Merge pull request #123 from ascent12/session-multi-gpu

Session Multi-GPU

backend/backend.c

@@ -12,7 +12,6 @@
 #include <wlr/backend/wayland.h>
 #include <wlr/backend/multi.h>
 #include <wlr/util/log.h>
-#include "backend/udev.h"
 
 void wlr_backend_init(struct wlr_backend *backend,
 		const struct wlr_backend_impl *impl) {
@@ -85,35 +84,29 @@ struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
 
 	// Attempt DRM+libinput
 
-	struct wlr_session *session = wlr_session_start(display);
+	struct wlr_session *session = wlr_session_create(display);
 	if (!session) {
 		wlr_log(L_ERROR, "Failed to start a DRM session");
 		return NULL;
 	}
 
-	struct wlr_udev *udev = wlr_udev_create(display);
+	int gpu = wlr_session_find_gpu(session);
-	if (!udev) {
+	if (gpu == -1) {
-		wlr_log(L_ERROR, "Failed to start udev");
+		wlr_log(L_ERROR, "Failed to open DRM device");
 		goto error_session;
 	}
 
-	int gpu = wlr_udev_find_gpu(udev, session);
+	backend = wlr_multi_backend_create(session);
-	if (gpu == -1) {
-		wlr_log(L_ERROR, "Failed to open DRM device");
-		goto error_udev;
-	}
-
-	backend = wlr_multi_backend_create(session, udev);
 	if (!backend) {
 		goto error_gpu;
 	}
 
-	struct wlr_backend *libinput = wlr_libinput_backend_create(display, session, udev);
+	struct wlr_backend *libinput = wlr_libinput_backend_create(display, session);
 	if (!libinput) {
 		goto error_multi;
 	}
 
-	struct wlr_backend *drm = wlr_drm_backend_create(display, session, udev, gpu);
+	struct wlr_backend *drm = wlr_drm_backend_create(display, session, gpu);
 	if (!drm) {
 		goto error_libinput;
 	}
@@ -128,9 +121,7 @@ error_multi:
 	wlr_backend_destroy(backend);
 error_gpu:
 	wlr_session_close_file(session, gpu);
-error_udev:
-	wlr_udev_destroy(udev);
 error_session:
-	wlr_session_finish(session);
+	wlr_session_destroy(session);
 	return NULL;
 }

backend/drm/backend.c

@@ -13,7 +13,6 @@
 #include <wlr/util/list.h>
 #include <wlr/util/log.h>
 #include <wlr/egl.h>
-#include "backend/udev.h"
 #include "backend/drm.h"
 
 static bool wlr_drm_backend_start(struct wlr_backend *_backend) {
@@ -32,7 +31,6 @@ static void wlr_drm_backend_destroy(struct wlr_backend *_backend) {
 		wlr_output_destroy(&output->output);
 	}
 
-	wlr_udev_signal_remove(backend->udev, &backend->drm_invalidated);
 	wlr_drm_renderer_free(&backend->renderer);
 	wlr_drm_resources_free(backend);
 	wlr_session_close_file(backend->session, backend->fd);
@@ -84,8 +82,6 @@ static void session_signal(struct wl_listener *listener, void *data) {
 static void drm_invalidated(struct wl_listener *listener, void *data) {
 	struct wlr_drm_backend *backend =
 		wl_container_of(listener, backend, drm_invalidated);
-	struct wlr_udev *udev = data;
-	(void)udev;
 
 	char *name = drmGetDeviceNameFromFd2(backend->fd);
 	wlr_log(L_DEBUG, "%s invalidated", name);
@@ -95,7 +91,7 @@ static void drm_invalidated(struct wl_listener *listener, void *data) {
 }
 
 struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
-		struct wlr_session *session, struct wlr_udev *udev, int gpu_fd) {
+		struct wlr_session *session, int gpu_fd) {
 	assert(display && session && gpu_fd >= 0);
 
 	char *name = drmGetDeviceNameFromFd2(gpu_fd);
@@ -112,7 +108,6 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 	wlr_backend_init(&backend->backend, &backend_impl);
 
 	backend->session = session;
-	backend->udev = udev;
 	backend->outputs = list_create();
 	if (!backend->outputs) {
 		wlr_log(L_ERROR, "Failed to allocate list");
@@ -128,7 +123,7 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 	backend->dev = st.st_rdev;
 
 	backend->drm_invalidated.notify = drm_invalidated;
-	wlr_udev_signal_add(udev, backend->dev, &backend->drm_invalidated);
+	wlr_session_signal_add(session, gpu_fd, &backend->drm_invalidated);
 
 	backend->display = display;
 	struct wl_event_loop *event_loop = wl_display_get_event_loop(display);

backend/libinput/backend.c

@@ -4,7 +4,6 @@
 #include <wlr/backend/session.h>
 #include <wlr/backend/interface.h>
 #include <wlr/util/log.h>
-#include "backend/udev.h"
 #include "backend/libinput.h"
 
 static int wlr_libinput_open_restricted(const char *path,
@@ -47,7 +46,7 @@ static bool wlr_libinput_backend_start(struct wlr_backend *_backend) {
 	struct wlr_libinput_backend *backend = (struct wlr_libinput_backend *)_backend;
 	wlr_log(L_DEBUG, "Initializing libinput");
 	backend->libinput_context = libinput_udev_create_context(&libinput_impl, backend,
-			backend->udev->udev);
+			backend->session->udev);
 	if (!backend->libinput_context) {
 		wlr_log(L_ERROR, "Failed to create libinput context");
 		return false;
@@ -139,8 +138,8 @@ static void session_signal(struct wl_listener *listener, void *data) {
 }
 
 struct wlr_backend *wlr_libinput_backend_create(struct wl_display *display,
-		struct wlr_session *session, struct wlr_udev *udev) {
+		struct wlr_session *session) {
-	assert(display && session && udev);
+	assert(display && session);
 
 	struct wlr_libinput_backend *backend = calloc(1, sizeof(struct wlr_libinput_backend));
 	if (!backend) {
@@ -155,7 +154,6 @@ struct wlr_backend *wlr_libinput_backend_create(struct wl_display *display,
 	}
 
 	backend->session = session;
-	backend->udev = udev;
 	backend->display = display;
 
 	backend->session_signal.notify = session_signal;

backend/meson.build

@@ -1,6 +1,5 @@
 backend_files = files(
   'backend.c',
-  'udev.c',
   'session/direct-ipc.c',
   'session/direct.c',
   'session/session.c',

backend/multi/backend.c

@@ -2,7 +2,6 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <wlr/backend/interface.h>
-#include <wlr/backend/udev.h>
 #include <wlr/backend/session.h>
 #include <wlr/util/log.h>
 #include "backend/multi.h"
@@ -36,8 +35,7 @@ static void multi_backend_destroy(struct wlr_backend *_backend) {
 		free(sub);
 	}
 	list_free(backend->backends);
-	wlr_session_finish(backend->session);
+	wlr_session_destroy(backend->session);
-	wlr_udev_destroy(backend->udev);
 	free(backend);
 }
 
@@ -59,8 +57,7 @@ struct wlr_backend_impl backend_impl = {
 	.get_egl = multi_backend_get_egl
 };
 
-struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session,
+struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session) {
-		struct wlr_udev *udev) {
 	struct wlr_multi_backend *backend =
 		calloc(1, sizeof(struct wlr_multi_backend));
 	if (!backend) {
@@ -78,7 +75,6 @@ struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session,
 	wlr_backend_init(&backend->backend, &backend_impl);
 
 	backend->session = session;
-	backend->udev = udev;
 	return &backend->backend;
 }
 

backend/session/direct-ipc.c

@@ -212,7 +212,7 @@ void direct_ipc_finish(int sock, pid_t pid) {
 	waitpid(pid, NULL, 0);
 }
 
-int direct_ipc_start(pid_t *pid_out) {
+int direct_ipc_init(pid_t *pid_out) {
 	if (!have_permissions()) {
 		return -1;
 	}

backend/session/direct.c

@@ -48,7 +48,7 @@ static int direct_session_open(struct wlr_session *base, const char *path) {
 	}
 
 	if (major(st.st_rdev) == DRM_MAJOR) {
-		session->base.drm_fd = fd;
+		direct_ipc_setmaster(session->sock, fd);
 	}
 
 	return fd;
@@ -65,8 +65,7 @@ static void direct_session_close(struct wlr_session *base, int fd) {
 	}
 
 	if (major(st.st_rdev) == DRM_MAJOR) {
-		direct_ipc_dropmaster(session->sock, session->base.drm_fd);
+		direct_ipc_dropmaster(session->sock, fd);
-		session->base.drm_fd = -1;
 	} else if (major(st.st_rdev) == INPUT_MAJOR) {
 		ioctl(fd, EVIOCREVOKE, 0);
 	}
@@ -79,7 +78,7 @@ static bool direct_change_vt(struct wlr_session *base, unsigned vt) {
 	return ioctl(session->tty_fd, VT_ACTIVATE, (int)vt) == 0;
 }
 
-static void direct_session_finish(struct wlr_session *base) {
+static void direct_session_destroy(struct wlr_session *base) {
 	struct direct_session *session = wl_container_of(base, session, base);
 	struct vt_mode mode = {
 		.mode = VT_AUTO,
@@ -109,11 +108,27 @@ static int vt_handler(int signo, void *data) {
 	if (session->base.active) {
 		session->base.active = false;
 		wl_signal_emit(&session->base.session_signal, session);
-		direct_ipc_dropmaster(session->sock, session->base.drm_fd);
+
+		struct wlr_device *dev;
+		wl_list_for_each(dev, &session->base.devices, link) {
+			if (major(dev->dev) == DRM_MAJOR) {
+				direct_ipc_dropmaster(session->sock,
+					dev->fd);
+			}
+		}
+
 		ioctl(session->tty_fd, VT_RELDISP, 1);
 	} else {
 		ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ);
-		direct_ipc_setmaster(session->sock, session->base.drm_fd);
+
+		struct wlr_device *dev;
+		wl_list_for_each(dev, &session->base.devices, link) {
+			if (major(dev->dev) == DRM_MAJOR) {
+				direct_ipc_setmaster(session->sock,
+					dev->fd);
+			}
+		}
+
 		session->base.active = true;
 		wl_signal_emit(&session->base.session_signal, session);
 	}
@@ -196,14 +211,14 @@ error:
 	return false;
 }
 
-static struct wlr_session *direct_session_start(struct wl_display *disp) {
+static struct wlr_session *direct_session_create(struct wl_display *disp) {
 	struct direct_session *session = calloc(1, sizeof(*session));
 	if (!session) {
 		wlr_log_errno(L_ERROR, "Allocation failed");
 		return NULL;
 	}
 
-	session->sock = direct_ipc_start(&session->child);
+	session->sock = direct_ipc_init(&session->child);
 	if (session->sock == -1) {
 		goto error_session;
 	}
@@ -221,10 +236,7 @@ static struct wlr_session *direct_session_start(struct wl_display *disp) {
 	wlr_log(L_INFO, "Successfully loaded direct session");
 
 	snprintf(session->base.seat, sizeof(session->base.seat), "%s", seat);
-	session->base.drm_fd = -1;
 	session->base.impl = &session_direct;
-	session->base.active = true;
-	wl_signal_init(&session->base.session_signal);
 	return &session->base;
 
 error_ipc:
@@ -236,8 +248,8 @@ error_session:
 }
 
 const struct session_impl session_direct = {
-	.start = direct_session_start,
+	.create = direct_session_create,
-	.finish = direct_session_finish,
+	.destroy = direct_session_destroy,
 	.open = direct_session_open,
 	.close = direct_session_close,
 	.change_vt = direct_change_vt,

backend/session/logind.c

@@ -1,4 +1,5 @@
 #define _POSIX_C_SOURCE 200809L
+#include <assert.h>
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -67,10 +68,6 @@ static int logind_take_device(struct wlr_session *base, const char *path) {
 		goto error;
 	}
 
-	if (major(st.st_rdev) == DRM_MAJOR) {
-		session->base.drm_fd = fd;
-	}
-
 error:
 	sd_bus_error_free(&error);
 	sd_bus_message_unref(msg);
@@ -97,10 +94,6 @@ static void logind_release_device(struct wlr_session *base, int fd) {
 		wlr_log(L_ERROR, "Failed to release device '%d'", fd);
 	}
 
-	if (major(st.st_rdev) == DRM_MAJOR) {
-		session->base.drm_fd = -1;
-	}
-
 	sd_bus_error_free(&error);
 	sd_bus_message_unref(msg);
 }
@@ -204,7 +197,7 @@ static void release_control(struct logind_session *session) {
 	sd_bus_message_unref(msg);
 }
 
-static void logind_session_finish(struct wlr_session *base) {
+static void logind_session_destroy(struct wlr_session *base) {
 	struct logind_session *session = wl_container_of(base, session, base);
 
 	release_control(session);
@@ -221,6 +214,20 @@ static int session_removed(sd_bus_message *msg, void *userdata, sd_bus_error *re
 	return 0;
 }
 
+static struct wlr_device *find_device(struct wlr_session *session, dev_t devnum) {
+	struct wlr_device *dev;
+
+	wl_list_for_each(dev, &session->devices, link) {
+		if (dev->dev == devnum) {
+			return dev;
+		}
+	}
+
+	wlr_log(L_ERROR, "Tried to use dev_t %lu not opened by session",
+		(unsigned long)devnum);
+	assert(0);
+}
+
 static int pause_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_error) {
 	struct logind_session *session = userdata;
 	int ret;
@@ -267,10 +274,14 @@ static int resume_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_
 	}
 
 	if (major == DRM_MAJOR) {
-		dup2(fd, session->base.drm_fd);
+		struct wlr_device *dev = find_device(&session->base, makedev(major, minor));
+		dup2(fd, dev->fd);
+
+		if (!session->base.active) {
 			session->base.active = true;
 			wl_signal_emit(&session->base.session_signal, session);
 		}
+	}
 
 error:
 	return 0;
@@ -316,7 +327,7 @@ static int dbus_event(int fd, uint32_t mask, void *data) {
 	return 1;
 }
 
-static struct wlr_session *logind_session_start(struct wl_display *disp) {
+static struct wlr_session *logind_session_create(struct wl_display *disp) {
 	int ret;
 	struct logind_session *session = calloc(1, sizeof(*session));
 	if (!session) {
@@ -374,10 +385,7 @@ static struct wlr_session *logind_session_start(struct wl_display *disp) {
 
 	wlr_log(L_INFO, "Successfully loaded logind session");
 
-	session->base.drm_fd = -1;
 	session->base.impl = &session_logind;
-	session->base.active = true;
-	wl_signal_init(&session->base.session_signal);
 	return &session->base;
 
 error_bus:
@@ -390,8 +398,8 @@ error:
 }
 
 const struct session_impl session_logind = {
-	.start = logind_session_start,
+	.create = logind_session_create,
-	.finish = logind_session_finish,
+	.destroy = logind_session_destroy,
 	.open = logind_take_device,
 	.close = logind_release_device,
 	.change_vt = logind_change_vt,

backend/session/session.c

@@ -1,5 +1,13 @@
+#include <assert.h>
 #include <stddef.h>
 #include <stdarg.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <libudev.h>
+#include <wayland-server.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
 #include <wlr/backend/session.h>
 #include <wlr/backend/session/interface.h>
 #include <wlr/util/log.h>
@@ -15,34 +23,159 @@ static const struct session_impl *impls[] = {
 	NULL,
 };
 
-struct wlr_session *wlr_session_start(struct wl_display *disp) {
+static int udev_event(int fd, uint32_t mask, void *data) {
+	struct wlr_session *session = data;
+
+	struct udev_device *udev_dev = udev_monitor_receive_device(session->mon);
+	if (!udev_dev) {
+		return 1;
+	}
+
+	const char *action = udev_device_get_action(udev_dev);
+
+	wlr_log(L_DEBUG, "udev event for %s (%s)",
+		udev_device_get_sysname(udev_dev), action);
+
+	if (!action || strcmp(action, "change") != 0) {
+		goto out;
+	}
+
+	dev_t devnum = udev_device_get_devnum(udev_dev);
+	struct wlr_device *dev;
+
+	wl_list_for_each(dev, &session->devices, link) {
+		if (dev->dev == devnum) {
+			wl_signal_emit(&dev->signal, session);
+			break;
+		}
+	}
+
+out:
+	udev_device_unref(udev_dev);
+	return 1;
+}
+
+struct wlr_session *wlr_session_create(struct wl_display *disp) {
+	struct wlr_session *session = NULL;
 	const struct session_impl **iter;
 
-	for (iter = impls; *iter; ++iter) {
+	for (iter = impls; !session && *iter; ++iter) {
-		struct wlr_session *session = (*iter)->start(disp);
+		session = (*iter)->create(disp);
-		if (session) {
-			return session;
-		}
 	}
 
+	if (!session) {
 		wlr_log(L_ERROR, "Failed to load session backend");
 		return NULL;
+	}
+
+	session->active = true;
+	wl_signal_init(&session->session_signal);
+	wl_list_init(&session->devices);
+
+	session->udev = udev_new();
+	if (!session->udev) {
+		wlr_log_errno(L_ERROR, "Failed to create udev context");
+		goto error_session;
+	}
+
+	session->mon = udev_monitor_new_from_netlink(session->udev, "udev");
+	if (!session->mon) {
+		wlr_log_errno(L_ERROR, "Failed to create udev monitor");
+		goto error_udev;
+	}
+
+	udev_monitor_filter_add_match_subsystem_devtype(session->mon, "drm", NULL);
+	udev_monitor_enable_receiving(session->mon);
+
+	struct wl_event_loop *event_loop = wl_display_get_event_loop(disp);
+	int fd = udev_monitor_get_fd(session->mon);
+
+	session->udev_event = wl_event_loop_add_fd(event_loop, fd,
+		WL_EVENT_READABLE, udev_event, session);
+	if (!session->udev_event) {
+		wlr_log_errno(L_ERROR, "Failed to create udev event source");
+		goto error_mon;
+	}
+
+	return session;
+
+error_mon:
+	udev_monitor_unref(session->mon);
+error_udev:
+	udev_unref(session->udev);
+error_session:
+	wlr_session_destroy(session);
+	return NULL;
 }
 
-void wlr_session_finish(struct wlr_session *session) {
+void wlr_session_destroy(struct wlr_session *session) {
 	if (!session) {
 		return;
 	}
 
-	session->impl->finish(session);
+	wl_event_source_remove(session->udev_event);
-};
+	udev_monitor_unref(session->mon);
+	udev_unref(session->udev);
+
+	session->impl->destroy(session);
+}
 
 int wlr_session_open_file(struct wlr_session *session, const char *path) {
-	return session->impl->open(session, path);
+	int fd = session->impl->open(session, path);
+	if (fd < 0) {
+		return fd;
+	}
+
+	struct wlr_device *dev = malloc(sizeof(*dev));
+	if (!dev) {
+		wlr_log_errno(L_ERROR, "Allocation failed");
+		goto error;
+	}
+
+	struct stat st;
+	if (fstat(fd, &st) < 0) {
+		wlr_log_errno(L_ERROR, "Stat failed");
+		goto error;
+	}
+
+	dev->fd = fd;
+	dev->dev = st.st_rdev;
+	wl_signal_init(&dev->signal);
+	wl_list_insert(&session->devices, &dev->link);
+
+	return fd;
+
+error:
+	free(dev);
+	return fd;
+}
+
+static struct wlr_device *find_device(struct wlr_session *session, int fd) {
+	struct wlr_device *dev;
+
+	wl_list_for_each(dev, &session->devices, link) {
+		if (dev->fd == fd) {
+			return dev;
+		}
+	}
+
+	wlr_log(L_ERROR, "Tried to use fd %d not opened by session", fd);
+	assert(0);
 }
 
 void wlr_session_close_file(struct wlr_session *session, int fd) {
+	struct wlr_device *dev = find_device(session, fd);
+
 	session->impl->close(session, fd);
+	wl_list_remove(&dev->link);
+	free(dev);
+}
+
+void wlr_session_signal_add(struct wlr_session *session, int fd,
+		struct wl_listener *listener) {
+	struct wlr_device *dev = find_device(session, fd);
+
+	wl_signal_add(&dev->signal, listener);
 }
 
 bool wlr_session_change_vt(struct wlr_session *session, unsigned vt) {
@@ -52,3 +185,119 @@ bool wlr_session_change_vt(struct wlr_session *session, unsigned vt) {
 
 	return session->impl->change_vt(session, vt);
 }
+
+/* Tests if 'path' is KMS compatible by trying to open it.
+ * It leaves the open device in *fd_out it it succeeds.
+ */
+static bool device_is_kms(struct wlr_session *restrict session,
+	const char *restrict path, int *restrict fd_out) {
+
+	int fd;
+
+	if (!path) {
+		return false;
+	}
+
+	fd = wlr_session_open_file(session, path);
+	if (fd < 0) {
+		return false;
+	}
+
+	drmModeRes *res = drmModeGetResources(fd);
+	if (!res) {
+		goto out_fd;
+	}
+
+	if (res->count_crtcs <= 0 || res->count_connectors <= 0 ||
+		res->count_encoders <= 0) {
+
+		goto out_res;
+	}
+
+	if (*fd_out >= 0) {
+		wlr_session_close_file(session, *fd_out);
+	}
+
+	*fd_out = fd;
+
+	drmModeFreeResources(res);
+	return true;
+
+out_res:
+	drmModeFreeResources(res);
+out_fd:
+	wlr_session_close_file(session, fd);
+	return false;
+}
+
+/* Tries to find the primary GPU by checking for the "boot_vga" attribute.
+ * If it's not found, it returns the first valid GPU it finds.
+ */
+int wlr_session_find_gpu(struct wlr_session *session) {
+	struct udev_enumerate *en = udev_enumerate_new(session->udev);
+	if (!en) {
+		wlr_log(L_ERROR, "Failed to create udev enumeration");
+		return -1;
+	}
+
+	udev_enumerate_add_match_subsystem(en, "drm");
+	udev_enumerate_add_match_sysname(en, "card[0-9]*");
+	udev_enumerate_scan_devices(en);
+
+	struct udev_list_entry *entry;
+	int fd = -1;
+
+	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(en)) {
+		bool is_boot_vga = false;
+
+		const char *path = udev_list_entry_get_name(entry);
+		struct udev_device *dev = udev_device_new_from_syspath(session->udev, path);
+		if (!dev) {
+			continue;
+		}
+
+		/*
+		const char *seat = udev_device_get_property_value(dev, "ID_SEAT");
+		if (!seat)
+			seat = "seat0";
+		if (strcmp(session->seat, seat) != 0) {
+			udev_device_unref(dev);
+			continue;
+		}
+		*/
+
+		// This is owned by 'dev', so we don't need to free it
+		struct udev_device *pci =
+			udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
+
+		if (pci) {
+			const char *id = udev_device_get_sysattr_value(pci, "boot_vga");
+			if (id && strcmp(id, "1") == 0) {
+				is_boot_vga = true;
+			}
+		}
+
+		// We already have a valid GPU
+		if (!is_boot_vga && fd >= 0) {
+			udev_device_unref(dev);
+			continue;
+		}
+
+		path = udev_device_get_devnode(dev);
+		if (!device_is_kms(session, path, &fd)) {
+			udev_device_unref(dev);
+			continue;
+		}
+
+		udev_device_unref(dev);
+
+		// We've found the primary GPU
+		if (is_boot_vga) {
+			break;
+		}
+	}
+
+	udev_enumerate_unref(en);
+
+	return fd;
+}

backend/udev.c

@@ -1,252 +0,0 @@
-#define _POSIX_C_SOURCE 200809L
-#include <libudev.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdint.h>
-#include <errno.h>
-#include <xf86drm.h>
-#include <xf86drmMode.h>
-#include <wayland-server.h>
-#include <wlr/backend/session.h>
-#include <wlr/util/log.h>
-#include "backend/udev.h"
-
-/* Tests if 'path' is KMS compatible by trying to open it.
- * It leaves the open device in *fd_out it it succeeds.
- */
-static bool device_is_kms(struct wlr_session *restrict session,
-	const char *restrict path, int *restrict fd_out) {
-
-	int fd;
-
-	if (!path) {
-		return false;
-	}
-
-	fd = wlr_session_open_file(session, path);
-	if (fd < 0) {
-		return false;
-	}
-
-	drmModeRes *res = drmModeGetResources(fd);
-	if (!res) {
-		goto out_fd;
-	}
-
-	if (res->count_crtcs <= 0 || res->count_connectors <= 0 ||
-		res->count_encoders <= 0) {
-
-		goto out_res;
-	}
-
-	if (*fd_out >= 0) {
-		wlr_session_close_file(session, *fd_out);
-	}
-
-	*fd_out = fd;
-
-	drmModeFreeResources(res);
-	return true;
-
-out_res:
-	drmModeFreeResources(res);
-out_fd:
-	wlr_session_close_file(session, fd);
-	return false;
-}
-
-/* Tries to find the primary GPU by checking for the "boot_vga" attribute.
- * If it's not found, it returns the first valid GPU it finds.
- */
-int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session) {
-	struct udev_enumerate *en = udev_enumerate_new(udev->udev);
-	if (!en) {
-		wlr_log(L_ERROR, "Failed to create udev enumeration");
-		return -1;
-	}
-
-	udev_enumerate_add_match_subsystem(en, "drm");
-	udev_enumerate_add_match_sysname(en, "card[0-9]*");
-	udev_enumerate_scan_devices(en);
-
-	struct udev_list_entry *entry;
-	int fd = -1;
-
-	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(en)) {
-		bool is_boot_vga = false;
-
-		const char *path = udev_list_entry_get_name(entry);
-		struct udev_device *dev = udev_device_new_from_syspath(udev->udev, path);
-		if (!dev) {
-			continue;
-		}
-
-		/*
-		const char *seat = udev_device_get_property_value(dev, "ID_SEAT");
-		if (!seat)
-			seat = "seat0";
-		if (strcmp(session->seat, seat) != 0) {
-			udev_device_unref(dev);
-			continue;
-		}
-		*/
-
-		// This is owned by 'dev', so we don't need to free it
-		struct udev_device *pci =
-			udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
-
-		if (pci) {
-			const char *id = udev_device_get_sysattr_value(pci, "boot_vga");
-			if (id && strcmp(id, "1") == 0) {
-				is_boot_vga = true;
-			}
-		}
-
-		// We already have a valid GPU
-		if (!is_boot_vga && fd >= 0) {
-			udev_device_unref(dev);
-			continue;
-		}
-
-		path = udev_device_get_devnode(dev);
-		if (!device_is_kms(session, path, &fd)) {
-			udev_device_unref(dev);
-			continue;
-		}
-
-		udev_device_unref(dev);
-
-		// We've found the primary GPU
-		if (is_boot_vga) {
-			break;
-		}
-	}
-
-	udev_enumerate_unref(en);
-
-	return fd;
-}
-
-static int udev_event(int fd, uint32_t mask, void *data) {
-	struct wlr_udev *udev = data;
-
-	struct udev_device *dev = udev_monitor_receive_device(udev->mon);
-	if (!dev) {
-		return 1;
-	}
-
-	const char *action = udev_device_get_action(dev);
-
-	wlr_log(L_DEBUG, "udev event for %s (%s)",
-			udev_device_get_sysname(dev), action);
-
-	if (!action || strcmp(action, "change") != 0) {
-		goto out;
-	}
-
-	dev_t devnum = udev_device_get_devnum(dev);
-	struct wlr_udev_dev *signal;
-
-	wl_list_for_each(signal, &udev->devices, link) {
-		if (signal->dev == devnum) {
-			wl_signal_emit(&signal->invalidate, udev);
-			break;
-		}
-	}
-
-out:
-	udev_device_unref(dev);
-	return 1;
-}
-
-struct wlr_udev *wlr_udev_create(struct wl_display *display) {
-	struct wlr_udev *udev = calloc(sizeof(struct wlr_udev), 1);
-	if (!udev) {
-		return NULL;
-	}
-	udev->udev = udev_new();
-	if (!udev->udev) {
-		wlr_log(L_ERROR, "Failed to create udev context");
-		goto error;
-	}
-
-	udev->mon = udev_monitor_new_from_netlink(udev->udev, "udev");
-	if (!udev->mon) {
-		wlr_log(L_ERROR, "Failed to create udev monitor");
-		goto error_udev;
-	}
-
-	udev_monitor_filter_add_match_subsystem_devtype(udev->mon, "drm", NULL);
-	udev_monitor_enable_receiving(udev->mon);
-
-	struct wl_event_loop *event_loop = wl_display_get_event_loop(display);
-	int fd = udev_monitor_get_fd(udev->mon);
-
-	udev->event = wl_event_loop_add_fd(event_loop, fd, WL_EVENT_READABLE,
-		udev_event, udev);
-	if (!udev->event) {
-		wlr_log(L_ERROR, "Failed to create udev event source");
-		goto error_mon;
-	}
-	
-	wl_list_init(&udev->devices);
-
-	wlr_log(L_DEBUG, "Successfully initialized udev");
-	return udev;
-
-error_mon:
-	udev_monitor_unref(udev->mon);
-error_udev:
-	udev_unref(udev->udev);
-error:
-	free(udev);
-	return NULL;
-}
-
-void wlr_udev_destroy(struct wlr_udev *udev) {
-	if (!udev) {
-		return;
-	}
-
-	struct wlr_udev_dev *dev, *tmp;
-	wl_list_for_each_safe(dev, tmp, &udev->devices, link) {
-		free(dev);
-	}
-
-	wl_event_source_remove(udev->event);
-	udev_monitor_unref(udev->mon);
-	udev_unref(udev->udev);
-	free(udev);
-}
-
-bool wlr_udev_signal_add(struct wlr_udev *udev, dev_t dev, struct wl_listener *listener) {
-	struct wlr_udev_dev *device = malloc(sizeof(*device));
-	if (!device) {
-		wlr_log(L_ERROR, "Allocation failed: %s", strerror(errno));
-		return false;
-	}
-
-	device->dev = dev;
-	wl_signal_init(&device->invalidate);
-	wl_signal_add(&device->invalidate, listener);
-	wl_list_insert(&udev->devices, &device->link);
-
-	return true;
-}
-
-void wlr_udev_signal_remove(struct wlr_udev *udev, struct wl_listener *listener) {
-	if (!udev || !listener) {
-		return;
-	}
-
-	struct wlr_udev_dev *dev, *tmp;
-	wl_list_for_each_safe(dev, tmp, &udev->devices, link) {
-		// The signal should only have a single listener
-		if (wl_signal_get(&dev->invalidate, listener->notify) != NULL) {
-			wl_list_remove(&dev->link);
-			free(dev);
-			return;
-		}
-	}
-}

include/backend/drm.h

@@ -7,7 +7,6 @@
 #include <wayland-server.h>
 #include <xf86drmMode.h>
 #include <EGL/egl.h>
-#include <libudev.h>
 #include <gbm.h>
 
 #include <wlr/backend/session.h>
@@ -16,7 +15,6 @@
 #include <wlr/egl.h>
 #include <wlr/util/list.h>
 
-#include <backend/udev.h>
 #include "drm-properties.h"
 
 struct wlr_drm_plane {
@@ -124,7 +122,6 @@ struct wlr_drm_backend {
 
 	struct wlr_drm_renderer renderer;
 	struct wlr_session *session;
-	struct wlr_udev *udev;
 };
 
 enum wlr_drm_output_state {

include/backend/libinput.h

@@ -6,13 +6,11 @@
 #include <wlr/backend/interface.h>
 #include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/util/list.h>
-#include "backend/udev.h"
 
 struct wlr_libinput_backend {
 	struct wlr_backend backend;
 
 	struct wlr_session *session;
-	struct wlr_udev *udev;
 	struct wl_display *display;
 
 	struct libinput *libinput_context;

include/backend/multi.h

@@ -3,7 +3,6 @@
 
 #include <wlr/backend/interface.h>
 #include <wlr/backend/multi.h>
-#include <wlr/backend/udev.h>
 #include <wlr/util/list.h>
 #include <wlr/backend/session.h>
 
@@ -11,7 +10,6 @@ struct wlr_multi_backend {
 	struct wlr_backend backend;
 
 	struct wlr_session *session;
-	struct wlr_udev *udev;
 	list_t *backends;
 };
 

include/backend/session/direct-ipc.h

@@ -7,6 +7,6 @@ int direct_ipc_open(int sock, const char *path);
 void direct_ipc_setmaster(int sock, int fd);
 void direct_ipc_dropmaster(int sock, int fd);
 void direct_ipc_finish(int sock, pid_t pid);
-int direct_ipc_start(pid_t *pid_out);
+int direct_ipc_init(pid_t *pid_out);
 
 #endif

include/backend/udev.h

@@ -1,29 +0,0 @@
-#ifndef _WLR_INTERNAL_UDEV_H
-#define _WLR_INTERNAL_UDEV_H
-
-#include <sys/types.h>
-#include <libudev.h>
-#include <wlr/backend/session.h>
-#include <wayland-server.h>
-#include <wlr/backend/udev.h>
-
-struct wlr_udev_dev {
-	dev_t dev;
-	struct wl_signal invalidate;
-
-	struct wl_list link;
-};
-
-struct wlr_udev {
-	struct udev *udev;
-	struct udev_monitor *mon;
-	struct wl_event_source *event;
-
-	struct wl_list devices;
-};
-
-int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session);
-bool wlr_udev_signal_add(struct wlr_udev *udev, dev_t dev, struct wl_listener *listener);
-void wlr_udev_signal_remove(struct wlr_udev *udev, struct wl_listener *listener);
-
-#endif

include/wlr/backend/drm.h

@@ -4,10 +4,9 @@
 #include <wayland-server.h>
 #include <wlr/backend/session.h>
 #include <wlr/backend.h>
-#include <wlr/backend/udev.h>
 
 struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
-		struct wlr_session *session, struct wlr_udev *udev, int gpu_fd);
+		struct wlr_session *session, int gpu_fd);
 
 bool wlr_backend_is_drm(struct wlr_backend *backend);
 

include/wlr/backend/libinput.h

@@ -5,11 +5,10 @@
 #include <wayland-server.h>
 #include <wlr/backend/session.h>
 #include <wlr/backend.h>
-#include <wlr/backend/udev.h>
 #include <wlr/types/wlr_input_device.h>
 
 struct wlr_backend *wlr_libinput_backend_create(struct wl_display *display,
-		struct wlr_session *session, struct wlr_udev *udev);
+		struct wlr_session *session);
 struct libinput_device *wlr_libinput_get_device_handle(struct wlr_input_device *dev);
 
 bool wlr_backend_is_libinput(struct wlr_backend *backend);

include/wlr/backend/multi.h

@@ -2,11 +2,9 @@
 #define _WLR_BACKEND_MULTI_H
 
 #include <wlr/backend.h>
-#include <wlr/backend/udev.h>
 #include <wlr/backend/session.h>
 
-struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session,
+struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session);
-		struct wlr_udev *udev);
 void wlr_multi_backend_add(struct wlr_backend *multi,
 		struct wlr_backend *backend);
 

include/wlr/backend/session.h

@@ -3,10 +3,19 @@
 
 #include <stdbool.h>
 #include <wayland-server.h>
+#include <libudev.h>
 #include <sys/types.h>
 
 struct session_impl;
 
+struct wlr_device {
+	int fd;
+	dev_t dev;
+	struct wl_signal signal;
+
+	struct wl_list link;
+};
+
 struct wlr_session {
 	const struct session_impl *impl;
 	/*
@@ -16,9 +25,14 @@ struct wlr_session {
 	struct wl_signal session_signal;
 	bool active;
 
-	int drm_fd;
 	unsigned vtnr;
 	char seat[8];
+
+	struct udev *udev;
+	struct udev_monitor *mon;
+	struct wl_event_source *udev_event;
+
+	struct wl_list devices;
 };
 
 /*
@@ -31,14 +45,14 @@ struct wlr_session {
  *
  * Returns NULL on error.
  */
-struct wlr_session *wlr_session_start(struct wl_display *disp);
+struct wlr_session *wlr_session_create(struct wl_display *disp);
 
 /*
  * Closes a previously opened session and restores the virtual terminal.
  * You should call wlr_session_close_file on each files you opened
  * with wlr_session_open_file before you call this.
  */
-void wlr_session_finish(struct wlr_session *session);
+void wlr_session_destroy(struct wlr_session *session);
 
 /*
  * Opens the file at path.
@@ -57,9 +71,13 @@ int wlr_session_open_file(struct wlr_session *session, const char *path);
  */
 void wlr_session_close_file(struct wlr_session *session, int fd);
 
+void wlr_session_signal_add(struct wlr_session *session, int fd,
+		struct wl_listener *listener);
 /*
  * Changes the virtual terminal.
  */
 bool wlr_session_change_vt(struct wlr_session *session, unsigned vt);
 
+int wlr_session_find_gpu(struct wlr_session *session);
+
 #endif

include/wlr/backend/session/interface.h

@@ -4,8 +4,8 @@
 #include <wlr/backend/session.h>
 
 struct session_impl {
-	struct wlr_session *(*start)(struct wl_display *disp);
+	struct wlr_session *(*create)(struct wl_display *disp);
-	void (*finish)(struct wlr_session *session);
+	void (*destroy)(struct wlr_session *session);
 	int (*open)(struct wlr_session *session, const char *path);
 	void (*close)(struct wlr_session *session, int fd);
 	bool (*change_vt)(struct wlr_session *session, unsigned vt);

include/wlr/backend/udev.h

@@ -1,9 +0,0 @@
-#ifndef _WLR_BACKEND_UDEV_H
-#define _WLR_BACKEND_UDEV_H
-
-struct wlr_udev;
-
-struct wlr_udev *wlr_udev_create(struct wl_display *display);
-void wlr_udev_destroy(struct wlr_udev *udev);
-
-#endif