drm/rockchip: support prime import sg table

The prime fd to handle ioctl was not used with rockchip before. Support
was added in order to pass graphics_Gbm and to support potential uses
within Chrome OS (e.g. zero-copy video decode, camera).

Signed-off-by: Haixia Shi <hshi@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180130202913.28724-3-thierry.escande@collabora.com

3 files changed, 115 insertions, 9 deletions

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index d85431400a0d..88084ca15115 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -230,6 +230,7 @@ static struct drm_driver rockchip_drm_driver = {
         .gem_prime_import       = drm_gem_prime_import,
         .gem_prime_export       = drm_gem_prime_export,
         .gem_prime_get_sg_table = rockchip_gem_prime_get_sg_table,
+        .gem_prime_import_sg_table      = rockchip_gem_prime_import_sg_table,
         .gem_prime_vmap         = rockchip_gem_prime_vmap,
         .gem_prime_vunmap       = rockchip_gem_prime_vunmap,
         .gem_prime_mmap         = rockchip_gem_mmap_buf,
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 1d9655576b6e..5d52020deca1 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -16,6 +16,8 @@
 #include <drm/drmP.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_vma_manager.h>
+
+#include <linux/dma-buf.h>
 #include <linux/iommu.h>
 
 #include "rockchip_drm_drv.h"
@@ -309,12 +311,10 @@ static void rockchip_gem_release_object(struct rockchip_gem_object *rk_obj)
 }
 
 struct rockchip_gem_object *
-        rockchip_gem_create_object(struct drm_device *drm, unsigned int size,
-                                   bool alloc_kmap)
+        rockchip_gem_alloc_object(struct drm_device *drm, unsigned int size)
 {
         struct rockchip_gem_object *rk_obj;
         struct drm_gem_object *obj;
-        int ret;
 
         size = round_up(size, PAGE_SIZE);
 
@@ -326,6 +326,20 @@ struct rockchip_gem_object *
 
         drm_gem_object_init(drm, obj, size);
 
+        return rk_obj;
+}
+
+struct rockchip_gem_object *
+rockchip_gem_create_object(struct drm_device *drm, unsigned int size,
+                           bool alloc_kmap)
+{
+        struct rockchip_gem_object *rk_obj;
+        int ret;
+
+        rk_obj = rockchip_gem_alloc_object(drm, size);
+        if (IS_ERR(rk_obj))
+                return rk_obj;
+
         ret = rockchip_gem_alloc_buf(rk_obj, alloc_kmap);
         if (ret)
                 goto err_free_rk_obj;
@@ -343,11 +357,21 @@ err_free_rk_obj:
  */
 void rockchip_gem_free_object(struct drm_gem_object *obj)
 {
-        struct rockchip_gem_object *rk_obj;
-
-        rk_obj = to_rockchip_obj(obj);
+        struct drm_device *drm = obj->dev;
+        struct rockchip_drm_private *private = drm->dev_private;
+        struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
 
-        rockchip_gem_free_buf(rk_obj);
+        if (obj->import_attach) {
+                if (private->domain) {
+                        rockchip_gem_iommu_unmap(rk_obj);
+                } else {
+                        dma_unmap_sg(drm->dev, rk_obj->sgt->sgl,
+                                     rk_obj->sgt->nents, DMA_BIDIRECTIONAL);
+                }
+                drm_prime_gem_destroy(obj, rk_obj->sgt);
+        } else {
+                rockchip_gem_free_buf(rk_obj);
+        }
 
         rockchip_gem_release_object(rk_obj);
 }
@@ -451,6 +475,86 @@ struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
         return sgt;
 }
 
+static unsigned long rockchip_sg_get_contiguous_size(struct sg_table *sgt,
+                                                     int count)
+{
+        struct scatterlist *s;
+        dma_addr_t expected = sg_dma_address(sgt->sgl);
+        unsigned int i;
+        unsigned long size = 0;
+
+        for_each_sg(sgt->sgl, s, count, i) {
+                if (sg_dma_address(s) != expected)
+                        break;
+                expected = sg_dma_address(s) + sg_dma_len(s);
+                size += sg_dma_len(s);
+        }
+        return size;
+}
+
+static int
+rockchip_gem_iommu_map_sg(struct drm_device *drm,
+                          struct dma_buf_attachment *attach,
+                          struct sg_table *sg,
+                          struct rockchip_gem_object *rk_obj)
+{
+        rk_obj->sgt = sg;
+        return rockchip_gem_iommu_map(rk_obj);
+}
+
+static int
+rockchip_gem_dma_map_sg(struct drm_device *drm,
+                        struct dma_buf_attachment *attach,
+                        struct sg_table *sg,
+                        struct rockchip_gem_object *rk_obj)
+{
+        int count = dma_map_sg(drm->dev, sg->sgl, sg->nents,
+                               DMA_BIDIRECTIONAL);
+        if (!count)
+                return -EINVAL;
+
+        if (rockchip_sg_get_contiguous_size(sg, count) < attach->dmabuf->size) {
+                DRM_ERROR("failed to map sg_table to contiguous linear address.\n");
+                dma_unmap_sg(drm->dev, sg->sgl, sg->nents,
+                             DMA_BIDIRECTIONAL);
+                return -EINVAL;
+        }
+
+        rk_obj->dma_addr = sg_dma_address(sg->sgl);
+        rk_obj->sgt = sg;
+        return 0;
+}
+
+struct drm_gem_object *
+rockchip_gem_prime_import_sg_table(struct drm_device *drm,
+                                   struct dma_buf_attachment *attach,
+                                   struct sg_table *sg)
+{
+        struct rockchip_drm_private *private = drm->dev_private;
+        struct rockchip_gem_object *rk_obj;
+        int ret;
+
+        rk_obj = rockchip_gem_alloc_object(drm, attach->dmabuf->size);
+        if (IS_ERR(rk_obj))
+                return ERR_CAST(rk_obj);
+
+        if (private->domain)
+                ret = rockchip_gem_iommu_map_sg(drm, attach, sg, rk_obj);
+        else
+                ret = rockchip_gem_dma_map_sg(drm, attach, sg, rk_obj);
+
+        if (ret < 0) {
+                DRM_ERROR("failed to import sg table: %d\n", ret);
+                goto err_free_rk_obj;
+        }
+
+        return &rk_obj->base;
+
+err_free_rk_obj:
+        rockchip_gem_release_object(rk_obj);
+        return ERR_PTR(ret);
+}
+
 void *rockchip_gem_prime_vmap(struct drm_gem_object *obj)
 {
         struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.h b/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
index f237375582fb..d41fa65219d2 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
@@ -36,8 +36,9 @@ struct rockchip_gem_object {
 
 struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj);
 struct drm_gem_object *
-rockchip_gem_prime_import_sg_table(struct drm_device *dev, size_t size,
-                                   struct sg_table *sgt);
+rockchip_gem_prime_import_sg_table(struct drm_device *dev,
+                                   struct dma_buf_attachment *attach,
+                                   struct sg_table *sg);
 void *rockchip_gem_prime_vmap(struct drm_gem_object *obj);
 void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);