[PATCH v4 8/9] drm/tegra: Support context isolation

From: cyndis
Date: Tue Mar 01 2022 - 11:15:51 EST


From: Mikko Perttunen <mperttunen@xxxxxxxxxx>

For engines that support context isolation, allocate a context when
opening a channel, and set up stream ID offset and context fields
when submitting a job.

Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
---
v4:
* Separate error and output values in get_streamid_offset API
* Improve error handling
* Rename job->context to job->memory_context for clarity
---
drivers/gpu/drm/tegra/drm.h | 2 ++
drivers/gpu/drm/tegra/submit.c | 21 +++++++++++++++-
drivers/gpu/drm/tegra/uapi.c | 45 ++++++++++++++++++++++++++++++++--
3 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index fc0a19554eac..608daba01587 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -80,6 +80,7 @@ struct tegra_drm_context {

/* Only used by new UAPI. */
struct xarray mappings;
+ struct host1x_context *memory_context;
};

struct tegra_drm_client_ops {
@@ -91,6 +92,7 @@ struct tegra_drm_client_ops {
int (*submit)(struct tegra_drm_context *context,
struct drm_tegra_submit *args, struct drm_device *drm,
struct drm_file *file);
+ int (*get_streamid_offset)(struct tegra_drm_client *client, u32 *offset);
};

int tegra_drm_submit(struct tegra_drm_context *context,
diff --git a/drivers/gpu/drm/tegra/submit.c b/drivers/gpu/drm/tegra/submit.c
index 6d6dd8c35475..fd0ba09e552a 100644
--- a/drivers/gpu/drm/tegra/submit.c
+++ b/drivers/gpu/drm/tegra/submit.c
@@ -498,6 +498,9 @@ static void release_job(struct host1x_job *job)
struct tegra_drm_submit_data *job_data = job->user_data;
u32 i;

+ if (job->memory_context)
+ host1x_context_put(job->memory_context);
+
for (i = 0; i < job_data->num_used_mappings; i++)
tegra_drm_mapping_put(job_data->used_mappings[i].mapping);

@@ -588,11 +591,24 @@ int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
goto put_job;
}

+ if (context->memory_context && context->client->ops->get_streamid_offset) {
+ int offset;
+
+ err = context->client->ops->get_streamid_offset(context->client, &offset);
+ if (!err) {
+ job->memory_context = context->memory_context;
+ job->engine_streamid_offset = offset;
+ host1x_context_get(job->memory_context);
+ } else if (err != -EOPNOTSUPP) {
+ goto unpin_job;
+ }
+ }
+
/* Boot engine. */
err = pm_runtime_resume_and_get(context->client->base.dev);
if (err < 0) {
SUBMIT_ERR(context, "could not power up engine: %d", err);
- goto unpin_job;
+ goto put_memory_context;
}

job->user_data = job_data;
@@ -627,6 +643,9 @@ int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,

goto put_job;

+put_memory_context:
+ if (job->memory_context)
+ host1x_context_put(job->memory_context);
unpin_job:
host1x_job_unpin(job);
put_job:
diff --git a/drivers/gpu/drm/tegra/uapi.c b/drivers/gpu/drm/tegra/uapi.c
index 9ab9179d2026..475febb6d86b 100644
--- a/drivers/gpu/drm/tegra/uapi.c
+++ b/drivers/gpu/drm/tegra/uapi.c
@@ -33,6 +33,9 @@ static void tegra_drm_channel_context_close(struct tegra_drm_context *context)
struct tegra_drm_mapping *mapping;
unsigned long id;

+ if (context->memory_context)
+ host1x_context_put(context->memory_context);
+
xa_for_each(&context->mappings, id, mapping)
tegra_drm_mapping_put(mapping);

@@ -72,6 +75,7 @@ static struct tegra_drm_client *tegra_drm_find_client(struct tegra_drm *tegra, u

int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data, struct drm_file *file)
{
+ struct host1x *host = tegra_drm_to_host1x(drm->dev_private);
struct tegra_drm_file *fpriv = file->driver_priv;
struct tegra_drm *tegra = drm->dev_private;
struct drm_tegra_channel_open *args = data;
@@ -102,10 +106,38 @@ int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data, struct drm_
}
}

+ /* Only allocate context if the engine supports context isolation. */
+ if (client->ops->get_streamid_offset) {
+ u32 offset;
+
+ err = client->ops->get_streamid_offset(client, &offset);
+ if (!err) {
+ context->memory_context =
+ host1x_context_alloc(host, get_task_pid(current, PIDTYPE_TGID));
+ } else if (err == -EOPNOTSUPP) {
+ context->memory_context = NULL;
+ } else {
+ goto put_channel;
+ }
+
+ if (IS_ERR(context->memory_context)) {
+ if (PTR_ERR(context->memory_context) != -EOPNOTSUPP) {
+ err = PTR_ERR(context->memory_context);
+ goto put_channel;
+ } else {
+ /*
+ * OK, HW does not support contexts or contexts
+ * are disabled.
+ */
+ context->memory_context = NULL;
+ }
+ }
+ }
+
err = xa_alloc(&fpriv->contexts, &args->context, context, XA_LIMIT(1, U32_MAX),
GFP_KERNEL);
if (err < 0)
- goto put_channel;
+ goto put_memctx;

context->client = client;
xa_init_flags(&context->mappings, XA_FLAGS_ALLOC1);
@@ -118,6 +150,9 @@ int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data, struct drm_

return 0;

+put_memctx:
+ if (context->memory_context)
+ host1x_context_put(context->memory_context);
put_channel:
host1x_channel_put(context->channel);
free:
@@ -156,6 +191,7 @@ int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data, struct drm_f
struct tegra_drm_mapping *mapping;
struct tegra_drm_context *context;
enum dma_data_direction direction;
+ struct device *mapping_dev;
int err = 0;

if (args->flags & ~DRM_TEGRA_CHANNEL_MAP_READ_WRITE)
@@ -177,6 +213,11 @@ int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data, struct drm_f

kref_init(&mapping->ref);

+ if (context->memory_context)
+ mapping_dev = &context->memory_context->dev;
+ else
+ mapping_dev = context->client->base.dev;
+
mapping->bo = tegra_gem_lookup(file, args->handle);
if (!mapping->bo) {
err = -EINVAL;
@@ -201,7 +242,7 @@ int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data, struct drm_f
goto put_gem;
}

- mapping->map = host1x_bo_pin(context->client->base.dev, mapping->bo, direction, NULL);
+ mapping->map = host1x_bo_pin(mapping_dev, mapping->bo, direction, NULL);
if (IS_ERR(mapping->map)) {
err = PTR_ERR(mapping->map);
goto put_gem;
--
2.35.0