[PATCH 2/3] drm/msm: add support for createblob_check driver hook

[Steve Cohen <cohens@codeaurora.org>]

Allow msm_kms devices to register a hook to check blob count
and blob size limitations before a new blob is created.

Signed-off-by: Steve Cohen <cohens@codeaurora.org>
---
 drivers/gpu/drm/msm/msm_drv.c | 25 +++++++++++++++++++++++++
 drivers/gpu/drm/msm/msm_kms.h |  1 +
 2 files changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index c84f0a8..d0b0419 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -680,6 +680,30 @@ static void msm_disable_vblank(struct drm_device *dev, unsigned int pipe)
 	vblank_ctrl_queue_work(priv, pipe, false);
 }
 
+static int msm_createblob_check (struct drm_device *dev, size_t length,
+		struct drm_file *file_priv)
+{
+	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_kms *kms = priv->kms;
+	unsigned int count = 0;
+	struct drm_property_blob *blob;
+
+	if (!kms)
+		return -EINVAL;
+
+	if (!kms->funcs->createblob_check)
+		return 0;
+
+	mutex_lock(&dev->mode_config.blob_lock);
+	list_for_each_entry(blob, &file_priv->blobs, head_file) {
+		if (count < UINT_MAX)
+			count++;
+	}
+	mutex_unlock(&dev->mode_config.blob_lock);
+
+	return kms->funcs->createblob_check(count, length);
+}
+
 /*
  * DRM ioctls:
  */
@@ -1011,6 +1035,7 @@ static struct drm_driver msm_driver = {
 	.gem_prime_vmap     = msm_gem_prime_vmap,
 	.gem_prime_vunmap   = msm_gem_prime_vunmap,
 	.gem_prime_mmap     = msm_gem_prime_mmap,
+	.createblob_check   = msm_createblob_check,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init       = msm_debugfs_init,
 #endif
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 1cbef6b..8a7e581 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -126,6 +126,7 @@ struct msm_kms_funcs {
 	/* debugfs: */
 	int (*debugfs_init)(struct msm_kms *kms, struct drm_minor *minor);
 #endif
+	int (*createblob_check)(unsigned int count, size_t length);
 };
 
 struct msm_kms;
-- 
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