Enable the GEM dma-buf import interfaces in addition to the export
interfaces. This lets vgem be used as a test source for other allocators
(e.g. Ion).

Signed-off-by: Laura Abbott <labb...@redhat.com>
---
 drivers/gpu/drm/vgem/vgem_drv.c | 135 ++++++++++++++++++++++++++++++++--------
 drivers/gpu/drm/vgem/vgem_drv.h |   3 +
 2 files changed, 111 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index b94feef..abc72e1 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -34,6 +34,9 @@
 #include <linux/ramfs.h>
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>
+
+#include <drm/drmP.h>
+
 #include "vgem_drv.h"
 
 #define DRIVER_NAME    "vgem"
@@ -42,40 +45,67 @@
 #define DRIVER_MAJOR   1
 #define DRIVER_MINOR   0
 
+#define VGEM_BO_IMPORT BIT(0)
+
+void vgem_gem_put_pages(struct drm_vgem_gem_object *obj)
+{
+       drm_gem_put_pages(&obj->base, obj->pages, false, false);
+       obj->pages = NULL;
+}
+
 static void vgem_gem_free_object(struct drm_gem_object *obj)
 {
        struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
 
+       if (vgem_obj->pages) {
+               if (vgem_obj->flags & VGEM_BO_IMPORT)
+                       drm_free_large(vgem_obj->pages);
+               else
+                       vgem_gem_put_pages(vgem_obj);
+       }
+
+       if (obj->import_attach)
+               drm_prime_gem_destroy(obj, vgem_obj->table);
+
        drm_gem_object_release(obj);
        kfree(vgem_obj);
 }
 
+int vgem_gem_get_pages(struct drm_vgem_gem_object *obj)
+{
+       struct page **pages;
+
+       if (obj->pages)
+               return 0;
+
+       pages = drm_gem_get_pages(&obj->base);
+       if (IS_ERR(pages)) {
+               return PTR_ERR(pages);
+       }
+
+       obj->pages = pages;
+
+       return 0;
+}
+
 static int vgem_gem_fault(struct vm_fault *vmf)
 {
        struct vm_area_struct *vma = vmf->vma;
        struct drm_vgem_gem_object *obj = vma->vm_private_data;
        /* We don't use vmf->pgoff since that has the fake offset */
        unsigned long vaddr = vmf->address;
-       struct page *page;
+       loff_t num_pages;
+       pgoff_t page_offset;
+       page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
 
-       page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,
-                                      (vaddr - vma->vm_start) >> PAGE_SHIFT);
-       if (!IS_ERR(page)) {
-               vmf->page = page;
-               return 0;
-       } else switch (PTR_ERR(page)) {
-               case -ENOSPC:
-               case -ENOMEM:
-                       return VM_FAULT_OOM;
-               case -EBUSY:
-                       return VM_FAULT_RETRY;
-               case -EFAULT:
-               case -EINVAL:
-                       return VM_FAULT_SIGBUS;
-               default:
-                       WARN_ON_ONCE(PTR_ERR(page));
-                       return VM_FAULT_SIGBUS;
-       }
+       num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
+
+       if (page_offset > num_pages)
+               return VM_FAULT_SIGBUS;
+
+       get_page(obj->pages[page_offset]);
+       vmf->page = obj->pages[page_offset];
+       return 0;
 }
 
 static const struct vm_operations_struct vgem_gem_vm_ops = {
@@ -112,7 +142,30 @@ static void vgem_preclose(struct drm_device *dev, struct 
drm_file *file)
        kfree(vfile);
 }
 
-/* ioctls */
+static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
+                                               unsigned long size)
+{
+       struct drm_vgem_gem_object *obj;
+       int ret;
+
+       obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+       if (!obj)
+               return ERR_PTR(-ENOMEM);
+
+       ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
+       if (ret) {
+               kfree(obj);
+               return ERR_PTR(ret);
+       }
+
+       return obj;
+}
+
+static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
+{
+       drm_gem_object_release(&obj->base);
+       kfree(obj);
+}
 
 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
                                              struct drm_file *file,
@@ -122,24 +175,25 @@ static struct drm_gem_object *vgem_gem_create(struct 
drm_device *dev,
        struct drm_vgem_gem_object *obj;
        int ret;
 
-       obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-       if (!obj)
-               return ERR_PTR(-ENOMEM);
+       obj = __vgem_gem_create(dev, size);
+       if (IS_ERR(obj))
+               return ERR_CAST(obj);
 
-       ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
+       ret = vgem_gem_get_pages(obj);
        if (ret)
                goto err_free;
 
        ret = drm_gem_handle_create(file, &obj->base, handle);
        drm_gem_object_unreference_unlocked(&obj->base);
        if (ret)
-               goto err;
+               goto err_pages;
 
        return &obj->base;
 
+err_pages:
+       vgem_gem_put_pages(obj);
 err_free:
-       kfree(obj);
-err:
+       __vgem_gem_destroy(obj);
        return ERR_PTR(ret);
 }
 
@@ -256,6 +310,30 @@ static struct sg_table *vgem_prime_get_sg_table(struct 
drm_gem_object *obj)
        return st;
 }
 
+static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device 
*dev,
+                       struct dma_buf_attachment *attach, struct sg_table *sg)
+{
+       struct drm_vgem_gem_object *obj;
+       int npages;
+
+       obj = __vgem_gem_create(dev, attach->dmabuf->size);
+       if (IS_ERR(obj))
+               return ERR_CAST(obj);
+
+       npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
+
+       obj->table = sg;
+       obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
+       obj->flags = VGEM_BO_IMPORT;
+       if (!obj->pages) {
+               __vgem_gem_destroy(obj);
+               return ERR_PTR(-ENOMEM);
+       }
+       drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
+                                       npages);
+       return &obj->base;
+}
+
 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 {
        long n_pages = obj->size >> PAGE_SHIFT;
@@ -314,8 +392,11 @@ static struct drm_driver vgem_driver = {
        .dumb_map_offset                = vgem_gem_dumb_map,
 
        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+       .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
        .gem_prime_pin = vgem_prime_pin,
+       .gem_prime_import = drm_gem_prime_import,
        .gem_prime_export = drm_gem_prime_export,
+       .gem_prime_import_sg_table = vgem_prime_import_sg_table,
        .gem_prime_get_sg_table = vgem_prime_get_sg_table,
        .gem_prime_vmap = vgem_prime_vmap,
        .gem_prime_vunmap = vgem_prime_vunmap,
diff --git a/drivers/gpu/drm/vgem/vgem_drv.h b/drivers/gpu/drm/vgem/vgem_drv.h
index cb59c7a..f5dd076 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.h
+++ b/drivers/gpu/drm/vgem/vgem_drv.h
@@ -43,6 +43,9 @@ struct vgem_file {
 #define to_vgem_bo(x) container_of(x, struct drm_vgem_gem_object, base)
 struct drm_vgem_gem_object {
        struct drm_gem_object base;
+       struct page **pages;
+       struct sg_table *table;
+       unsigned long flags;
 };
 
 int vgem_fence_open(struct vgem_file *file);
-- 
2.7.4

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