kmscon: replace gpu selection modes with new --gpu option

Instead of using one option for each selection mode, we now provide a new
option --gpus. It takes as argument the selection mode to use.

We also remove the --video-devices option as it doesn't fit into the big
picture. Instead, we should provide a blacklist and users would then use
--gpu=all --blacklist-video=<blacklist> instead.

However, blacklisting is also required for input devices and until we
figure it out, we will provide no blacklisting at all.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

src/kmscon_conf.c

@@ -126,14 +126,10 @@ static void print_help()
 		"\t                                  Create new terminal session\n"
 		"\n"
 		"Video Options:\n"
-		"\t    --video-devices <d1,d2> [all]   List of video devices to be used\n"
-		"\t                                    by kmscon. This can be a list of\n"
-		"\t                                    paths to /dev/* or \"all\"\n"
 		"\t    --drm                   [on]    Use DRM if available\n"
 		"\t    --hwaccel               [off]   Use 3D hardware-acceleration if\n"
 		"\t                                    available\n"
-		"\t    --primary-gpu-only      [off]   Use primary GPU only\n"
+		"\t    --gpus={all,aux,primary}[all]   GPU selection mode\n"
-		"\t    --all-gpus              [on]    Use all GPUs unconditionally\n"
 		"\t    --render-engine <eng>   [-]     Console renderer\n"
 		"\t    --render-timing         [off]   Print renderer timing information\n"
 		"\n"
@@ -350,6 +346,56 @@ static int file_login(struct conf_option *opt, bool on, const char *arg)
 	return 0;
 }
 
+/*
+ * GPU selection type
+ * The GPU selection mode is a simple string to enum parser.
+ */
+
+static void conf_default_gpus(struct conf_option *opt)
+{
+	conf_uint.set_default(opt);
+}
+
+static void conf_free_gpus(struct conf_option *opt)
+{
+	conf_uint.free(opt);
+}
+
+static int conf_parse_gpus(struct conf_option *opt, bool on, const char *arg)
+{
+	struct kmscon_conf_t *conf = KMSCON_CONF_FROM_FIELD(opt->mem, gpus);
+	unsigned int mode;
+
+	if (!strcmp(arg, "all")) {
+		mode = KMSCON_GPU_ALL;
+	} else if (!strcmp(arg, "aux") || !strcmp(arg, "auxiliary")) {
+		mode = KMSCON_GPU_AUX;
+	} else if (!strcmp(arg, "primary") || !strcmp(arg, "single")) {
+		mode = KMSCON_GPU_PRIMARY;
+	} else {
+		log_error("invalid GPU selection mode --gpus='%s'", arg);
+		return -EFAULT;
+	}
+
+	opt->type->free(opt);
+	conf->gpus = mode;
+	return 0;
+}
+
+static int conf_copy_gpus(struct conf_option *opt,
+			  const struct conf_option *src)
+{
+	return conf_uint.copy(opt, src);
+}
+
+static const struct conf_type conf_gpus = {
+	.flags = CONF_HAS_ARG,
+	.set_default = conf_default_gpus,
+	.free = conf_free_gpus,
+	.parse = conf_parse_gpus,
+	.copy = conf_copy_gpus,
+};
+
 /*
  * Custom Afterchecks
  * Several other options have side-effects on other options. We use afterchecks
@@ -423,8 +469,6 @@ static int aftercheck_vt(struct conf_option *opt, int argc, char **argv,
 
 static char *def_seats[] = { "seat0", NULL };
 
-static char *def_video_devices[] = { "all", NULL };
-
 static struct conf_grab def_grab_scroll_up =
 		CONF_SINGLE_GRAB(SHL_SHIFT_MASK, XKB_KEY_Up);
 
@@ -510,11 +554,9 @@ int kmscon_conf_new(struct conf_ctx **out)
 		CONF_OPTION_GRAB(0, "grab-terminal-new", &conf->grab_terminal_new, &def_grab_terminal_new),
 
 		/* Video Options */
-		CONF_OPTION_STRING_LIST(0, "video-devices", &conf->video_devices, def_video_devices),
 		CONF_OPTION_BOOL_FULL(0, "drm", aftercheck_drm, NULL, NULL, &conf->drm, true),
 		CONF_OPTION_BOOL(0, "hwaccel", &conf->hwaccel, false),
-		CONF_OPTION_BOOL(0, "primary-gpu-only", &conf->primary_gpu_only, false),
+		CONF_OPTION(0, 0, "gpus", &conf_gpus, NULL, NULL, NULL, &conf->gpus, KMSCON_GPU_ALL),
-		CONF_OPTION_BOOL(0, "all-gpus", &conf->all_gpus, true),
 		CONF_OPTION_STRING(0, "render-engine", &conf->render_engine, NULL),
 		CONF_OPTION_BOOL(0, "render-timing", &conf->render_timing, false),
 

src/kmscon_conf.h

@@ -37,6 +37,12 @@
 #include "conf.h"
 #include "shl_dlist.h"
 
+enum kmscon_conf_gpu_selection {
+	KMSCON_GPU_ALL,
+	KMSCON_GPU_AUX,
+	KMSCON_GPU_PRIMARY,
+};
+
 struct kmscon_conf_t {
 	/* General Options */
 	/* show help/usage information */
@@ -115,19 +121,15 @@ struct kmscon_conf_t {
 	struct conf_grab *grab_terminal_new;
 
 	/* Video Options */
-	/* whitelist of usable video devices or "all" */
-	char **video_devices;
 	/* use DRM if available */
 	bool drm;
 	/* use 3D hardware-acceleration if available */
 	bool hwaccel;
-	/* use only primary GPU */
+	/* gpu selection mode */
-	bool primary_gpu_only;
+	unsigned int gpus;
-	/* use all GPUs unconditionally */
-	bool all_gpus;
 	/* render engine */
 	char *render_engine;
-	/* print rendering engine timing information */
+	/* print render-engine timing information */
 	bool render_timing;
 
 	/* Font Options */

src/kmscon_main.c

@@ -216,26 +216,13 @@ static void app_seat_video_event(struct uterm_video *video,
 	}
 }
 
-static bool app_seat_is_ignored(struct app_seat *seat,
+static bool app_seat_gpu_is_ignored(struct app_seat *seat,
-				unsigned int type,
+				    unsigned int type,
-				bool drm_backed,
+				    bool drm_backed,
-				bool primary,
+				    bool primary,
-				bool aux,
+				    bool aux,
-				const char *node)
+				    const char *node)
 {
-	unsigned int i;
-
-	if (!shl_string_list_is(seat->conf->video_devices, "all")) {
-		for (i = 0; seat->conf->video_devices[i]; ++i) {
-			if (!strcmp(seat->conf->video_devices[i], node))
-				return false;
-		}
-
-		log_info("ignoring video device %s on seat %s as it is not in the whitelist",
-			 node, seat->name);
-		return true;
-	}
-
 	switch (type) {
 	case UTERM_MONITOR_FBDEV:
 		if (seat->conf->drm) {
@@ -244,11 +231,6 @@ static bool app_seat_is_ignored(struct app_seat *seat,
 					 node, seat->name);
 				return true;
 			}
-			if (primary) {
-				log_info("ignoring video device %s on seat %s as it is a primary fbdev device",
-					 node, seat->name);
-				return true;
-			}
 		}
 		break;
 	case UTERM_MONITOR_DRM:
@@ -264,13 +246,13 @@ static bool app_seat_is_ignored(struct app_seat *seat,
 		return true;
 	}
 
-	if (seat->conf->primary_gpu_only && !primary) {
+	if (seat->conf->gpus == KMSCON_GPU_PRIMARY && !primary) {
 		log_info("ignoring video device %s on seat %s as it is no primary GPU",
 			 node, seat->name);
 		return true;
 	}
 
-	if (!seat->conf->all_gpus && !primary && !aux) {
+	if (seat->conf->gpus == KMSCON_GPU_AUX && !primary && !aux) {
 		log_info("ignoring video device %s on seat %s as it is neither a primary nor auxiliary GPU",
 			 node, seat->name);
 		return true;
@@ -289,11 +271,11 @@ static int app_seat_add_video(struct app_seat *seat,
 	unsigned int mode;
 	struct app_video *vid;
 
-	if (app_seat_is_ignored(seat, type,
+	if (app_seat_gpu_is_ignored(seat, type,
-				flags & UTERM_MONITOR_DRM_BACKED,
+				    flags & UTERM_MONITOR_DRM_BACKED,
-				flags & UTERM_MONITOR_PRIMARY,
+				    flags & UTERM_MONITOR_PRIMARY,
-				flags & UTERM_MONITOR_AUX,
+				    flags & UTERM_MONITOR_AUX,
-				node))
+				    node))
 		return -ERANGE;
 
 	log_debug("new video device %s on seat %s", node, seat->name);

src/uterm_monitor.c

@@ -401,14 +401,12 @@ static int get_fb_id(struct udev_device *dev)
  * used as additional GPU together with but also independent of the primary GPU.
  *
  * UTERM_MONITOR_PRIMARY:
- * A primary GPU is a GPU that can be used independently. An application
+ * A primary GPU is the main GPU in the system which is used to display boot
- * can always use such CPUs without getting into troubles. For instance, under
+ * graphics. Older systems used to have them hardwired, but especially embedded
- * dual-GPU systems, there is often only one display controller but both DRM
+ * systems tend to no longer have primary GPUs so this flag cannot be guaranteed
- * devices advertice modesetting capability. The application can now rely on
+ * to be set for all systems.
- * this flag to mark the GPU that actually should be used for modesetting. The
+ * Hence, this flag shouldn't be used by default but rather as fallback if the
- * other GPU is neither PRIMARY nor AUX and shouldn't be used by the application
+ * user selects "primary GPU only" flag or similar.
- * except for offloading rendering-work or similar.
- * Note, that multiple GPUs can be marked primary (including fbdev devices).
  */
 
 static unsigned int get_fbdev_flags(struct uterm_monitor *mon, const char *node)