From: Russell King <rmk+ker...@arm.linux.org.uk>
We can easily exhaust the MMU space since we leave mappings in place
until the underlying buffers are freed.
Solve this by reaping inactive MMU entries using the drm_mm scanning
facility to select candidate(s), which will then have their MMU
mappings released.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/staging/etnaviv/etnaviv_mmu.c | 61 ++++++++++++++++++++++++++++++++++-
1 file changed, 60 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/etnaviv/etnaviv_mmu.c
b/drivers/staging/etnaviv/etnaviv_mmu.c
index 89c5713f52bc..5647768c2be4 100644
--- a/drivers/staging/etnaviv/etnaviv_mmu.c
+++ b/drivers/staging/etnaviv/etnaviv_mmu.c
@@ -94,6 +94,7 @@ int etnaviv_iommu_unmap(struct etnaviv_iommu *iommu, uint32_t
iova,
int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
struct etnaviv_gem_object *etnaviv_obj)
{
+ struct etnaviv_drm_private *priv = etnaviv_obj->base.dev->dev_private;
struct sg_table *sgt = etnaviv_obj->sgt;
struct drm_mm_node *node;
int ret;
@@ -117,6 +118,10 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
return -ENOMEM;
while (1) {
+ struct etnaviv_gem_object *o, *n;
+ struct list_head list;
+ bool found;
+
ret = drm_mm_insert_node_in_range(&mmu->mm, node,
etnaviv_obj->base.size, 0, mmu->last_iova, ~0UL,
DRM_MM_SEARCH_DEFAULT);
@@ -134,7 +139,58 @@ int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
continue;
}
- break;
+ /* Try to retire some entries */
+ drm_mm_init_scan(&mmu->mm, etnaviv_obj->base.size, 0, 0);
+
+ found = 0;
+ INIT_LIST_HEAD(&list);
+ list_for_each_entry(o, &priv->inactive_list, mm_list) {
+ if (!o->gpu_vram_node ||
+ o->gpu_vram_node->mm != &mmu->mm)
+ continue;
+
+ /*
+ * If it's on the submit list, then it is part of
+ * a submission, and we want to keep its entry.
+ */
+ if (!list_empty(&o->submit_entry))
+ continue;
+
+ list_add(&o->submit_entry, &list);
+ if (drm_mm_scan_add_block(o->gpu_vram_node)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ /* Nothing found, clean up and fail */
+ list_for_each_entry_safe(o, n, &list, submit_entry)
+
BUG_ON(drm_mm_scan_remove_block(o->gpu_vram_node));
+ break;
+ }
+
+ /*
+ * drm_mm does not allow any other operations while
+ * scanning, so we have to remove all blocks first.
+ * If drm_mm_scan_remove_block() returns false, we
+ * can leave the block pinned.
+ */
+ list_for_each_entry_safe(o, n, &list, submit_entry)
+ if (!drm_mm_scan_remove_block(o->gpu_vram_node))
+ list_del_init(&o->submit_entry);
+
+ list_for_each_entry_safe(o, n, &list, submit_entry) {
+ list_del_init(&o->submit_entry);
+ etnaviv_iommu_unmap_gem(mmu, o);
+ }
+
+ /*
+ * We removed enough mappings so that the new allocation will
+ * succeed. Ensure that the MMU will be flushed and retry
+ * the allocation one more time.
+ */
+ mmu->need_flush = true;
}
if (ret < 0) {
@@ -169,6 +225,9 @@ void etnaviv_iommu_unmap_gem(struct etnaviv_iommu *mmu,
etnaviv_obj->base.size);
drm_mm_remove_node(etnaviv_obj->gpu_vram_node);
kfree(etnaviv_obj->gpu_vram_node);
+
+ etnaviv_obj->gpu_vram_node = NULL;
+ etnaviv_obj->iova = 0;
}
}
--
2.1.4
