Implementations of the vmap/vunmap GEM callbacks may perform pinning
of the BO and may acquire the associated reservation object's lock.
It's somewhat inconvenient to callers that simply require a mapping of
the contained memory; and also ipmplies a certain overhead.
Therefore provide drm_gem_vram_vmap_local() drm_gem_vram_vunmap_local(),
which only perform the vmap/vunmap operations. Callers have to hold the
reservation lock while the mapping persists; or have to pin the BO by
themselves.
This patch connects GEM VRAM helpers to GEM object functions with
equivalent functionality.
v4:
* move driver changes into separate patches (Daniel)
* update documentation (Daniel)
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/drm_gem_vram_helper.c | 141 +++++++++++++++++---------
include/drm/drm_gem_vram_helper.h | 2 +
2 files changed, 95 insertions(+), 48 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c
index 02ca22e90290..c7fba3a0758e 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -379,47 +379,6 @@ int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
}
EXPORT_SYMBOL(drm_gem_vram_unpin);
-static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
- struct dma_buf_map *map)
-{
- int ret;
-
- if (gbo->vmap_use_count > 0)
- goto out;
-
- ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
- if (ret)
- return ret;
-
-out:
- ++gbo->vmap_use_count;
- *map = gbo->map;
-
- return 0;
-}
-
-static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
- struct dma_buf_map *map)
-{
- struct drm_device *dev = gbo->bo.base.dev;
-
- if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
- return;
-
- if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
- return; /* BUG: map not mapped from this BO */
-
- if (--gbo->vmap_use_count > 0)
- return;
-
- /*
- * Permanently mapping and unmapping buffers adds overhead from
- * updating the page tables and creates debugging output. Therefore,
- * we delay the actual unmap operation until the BO gets evicted
- * from memory. See drm_gem_vram_bo_driver_move_notify().
- */
-}
-
/**
* drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
* space
@@ -447,7 +406,7 @@ int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
ret = drm_gem_vram_pin_locked(gbo, 0);
if (ret)
goto err_ttm_bo_unreserve;
- ret = drm_gem_vram_kmap_locked(gbo, map);
+ ret = drm_gem_vram_vmap_local(gbo, map);
if (ret)
goto err_drm_gem_vram_unpin_locked;
@@ -479,13 +438,83 @@ void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *ma
if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
return;
- drm_gem_vram_kunmap_locked(gbo, map);
+ drm_gem_vram_vunmap_local(gbo, map);
drm_gem_vram_unpin_locked(gbo);
ttm_bo_unreserve(&gbo->bo);
}
EXPORT_SYMBOL(drm_gem_vram_vunmap);
+/**
+ * drm_gem_vram_vmap_local() - Maps a GEM VRAM object into kernel address space
+ * @gbo: The GEM VRAM object to map
+ * @map: Returns the kernel virtual address of the VRAM GEM object's backing
+ * store.
+ *
+ * The vmap_local function maps the buffer of a GEM VRAM object into kernel address
+ * space. Call drm_gem_vram_vunmap_local() with the returned address to unmap and
+ * unpin the GEM VRAM object.
+ *
+ * The function is called with the BO's reservation object locked. For short-term
+ * mappings, callers must hold the BO's reservation lock until after unmapping the
+ * buffer.
+ *
+ * Returns:
+ * 0 on success, or a negative error code otherwise.
+ */
+int drm_gem_vram_vmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
+{
+ int ret;
+
+ dma_resv_assert_held(gbo->bo.base.resv);
+
+ if (gbo->vmap_use_count > 0)
+ goto out;
+
+ ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
+ if (ret)
+ return ret;
+
+out:
+ ++gbo->vmap_use_count;
+ *map = gbo->map;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_gem_vram_vmap_local);
+
+/**
+ * drm_gem_vram_vunmap_local() - Unmaps a GEM VRAM object
+ * @gbo: The GEM VRAM object to unmap
+ * @map: Kernel virtual address where the VRAM GEM object was mapped
+ *
+ * A call to drm_gem_vram_vunmap_local() unmaps a GEM VRAM object's buffer. See
+ * the documentation for drm_gem_vram_vmap_local() for more information.
+ */
+void drm_gem_vram_vunmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
+{
+ struct drm_device *dev = gbo->bo.base.dev;
+
+ dma_resv_assert_held(gbo->bo.base.resv);
+
+ if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
+ return;
+
+ if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
+ return; /* BUG: map not mapped from this BO */
+
+ if (--gbo->vmap_use_count > 0)
+ return;
+
+ /*
+ * Permanently mapping and unmapping buffers adds overhead from
+ * updating the page tables and creates debugging output. Therefore,
+ * we delay the actual unmap operation until the BO gets evicted
+ * from memory. See drm_gem_vram_bo_driver_move_notify().
+ */
+}
+EXPORT_SYMBOL(drm_gem_vram_vunmap_local);
+
/**
* drm_gem_vram_fill_create_dumb() - \
Helper for implementing &struct drm_driver.dumb_create
@@ -871,17 +900,33 @@ static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_bu
drm_gem_vram_vunmap(gbo, map);
}
+static int drm_gem_vram_object_vmap_local(struct drm_gem_object *gem, struct dma_buf_map *map)
+{
+ struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
+
+ return drm_gem_vram_vmap_local(gbo, map);
+}
+
+static void drm_gem_vram_object_vunmap_local(struct drm_gem_object *gem, struct dma_buf_map *map)
+{
+ struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
+
+ drm_gem_vram_vunmap_local(gbo, map);
+}
+
/*
* GEM object funcs
*/
static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
- .free = drm_gem_vram_object_free,
- .pin = drm_gem_vram_object_pin,
- .unpin = drm_gem_vram_object_unpin,
- .vmap = drm_gem_vram_object_vmap,
+ .free = drm_gem_vram_object_free,
+ .pin = drm_gem_vram_object_pin,
+ .unpin = drm_gem_vram_object_unpin,
+ .vmap = drm_gem_vram_object_vmap,
.vunmap = drm_gem_vram_object_vunmap,
- .mmap = drm_gem_ttm_mmap,
+ .vmap_local = drm_gem_vram_object_vmap_local,
+ .vunmap_local = drm_gem_vram_object_vunmap_local,
+ .mmap = drm_gem_ttm_mmap,
.print_info = drm_gem_ttm_print_info,
};
diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index a4bac02249c2..bd6a60e7c22b 100644
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -99,6 +99,8 @@ int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
+int drm_gem_vram_vmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
+void drm_gem_vram_vunmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
int drm_gem_vram_fill_create_dumb(struct drm_file *file,
struct drm_device *dev,
--
2.29.2
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