->num_used_mappings; i++) {
+		struct tegra_bo *bo = host1x_to_tegra_bo(
+			job_data->used_mappings[contended].mapping->bo);
+
+		if (i == contended)
+			continue;
+
+		err = dma_resv_lock_interruptible(bo->gem.resv, acquire_ctx);
+		if (err) {
+			int j;
+
+			for (j = 0; j < i; j++) {
+				bo = host1x_to_tegra_bo(
+					job_data->used_mappings[j].mapping->bo);
+				dma_resv_unlock(bo->gem.resv);
+			}
+
+			if (contended != -1 && contended >= i) {
+				bo = host1x_to_tegra_bo(
+					job_data->used_mappings[contended].mapping->bo);
+				dma_resv_unlock(bo->gem.resv);
+			}
+
+			if (err == -EDEADLK) {
+				contended = i;
+				goto retry;
+			}
+
+			ww_acquire_done(acquire_ctx);
+			return err;
+		}
+	}
+
+	ww_acquire_done(acquire_ctx);
+
+	for (i = 0; i < job_data->num_used_mappings; i++) {
+		struct tegra_drm_used_mapping *um = &job_data->used_mappings[i];
+		struct tegra_bo *bo = host1x_to_tegra_bo(
+			job_data->used_mappings[i].mapping->bo);
+
+		if (um->flags & DRM_TEGRA_SUBMIT_BUF_RESV_READ) {
+			err = dma_resv_reserve_shared(bo->gem.resv, 1);
+			if (err < 0)
+				goto unlock_resv;
+		}
+	}
+
+	return 0;
+
+unlock_resv:
+	submit_unlock_resv(job_data, acquire_ctx);
+
+	return err;
+}
+
+static int submit_process_bufs(struct drm_device *drm, struct gather_bo *bo,
+			       struct tegra_drm_job_data *job_data,
+			       struct tegra_drm_channel_ctx *ctx,
+			       struct drm_tegra_channel_submit *args,
+			       struct ww_acquire_ctx *acquire_ctx)
+{
+	struct drm_tegra_submit_buf __user *user_bufs_ptr =
+		u64_to_user_ptr(args->bufs_ptr);
+	struct tegra_drm_mapping *mapping;
+	struct drm_tegra_submit_buf buf;
+	unsigned long copy_err;
+	int err;
+	u32 i;
+
+	job_data->used_mappings =
+		kcalloc(args->num_bufs, sizeof(*job_data->used_mappings), GFP_KERNEL);
+	if (!job_data->used_mappings)
+		return -ENOMEM;
+
+	for (i = 0; i < args->num_bufs; i++) {
+		copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));
+		if (copy_err) {
+			err = -EFAULT;
+			goto drop_refs;
+		}
+
+		if (buf.flags & ~(DRM_TEGRA_SUBMIT_BUF_WRITE_RELOC |
+				  DRM_TEGRA_SUBMIT_BUF_RELOC_BLOCKLINEAR |
+				  DRM_TEGRA_SUBMIT_BUF_RESV_READ |
+				  DRM_TEGRA_SUBMIT_BUF_RESV_WRITE)) {
+			err = -EINVAL;
+			goto drop_refs;
+		}
+
+		if (buf.reserved[0] || buf.reserved[1]) {
+			err = -EINVAL;
+			goto drop_refs;
+		}
+
+		mapping = tegra_drm_mapping_get(ctx, buf.mapping_id);
+		if (!mapping) {
+			drm_info(drm, "invalid mapping_id for buf: %u",
+				 buf.mapping_id);
+			err = -EINVAL;
+			goto drop_refs;
+		}
+
+		if (buf.flags & DRM_TEGRA_SUBMIT_BUF_WRITE_RELOC) {
+			err = submit_write_reloc(bo, &buf, mapping);
+			if (err) {
+				tegra_drm_mapping_put(mapping);
+				goto drop_refs;
+			}
+		}
+
+		job_data->used_mappings[i].mapping = mapping;
+		job_data->used_mappings[i].flags = buf.flags;
+	}
+
+	return 0;
+
+drop_refs:
+	for (;;) {
+		if (i-- == 0)
+			break;
+
+		tegra_drm_mapping_put(job_data->used_mappings[i].mapping);
+	}
+
+	kfree(job_data->used_mappings);
+	job_data->used_mappings = NULL;
+
+	return err;
+}
+
+static int submit_create_job(struct drm_device *drm, struct host1x_job **pjob,
+			     struct gather_bo *bo,
+			     struct tegra_drm_channel_ctx *ctx,
+			     struct drm_tegra_channel_submit *args,
+			     struct drm_file *file)
+{
+	struct drm_tegra_submit_cmd __user *user_cmds_ptr =
+		u64_to_user_ptr(args->cmds_ptr);
+	struct drm_tegra_submit_cmd cmd;
+	struct host1x_job *job;
+	unsigned long copy_err;
+	u32 i, gather_offset = 0;
+	int err = 0;
+
+	job = host1x_job_alloc(ctx->channel, args->num_cmds, 0);
+	if (!job)
+		return -ENOMEM;
+
+	job->client = &ctx->client->base;
+	job->class = ctx->client->base.class;
+	job->serialize = true;
+
+	for (i = 0; i < args->num_cmds; i++) {
+		copy_err = copy_from_user(&cmd, user_cmds_ptr+i, sizeof(cmd));
+		if (copy_err) {
+			err = -EFAULT;
+			goto free_job;
+		}
+
+		if (cmd.type == DRM_TEGRA_SUBMIT_CMD_GATHER_UPTR) {
+			if (cmd.gather_uptr.reserved[0] ||
+			    cmd.gather_uptr.reserved[1] ||
+			    cmd.gather_uptr.reserved[2]) {
+				err = -EINVAL;
+				goto free_job;
+			}
+
+			/* Check for maximum gather size */
+			if (cmd.gather_uptr.words > 16383) {
+				err = -EINVAL;
+				goto free_job;
+			}
+
+			host1x_job_add_gather(job, &bo->base,
+					      cmd.gather_uptr.words,
+					      gather_offset*4);
+
+			gather_offset += cmd.gather_uptr.words;
+
+			if (gather_offset > bo->gather_data_len) {
+				err = -EINVAL;
+				goto free_job;
+			}
+		} else if (cmd.type == DRM_TEGRA_SUBMIT_CMD_WAIT_SYNCPT) {
+			if (cmd.wait_syncpt.reserved[0] ||
+			    cmd.wait_syncpt.reserved[1]) {
+				err = -EINVAL;
+				goto free_job;
+			}
+
+			host1x_job_add_wait(job, cmd.wait_syncpt.id,
+					    cmd.wait_syncpt.threshold);
+		} else if (cmd.type == DRM_TEGRA_SUBMIT_CMD_WAIT_SYNC_FILE) {
+			struct dma_fence *f;
+
+			if (cmd.wait_sync_file.reserved[0] ||
+			    cmd.wait_sync_file.reserved[1] ||
+			    cmd.wait_sync_file.reserved[2]) {
+				err = -EINVAL;
+				goto free_job;
+			}
+
+			f = sync_file_get_fence(cmd.wait_sync_file.fd);
+			if (!f) {
+				err = -EINVAL;
+				goto free_job;
+			}
+
+			err = dma_fence_wait(f, true);
+			dma_fence_put(f);
+
+			if (err)
+				goto free_job;
+		} else {
+			err = -EINVAL;
+			goto free_job;
+		}
+	}
+
+	if (gather_offset == 0) {
+		drm_info(drm, "job must have at least one gather");
+		err = -EINVAL;
+		goto free_job;
+	}
+
+	*pjob = job;
+
+	return 0;
+
+free_job:
+	host1x_job_put(job);
+
+	return err;
+}
+
+static int submit_handle_syncpts(struct drm_device *drm, struct host1x_job *job,
+				 struct drm_tegra_submit_syncpt_incr *incr,
+				 struct drm_tegra_channel_submit *args)
+{
+	struct drm_tegra_submit_syncpt_incr __user *user_incrs_ptr =
+		u64_to_user_ptr(args->syncpt_incrs_ptr);
+	struct host1x_syncpt *sp;
+	unsigned long copy_err;
+
+	if (args->num_syncpt_incrs != 1) {
+		drm_info(drm, "Only 1 syncpoint supported for now");
+		return -EINVAL;
+	}
+
+	copy_err = copy_from_user(incr, user_incrs_ptr, sizeof(*incr));
+	if (copy_err)
+		return -EFAULT;
+
+	if ((incr->flags & ~DRM_TEGRA_SUBMIT_SYNCPT_INCR_CREATE_SYNC_FILE) ||
+	    incr->reserved[0] || incr->reserved[1] || incr->reserved[2])
+		return -EINVAL;
+
+	/* Syncpt ref will be dropped on job release */
+	sp = host1x_syncpt_fd_get(incr->syncpt_fd);
+	if (IS_ERR(sp))
+		return PTR_ERR(sp);
+
+	job->syncpt = sp;
+	job->syncpt_incrs = incr->num_incrs;
+
+	return 0;
+}
+
+static int submit_create_postfences(struct host1x_job *job,
+				    struct drm_tegra_submit_syncpt_incr *incr,
+				    struct drm_tegra_channel_submit *args)
+{
+	struct tegra_drm_job_data *job_data = job->user_data;
+	struct dma_fence *fence;
+	int err = 0;
+	u32 i;
+
+	fence = host1x_fence_create(job->syncpt, job->syncpt_end);
+	if (IS_ERR(fence))
+		return PTR_ERR(fence);
+
+	incr->fence_value = job->syncpt_end;
+
+	for (i = 0; i < job_data->num_used_mappings; i++) {
+		struct tegra_drm_used_mapping *um = &job_data->used_mappings[i];
+		struct tegra_bo *bo = host1x_to_tegra_bo(um->mapping->bo);
+
+		if (um->flags & DRM_TEGRA_SUBMIT_BUF_RESV_READ)
+			dma_resv_add_shared_fence(bo->gem.resv, fence);
+
+		if (um->flags & DRM_TEGRA_SUBMIT_BUF_RESV_WRITE)
+			dma_resv_add_excl_fence(bo->gem.resv, fence);
+	}
+
+	if (incr->flags & DRM_TEGRA_SUBMIT_SYNCPT_INCR_CREATE_SYNC_FILE) {
+		struct sync_file *sf;
+
+		err = get_unused_fd_flags(O_CLOEXEC);
+		if (err < 0)
+			goto put_fence;
+
+		sf = sync_file_create(fence);
+		if (!sf) {
+			err = -ENOMEM;
+			goto put_fence;
+		}
+
+		fd_install(err, sf->file);
+		incr->sync_file_fd = err;
+		err = 0;
+	}
+
+put_fence:
+	dma_fence_put(fence);
+
+	return err;
+}
+
+static int submit_copy_postfences(struct drm_tegra_submit_syncpt_incr *incr,
+				  struct drm_tegra_channel_submit *args)
+{
+	unsigned long copy_err;
+
+	struct drm_tegra_submit_syncpt_incr __user *user_incrs_ptr =
+		u64_to_user_ptr(args->syncpt_incrs_ptr);
+
+	copy_err = copy_to_user(user_incrs_ptr, incr, sizeof(*incr));
+	if (copy_err)
+		return -EFAULT;
+
+	return 0;
+}
+
+static void release_job(struct host1x_job *job)
+{
+	struct tegra_drm_client *client =
+		container_of(job->client, struct tegra_drm_client, base);
+	struct tegra_drm_job_data *job_data = job->user_data;
+	u32 i;
+
+	for (i = 0; i < job_data->num_used_mappings; i++)
+		tegra_drm_mapping_put(job_data->used_mappings[i].mapping);
+
+	kfree(job_data->used_mappings);
+	kfree(job_data);
+
+	if (client->ops->power_off)
+		client->ops->power_off(client);
+}
+
+int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
+				   struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct drm_tegra_channel_submit *args = data;
+	struct drm_tegra_submit_syncpt_incr incr;
+	struct tegra_drm_job_data *job_data;
+	struct ww_acquire_ctx acquire_ctx;
+	struct tegra_drm_channel_ctx *ctx;
+	struct host1x_job *job;
+	struct gather_bo *bo;
+	u32 i;
+	int err;
+
+	if (args->reserved[0] || args->reserved[1] || args->reserved[2] ||
+	    args->reserved[3])
+		return -EINVAL;
+
+	ctx = tegra_drm_channel_ctx_lock(fpriv, args->channel_ctx);
+	if (!ctx)
+		return -EINVAL;
+
+	err = submit_copy_gather_data(drm, &bo, args);
+	if (err)
+		goto unlock;
+
+	job_data = kzalloc(sizeof(*job_data), GFP_KERNEL);
+	if (!job_data) {
+		err = -ENOMEM;
+		goto put_bo;
+	}
+
+	err = submit_process_bufs(drm, bo, job_data, ctx, args, &acquire_ctx);
+	if (err)
+		goto free_job_data;
+
+	err = submit_create_job(drm, &job, bo, ctx, args, file);
+	if (err)
+		goto free_job_data;
+
+	err = submit_handle_syncpts(drm, job, &incr, args);
+	if (err)
+		goto put_job;
+
+	err = host1x_job_pin(job, ctx->client->base.dev);
+	if (err)
+		goto put_job;
+
+	if (ctx->client->ops->power_on)
+		ctx->client->ops->power_on(ctx->client);
+	job->user_data = job_data;
+	job->release = release_job;
+	job->timeout = min(args->timeout_us / 1000, 10000U);
+	if (job->timeout == 0)
+		job->timeout = 1;
+
+	/*
+	 * job_data is now part of job reference counting, so don't release
+	 * it from here.
+	 */
+	job_data = NULL;
+
+	err = submit_handle_resv(job->user_data, &acquire_ctx);
+	if (err)
+		goto unpin_job;
+
+	err = host1x_job_submit(job);
+	if (err)
+		goto unlock_resv;
+
+	err = submit_create_postfences(job, &incr, args);
+
+	submit_unlock_resv(job->user_data, &acquire_ctx);
+
+	if (err == 0)
+		err = submit_copy_postfences(&incr, args);
+
+	goto put_job;
+
+unlock_resv:
+	submit_unlock_resv(job->user_data, &acquire_ctx);
+unpin_job:
+	host1x_job_unpin(job);
+put_job:
+	host1x_job_put(job);
+free_job_data:
+	if (job_data && job_data->used_mappings) {
+		for (i = 0; i < job_data->num_used_mappings; i++)
+			tegra_drm_mapping_put(job_data->used_mappings[i].mapping);
+		kfree(job_data->used_mappings);
+	}
+	if (job_data)
+		kfree(job_data);
+put_bo:
+	kref_put(&bo->ref, gather_bo_release);
+unlock:
+	mutex_unlock(&fpriv->lock);
+	return err;
+}
diff --git a/drivers/gpu/drm/tegra/uapi/uapi.c b/drivers/gpu/drm/tegra/uapi/uapi.c
new file mode 100644
index 000000000000..287b83105b09
--- /dev/null
+++ b/drivers/gpu/drm/tegra/uapi/uapi.c
@@ -0,0 +1,328 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 NVIDIA Corporation */
+
+#include <linux/host1x.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+
+#include "../uapi.h"
+#include "../drm.h"
+
+struct tegra_drm_channel_ctx *
+tegra_drm_channel_ctx_lock(struct tegra_drm_file *file, u32 id)
+{
+	struct tegra_drm_channel_ctx *ctx;
+
+	mutex_lock(&file->lock);
+	ctx = xa_load(&file->contexts, id);
+	if (!ctx)
+		mutex_unlock(&file->lock);
+
+	return ctx;
+}
+
+static void tegra_drm_mapping_release(struct kref *ref)
+{
+	struct tegra_drm_mapping *mapping =
+		container_of(ref, struct tegra_drm_mapping, ref);
+
+	if (mapping->sgt)
+		dma_unmap_sgtable(mapping->dev, mapping->sgt,
+				  mapping->direction, DMA_ATTR_SKIP_CPU_SYNC);
+
+	host1x_bo_unpin(mapping->dev, mapping->bo, mapping->sgt);
+	host1x_bo_put(mapping->bo);
+
+	kfree(mapping);
+}
+
+void tegra_drm_mapping_put(struct tegra_drm_mapping *mapping)
+{
+	kref_put(&mapping->ref, tegra_drm_mapping_release);
+}
+
+static void tegra_drm_channel_ctx_close(struct tegra_drm_channel_ctx *ctx)
+{
+	unsigned long mapping_id;
+	struct tegra_drm_mapping *mapping;
+
+	xa_for_each(&ctx->mappings, mapping_id, mapping)
+		tegra_drm_mapping_put(mapping);
+
+	xa_destroy(&ctx->mappings);
+
+	host1x_channel_put(ctx->channel);
+
+	kfree(ctx);
+}
+
+int close_channel_ctx(int id, void *p, void *data)
+{
+	struct tegra_drm_channel_ctx *ctx = p;
+
+	tegra_drm_channel_ctx_close(ctx);
+
+	return 0;
+}
+
+void tegra_drm_uapi_close_file(struct tegra_drm_file *file)
+{
+	unsigned long ctx_id;
+	struct tegra_drm_channel_ctx *ctx;
+
+	xa_for_each(&file->contexts, ctx_id, ctx)
+		tegra_drm_channel_ctx_close(ctx);
+
+	xa_destroy(&file->contexts);
+}
+
+int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data,
+				 struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct tegra_drm *tegra = drm->dev_private;
+	struct drm_tegra_channel_open *args = data;
+	struct tegra_drm_client *client = NULL;
+	struct tegra_drm_channel_ctx *ctx;
+	int err;
+
+	if (args->flags || args->reserved[0] || args->reserved[1])
+		return -EINVAL;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	err = -ENODEV;
+	list_for_each_entry(client, &tegra->clients, list) {
+		if (client->base.class == args->host1x_class) {
+			err = 0;
+			break;
+		}
+	}
+	if (err)
+		goto free_ctx;
+
+	if (client->shared_channel) {
+		ctx->channel = host1x_channel_get(client->shared_channel);
+	} else {
+		ctx->channel = host1x_channel_request(&client->base);
+		if (!ctx->channel) {
+			err = -EBUSY;
+			goto free_ctx;
+		}
+	}
+
+	err = xa_alloc(&fpriv->contexts, &args->channel_ctx, ctx,
+		       XA_LIMIT(1, U32_MAX), GFP_KERNEL);
+	if (err < 0) {
+		mutex_unlock(&fpriv->lock);
+		goto put_channel;
+	}
+
+	ctx->client = client;
+	xa_init_flags(&ctx->mappings, XA_FLAGS_ALLOC);
+
+	args->hardware_version = client->version;
+
+	return 0;
+
+put_channel:
+	host1x_channel_put(ctx->channel);
+free_ctx:
+	kfree(ctx);
+
+	return err;
+}
+
+int tegra_drm_ioctl_channel_close(struct drm_device *drm, void *data,
+				  struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct drm_tegra_channel_close *args = data;
+	struct tegra_drm_channel_ctx *ctx;
+
+	if (args->reserved[0])
+		return -EINVAL;
+
+	ctx = tegra_drm_channel_ctx_lock(fpriv, args->channel_ctx);
+	if (!ctx)
+		return -EINVAL;
+
+	xa_erase(&fpriv->contexts, args->channel_ctx);
+
+	mutex_unlock(&fpriv->lock);
+
+	tegra_drm_channel_ctx_close(ctx);
+
+	return 0;
+}
+
+int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data,
+				struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct drm_tegra_channel_map *args = data;
+	struct tegra_drm_channel_ctx *ctx;
+	struct tegra_drm_mapping *mapping;
+	struct drm_gem_object *gem;
+	u32 mapping_id;
+	int err = 0;
+
+	if (args->flags & ~DRM_TEGRA_CHANNEL_MAP_READWRITE)
+		return -EINVAL;
+	if (args->reserved[0] || args->reserved[1])
+		return -EINVAL;
+
+	if (!IS_ALIGNED(args->offset, 0x1000) ||
+	    !IS_ALIGNED(args->length, 0x1000))
+		return -EINVAL;
+
+	ctx = tegra_drm_channel_ctx_lock(fpriv, args->channel_ctx);
+	if (!ctx)
+		return -EINVAL;
+
+	mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
+	if (!mapping) {
+		err = -ENOMEM;
+		goto unlock;
+	}
+
+	kref_init(&mapping->ref);
+
+	gem = drm_gem_object_lookup(file, args->handle);
+	if (!gem) {
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	if (args->offset >= gem->size || args->length > gem->size ||
+	    args->offset > gem->size - args->length) {
+		err = -EINVAL;
+		goto put_gem;
+	}
+
+	mapping->dev = ctx->client->base.dev;
+	mapping->bo = &container_of(gem, struct tegra_bo, gem)->base;
+
+	if (!iommu_get_domain_for_dev(mapping->dev) ||
+	    ctx->client->base.group) {
+		host1x_bo_pin(mapping->dev, mapping->bo,
+			      &mapping->iova);
+	} else {
+		mapping->direction = DMA_TO_DEVICE;
+		if (args->flags & DRM_TEGRA_CHANNEL_MAP_READWRITE)
+			mapping->direction = DMA_BIDIRECTIONAL;
+
+		mapping->sgt =
+			host1x_bo_pin(mapping->dev, mapping->bo, NULL);
+		if (IS_ERR(mapping->sgt)) {
+			err = PTR_ERR(mapping->sgt);
+			goto put_gem;
+		}
+
+		err = dma_map_sgtable(mapping->dev, mapping->sgt,
+				      mapping->direction,
+				      DMA_ATTR_SKIP_CPU_SYNC);
+		if (err)
+			goto unpin;
+
+		/* TODO only map the requested part */
+		mapping->iova =
+			sg_dma_address(mapping->sgt->sgl) + args->offset;
+	}
+
+	mutex_unlock(&fpriv->lock);
+
+	err = xa_alloc(&ctx->mappings, &mapping_id, mapping,
+		       XA_LIMIT(1, U32_MAX), GFP_KERNEL);
+	if (err < 0)
+		goto unmap;
+
+	/* TODO: if appropriate, return actual IOVA */
+	args->iova = U64_MAX;
+	args->mapping_id = mapping_id;
+
+	return 0;
+
+unmap:
+	if (mapping->sgt) {
+		dma_unmap_sgtable(mapping->dev, mapping->sgt,
+				  mapping->direction, DMA_ATTR_SKIP_CPU_SYNC);
+	}
+unpin:
+	host1x_bo_unpin(mapping->dev, mapping->bo, mapping->sgt);
+put_gem:
+	drm_gem_object_put(gem);
+	kfree(mapping);
+unlock:
+	mutex_unlock(&fpriv->lock);
+	return err;
+}
+
+int tegra_drm_ioctl_channel_unmap(struct drm_device *drm, void *data,
+				  struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct drm_tegra_channel_unmap *args = data;
+	struct tegra_drm_channel_ctx *ctx;
+	struct tegra_drm_mapping *mapping;
+
+	if (args->reserved[0] || args->reserved[1])
+		return -EINVAL;
+
+	ctx = tegra_drm_channel_ctx_lock(fpriv, args->channel_ctx);
+	if (!ctx)
+		return -EINVAL;
+
+	mapping = xa_erase(&ctx->mappings, args->mapping_id);
+
+	mutex_unlock(&fpriv->lock);
+
+	if (mapping) {
+		tegra_drm_mapping_put(mapping);
+		return 0;
+	} else {
+		return -EINVAL;
+	}
+}
+
+int tegra_drm_ioctl_gem_create(struct drm_device *drm, void *data,
+			       struct drm_file *file)
+{
+	struct drm_tegra_gem_create *args = data;
+	struct tegra_bo *bo;
+
+	if (args->flags)
+		return -EINVAL;
+
+	bo = tegra_bo_create_with_handle(file, drm, args->size, args->flags,
+					 &args->handle);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	return 0;
+}
+
+int tegra_drm_ioctl_gem_mmap(struct drm_device *drm, void *data,
+			     struct drm_file *file)
+{
+	struct drm_tegra_gem_mmap *args = data;
+	struct drm_gem_object *gem;
+	struct tegra_bo *bo;
+
+	gem = drm_gem_object_lookup(file, args->handle);
+	if (!gem)
+		return -EINVAL;
+
+	bo = to_tegra_bo(gem);
+
+	args->offset = drm_vma_node_offset_addr(&bo->gem.vma_node);
+
+	drm_gem_object_put(gem);
+
+	return 0;
+}