drm: Move GEM memory managers into modules

DRM core uses the GEM base object to access GEM functionality. It does
not depend on individual implementations. Move the code into modules.

Also move the CMA framebuffer helpers into the CMA's module, as they're
not usable without CMA.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211020131941.15367-4-tzimmermann@suse.de

drivers/gpu/drm/Kconfig

@@ -212,7 +212,7 @@ config DRM_TTM_HELPER
 	  Helpers for ttm-based gem objects
 
 config DRM_GEM_CMA_HELPER
-	bool
+	tristate
 	depends on DRM
 	help
 	  Choose this if you need the GEM CMA helper functions
@@ -225,7 +225,7 @@ config DRM_KMS_CMA_HELPER
 	  Choose this if you need the KMS CMA helper functions
 
 config DRM_GEM_SHMEM_HELPER
-	bool
+	tristate
 	depends on DRM && MMU
 	help
 	  Choose this if you need the GEM shmem helper functions

drivers/gpu/drm/Makefile

@@ -24,8 +24,6 @@ drm-$(CONFIG_DRM_LEGACY) += drm_agpsupport.o drm_bufs.o drm_context.o drm_dma.o
 			    drm_scatter.o drm_vm.o
 drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
-drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
-drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o
 drm-$(CONFIG_DRM_PANEL) += drm_panel.o
 drm-$(CONFIG_OF) += drm_of.o
 drm-$(CONFIG_PCI) += drm_pci.o
@@ -35,6 +33,13 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o drm_privacy_screen_x86.
 
 obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
 
+drm_cma_helper-y := drm_gem_cma_helper.o
+drm_cma_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
+obj-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_cma_helper.o
+
+drm_shmem_helper-y := drm_gem_shmem_helper.o
+obj-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_shmem_helper.o
+
 drm_vram_helper-y := drm_gem_vram_helper.o
 obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o
 
@@ -54,7 +59,6 @@ drm_kms_helper-y := drm_bridge_connector.o drm_crtc_helper.o drm_dp_helper.o \
 
 drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
-drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
 drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o
 drm_kms_helper-$(CONFIG_DRM_DP_CEC) += drm_dp_cec.o
 

drivers/gpu/drm/drm_gem_cma_helper.c

@@ -13,6 +13,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/mm.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 
@@ -578,3 +579,6 @@ drm_gem_cma_prime_import_sg_table_vmap(struct drm_device *dev,
 	return obj;
 }
 EXPORT_SYMBOL(drm_gem_cma_prime_import_sg_table_vmap);
+
+MODULE_DESCRIPTION("DRM CMA memory-management helpers");
+MODULE_LICENSE("GPL");

drivers/gpu/drm/drm_gem_shmem_helper.c

@@ -5,6 +5,7 @@
 
 #include <linux/dma-buf.h>
 #include <linux/export.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/shmem_fs.h>
 #include <linux/slab.h>
@@ -774,3 +775,6 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
 	return &shmem->base;
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
+
+MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
+MODULE_LICENSE("GPL v2");