[PATCH 7/9] drm/xen: Implement mmap as GEM object function

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Moving the driver-specific mmap code into a GEM object function allows
for using DRM helpers for various mmap callbacks.

The respective xen functions are being removed. The file_operations
structure fops is now being created by the helper macro
DEFINE_DRM_GEM_FOPS().

Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
 drivers/gpu/drm/xen/xen_drm_front.c     |  16 +---
 drivers/gpu/drm/xen/xen_drm_front_gem.c | 108 +++++++++---------------
 drivers/gpu/drm/xen/xen_drm_front_gem.h |   7 --
 3 files changed, 44 insertions(+), 87 deletions(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front.c 
b/drivers/gpu/drm/xen/xen_drm_front.c
index 9f14d99c763c..434064c820e8 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -469,19 +469,7 @@ static void xen_drm_drv_release(struct drm_device *dev)
        kfree(drm_info);
 }
 
-static const struct file_operations xen_drm_dev_fops = {
-       .owner          = THIS_MODULE,
-       .open           = drm_open,
-       .release        = drm_release,
-       .unlocked_ioctl = drm_ioctl,
-#ifdef CONFIG_COMPAT
-       .compat_ioctl   = drm_compat_ioctl,
-#endif
-       .poll           = drm_poll,
-       .read           = drm_read,
-       .llseek         = no_llseek,
-       .mmap           = xen_drm_front_gem_mmap,
-};
+DEFINE_DRM_GEM_FOPS(xen_drm_dev_fops);
 
 static const struct drm_driver xen_drm_driver = {
        .driver_features           = DRIVER_GEM | DRIVER_MODESET | 
DRIVER_ATOMIC,
@@ -489,7 +477,7 @@ static const struct drm_driver xen_drm_driver = {
        .prime_handle_to_fd        = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle        = drm_gem_prime_fd_to_handle,
        .gem_prime_import_sg_table = xen_drm_front_gem_import_sg_table,
-       .gem_prime_mmap            = xen_drm_front_gem_prime_mmap,
+       .gem_prime_mmap            = drm_gem_prime_mmap,
        .dumb_create               = xen_drm_drv_dumb_create,
        .fops                      = &xen_drm_dev_fops,
        .name                      = "xendrm-du",
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c 
b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index b293c67230ef..dd358ba2bf8e 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -57,6 +57,47 @@ static void gem_free_pages_array(struct xen_gem_object 
*xen_obj)
        xen_obj->pages = NULL;
 }
 
+static int xen_drm_front_gem_object_mmap(struct drm_gem_object *gem_obj,
+                                        struct vm_area_struct *vma)
+{
+       struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
+       int ret;
+
+       vma->vm_ops = gem_obj->funcs->vm_ops;
+
+       /*
+        * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
+        * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
+        * the whole buffer.
+        */
+       vma->vm_flags &= ~VM_PFNMAP;
+       vma->vm_flags |= VM_MIXEDMAP;
+       vma->vm_pgoff = 0;
+
+       /*
+        * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
+        * all memory which is shared with other entities in the system
+        * (including the hypervisor and other guests) must reside in memory
+        * which is mapped as Normal Inner Write-Back Outer Write-Back
+        * Inner-Shareable.
+        */
+       vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+
+       /*
+        * vm_operations_struct.fault handler will be called if CPU access
+        * to VM is here. For GPUs this isn't the case, because CPU  doesn't
+        * touch the memory. Insert pages now, so both CPU and GPU are happy.
+        *
+        * FIXME: as we insert all the pages now then no .fault handler must
+        * be called, so don't provide one
+        */
+       ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
+       if (ret < 0)
+               DRM_ERROR("Failed to map pages into vma: %d\n", ret);
+
+       return ret;
+}
+
 static const struct vm_operations_struct xen_drm_drv_vm_ops = {
        .open           = drm_gem_vm_open,
        .close          = drm_gem_vm_close,
@@ -67,6 +108,7 @@ static const struct drm_gem_object_funcs 
xen_drm_front_gem_object_funcs = {
        .get_sg_table = xen_drm_front_gem_get_sg_table,
        .vmap = xen_drm_front_gem_prime_vmap,
        .vunmap = xen_drm_front_gem_prime_vunmap,
+       .mmap = xen_drm_front_gem_object_mmap,
        .vm_ops = &xen_drm_drv_vm_ops,
 };
 
@@ -238,58 +280,6 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
        return &xen_obj->base;
 }
 
-static int gem_mmap_obj(struct xen_gem_object *xen_obj,
-                       struct vm_area_struct *vma)
-{
-       int ret;
-
-       /*
-        * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
-        * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
-        * the whole buffer.
-        */
-       vma->vm_flags &= ~VM_PFNMAP;
-       vma->vm_flags |= VM_MIXEDMAP;
-       vma->vm_pgoff = 0;
-       /*
-        * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
-        * all memory which is shared with other entities in the system
-        * (including the hypervisor and other guests) must reside in memory
-        * which is mapped as Normal Inner Write-Back Outer Write-Back
-        * Inner-Shareable.
-        */
-       vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-
-       /*
-        * vm_operations_struct.fault handler will be called if CPU access
-        * to VM is here. For GPUs this isn't the case, because CPU
-        * doesn't touch the memory. Insert pages now, so both CPU and GPU are
-        * happy.
-        * FIXME: as we insert all the pages now then no .fault handler must
-        * be called, so don't provide one
-        */
-       ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
-       if (ret < 0)
-               DRM_ERROR("Failed to map pages into vma: %d\n", ret);
-
-       return ret;
-}
-
-int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
-{
-       struct xen_gem_object *xen_obj;
-       struct drm_gem_object *gem_obj;
-       int ret;
-
-       ret = drm_gem_mmap(filp, vma);
-       if (ret < 0)
-               return ret;
-
-       gem_obj = vma->vm_private_data;
-       xen_obj = to_xen_gem_obj(gem_obj);
-       return gem_mmap_obj(xen_obj, vma);
-}
-
 int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj, struct 
dma_buf_map *map)
 {
        struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
@@ -313,17 +303,3 @@ void xen_drm_front_gem_prime_vunmap(struct drm_gem_object 
*gem_obj,
 {
        vunmap(map->vaddr);
 }
-
-int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
-                                struct vm_area_struct *vma)
-{
-       struct xen_gem_object *xen_obj;
-       int ret;
-
-       ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
-       if (ret < 0)
-               return ret;
-
-       xen_obj = to_xen_gem_obj(gem_obj);
-       return gem_mmap_obj(xen_obj, vma);
-}
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h 
b/drivers/gpu/drm/xen/xen_drm_front_gem.h
index a4e67d0a149c..eaea470f7001 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.h
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h
@@ -15,9 +15,7 @@ struct dma_buf_attachment;
 struct dma_buf_map;
 struct drm_device;
 struct drm_gem_object;
-struct file;
 struct sg_table;
-struct vm_area_struct;
 
 struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev,
                                                size_t size);
@@ -33,15 +31,10 @@ struct page **xen_drm_front_gem_get_pages(struct 
drm_gem_object *obj);
 
 void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj);
 
-int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma);
-
 int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj,
                                 struct dma_buf_map *map);
 
 void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
                                    struct dma_buf_map *map);
 
-int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
-                                struct vm_area_struct *vma);
-
 #endif /* __XEN_DRM_FRONT_GEM_H */
-- 
2.31.1