drm: Implement drmCheckModesettingSupported() for FreeBSD

Add the missing implementation of drmCheckModesettingSupported()
to detect KMS support on FreeBSD (and GNU/kFreeBSD).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72847
Signed-off-by: Konstantin Belousov <kib@freebsd.org>
Signed-off-by: Robert Millan <rmh@freebsd.org>

2 files changed, 36 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 969fb83b..d2d19d66 100644
--- a/configure.ac
+++ b/configure.ac
@@ -185,6 +185,8 @@ AC_CANONICAL_HOST
 if test "x$LIBKMS" = xauto ; then
         case $host_os in
                 linux*)         LIBKMS="yes" ;;
+                freebsd* | kfreebsd*-gnu)
+                                LIBKMS="yes" ;;
                 *)              LIBKMS="no" ;;
         esac
 fi
diff --git a/xf86drmMode.c b/xf86drmMode.c
index dd7966ef..a6bb2ee4 100644
--- a/xf86drmMode.c
+++ b/xf86drmMode.c
@@ -723,7 +723,7 @@ int drmModeConnectorSetProperty(int fd, uint32_t connector_id, uint32_t property
 */
 int drmCheckModesettingSupported(const char *busid)
 {
-#ifdef __linux__
+#if defined (__linux__)
         char pci_dev_dir[1024];
         int domain, bus, dev, func;
         DIR *sysdir;
@@ -773,6 +773,39 @@ int drmCheckModesettingSupported(const char *busid)
         closedir(sysdir);
         if (found)
                 return 0;
+#elif defined (__FreeBSD__) || defined (__FreeBSD_kernel__)
+        char kbusid[1024], sbusid[1024];
+        char oid[128];
+        int domain, bus, dev, func;
+        int i, modesetting, ret;
+        size_t len;
+
+        ret = sscanf(busid, "pci:%04x:%02x:%02x.%d", &domain, &bus, &dev,
+            &func);
+        if (ret != 4)
+                return -EINVAL;
+        snprintf(kbusid, sizeof(kbusid), "pci:%04x:%02x:%02x.%d", domain, bus,
+            dev, func);
+
+        /* How many GPUs do we expect in the machine ? */
+        for (i = 0; i < 16; i++) {
+                snprintf(oid, sizeof(oid), "hw.dri.%d.busid", i);
+                len = sizeof(sbusid);
+                ret = sysctlbyname(oid, sbusid, &len, NULL, 0);
+                if (ret == -1) {
+                        if (errno == ENOENT)
+                                continue;
+                        return -EINVAL;
+                }
+                if (strcmp(sbusid, kbusid) != 0)
+                        continue;
+                snprintf(oid, sizeof(oid), "hw.dri.%d.modesetting", i);
+                len = sizeof(modesetting);
+                ret = sysctlbyname(oid, &modesetting, &len, NULL, 0);
+                if (ret == -1 || len != sizeof(modesetting))
+                        return -EINVAL;
+                return (modesetting ? 0 : -ENOSYS);
+        }
 #endif
         return -ENOSYS;