drm: Move nomodeset kernel parameter to the DRM subsystem

The "nomodeset" kernel cmdline parameter is handled by the vgacon driver
but the exported vgacon_text_force() symbol is only used by DRM drivers.

It makes much more sense for the parameter logic to be in the subsystem
of the drivers that are making use of it.

Let's move the vgacon_text_force() function and related logic to the DRM
subsystem. While doing that, rename it to drm_firmware_drivers_only() and
make it return true if "nomodeset" was used and false otherwise. This is
a better description of the condition that the drivers are testing for.
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211112133230.1595307-4-javierm@redhat.com

drivers/gpu/drm/Makefile

@@ -33,6 +33,8 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o drm_privacy_screen_x86.
 
 obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
 
+obj-$(CONFIG_VGA_CONSOLE) += drm_nomodeset.o
+
 drm_cma_helper-y := drm_gem_cma_helper.o
 obj-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_cma_helper.o
 

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -31,7 +31,6 @@
 #include "amdgpu_drv.h"
 
 #include <drm/drm_pciids.h>
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
@@ -2516,7 +2515,7 @@ static int __init amdgpu_init(void)
 {
 	int r;
 
-	if (vgacon_text_force())
+	if (drm_firmware_drivers_only())
 		return -EINVAL;
 
 	r = amdgpu_sync_init();

drivers/gpu/drm/ast/ast_drv.c

@@ -26,7 +26,6 @@
  * Authors: Dave Airlie <airlied@redhat.com>
  */
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 
@@ -233,7 +232,7 @@ static struct pci_driver ast_pci_driver = {
 
 static int __init ast_init(void)
 {
-	if (vgacon_text_force() && ast_modeset == -1)
+	if (drm_firmware_drivers_only() && ast_modeset == -1)
 		return -EINVAL;
 
 	if (ast_modeset == 0)

drivers/gpu/drm/i915/i915_module.c

@@ -4,7 +4,7 @@
  * Copyright © 2021 Intel Corporation
  */
 
-#include <linux/console.h>
+#include <drm/drm_drv.h>
 
 #include "gem/i915_gem_context.h"
 #include "gem/i915_gem_object.h"
@@ -31,7 +31,7 @@ static int i915_check_nomodeset(void)
 	if (i915_modparams.modeset == 0)
 		use_kms = false;
 
-	if (vgacon_text_force() && i915_modparams.modeset == -1)
+	if (drm_firmware_drivers_only() && i915_modparams.modeset == -1)
 		use_kms = false;
 
 	if (!use_kms) {

drivers/gpu/drm/mgag200/mgag200_drv.c

@@ -6,7 +6,6 @@
  *          Dave Airlie
  */
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vmalloc.h>
@@ -378,7 +377,7 @@ static struct pci_driver mgag200_pci_driver = {
 
 static int __init mgag200_init(void)
 {
-	if (vgacon_text_force() && mgag200_modeset == -1)
+	if (drm_firmware_drivers_only() && mgag200_modeset == -1)
 		return -EINVAL;
 
 	if (mgag200_modeset == 0)

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -22,7 +22,6 @@
  * Authors: Ben Skeggs
  */
 
-#include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -32,6 +31,7 @@
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_vblank.h>
@@ -1358,7 +1358,7 @@ nouveau_drm_init(void)
 	nouveau_display_options();
 
 	if (nouveau_modeset == -1) {
-		if (vgacon_text_force())
+		if (drm_firmware_drivers_only())
 			nouveau_modeset = 0;
 	}
 

drivers/gpu/drm/qxl/qxl_drv.c

@@ -29,7 +29,6 @@
 
 #include "qxl_drv.h"
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vgaarb.h>
@@ -295,7 +294,7 @@ static struct drm_driver qxl_driver = {
 
 static int __init qxl_init(void)
 {
-	if (vgacon_text_force() && qxl_modeset == -1)
+	if (drm_firmware_drivers_only() && qxl_modeset == -1)
 		return -EINVAL;
 
 	if (qxl_modeset == 0)

drivers/gpu/drm/radeon/radeon_drv.c

@@ -31,7 +31,6 @@
 
 
 #include <linux/compat.h>
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
@@ -637,7 +636,7 @@ static struct pci_driver radeon_kms_pci_driver = {
 
 static int __init radeon_module_init(void)
 {
-	if (vgacon_text_force() && radeon_modeset == -1)
+	if (drm_firmware_drivers_only() && radeon_modeset == -1)
 		radeon_modeset = 0;
 
 	if (radeon_modeset == 0)

drivers/gpu/drm/tiny/bochs.c

 // SPDX-License-Identifier: GPL-2.0-or-later
 
-#include <linux/console.h>
 #include <linux/pci.h>
 
 #include <drm/drm_aperture.h>
@@ -719,7 +718,7 @@ static struct pci_driver bochs_pci_driver = {
 
 static int __init bochs_init(void)
 {
-	if (vgacon_text_force() && bochs_modeset == -1)
+	if (drm_firmware_drivers_only() && bochs_modeset == -1)
 		return -EINVAL;
 
 	if (bochs_modeset == 0)

drivers/gpu/drm/tiny/cirrus.c

@@ -16,7 +16,6 @@
  * Copyright 1999-2001 Jeff Garzik <jgarzik@pobox.com>
  */
 
-#include <linux/console.h>
 #include <linux/dma-buf-map.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -636,8 +635,9 @@ static struct pci_driver cirrus_pci_driver = {
 
 static int __init cirrus_init(void)
 {
-	if (vgacon_text_force())
+	if (drm_firmware_drivers_only())
 		return -EINVAL;
+
 	return pci_register_driver(&cirrus_pci_driver);
 }
 

drivers/gpu/drm/vboxvideo/vbox_drv.c

@@ -7,7 +7,6 @@
  *          Michael Thayer <michael.thayer@oracle.com,
  *          Hans de Goede <hdegoede@redhat.com>
  */
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vt_kern.h>
@@ -193,7 +192,7 @@ static const struct drm_driver driver = {
 
 static int __init vbox_init(void)
 {
-	if (vgacon_text_force() && vbox_modeset == -1)
+	if (drm_firmware_drivers_only() && vbox_modeset == -1)
 		return -EINVAL;
 
 	if (vbox_modeset == 0)

drivers/gpu/drm/virtio/virtgpu_drv.c

@@ -27,7 +27,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/console.h>
 #include <linux/pci.h>
 #include <linux/poll.h>
 #include <linux/wait.h>
@@ -104,7 +103,7 @@ static int virtio_gpu_probe(struct virtio_device *vdev)
 	struct drm_device *dev;
 	int ret;
 
-	if (vgacon_text_force() && virtio_gpu_modeset == -1)
+	if (drm_firmware_drivers_only() && virtio_gpu_modeset == -1)
 		return -EINVAL;
 
 	if (virtio_gpu_modeset == 0)

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -25,7 +25,6 @@
  *
  **************************************************************************/
 
-#include <linux/console.h>
 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -1651,7 +1650,7 @@ static int __init vmwgfx_init(void)
 {
 	int ret;
 
-	if (vgacon_text_force())
+	if (drm_firmware_drivers_only())
 		return -EINVAL;
 
 	ret = pci_register_driver(&vmw_pci_driver);

drivers/video/console/vgacon.c

@@ -97,30 +97,9 @@ static int 		vga_video_font_height;
 static int 		vga_scan_lines		__read_mostly;
 static unsigned int 	vga_rolled_over; /* last vc_origin offset before wrap */
 
-static bool vgacon_text_mode_force;
 static bool vga_hardscroll_enabled;
 static bool vga_hardscroll_user_enable = true;
 
-bool vgacon_text_force(void)
-{
-	return vgacon_text_mode_force;
-}
-EXPORT_SYMBOL(vgacon_text_force);
-
-static int __init text_mode(char *str)
-{
-	vgacon_text_mode_force = true;
-
-	pr_warn("You have booted with nomodeset. This means your GPU drivers are DISABLED\n");
-	pr_warn("Any video related functionality will be severely degraded, and you may not even be able to suspend the system properly\n");
-	pr_warn("Unless you actually understand what nomodeset does, you should reboot without enabling it\n");
-
-	return 1;
-}
-
-/* force text mode - used by kernel modesetting */
-__setup("nomodeset", text_mode);
-
 static int __init no_scroll(char *str)
 {
 	/*

gpu/drm/drm_nomodeset.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+#include <linux/types.h>
+
+static bool drm_nomodeset;
+
+bool drm_firmware_drivers_only(void)
+{
+	return drm_nomodeset;
+}
+EXPORT_SYMBOL(drm_firmware_drivers_only);
+
+static int __init disable_modeset(char *str)
+{
+	drm_nomodeset = true;
+
+	pr_warn("You have booted with nomodeset. This means your GPU drivers are DISABLED\n");
+	pr_warn("Any video related functionality will be severely degraded, and you may not even be able to suspend the system properly\n");
+	pr_warn("Unless you actually understand what nomodeset does, you should reboot without enabling it\n");
+
+	return 1;
+}
+
+/* Disable kernel modesetting */
+__setup("nomodeset", disable_modeset);

include/drm/drm_drv.h

@@ -601,5 +601,10 @@ static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
 
 int drm_dev_set_unique(struct drm_device *dev, const char *name);
 
+#ifdef CONFIG_VGA_CONSOLE
+extern bool drm_firmware_drivers_only(void);
+#else
+static inline bool drm_firmware_drivers_only(void) { return false; }
+#endif
 
 #endif

include/linux/console.h

@@ -219,12 +219,6 @@ extern atomic_t ignore_console_lock_warning;
 #define VESA_HSYNC_SUSPEND      2
 #define VESA_POWERDOWN          3
 
-#ifdef CONFIG_VGA_CONSOLE
-extern bool vgacon_text_force(void);
-#else
-static inline bool vgacon_text_force(void) { return false; }
-#endif
-
 extern void console_init(void);
 
 /* For deferred console takeover */