nouveau: add PRIME support

This adds prime->fd and fd->prime support to nouveau,
it passes the SG object to TTM, and then populates the
GART entries using it.

v2: add stubbed kmap + use new function to fill out pages array
for faulting + add reimport test.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c
new file mode 100644
index 000000000000..ed6b8465260a
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -0,0 +1,163 @@
+
+#include "drmP.h"
+#include "drm.h"
+
+#include "nouveau_drv.h"
+#include "nouveau_drm.h"
+#include "nouveau_dma.h"
+
+#include <linux/dma-buf.h>
+
+static struct sg_table *nouveau_gem_map_dma_buf(struct dma_buf_attachment *attachment,
+					  enum dma_data_direction dir)
+{
+	struct nouveau_bo *nvbo = attachment->dmabuf->priv;
+	struct drm_device *dev = nvbo->gem->dev;
+	int npages = nvbo->bo.num_pages;
+	struct sg_table *sg;
+	int nents;
+
+	mutex_lock(&dev->struct_mutex);
+	sg = drm_prime_pages_to_sg(nvbo->bo.ttm->pages, npages);
+	nents = dma_map_sg(attachment->dev, sg->sgl, sg->nents, dir);
+	mutex_unlock(&dev->struct_mutex);
+	return sg;
+}
+
+static void nouveau_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
+				      struct sg_table *sg, enum dma_data_direction dir)
+{
+	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
+	sg_free_table(sg);
+	kfree(sg);
+}
+
+static void nouveau_gem_dmabuf_release(struct dma_buf *dma_buf)
+{
+	struct nouveau_bo *nvbo = dma_buf->priv;
+
+	if (nvbo->gem->export_dma_buf == dma_buf) {
+		nvbo->gem->export_dma_buf = NULL;
+		drm_gem_object_unreference_unlocked(nvbo->gem);
+	}
+}
+
+static void *nouveau_gem_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
+{
+	return NULL;
+}
+
+static void nouveau_gem_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
+{
+
+}
+static void *nouveau_gem_kmap(struct dma_buf *dma_buf, unsigned long page_num)
+{
+	return NULL;
+}
+
+static void nouveau_gem_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
+{
+
+}
+
+struct dma_buf_ops nouveau_dmabuf_ops =  {
+	.map_dma_buf = nouveau_gem_map_dma_buf,
+	.unmap_dma_buf = nouveau_gem_unmap_dma_buf,
+	.release = nouveau_gem_dmabuf_release,
+	.kmap = nouveau_gem_kmap,
+	.kmap_atomic = nouveau_gem_kmap_atomic,
+	.kunmap = nouveau_gem_kunmap,
+	.kunmap_atomic = nouveau_gem_kunmap_atomic,
+};
+
+static int
+nouveau_prime_new(struct drm_device *dev,
+		  size_t size,
+		  struct sg_table *sg,
+		  struct nouveau_bo **pnvbo)
+{
+	struct nouveau_bo *nvbo;
+	u32 flags = 0;
+	int ret;
+
+	flags = TTM_PL_FLAG_TT;
+
+	ret = nouveau_bo_new(dev, size, 0, flags, 0, 0,
+			     sg, pnvbo);
+	if (ret)
+		return ret;
+	nvbo = *pnvbo;
+
+	/* we restrict allowed domains on nv50+ to only the types
+	 * that were requested at creation time.  not possibly on
+	 * earlier chips without busting the ABI.
+	 */
+	nvbo->valid_domains = NOUVEAU_GEM_DOMAIN_GART;
+	nvbo->gem = drm_gem_object_alloc(dev, nvbo->bo.mem.size);
+	if (!nvbo->gem) {
+		nouveau_bo_ref(NULL, pnvbo);
+		return -ENOMEM;
+	}
+
+	nvbo->gem->driver_private = nvbo;
+	return 0;
+}
+
+struct dma_buf *nouveau_gem_prime_export(struct drm_device *dev,
+				struct drm_gem_object *obj, int flags)
+{
+	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
+	int ret = 0;
+
+	/* pin buffer into GTT */
+	ret = nouveau_bo_pin(nvbo, TTM_PL_FLAG_TT);
+	if (ret)
+		return ERR_PTR(-EINVAL);
+
+	return dma_buf_export(nvbo, &nouveau_dmabuf_ops, obj->size, flags);
+}
+
+struct drm_gem_object *nouveau_gem_prime_import(struct drm_device *dev,
+				struct dma_buf *dma_buf)
+{
+	struct dma_buf_attachment *attach;
+	struct sg_table *sg;
+	struct nouveau_bo *nvbo;
+	int ret;
+
+	if (dma_buf->ops == &nouveau_dmabuf_ops) {
+		nvbo = dma_buf->priv;
+		if (nvbo->gem) {
+			if (nvbo->gem->dev == dev) {
+				drm_gem_object_reference(nvbo->gem);
+				return nvbo->gem;
+			}
+		}
+	}
+	/* need to attach */
+	attach = dma_buf_attach(dma_buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_PTR(PTR_ERR(attach));
+
+	sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sg)) {
+		ret = PTR_ERR(sg);
+		goto fail_detach;
+	}
+
+	ret = nouveau_prime_new(dev, dma_buf->size, sg, &nvbo);
+	if (ret)
+		goto fail_unmap;
+
+	nvbo->gem->import_attach = attach;
+
+	return nvbo->gem;
+
+fail_unmap:
+	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+fail_detach:
+	dma_buf_detach(dma_buf, attach);
+	return ERR_PTR(ret);
+}
+