i915: add dma-buf vmap support for exporting vmapped buffer
This is used to export a vmapping to the udl driver so that
i915 and udl can share the udl scanout.
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 4fba63e..aa308e1 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -74,6 +74,59 @@
}
}
+static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
+{
+ struct drm_i915_gem_object *obj = dma_buf->priv;
+ struct drm_device *dev = obj->base.dev;
+ int ret;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (obj->dma_buf_vmapping) {
+ obj->vmapping_count++;
+ goto out_unlock;
+ }
+
+ if (!obj->pages) {
+ ret = i915_gem_object_get_pages_gtt(obj, __GFP_NORETRY | __GFP_NOWARN);
+ if (ret) {
+ mutex_unlock(&dev->struct_mutex);
+ return ERR_PTR(ret);
+ }
+ }
+
+ obj->dma_buf_vmapping = vmap(obj->pages, obj->base.size / PAGE_SIZE, 0, PAGE_KERNEL);
+ if (!obj->dma_buf_vmapping) {
+ DRM_ERROR("failed to vmap object\n");
+ goto out_unlock;
+ }
+
+ obj->vmapping_count = 1;
+out_unlock:
+ mutex_unlock(&dev->struct_mutex);
+ return obj->dma_buf_vmapping;
+}
+
+static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
+{
+ struct drm_i915_gem_object *obj = dma_buf->priv;
+ struct drm_device *dev = obj->base.dev;
+ int ret;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return;
+
+ --obj->vmapping_count;
+ if (obj->vmapping_count == 0) {
+ vunmap(obj->dma_buf_vmapping);
+ obj->dma_buf_vmapping = NULL;
+ }
+ mutex_unlock(&dev->struct_mutex);
+}
+
static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
{
return NULL;
@@ -107,6 +160,8 @@
.kunmap = i915_gem_dmabuf_kunmap,
.kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
.mmap = i915_gem_dmabuf_mmap,
+ .vmap = i915_gem_dmabuf_vmap,
+ .vunmap = i915_gem_dmabuf_vunmap,
};
struct dma_buf *i915_gem_prime_export(struct drm_device *dev,