wlroots/backend/udev.c

254 lines
5.5 KiB
C

#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/session.h>
#include "backend.h"
#include "backend/drm/backend.h"
#include "backend/udev.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;
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);
}
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;
}
}
}