[PATCH v2 8/8] drm/tegra: Support context isolation

Mikko Perttunen
2021-09-16T14:36:04Z

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@nvidia.com>
---
drivers/gpu/drm/tegra/drm.h | 2 ++
drivers/gpu/drm/tegra/submit.c | 13 +++++++++++++
drivers/gpu/drm/tegra/uapi.c | 34 ++++++++++++++++++++++++++++++++--
3 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index fc0a19554eac..717e9f81ee1f 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);
};

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 776f825df52f..b6008246bebe 100644
--- a/drivers/gpu/drm/tegra/submit.c
+++ b/drivers/gpu/drm/tegra/submit.c
@@ -469,6 +469,9 @@ static void release_job(struct host1x_job *job)
struct tegra_drm_submit_data *job_data = job->user_data;
u32 i;

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

@@ -572,6 +575,16 @@ int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
job->release = release_job;
job->timeout = 10000;

+ if (context->memory_context && context->client->ops->get_streamid_offset) {
+ int offset = context->client->ops->get_streamid_offset(context->client);
+
+ if (offset >= 0) {
+ job->context = context->memory_context;
+ job->engine_streamid_offset = offset;
+ host1x_context_get(job->context);
+ }
+ }
+
/*
* job_data is now part of job reference counting, so don't release
* it from here.
diff --git a/drivers/gpu/drm/tegra/uapi.c b/drivers/gpu/drm/tegra/uapi.c
index 690a339c52ec..bfded46b974a 100644
--- a/drivers/gpu/drm/tegra/uapi.c
+++ b/drivers/gpu/drm/tegra/uapi.c
@@ -37,6 +37,9 @@ 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);

@@ -76,6 +79,7 @@ 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;
@@ -106,10 +110,29 @@ 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 &&
+ client->ops->get_streamid_offset(client) >= 0) {
+ context->memory_context =
+ host1x_context_alloc(host, get_task_pid(current, PIDTYPE_TGID));
+ 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);
@@ -122,6 +145,9 @@ 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:
@@ -180,7 +206,11 @@ int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data, struct drm_f

kref_init(&mapping->ref);

- mapping->dev = context->client->base.dev;
+ 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;