RE: [PATCH v3 5/5] drm/i915/gem: Migrate to system at dma-buf map time

["Ruhl, Michael J" <michael.j.ruhl@intel.com>]

>-----Original Message-----
>From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of
>Thomas Hellström
>Sent: Monday, June 28, 2021 10:46 AM
>To: intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org
>Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>; Auld, Matthew
><matthew.auld@intel.com>
>Subject: [PATCH v3 5/5] drm/i915/gem: Migrate to system at dma-buf map
>time
>
>Until we support p2p dma or as a complement to that, migrate data
>to system memory at dma-buf map time if possible.
>
>v2:
>- Rebase on dynamic exporter. Update the igt_dmabuf_import_same_driver
>  selftest to migrate if we are LMEM capable.
>
>Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
>---
> drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c           | 7 ++++++-
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 4 +++-
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>index 1d1eeb167d28..5207aa3af009 100644
>--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>@@ -29,7 +29,12 @@ static struct sg_table *i915_gem_map_dma_buf(struct
>dma_buf_attachment *attachme
>
> 	assert_object_held(obj);
>
>-	ret = i915_gem_object_pin_pages(obj);
>+	if (!i915_gem_object_can_migrate(obj, INTEL_REGION_SMEM))
>+		return ERR_PTR(-EOPNOTSUPP);
>+
>+	ret = i915_gem_object_migrate(obj, NULL, INTEL_REGION_SMEM);
>+	if (!ret)
>+		ret = i915_gem_object_pin_pages(obj);
> 	if (ret)
> 		goto err;

With the caveats of the previous patches this looks good.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>

Mike

>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 24735d6c12a2..b6278dba98d0 100644
>--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
>+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
>@@ -94,7 +94,9 @@ static int igt_dmabuf_import_same_driver(void *arg)
> 	int err;
>
> 	force_different_devices = true;
>-	obj = i915_gem_object_create_shmem(i915, PAGE_SIZE);
>+	obj = i915_gem_object_create_lmem(i915, PAGE_SIZE, 0);
>+	if (IS_ERR(obj))
>+		obj = i915_gem_object_create_shmem(i915, PAGE_SIZE);
> 	if (IS_ERR(obj))
> 		goto out_ret;
>
>--
>2.31.1