[PATCH] drm/msm: Do not unpin/evict exported dma-buf's

Rob Clark
2021-04-26T23:50:02Z

From: Rob Clark <robdclark@chromium.org>

Our initial logic for excluding dma-bufs was not quite right. In
particular we want msm_gem_get/put_pages() path used for exported
dma-bufs to increment/decrement the pin-count.

Also, in case the importer is vmap'ing the dma-buf, we need to be
sure to update the object's status, because it is now no longer
potentially evictable.

Fixes: 63f17ef83428 drm/msm: Support evicting GEM objects to swap
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/gpu/drm/msm/msm_gem.c | 16 +++++++++++++++-
drivers/gpu/drm/msm/msm_gem.h | 4 ++--
2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 09ef4ec6eb34..17f85d2f23ab 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -190,13 +190,25 @@ struct page **msm_gem_get_pages(struct drm_gem_object *obj)
}

p = get_pages(obj);
+
+ if (!IS_ERR(p)) {
+ msm_obj->pin_count++;
+ update_inactive(msm_obj);
+ }
+
msm_gem_unlock(obj);
return p;
}

void msm_gem_put_pages(struct drm_gem_object *obj)
{
- /* when we start tracking the pin count, then do something here */
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+ msm_gem_lock(obj);
+ msm_obj->pin_count--;
+ GEM_WARN_ON(msm_obj->pin_count < 0);
+ update_inactive(msm_obj);
+ msm_gem_unlock(obj);
}

int msm_gem_mmap_obj(struct drm_gem_object *obj,
@@ -646,6 +658,8 @@ static void *get_vaddr(struct drm_gem_object *obj, unsigned madv)
ret = -ENOMEM;
goto fail;
}
+
+ update_inactive(msm_obj);
}

return msm_obj->vaddr;
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 1b519fcd8418..66fb40b87122 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -228,7 +228,7 @@ static inline bool is_active(struct msm_gem_object *msm_obj)
/* imported/exported objects are not purgeable: */
static inline bool is_unpurgeable(struct msm_gem_object *msm_obj)
{
- return msm_obj->base.dma_buf && msm_obj->base.import_attach;
+ return msm_obj->base.import_attach || msm_obj->pin_count;
}

static inline bool is_purgeable(struct msm_gem_object *msm_obj)
@@ -278,7 +278,7 @@ static inline void mark_unpurgeable(struct msm_gem_object *msm_obj)

static inline bool is_unevictable(struct msm_gem_object *msm_obj)
{
- return is_unpurgeable(msm_obj) || msm_obj->pin_count || msm_obj->vaddr;
+ return is_unpurgeable(msm_obj) || msm_obj->vaddr;
}

static inline void mark_evictable(struct msm_gem_object *msm_obj)
--
2.30.2