[PATCH v7 06/21] drm/i915: Prepare to dynamic dma-buf locking specification

From: Dmitry Osipenko
Date: Mon Oct 17 2022 - 13:25:12 EST


Prepare i915 driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions
and handling cases where importer now holds the reservation lock.

Acked-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_object.c | 14 ++++++++++++++
.../gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 16 ++++++++--------
3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index f5062d0c6333..07eee1c09aaf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -72,7 +72,7 @@ static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf,
struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
void *vaddr;

- vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
+ vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
if (IS_ERR(vaddr))
return PTR_ERR(vaddr);

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 85482a04d158..7cab89618bad 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -290,7 +290,21 @@ void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj)
__i915_gem_object_free_mmaps(obj);

atomic_set(&obj->mm.pages_pin_count, 0);
+
+ /*
+ * dma_buf_unmap_attachment() requires reservation to be
+ * locked. The imported GEM shouldn't share reservation lock
+ * and ttm_bo_cleanup_memtype_use() shouldn't be invoked for
+ * dma-buf, so it's safe to take the lock.
+ */
+ if (obj->base.import_attach)
+ i915_gem_object_lock(obj, NULL);
+
__i915_gem_object_put_pages(obj);
+
+ if (obj->base.import_attach)
+ i915_gem_object_unlock(obj);
+
GEM_BUG_ON(i915_gem_object_has_pages(obj));
}

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
index 51ed824b020c..f2f3cfad807b 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
@@ -213,7 +213,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
goto out_import;
}

- st = dma_buf_map_attachment(import_attach, DMA_BIDIRECTIONAL);
+ st = dma_buf_map_attachment_unlocked(import_attach, DMA_BIDIRECTIONAL);
if (IS_ERR(st)) {
err = PTR_ERR(st);
goto out_detach;
@@ -226,7 +226,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
timeout = -ETIME;
}
err = timeout > 0 ? 0 : timeout;
- dma_buf_unmap_attachment(import_attach, st, DMA_BIDIRECTIONAL);
+ dma_buf_unmap_attachment_unlocked(import_attach, st, DMA_BIDIRECTIONAL);
out_detach:
dma_buf_detach(dmabuf, import_attach);
out_import:
@@ -296,7 +296,7 @@ static int igt_dmabuf_import(void *arg)
goto out_obj;
}

- err = dma_buf_vmap(dmabuf, &map);
+ err = dma_buf_vmap_unlocked(dmabuf, &map);
dma_map = err ? NULL : map.vaddr;
if (!dma_map) {
pr_err("dma_buf_vmap failed\n");
@@ -337,7 +337,7 @@ static int igt_dmabuf_import(void *arg)

err = 0;
out_dma_map:
- dma_buf_vunmap(dmabuf, &map);
+ dma_buf_vunmap_unlocked(dmabuf, &map);
out_obj:
i915_gem_object_put(obj);
out_dmabuf:
@@ -358,7 +358,7 @@ static int igt_dmabuf_import_ownership(void *arg)
if (IS_ERR(dmabuf))
return PTR_ERR(dmabuf);

- err = dma_buf_vmap(dmabuf, &map);
+ err = dma_buf_vmap_unlocked(dmabuf, &map);
ptr = err ? NULL : map.vaddr;
if (!ptr) {
pr_err("dma_buf_vmap failed\n");
@@ -367,7 +367,7 @@ static int igt_dmabuf_import_ownership(void *arg)
}

memset(ptr, 0xc5, PAGE_SIZE);
- dma_buf_vunmap(dmabuf, &map);
+ dma_buf_vunmap_unlocked(dmabuf, &map);

obj = to_intel_bo(i915_gem_prime_import(&i915->drm, dmabuf));
if (IS_ERR(obj)) {
@@ -418,7 +418,7 @@ static int igt_dmabuf_export_vmap(void *arg)
}
i915_gem_object_put(obj);

- err = dma_buf_vmap(dmabuf, &map);
+ err = dma_buf_vmap_unlocked(dmabuf, &map);
ptr = err ? NULL : map.vaddr;
if (!ptr) {
pr_err("dma_buf_vmap failed\n");
@@ -435,7 +435,7 @@ static int igt_dmabuf_export_vmap(void *arg)
memset(ptr, 0xc5, dmabuf->size);

err = 0;
- dma_buf_vunmap(dmabuf, &map);
+ dma_buf_vunmap_unlocked(dmabuf, &map);
out:
dma_buf_put(dmabuf);
return err;
--
2.37.3