drm/radeon: Move AGP helpers into radeon driver

Radeon calls DRMs core AGP helpers. These helpers are only required
by legacy drivers. Reimplement the code in radeon to uncouple radeon
from the legacy code.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Acked-by: Christian König <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/radeon/radeon.h

···
 /*
  * AGP
  */
+#if IS_ENABLED(CONFIG_AGP)
+struct drm_agp_head *radeon_agp_head_init(struct drm_device *dev);
+#else
+static inline struct drm_agp_head *radeon_agp_head_init(struct drm_device *dev)
+{
+	return NULL;
+}
+#endif
 int radeon_agp_init(struct radeon_device *rdev);
 void radeon_agp_resume(struct radeon_device *rdev);
 void radeon_agp_suspend(struct radeon_device *rdev);

drivers/gpu/drm/radeon/radeon_agp.c

···
 		PCI_VENDOR_ID_SONY, 0x8175, 1},
 	{ 0, 0, 0, 0, 0, 0, 0 },
 };
+
+struct drm_agp_head *radeon_agp_head_init(struct drm_device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev->dev);
+	struct drm_agp_head *head = NULL;
+
+	head = kzalloc(sizeof(*head), GFP_KERNEL);
+	if (!head)
+		return NULL;
+	head->bridge = agp_find_bridge(pdev);
+	if (!head->bridge) {
+		head->bridge = agp_backend_acquire(pdev);
+		if (!head->bridge) {
+			kfree(head);
+			return NULL;
+		}
+		agp_copy_info(head->bridge, &head->agp_info);
+		agp_backend_release(head->bridge);
+	} else {
+		agp_copy_info(head->bridge, &head->agp_info);
+	}
+	if (head->agp_info.chipset == NOT_SUPPORTED) {
+		kfree(head);
+		return NULL;
+	}
+	INIT_LIST_HEAD(&head->memory);
+	head->cant_use_aperture = head->agp_info.cant_use_aperture;
+	head->page_mask = head->agp_info.page_mask;
+	head->base = head->agp_info.aper_base;
+
+	return head;
+}
+
+static int radeon_agp_head_acquire(struct drm_device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev->dev);
+
+	if (!dev->agp)
+		return -ENODEV;
+	if (dev->agp->acquired)
+		return -EBUSY;
+	dev->agp->bridge = agp_backend_acquire(pdev);
+	if (!dev->agp->bridge)
+		return -ENODEV;
+	dev->agp->acquired = 1;
+	return 0;
+}
+
+static int radeon_agp_head_release(struct drm_device *dev)
+{
+	if (!dev->agp || !dev->agp->acquired)
+		return -EINVAL;
+	agp_backend_release(dev->agp->bridge);
+	dev->agp->acquired = 0;
+	return 0;
+}
+
+static int radeon_agp_head_enable(struct drm_device *dev, struct drm_agp_mode mode)
+{
+	if (!dev->agp || !dev->agp->acquired)
+		return -EINVAL;
+
+	dev->agp->mode = mode.mode;
+	agp_enable(dev->agp->bridge, mode.mode);
+	dev->agp->enabled = 1;
+	return 0;
+}
+
+static int radeon_agp_head_info(struct drm_device *dev, struct drm_agp_info *info)
+{
+	struct agp_kern_info *kern;
+
+	if (!dev->agp || !dev->agp->acquired)
+		return -EINVAL;
+
+	kern = &dev->agp->agp_info;
+	info->agp_version_major = kern->version.major;
+	info->agp_version_minor = kern->version.minor;
+	info->mode = kern->mode;
+	info->aperture_base = kern->aper_base;
+	info->aperture_size = kern->aper_size * 1024 * 1024;
+	info->memory_allowed = kern->max_memory << PAGE_SHIFT;
+	info->memory_used = kern->current_memory << PAGE_SHIFT;
+	info->id_vendor = kern->device->vendor;
+	info->id_device = kern->device->device;
+
+	return 0;
+}
 #endif
 
 int radeon_agp_init(struct radeon_device *rdev)
···
 	int ret;
 
 	/* Acquire AGP. */
-	ret = drm_agp_acquire(rdev->ddev);
+	ret = radeon_agp_head_acquire(rdev->ddev);
 	if (ret) {
 		DRM_ERROR("Unable to acquire AGP: %d\n", ret);
 		return ret;
 	}
 
-	ret = drm_agp_info(rdev->ddev, &info);
+	ret = radeon_agp_head_info(rdev->ddev, &info);
 	if (ret) {
-		drm_agp_release(rdev->ddev);
+		radeon_agp_head_release(rdev->ddev);
 		DRM_ERROR("Unable to get AGP info: %d\n", ret);
 		return ret;
 	}
 
 	if (rdev->ddev->agp->agp_info.aper_size < 32) {
-		drm_agp_release(rdev->ddev);
+		radeon_agp_head_release(rdev->ddev);
 		dev_warn(rdev->dev, "AGP aperture too small (%zuM) "
 			"need at least 32M, disabling AGP\n",
 			rdev->ddev->agp->agp_info.aper_size);
···
 	}
 
 	mode.mode &= ~RADEON_AGP_FW_MODE; /* disable fw */
-	ret = drm_agp_enable(rdev->ddev, mode);
+	ret = radeon_agp_head_enable(rdev->ddev, mode);
 	if (ret) {
 		DRM_ERROR("Unable to enable AGP (mode = 0x%lx)\n", mode.mode);
-		drm_agp_release(rdev->ddev);
+		radeon_agp_head_release(rdev->ddev);
 		return ret;
 	}
 
···
 {
 #if IS_ENABLED(CONFIG_AGP)
 	if (rdev->ddev->agp && rdev->ddev->agp->acquired) {
-		drm_agp_release(rdev->ddev);
+		radeon_agp_head_release(rdev->ddev);
 	}
 #endif
 }

drivers/gpu/drm/radeon/radeon_drv.c

···
 	pci_set_drvdata(pdev, dev);
 
 	if (pci_find_capability(pdev, PCI_CAP_ID_AGP))
-		dev->agp = drm_agp_init(dev);
+		dev->agp = radeon_agp_head_init(dev);
 	if (dev->agp) {
 		dev->agp->agp_mtrr = arch_phys_wc_add(
 			dev->agp->agp_info.aper_base,