iwx_dma_contig_free() uvm_fault

[Jonathan Gray]

trace from the first png is:

uvm_fault
iwx_stop_device+0x6f3:  movq    0x10(%rdi),%r11
iwx_stop+0x214
iwx_init_task+0x8d
taskq_thread+0x129

line 1882 of if_iwx.c from OPENBSD_7_7

  1870  void
  1871  iwx_dma_contig_free(struct iwx_dma_info *dma)
  1872  {
  1873          if (dma->map != NULL) {
  1874                  if (dma->vaddr != NULL) {
  1875                          bus_dmamap_sync(dma->tag, dma->map, 0, 
dma->size,
  1876                              BUS_DMASYNC_POSTREAD | 
BUS_DMASYNC_POSTWRITE);
  1877                          bus_dmamap_unload(dma->tag, dma->map);
  1878                          bus_dmamem_unmap(dma->tag, dma->vaddr, 
dma->size);
  1879                          bus_dmamem_free(dma->tag, &dma->seg, 1);
  1880                          dma->vaddr = NULL;
  1881                  }
  1882                  bus_dmamap_destroy(dma->tag, dma->map);
  1883                  dma->map = NULL;
  1884          }
  1885  }