diff options
Diffstat (limited to 'backend/drm/udev.c')
| -rw-r--r-- | backend/drm/udev.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/backend/drm/udev.c b/backend/drm/udev.c new file mode 100644 index 00000000..e5470157 --- /dev/null +++ b/backend/drm/udev.c @@ -0,0 +1,214 @@ +#define _POSIX_C_SOURCE 200809L + +#include <libudev.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <xf86drm.h> +#include <xf86drmMode.h> +#include <wayland-server.h> + +#include <wlr/session.h> + +#include "backend.h" +#include "backend/drm/backend.h" +#include "backend/drm/udev.h" +#include "backend/drm/drm.h" +#include "common/log.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; + char *drm_path = NULL; + + 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; + } + + free(drm_path); + drm_path = strdup(path); + + udev_device_unref(dev); + + // We've found the primary GPU + if (is_boot_vga) { + break; + } + } + + udev_enumerate_unref(en); + + udev->drm_path = drm_path; + return fd; +} + +static int udev_event(int fd, uint32_t mask, void *data) { + struct wlr_udev *udev = data; + struct wlr_backend_state *state = wl_container_of(udev, state, udev); + + struct udev_device *dev = udev_monitor_receive_device(udev->mon); + if (!dev) { + return 1; + } + + const char *path = udev_device_get_devnode(dev); + if (!path || strcmp(path, udev->drm_path) != 0) { + goto out; + } + + const char *action = udev_device_get_action(dev); + if (!action || strcmp(action, "change") != 0) { + goto out; + } + + wlr_drm_scan_connectors(state); + +out: + udev_device_unref(dev); + return 1; +} + +bool wlr_udev_init(struct wl_display *display, struct wlr_udev *udev) { + udev->udev = udev_new(); + if (!udev->udev) { + wlr_log(L_ERROR, "Failed to create udev context"); + return false; + } + + 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; + } + + udev->drm_path = NULL; + + return true; + +error_mon: + udev_monitor_unref(udev->mon); +error_udev: + udev_unref(udev->udev); + return false; +} + +void wlr_udev_free(struct wlr_udev *udev) { + if (!udev) { + return; + } + + wl_event_source_remove(udev->event); + + udev_monitor_unref(udev->mon); + udev_unref(udev->udev); + free(udev->drm_path); +} |