static void xenfb_handle_events(struct XenFB *xenfb) { uint32_t prod, cons; struct xenfb_page *page = xenfb->c.page; prod = page->out_prod; if (prod == page->out_cons) return; xen_rmb(); /* ensure we see ring contents up to prod */ for (cons = page->out_cons; cons != prod; cons++) { union xenfb_out_event *event = &XENFB_OUT_RING_REF(page, cons); int x, y, w, h; switch (event->type) { case XENFB_TYPE_UPDATE: if (xenfb->up_count == UP_QUEUE) xenfb->up_fullscreen = 1; if (xenfb->up_fullscreen) break; x = MAX(event->update.x, 0); y = MAX(event->update.y, 0); w = MIN(event->update.width, xenfb->width - x); h = MIN(event->update.height, xenfb->height - y); if (w < 0 || h < 0) { xen_be_printf(&xenfb->c.xendev, 1, "bogus update ignored\n"); break; } if (x != event->update.x || y != event->update.y || w != event->update.width || h != event->update.height) { xen_be_printf(&xenfb->c.xendev, 1, "bogus update clipped\n"); } if (w == xenfb->width && h > xenfb->height / 2) { /* scroll detector: updated more than 50% of the lines, * don't bother keeping track of the rectangles then */ xenfb->up_fullscreen = 1; } else { xenfb->up_rects[xenfb->up_count].x = x; xenfb->up_rects[xenfb->up_count].y = y; xenfb->up_rects[xenfb->up_count].w = w; xenfb->up_rects[xenfb->up_count].h = h; xenfb->up_count++; } break; #ifdef XENFB_TYPE_RESIZE case XENFB_TYPE_RESIZE: if (xenfb_configure_fb(xenfb, xenfb->fb_len, event->resize.width, event->resize.height, event->resize.depth, xenfb->fb_len, event->resize.offset, event->resize.stride) < 0) break; xenfb_invalidate(xenfb); break; #endif } } xen_mb(); /* ensure we're done with ring contents */ page->out_cons = cons; }