static void ahci_start_transfer(IDEDMA *dma) { AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma); IDEState *s = &ad->port.ifs[0]; uint32_t size = (uint32_t)(s->data_end - s->data_ptr); /* write == ram -> device */ uint32_t opts = le32_to_cpu(ad->cur_cmd->opts); int is_write = opts & AHCI_CMD_WRITE; int is_atapi = opts & AHCI_CMD_ATAPI; int has_sglist = 0; if (is_atapi && !ad->done_atapi_packet) { /* already prepopulated iobuffer */ ad->done_atapi_packet = true; size = 0; goto out; } if (!ahci_populate_sglist(ad, &s->sg, s->io_buffer_offset)) { has_sglist = 1; } DPRINTF(ad->port_no, "%sing %d bytes on %s w/%s sglist\n", is_write ? "writ" : "read", size, is_atapi ? "atapi" : "ata", has_sglist ? "" : "o"); if (has_sglist && size) { if (is_write) { dma_buf_write(s->data_ptr, size, &s->sg); } else { dma_buf_read(s->data_ptr, size, &s->sg); } } out: /* declare that we processed everything */ s->data_ptr = s->data_end; /* Update number of transferred bytes, destroy sglist */ ahci_commit_buf(dma, size); s->end_transfer_func(s); if (!(s->status & DRQ_STAT)) { /* done with PIO send/receive */ ahci_write_fis_pio(ad, le32_to_cpu(ad->cur_cmd->status)); } }