Merge pull request #182 from ascent12/drm-multi-gpu

DRM Multi-GPU

1 files changed, 189 insertions, 0 deletions

diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c
new file mode 100644
index 00000000..e7374a00
--- /dev/null
+++ b/backend/drm/atomic.c
@@ -0,0 +1,189 @@
+#include <gbm.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <wlr/util/log.h>
+#include "backend/drm/drm.h"
+#include "backend/drm/iface.h"
+#include "backend/drm/util.h"
+
+struct atomic {
+	drmModeAtomicReq *req;
+	int cursor;
+	bool failed;
+};
+
+static void atomic_begin(struct wlr_drm_crtc *crtc, struct atomic *atom) {
+	if (!crtc->atomic) {
+		crtc->atomic = drmModeAtomicAlloc();
+		if (!crtc->atomic) {
+			wlr_log_errno(L_ERROR, "Allocation failed");
+			atom->failed = true;
+			return;
+		}
+	}
+
+	atom->req = crtc->atomic;
+	atom->cursor = drmModeAtomicGetCursor(atom->req);
+	atom->failed = false;
+}
+
+static bool atomic_end(int drm_fd, struct atomic *atom) {
+	if (atom->failed) {
+		return false;
+	}
+
+	uint32_t flags = DRM_MODE_ATOMIC_TEST_ONLY | DRM_MODE_ATOMIC_NONBLOCK;
+
+	if (drmModeAtomicCommit(drm_fd, atom->req, flags, NULL)) {
+		wlr_log_errno(L_ERROR, "Atomic test failed");
+		drmModeAtomicSetCursor(atom->req, atom->cursor);
+		return false;
+	}
+
+	return true;
+}
+
+static bool atomic_commit(int drm_fd, struct atomic *atom,
+		struct wlr_drm_connector *conn, uint32_t flag, bool modeset) {
+	if (atom->failed) {
+		return false;
+	}
+
+	uint32_t flags = DRM_MODE_PAGE_FLIP_EVENT | flag;
+
+	int ret = drmModeAtomicCommit(drm_fd, atom->req, flags, conn);
+	if (ret) {
+		wlr_log_errno(L_ERROR, "%s: Atomic commit failed (%s)",
+			conn->output.name, modeset ? "modeset" : "pageflip");
+
+		// Try to commit without new changes
+		drmModeAtomicSetCursor(atom->req, atom->cursor);
+		if (drmModeAtomicCommit(drm_fd, atom->req, flags, conn)) {
+			wlr_log_errno(L_ERROR, "%s: Atomic commit failed (%s)",
+				conn->output.name, modeset ? "modeset" : "pageflip");
+		}
+	}
+
+	drmModeAtomicSetCursor(atom->req, 0);
+
+	return !ret;
+}
+
+static inline void atomic_add(struct atomic *atom, uint32_t id, uint32_t prop, uint64_t val) {
+	if (!atom->failed && drmModeAtomicAddProperty(atom->req, id, prop, val) < 0) {
+		wlr_log_errno(L_ERROR, "Failed to add atomic DRM property");
+		atom->failed = true;
+	}
+}
+
+static void set_plane_props(struct atomic *atom, struct wlr_drm_plane *plane,
+		uint32_t crtc_id, uint32_t fb_id, bool set_crtc_xy) {
+	uint32_t id = plane->id;
+	const union wlr_drm_plane_props *props = &plane->props;
+
+	// The src_* properties are in 16.16 fixed point
+	atomic_add(atom, id, props->src_x, 0);
+	atomic_add(atom, id, props->src_y, 0);
+	atomic_add(atom, id, props->src_w, plane->surf.width << 16);
+	atomic_add(atom, id, props->src_h, plane->surf.height << 16);
+	atomic_add(atom, id, props->crtc_w, plane->surf.width);
+	atomic_add(atom, id, props->crtc_h, plane->surf.height);
+	atomic_add(atom, id, props->fb_id, fb_id);
+	atomic_add(atom, id, props->crtc_id, crtc_id);
+	if (set_crtc_xy) {
+		atomic_add(atom, id, props->crtc_x, 0);
+		atomic_add(atom, id, props->crtc_y, 0);
+	}
+}
+
+static bool atomic_crtc_pageflip(struct wlr_drm_backend *drm,
+		struct wlr_drm_connector *conn,
+		struct wlr_drm_crtc *crtc,
+		uint32_t fb_id, drmModeModeInfo *mode) {
+	if (mode) {
+		if (crtc->mode_id) {
+			drmModeDestroyPropertyBlob(drm->fd, crtc->mode_id);
+		}
+
+		if (drmModeCreatePropertyBlob(drm->fd, mode, sizeof(*mode), &crtc->mode_id)) {
+			wlr_log_errno(L_ERROR, "Unable to create property blob");
+			return false;
+		}
+	}
+
+	struct atomic atom;
+
+	atomic_begin(crtc, &atom);
+	atomic_add(&atom, conn->id, conn->props.crtc_id, crtc->id);
+	atomic_add(&atom, crtc->id, crtc->props.mode_id, crtc->mode_id);
+	atomic_add(&atom, crtc->id, crtc->props.active, 1);
+	set_plane_props(&atom, crtc->primary, crtc->id, fb_id, true);
+	return atomic_commit(drm->fd, &atom, conn,
+		mode ? DRM_MODE_ATOMIC_ALLOW_MODESET : DRM_MODE_ATOMIC_NONBLOCK,
+		mode);
+}
+
+static void atomic_conn_enable(struct wlr_drm_backend *drm,
+		struct wlr_drm_connector *conn, bool enable) {
+	struct wlr_drm_crtc *crtc = conn->crtc;
+	struct atomic atom;
+
+	atomic_begin(crtc, &atom);
+	atomic_add(&atom, crtc->id, crtc->props.active, enable);
+	atomic_end(drm->fd, &atom);
+}
+
+bool legacy_crtc_set_cursor(struct wlr_drm_backend *drm,
+		struct wlr_drm_crtc *crtc, struct gbm_bo *bo);
+
+static bool atomic_crtc_set_cursor(struct wlr_drm_backend *drm,
+		struct wlr_drm_crtc *crtc, struct gbm_bo *bo) {
+	if (!crtc || !crtc->cursor) {
+		return true;
+	}
+
+	struct wlr_drm_plane *plane = crtc->cursor;
+	// We can't use atomic operations on fake planes
+	if (plane->id == 0) {
+		return legacy_crtc_set_cursor(drm, crtc, bo);
+	}
+
+	struct atomic atom;
+
+	atomic_begin(crtc, &atom);
+
+	if (bo) {
+		set_plane_props(&atom, plane, crtc->id, get_fb_for_bo(bo), false);
+	} else {
+		atomic_add(&atom, plane->id, plane->props.fb_id, 0);
+		atomic_add(&atom, plane->id, plane->props.crtc_id, 0);
+	}
+
+	return atomic_end(drm->fd, &atom);
+}
+
+bool legacy_crtc_move_cursor(struct wlr_drm_backend *drm,
+		struct wlr_drm_crtc *crtc, int x, int y);
+
+static bool atomic_crtc_move_cursor(struct wlr_drm_backend *drm,
+		struct wlr_drm_crtc *crtc, int x, int y) {
+	struct wlr_drm_plane *plane = crtc->cursor;
+	// We can't use atomic operations on fake planes
+	if (plane->id == 0) {
+		return legacy_crtc_move_cursor(drm, crtc, x, y);
+	}
+
+	struct atomic atom;
+
+	atomic_begin(crtc, &atom);
+	atomic_add(&atom, plane->id, plane->props.crtc_x, x);
+	atomic_add(&atom, plane->id, plane->props.crtc_y, y);
+	return atomic_end(drm->fd, &atom);
+}
+
+const struct wlr_drm_interface atomic_iface = {
+	.conn_enable = atomic_conn_enable,
+	.crtc_pageflip = atomic_crtc_pageflip,
+	.crtc_set_cursor = atomic_crtc_set_cursor,
+	.crtc_move_cursor = atomic_crtc_move_cursor,
+};