error: Avoid unnecessary error_propagate() after error_setg()
[qemu/ar7.git] / hw / ppc / spapr_vio.c
blob731080d989f133a6861755d6b6ea93685933e473
1 /*
2 * QEMU sPAPR VIO code
4 * Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
5 * Based on the s390 virtio bus code:
6 * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
22 #include "qemu/osdep.h"
23 #include "qemu/error-report.h"
24 #include "qapi/error.h"
25 #include "qapi/visitor.h"
26 #include "qemu/log.h"
27 #include "hw/loader.h"
28 #include "elf.h"
29 #include "hw/sysbus.h"
30 #include "sysemu/kvm.h"
31 #include "sysemu/device_tree.h"
32 #include "kvm_ppc.h"
33 #include "migration/vmstate.h"
34 #include "sysemu/qtest.h"
36 #include "hw/ppc/spapr.h"
37 #include "hw/ppc/spapr_vio.h"
38 #include "hw/ppc/fdt.h"
39 #include "trace.h"
41 #include <libfdt.h>
43 #define SPAPR_VIO_REG_BASE 0x71000000
45 static char *spapr_vio_get_dev_name(DeviceState *qdev)
47 SpaprVioDevice *dev = VIO_SPAPR_DEVICE(qdev);
48 SpaprVioDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
50 /* Device tree style name device@reg */
51 return g_strdup_printf("%s@%x", pc->dt_name, dev->reg);
54 static void spapr_vio_bus_class_init(ObjectClass *klass, void *data)
56 BusClass *k = BUS_CLASS(klass);
58 k->get_dev_path = spapr_vio_get_dev_name;
59 k->get_fw_dev_path = spapr_vio_get_dev_name;
62 static const TypeInfo spapr_vio_bus_info = {
63 .name = TYPE_SPAPR_VIO_BUS,
64 .parent = TYPE_BUS,
65 .class_init = spapr_vio_bus_class_init,
66 .instance_size = sizeof(SpaprVioBus),
69 SpaprVioDevice *spapr_vio_find_by_reg(SpaprVioBus *bus, uint32_t reg)
71 BusChild *kid;
72 SpaprVioDevice *dev = NULL;
74 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
75 dev = (SpaprVioDevice *)kid->child;
76 if (dev->reg == reg) {
77 return dev;
81 return NULL;
84 static int vio_make_devnode(SpaprVioDevice *dev,
85 void *fdt)
87 SpaprVioDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
88 int vdevice_off, node_off, ret;
89 char *dt_name;
90 const char *dt_compatible;
92 vdevice_off = fdt_path_offset(fdt, "/vdevice");
93 if (vdevice_off < 0) {
94 return vdevice_off;
97 dt_name = spapr_vio_get_dev_name(DEVICE(dev));
98 node_off = fdt_add_subnode(fdt, vdevice_off, dt_name);
99 g_free(dt_name);
100 if (node_off < 0) {
101 return node_off;
104 ret = fdt_setprop_cell(fdt, node_off, "reg", dev->reg);
105 if (ret < 0) {
106 return ret;
109 if (pc->dt_type) {
110 ret = fdt_setprop_string(fdt, node_off, "device_type",
111 pc->dt_type);
112 if (ret < 0) {
113 return ret;
117 if (pc->get_dt_compatible) {
118 dt_compatible = pc->get_dt_compatible(dev);
119 } else {
120 dt_compatible = pc->dt_compatible;
123 if (dt_compatible) {
124 ret = fdt_setprop_string(fdt, node_off, "compatible",
125 dt_compatible);
126 if (ret < 0) {
127 return ret;
131 if (dev->irq) {
132 uint32_t ints_prop[2];
134 spapr_dt_irq(ints_prop, dev->irq, false);
135 ret = fdt_setprop(fdt, node_off, "interrupts", ints_prop,
136 sizeof(ints_prop));
137 if (ret < 0) {
138 return ret;
142 ret = spapr_tcet_dma_dt(fdt, node_off, "ibm,my-dma-window", dev->tcet);
143 if (ret < 0) {
144 return ret;
147 if (pc->devnode) {
148 ret = (pc->devnode)(dev, fdt, node_off);
149 if (ret < 0) {
150 return ret;
154 return node_off;
158 * CRQ handling
160 static target_ulong h_reg_crq(PowerPCCPU *cpu, SpaprMachineState *spapr,
161 target_ulong opcode, target_ulong *args)
163 target_ulong reg = args[0];
164 target_ulong queue_addr = args[1];
165 target_ulong queue_len = args[2];
166 SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
168 if (!dev) {
169 hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
170 return H_PARAMETER;
173 /* We can't grok a queue size bigger than 256M for now */
174 if (queue_len < 0x1000 || queue_len > 0x10000000) {
175 hcall_dprintf("Queue size too small or too big (0x" TARGET_FMT_lx
176 ")\n", queue_len);
177 return H_PARAMETER;
180 /* Check queue alignment */
181 if (queue_addr & 0xfff) {
182 hcall_dprintf("Queue not aligned (0x" TARGET_FMT_lx ")\n", queue_addr);
183 return H_PARAMETER;
186 /* Check if device supports CRQs */
187 if (!dev->crq.SendFunc) {
188 hcall_dprintf("Device does not support CRQ\n");
189 return H_NOT_FOUND;
192 /* Already a queue ? */
193 if (dev->crq.qsize) {
194 hcall_dprintf("CRQ already registered\n");
195 return H_RESOURCE;
197 dev->crq.qladdr = queue_addr;
198 dev->crq.qsize = queue_len;
199 dev->crq.qnext = 0;
201 trace_spapr_vio_h_reg_crq(reg, queue_addr, queue_len);
202 return H_SUCCESS;
205 static target_ulong free_crq(SpaprVioDevice *dev)
207 dev->crq.qladdr = 0;
208 dev->crq.qsize = 0;
209 dev->crq.qnext = 0;
211 trace_spapr_vio_free_crq(dev->reg);
213 return H_SUCCESS;
216 static target_ulong h_free_crq(PowerPCCPU *cpu, SpaprMachineState *spapr,
217 target_ulong opcode, target_ulong *args)
219 target_ulong reg = args[0];
220 SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
222 if (!dev) {
223 hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
224 return H_PARAMETER;
227 return free_crq(dev);
230 static target_ulong h_send_crq(PowerPCCPU *cpu, SpaprMachineState *spapr,
231 target_ulong opcode, target_ulong *args)
233 target_ulong reg = args[0];
234 target_ulong msg_hi = args[1];
235 target_ulong msg_lo = args[2];
236 SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
237 uint64_t crq_mangle[2];
239 if (!dev) {
240 hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
241 return H_PARAMETER;
243 crq_mangle[0] = cpu_to_be64(msg_hi);
244 crq_mangle[1] = cpu_to_be64(msg_lo);
246 if (dev->crq.SendFunc) {
247 return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
250 return H_HARDWARE;
253 static target_ulong h_enable_crq(PowerPCCPU *cpu, SpaprMachineState *spapr,
254 target_ulong opcode, target_ulong *args)
256 target_ulong reg = args[0];
257 SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
259 if (!dev) {
260 hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
261 return H_PARAMETER;
264 return 0;
267 /* Returns negative error, 0 success, or positive: queue full */
268 int spapr_vio_send_crq(SpaprVioDevice *dev, uint8_t *crq)
270 int rc;
271 uint8_t byte;
273 if (!dev->crq.qsize) {
274 error_report("spapr_vio_send_creq on uninitialized queue");
275 return -1;
278 /* Maybe do a fast path for KVM just writing to the pages */
279 rc = spapr_vio_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
280 if (rc) {
281 return rc;
283 if (byte != 0) {
284 return 1;
287 rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
288 &crq[8], 8);
289 if (rc) {
290 return rc;
293 kvmppc_eieio();
295 rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
296 if (rc) {
297 return rc;
300 dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
302 if (dev->signal_state & 1) {
303 spapr_vio_irq_pulse(dev);
306 return 0;
309 /* "quiesce" handling */
311 static void spapr_vio_quiesce_one(SpaprVioDevice *dev)
313 if (dev->tcet) {
314 device_legacy_reset(DEVICE(dev->tcet));
316 free_crq(dev);
319 void spapr_vio_set_bypass(SpaprVioDevice *dev, bool bypass)
321 if (!dev->tcet) {
322 return;
325 memory_region_set_enabled(&dev->mrbypass, bypass);
326 memory_region_set_enabled(spapr_tce_get_iommu(dev->tcet), !bypass);
328 dev->tcet->bypass = bypass;
331 static void rtas_set_tce_bypass(PowerPCCPU *cpu, SpaprMachineState *spapr,
332 uint32_t token,
333 uint32_t nargs, target_ulong args,
334 uint32_t nret, target_ulong rets)
336 SpaprVioBus *bus = spapr->vio_bus;
337 SpaprVioDevice *dev;
338 uint32_t unit, enable;
340 if (nargs != 2) {
341 rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
342 return;
344 unit = rtas_ld(args, 0);
345 enable = rtas_ld(args, 1);
346 dev = spapr_vio_find_by_reg(bus, unit);
347 if (!dev) {
348 rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
349 return;
352 if (!dev->tcet) {
353 rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
354 return;
357 spapr_vio_set_bypass(dev, !!enable);
359 rtas_st(rets, 0, RTAS_OUT_SUCCESS);
362 static void rtas_quiesce(PowerPCCPU *cpu, SpaprMachineState *spapr,
363 uint32_t token,
364 uint32_t nargs, target_ulong args,
365 uint32_t nret, target_ulong rets)
367 SpaprVioBus *bus = spapr->vio_bus;
368 BusChild *kid;
369 SpaprVioDevice *dev = NULL;
371 if (nargs != 0) {
372 rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
373 return;
376 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
377 dev = (SpaprVioDevice *)kid->child;
378 spapr_vio_quiesce_one(dev);
381 rtas_st(rets, 0, RTAS_OUT_SUCCESS);
384 static SpaprVioDevice *reg_conflict(SpaprVioDevice *dev)
386 SpaprVioBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
387 BusChild *kid;
388 SpaprVioDevice *other;
391 * Check for a device other than the given one which is already
392 * using the requested address. We have to open code this because
393 * the given dev might already be in the list.
395 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
396 other = VIO_SPAPR_DEVICE(kid->child);
398 if (other != dev && other->reg == dev->reg) {
399 return other;
403 return 0;
406 static void spapr_vio_busdev_reset(DeviceState *qdev)
408 SpaprVioDevice *dev = VIO_SPAPR_DEVICE(qdev);
409 SpaprVioDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
411 /* Shut down the request queue and TCEs if necessary */
412 spapr_vio_quiesce_one(dev);
414 dev->signal_state = 0;
416 spapr_vio_set_bypass(dev, false);
417 if (pc->reset) {
418 pc->reset(dev);
423 * The register property of a VIO device is defined in libvirt using
424 * 0x1000 as a base register number plus a 0x1000 increment. For the
425 * VIO tty device, the base number is changed to 0x30000000. QEMU uses
426 * a base register number of 0x71000000 and then a simple increment.
428 * The formula below tries to compute a unique index number from the
429 * register value that will be used to define the IRQ number of the
430 * VIO device.
432 * A maximum of 256 VIO devices is covered. Collisions are possible
433 * but they will be detected when the IRQ is claimed.
435 static inline uint32_t spapr_vio_reg_to_irq(uint32_t reg)
437 uint32_t irq;
439 if (reg >= SPAPR_VIO_REG_BASE) {
441 * VIO device register values when allocated by QEMU. For
442 * these, we simply mask the high bits to fit the overall
443 * range: [0x00 - 0xff].
445 * The nvram VIO device (reg=0x71000000) is a static device of
446 * the pseries machine and so is always allocated by QEMU. Its
447 * IRQ number is 0x0.
449 irq = reg & 0xff;
451 } else if (reg >= 0x30000000) {
453 * VIO tty devices register values, when allocated by libvirt,
454 * are mapped in range [0xf0 - 0xff], gives us a maximum of 16
455 * vtys.
457 irq = 0xf0 | ((reg >> 12) & 0xf);
459 } else {
461 * Other VIO devices register values, when allocated by
462 * libvirt, should be mapped in range [0x00 - 0xef]. Conflicts
463 * will be detected when IRQ is claimed.
465 irq = (reg >> 12) & 0xff;
468 return SPAPR_IRQ_VIO | irq;
471 static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
473 SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
474 SpaprVioDevice *dev = (SpaprVioDevice *)qdev;
475 SpaprVioDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
476 char *id;
477 Error *local_err = NULL;
479 if (dev->reg != -1) {
481 * Explicitly assigned address, just verify that no-one else
482 * is using it. other mechanism). We have to open code this
483 * rather than using spapr_vio_find_by_reg() because sdev
484 * itself is already in the list.
486 SpaprVioDevice *other = reg_conflict(dev);
488 if (other) {
489 error_setg(errp, "%s and %s devices conflict at address %#x",
490 object_get_typename(OBJECT(qdev)),
491 object_get_typename(OBJECT(&other->qdev)),
492 dev->reg);
493 return;
495 } else {
496 /* Need to assign an address */
497 SpaprVioBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
499 do {
500 dev->reg = bus->next_reg++;
501 } while (reg_conflict(dev));
504 /* Don't overwrite ids assigned on the command line */
505 if (!dev->qdev.id) {
506 id = spapr_vio_get_dev_name(DEVICE(dev));
507 dev->qdev.id = id;
510 dev->irq = spapr_vio_reg_to_irq(dev->reg);
512 if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
513 dev->irq = spapr_irq_findone(spapr, &local_err);
514 if (local_err) {
515 error_propagate(errp, local_err);
516 return;
520 spapr_irq_claim(spapr, dev->irq, false, &local_err);
521 if (local_err) {
522 error_propagate(errp, local_err);
523 return;
526 if (pc->rtce_window_size) {
527 uint32_t liobn = SPAPR_VIO_LIOBN(dev->reg);
529 memory_region_init(&dev->mrroot, OBJECT(dev), "iommu-spapr-root",
530 ram_size);
531 memory_region_init_alias(&dev->mrbypass, OBJECT(dev),
532 "iommu-spapr-bypass", get_system_memory(),
533 0, ram_size);
534 memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass, 1);
535 address_space_init(&dev->as, &dev->mrroot, qdev->id);
537 dev->tcet = spapr_tce_new_table(qdev, liobn);
538 spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
539 pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT);
540 dev->tcet->vdev = dev;
541 memory_region_add_subregion_overlap(&dev->mrroot, 0,
542 spapr_tce_get_iommu(dev->tcet), 2);
545 pc->realize(dev, errp);
548 static target_ulong h_vio_signal(PowerPCCPU *cpu, SpaprMachineState *spapr,
549 target_ulong opcode,
550 target_ulong *args)
552 target_ulong reg = args[0];
553 target_ulong mode = args[1];
554 SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
555 SpaprVioDeviceClass *pc;
557 if (!dev) {
558 return H_PARAMETER;
561 pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
563 if (mode & ~pc->signal_mask) {
564 return H_PARAMETER;
567 dev->signal_state = mode;
569 return H_SUCCESS;
572 SpaprVioBus *spapr_vio_bus_init(void)
574 SpaprVioBus *bus;
575 BusState *qbus;
576 DeviceState *dev;
578 /* Create bridge device */
579 dev = qdev_new(TYPE_SPAPR_VIO_BRIDGE);
580 sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
582 /* Create bus on bridge device */
583 qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
584 bus = SPAPR_VIO_BUS(qbus);
585 bus->next_reg = SPAPR_VIO_REG_BASE;
587 /* hcall-vio */
588 spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
590 /* hcall-crq */
591 spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
592 spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
593 spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
594 spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
596 /* RTAS calls */
597 spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
598 rtas_set_tce_bypass);
599 spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
601 return bus;
604 static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data)
606 DeviceClass *dc = DEVICE_CLASS(klass);
608 dc->fw_name = "vdevice";
611 static const TypeInfo spapr_vio_bridge_info = {
612 .name = TYPE_SPAPR_VIO_BRIDGE,
613 .parent = TYPE_SYS_BUS_DEVICE,
614 .class_init = spapr_vio_bridge_class_init,
617 const VMStateDescription vmstate_spapr_vio = {
618 .name = "spapr_vio",
619 .version_id = 1,
620 .minimum_version_id = 1,
621 .fields = (VMStateField[]) {
622 /* Sanity check */
623 VMSTATE_UINT32_EQUAL(reg, SpaprVioDevice, NULL),
624 VMSTATE_UINT32_EQUAL(irq, SpaprVioDevice, NULL),
626 /* General VIO device state */
627 VMSTATE_UINT64(signal_state, SpaprVioDevice),
628 VMSTATE_UINT64(crq.qladdr, SpaprVioDevice),
629 VMSTATE_UINT32(crq.qsize, SpaprVioDevice),
630 VMSTATE_UINT32(crq.qnext, SpaprVioDevice),
632 VMSTATE_END_OF_LIST()
636 static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
638 DeviceClass *k = DEVICE_CLASS(klass);
639 k->realize = spapr_vio_busdev_realize;
640 k->reset = spapr_vio_busdev_reset;
641 k->bus_type = TYPE_SPAPR_VIO_BUS;
644 static const TypeInfo spapr_vio_type_info = {
645 .name = TYPE_VIO_SPAPR_DEVICE,
646 .parent = TYPE_DEVICE,
647 .instance_size = sizeof(SpaprVioDevice),
648 .abstract = true,
649 .class_size = sizeof(SpaprVioDeviceClass),
650 .class_init = vio_spapr_device_class_init,
653 static void spapr_vio_register_types(void)
655 type_register_static(&spapr_vio_bus_info);
656 type_register_static(&spapr_vio_bridge_info);
657 type_register_static(&spapr_vio_type_info);
660 type_init(spapr_vio_register_types)
662 static int compare_reg(const void *p1, const void *p2)
664 SpaprVioDevice const *dev1, *dev2;
666 dev1 = (SpaprVioDevice *)*(DeviceState **)p1;
667 dev2 = (SpaprVioDevice *)*(DeviceState **)p2;
669 if (dev1->reg < dev2->reg) {
670 return -1;
672 if (dev1->reg == dev2->reg) {
673 return 0;
676 /* dev1->reg > dev2->reg */
677 return 1;
680 void spapr_dt_vdevice(SpaprVioBus *bus, void *fdt)
682 DeviceState *qdev, **qdevs;
683 BusChild *kid;
684 int i, num, ret = 0;
685 int node;
687 _FDT(node = fdt_add_subnode(fdt, 0, "vdevice"));
689 _FDT(fdt_setprop_string(fdt, node, "device_type", "vdevice"));
690 _FDT(fdt_setprop_string(fdt, node, "compatible", "IBM,vdevice"));
691 _FDT(fdt_setprop_cell(fdt, node, "#address-cells", 1));
692 _FDT(fdt_setprop_cell(fdt, node, "#size-cells", 0));
693 _FDT(fdt_setprop_cell(fdt, node, "#interrupt-cells", 2));
694 _FDT(fdt_setprop(fdt, node, "interrupt-controller", NULL, 0));
696 /* Count qdevs on the bus list */
697 num = 0;
698 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
699 num++;
702 /* Copy out into an array of pointers */
703 qdevs = g_new(DeviceState *, num);
704 num = 0;
705 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
706 qdevs[num++] = kid->child;
709 /* Sort the array */
710 qsort(qdevs, num, sizeof(qdev), compare_reg);
712 /* Hack alert. Give the devices to libfdt in reverse order, we happen
713 * to know that will mean they are in forward order in the tree. */
714 for (i = num - 1; i >= 0; i--) {
715 SpaprVioDevice *dev = (SpaprVioDevice *)(qdevs[i]);
716 SpaprVioDeviceClass *vdc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
718 ret = vio_make_devnode(dev, fdt);
719 if (ret < 0) {
720 error_report("Couldn't create device node /vdevice/%s@%"PRIx32,
721 vdc->dt_name, dev->reg);
722 exit(1);
726 g_free(qdevs);
729 gchar *spapr_vio_stdout_path(SpaprVioBus *bus)
731 SpaprVioDevice *dev;
732 char *name, *path;
734 dev = spapr_vty_get_default(bus);
735 if (!dev) {
736 return NULL;
739 name = spapr_vio_get_dev_name(DEVICE(dev));
740 path = g_strdup_printf("/vdevice/%s", name);
742 g_free(name);
743 return path;