diff mbox series

[v3,01/12] drm: add gem array helpers

Message ID 20190619090420.6667-2-kraxel@redhat.com (mailing list archive)
State New, archived
Headers show
Series drm/virtio: switch from ttm to gem shmem helpers. | expand

Commit Message

Gerd Hoffmann June 19, 2019, 9:04 a.m. UTC 
Add struct and helper functions to manage an array of gem objects.
See added kernel docs for details.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 include/drm/drm_gem_array_helper.h     | 15 +++++
 drivers/gpu/drm/drm_gem_array_helper.c | 76 ++++++++++++++++++++++++++
 drivers/gpu/drm/Makefile               |  3 +-
 3 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 include/drm/drm_gem_array_helper.h
 create mode 100644 drivers/gpu/drm/drm_gem_array_helper.c

Comments

Emil Velikov June 19, 2019, 10:32 a.m. UTC | #1 
Hi Gerd,

On 2019/06/19, Gerd Hoffmann wrote:

> +/**
> + * drm_gem_array_from_handles -- lookup an array of gem handles.
> + *
> + * @drm_file: drm file-private structure to use for the handle look up
> + * @handles: the array of handles to lookup.
> + * @nents: the numer of handles.
> + *
> + * Returns: An array of gem objects on success, NULL on failure.
> + */
> +struct drm_gem_object_array*
> +drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents)
> +{
> +	struct drm_gem_object_array *objs;
> +	u32 i;
> +
> +	objs = drm_gem_array_alloc(nents);
> +	if (!objs)
> +		return NULL;
> +
> +	for (i = 0; i < nents; i++) {
> +		objs->objs[i] = drm_gem_object_lookup(drm_file, handles[i]);
> +		if (!objs->objs[i]) {
Missing object put for the 0..i-1 handles. Personally I would:
    objs->nents = i;
    drm_gem_array_put_free(objs);
    return NULL;

> +			drm_gem_array_put_free(objs);
> +			return NULL;
> +		}
> +	}
> +	return objs;
> +}
Missing EXPORT_SYMBOL?

> +
> +/**
> + * drm_gem_array_put_free -- put gem objects and free array.
> + *
> + * @objs: the gem object array.
> + */
> +void drm_gem_array_put_free(struct drm_gem_object_array *objs)
> +{
> +	u32 i;
> +
> +	for (i = 0; i < objs->nents; i++) {
> +		if (!objs->objs[i])
> +			continue;
> +		drm_gem_object_put_unlocked(objs->objs[i]);
> +	}
> +	drm_gem_array_free(objs);
> +}
Ditto?

HTH
Emil
Daniel Vetter June 19, 2019, 10:54 a.m. UTC | #2 
On Wed, Jun 19, 2019 at 11:04:09AM +0200, Gerd Hoffmann wrote:
> Add struct and helper functions to manage an array of gem objects.
> See added kernel docs for details.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Hm, feels like jumping ahead here, I think there's too much still
in-flight:
- Christian is pondering some improved ww_mutex lock/unlock helpers.
  That'll probably change a lot of this code too.
- If we do more helpers, then I think we should have a consistent story
  across everything. These here don't really fit into the existing gem
  lock/unlock helpers.
- We probably want to design something coherent to replace all the ttm
  execbuf utils, i.e. bo lookup, locking, updating reservation objects,
  all that.
- I think this needs more than one driver to proof itself.

Maybe long-term we could have a drm_gem_eu_helper.c or so which contains
all that. But that's still some ways off.

I'd go back to the virtio-only conversion, and once we have more of this
stuff settled, we can look at how to properly design some nice&consistent
helpers.

Cheers, Daniel
> ---
>  include/drm/drm_gem_array_helper.h     | 15 +++++
>  drivers/gpu/drm/drm_gem_array_helper.c | 76 ++++++++++++++++++++++++++
>  drivers/gpu/drm/Makefile               |  3 +-
>  3 files changed, 93 insertions(+), 1 deletion(-)
>  create mode 100644 include/drm/drm_gem_array_helper.h
>  create mode 100644 drivers/gpu/drm/drm_gem_array_helper.c
> 
> diff --git a/include/drm/drm_gem_array_helper.h b/include/drm/drm_gem_array_helper.h
> new file mode 100644
> index 000000000000..adf7961247b3
> --- /dev/null
> +++ b/include/drm/drm_gem_array_helper.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __DRM_GEM_ARRAY_HELPER_H__
> +#define __DRM_GEM_ARRAY_HELPER_H__
> +
> +struct drm_gem_object_array {
> +	u32 nents;
> +	struct drm_gem_object *objs[];
> +};
> +
> +struct drm_gem_object_array *drm_gem_array_alloc(u32 nents);
> +struct drm_gem_object_array *
> +drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents);
> +void drm_gem_array_put_free(struct drm_gem_object_array *objs);
> +
> +#endif /* __DRM_GEM_ARRAY_HELPER_H__ */
> diff --git a/drivers/gpu/drm/drm_gem_array_helper.c b/drivers/gpu/drm/drm_gem_array_helper.c
> new file mode 100644
> index 000000000000..d35c77c4a02d
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_gem_array_helper.c
> @@ -0,0 +1,76 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#include <drm/drm_gem.h>
> +#include <drm/drm_gem_array_helper.h>
> +
> +/**
> + * drm_gem_array_alloc -- allocate gem object array of the given size.
> + *
> + * @nents: number of entries needed.
> + *
> + * Returns: An array of gem objects on success, NULL on failure.
> + */
> +struct drm_gem_object_array *drm_gem_array_alloc(u32 nents)
> +{
> +	struct drm_gem_object_array *objs;
> +	size_t size = sizeof(*objs) + sizeof(objs->objs[0]) * nents;
> +
> +	objs = kzalloc(size, GFP_KERNEL);
> +	if (!objs)
> +		return NULL;
> +
> +	objs->nents = nents;
> +	return objs;
> +}
> +EXPORT_SYMBOL(drm_gem_array_alloc);
> +
> +static void drm_gem_array_free(struct drm_gem_object_array *objs)
> +{
> +	kfree(objs);
> +}
> +
> +/**
> + * drm_gem_array_from_handles -- lookup an array of gem handles.
> + *
> + * @drm_file: drm file-private structure to use for the handle look up
> + * @handles: the array of handles to lookup.
> + * @nents: the numer of handles.
> + *
> + * Returns: An array of gem objects on success, NULL on failure.
> + */
> +struct drm_gem_object_array*
> +drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents)
> +{
> +	struct drm_gem_object_array *objs;
> +	u32 i;
> +
> +	objs = drm_gem_array_alloc(nents);
> +	if (!objs)
> +		return NULL;
> +
> +	for (i = 0; i < nents; i++) {
> +		objs->objs[i] = drm_gem_object_lookup(drm_file, handles[i]);
> +		if (!objs->objs[i]) {
> +			drm_gem_array_put_free(objs);
> +			return NULL;
> +		}
> +	}
> +	return objs;
> +}
> +
> +/**
> + * drm_gem_array_put_free -- put gem objects and free array.
> + *
> + * @objs: the gem object array.
> + */
> +void drm_gem_array_put_free(struct drm_gem_object_array *objs)
> +{
> +	u32 i;
> +
> +	for (i = 0; i < objs->nents; i++) {
> +		if (!objs->objs[i])
> +			continue;
> +		drm_gem_object_put_unlocked(objs->objs[i]);
> +	}
> +	drm_gem_array_free(objs);
> +}
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 9d630a28a788..d32e7de0937b 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -43,7 +43,8 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper
>  		drm_simple_kms_helper.o drm_modeset_helper.o \
>  		drm_scdc_helper.o drm_gem_framebuffer_helper.o \
>  		drm_atomic_state_helper.o drm_damage_helper.o \
> -		drm_format_helper.o drm_self_refresh_helper.o
> +		drm_format_helper.o drm_self_refresh_helper.o \
> +		drm_gem_array_helper.o
>  
>  drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
>  drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
> -- 
> 2.18.1
>
Gerd Hoffmann June 19, 2019, 11:27 a.m. UTC | #3 
> > +struct drm_gem_object_array*
> > +drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents)
> > +{
> > +	struct drm_gem_object_array *objs;
> > +	u32 i;
> > +
> > +	objs = drm_gem_array_alloc(nents);
> > +	if (!objs)
> > +		return NULL;
> > +
> > +	for (i = 0; i < nents; i++) {
> > +		objs->objs[i] = drm_gem_object_lookup(drm_file, handles[i]);
> > +		if (!objs->objs[i]) {
> Missing object put for the 0..i-1 handles. Personally I would:

No. drm_gem_array_alloc initializes objs->nents and
drm_gem_array_put_free() loops over the whole array,
skipping NULL pointers.

> > +			drm_gem_array_put_free(objs);
> > +			return NULL;
> > +		}
> > +	}
> > +	return objs;
> > +}
> Missing EXPORT_SYMBOL?

Oops.  I had that fixed.  Possibly squashed into the wrong patch.

> Ditto?

Yes.

cheers,
  Gerd
diff mbox series

Patch

diff --git a/include/drm/drm_gem_array_helper.h b/include/drm/drm_gem_array_helper.h
new file mode 100644
index 000000000000..adf7961247b3
--- /dev/null
+++ b/include/drm/drm_gem_array_helper.h
@@ -0,0 +1,15 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DRM_GEM_ARRAY_HELPER_H__
+#define __DRM_GEM_ARRAY_HELPER_H__
+
+struct drm_gem_object_array {
+	u32 nents;
+	struct drm_gem_object *objs[];
+};
+
+struct drm_gem_object_array *drm_gem_array_alloc(u32 nents);
+struct drm_gem_object_array *
+drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents);
+void drm_gem_array_put_free(struct drm_gem_object_array *objs);
+
+#endif /* __DRM_GEM_ARRAY_HELPER_H__ */
diff --git a/drivers/gpu/drm/drm_gem_array_helper.c b/drivers/gpu/drm/drm_gem_array_helper.c
new file mode 100644
index 000000000000..d35c77c4a02d
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_array_helper.c
@@ -0,0 +1,76 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_array_helper.h>
+
+/**
+ * drm_gem_array_alloc -- allocate gem object array of the given size.
+ *
+ * @nents: number of entries needed.
+ *
+ * Returns: An array of gem objects on success, NULL on failure.
+ */
+struct drm_gem_object_array *drm_gem_array_alloc(u32 nents)
+{
+	struct drm_gem_object_array *objs;
+	size_t size = sizeof(*objs) + sizeof(objs->objs[0]) * nents;
+
+	objs = kzalloc(size, GFP_KERNEL);
+	if (!objs)
+		return NULL;
+
+	objs->nents = nents;
+	return objs;
+}
+EXPORT_SYMBOL(drm_gem_array_alloc);
+
+static void drm_gem_array_free(struct drm_gem_object_array *objs)
+{
+	kfree(objs);
+}
+
+/**
+ * drm_gem_array_from_handles -- lookup an array of gem handles.
+ *
+ * @drm_file: drm file-private structure to use for the handle look up
+ * @handles: the array of handles to lookup.
+ * @nents: the numer of handles.
+ *
+ * Returns: An array of gem objects on success, NULL on failure.
+ */
+struct drm_gem_object_array*
+drm_gem_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents)
+{
+	struct drm_gem_object_array *objs;
+	u32 i;
+
+	objs = drm_gem_array_alloc(nents);
+	if (!objs)
+		return NULL;
+
+	for (i = 0; i < nents; i++) {
+		objs->objs[i] = drm_gem_object_lookup(drm_file, handles[i]);
+		if (!objs->objs[i]) {
+			drm_gem_array_put_free(objs);
+			return NULL;
+		}
+	}
+	return objs;
+}
+
+/**
+ * drm_gem_array_put_free -- put gem objects and free array.
+ *
+ * @objs: the gem object array.
+ */
+void drm_gem_array_put_free(struct drm_gem_object_array *objs)
+{
+	u32 i;
+
+	for (i = 0; i < objs->nents; i++) {
+		if (!objs->objs[i])
+			continue;
+		drm_gem_object_put_unlocked(objs->objs[i]);
+	}
+	drm_gem_array_free(objs);
+}
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 9d630a28a788..d32e7de0937b 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -43,7 +43,8 @@  drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper
 		drm_simple_kms_helper.o drm_modeset_helper.o \
 		drm_scdc_helper.o drm_gem_framebuffer_helper.o \
 		drm_atomic_state_helper.o drm_damage_helper.o \
-		drm_format_helper.o drm_self_refresh_helper.o
+		drm_format_helper.o drm_self_refresh_helper.o \
+		drm_gem_array_helper.o
 
 drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o