xref: /openbmc/qemu/include/hw/qdev-core.h (revision 0df750e9)
1 #ifndef QDEV_CORE_H
2 #define QDEV_CORE_H
3 
4 #include "qemu/queue.h"
5 #include "qemu/bitmap.h"
6 #include "qemu/rcu.h"
7 #include "qemu/rcu_queue.h"
8 #include "qom/object.h"
9 #include "hw/hotplug.h"
10 #include "hw/resettable.h"
11 
12 enum {
13     DEV_NVECTORS_UNSPECIFIED = -1,
14 };
15 
16 #define TYPE_DEVICE "device"
17 OBJECT_DECLARE_TYPE(DeviceState, DeviceClass, DEVICE)
18 
19 typedef enum DeviceCategory {
20     DEVICE_CATEGORY_BRIDGE,
21     DEVICE_CATEGORY_USB,
22     DEVICE_CATEGORY_STORAGE,
23     DEVICE_CATEGORY_NETWORK,
24     DEVICE_CATEGORY_INPUT,
25     DEVICE_CATEGORY_DISPLAY,
26     DEVICE_CATEGORY_SOUND,
27     DEVICE_CATEGORY_MISC,
28     DEVICE_CATEGORY_CPU,
29     DEVICE_CATEGORY_MAX
30 } DeviceCategory;
31 
32 typedef void (*DeviceRealize)(DeviceState *dev, Error **errp);
33 typedef void (*DeviceUnrealize)(DeviceState *dev);
34 typedef void (*DeviceReset)(DeviceState *dev);
35 typedef void (*BusRealize)(BusState *bus, Error **errp);
36 typedef void (*BusUnrealize)(BusState *bus);
37 
38 /**
39  * DeviceClass:
40  * @props: Properties accessing state fields.
41  * @realize: Callback function invoked when the #DeviceState:realized
42  * property is changed to %true.
43  * @unrealize: Callback function invoked when the #DeviceState:realized
44  * property is changed to %false.
45  * @hotpluggable: indicates if #DeviceClass is hotpluggable, available
46  * as readonly "hotpluggable" property of #DeviceState instance
47  *
48  * # Realization #
49  * Devices are constructed in two stages,
50  * 1) object instantiation via object_initialize() and
51  * 2) device realization via #DeviceState:realized property.
52  * The former may not fail (and must not abort or exit, since it is called
53  * during device introspection already), and the latter may return error
54  * information to the caller and must be re-entrant.
55  * Trivial field initializations should go into #TypeInfo.instance_init.
56  * Operations depending on @props static properties should go into @realize.
57  * After successful realization, setting static properties will fail.
58  *
59  * As an interim step, the #DeviceState:realized property can also be
60  * set with qdev_realize().
61  * In the future, devices will propagate this state change to their children
62  * and along busses they expose.
63  * The point in time will be deferred to machine creation, so that values
64  * set in @realize will not be introspectable beforehand. Therefore devices
65  * must not create children during @realize; they should initialize them via
66  * object_initialize() in their own #TypeInfo.instance_init and forward the
67  * realization events appropriately.
68  *
69  * Any type may override the @realize and/or @unrealize callbacks but needs
70  * to call the parent type's implementation if keeping their functionality
71  * is desired. Refer to QOM documentation for further discussion and examples.
72  *
73  * <note>
74  *   <para>
75  * Since TYPE_DEVICE doesn't implement @realize and @unrealize, types
76  * derived directly from it need not call their parent's @realize and
77  * @unrealize.
78  * For other types consult the documentation and implementation of the
79  * respective parent types.
80  *   </para>
81  * </note>
82  *
83  * # Hiding a device #
84  * To hide a device, a DeviceListener function hide_device() needs to
85  * be registered.
86  * It can be used to defer adding a device and therefore hide it from
87  * the guest. The handler registering to this DeviceListener can save
88  * the QOpts passed to it for re-using it later. It must return if it
89  * wants the device to be hidden or visible. When the handler function
90  * decides the device shall be visible it will be added with
91  * qdev_device_add() and realized as any other device. Otherwise
92  * qdev_device_add() will return early without adding the device. The
93  * guest will not see a "hidden" device until it was marked visible
94  * and qdev_device_add called again.
95  *
96  */
97 struct DeviceClass {
98     /*< private >*/
99     ObjectClass parent_class;
100     /*< public >*/
101 
102     DECLARE_BITMAP(categories, DEVICE_CATEGORY_MAX);
103     const char *fw_name;
104     const char *desc;
105 
106     /*
107      * The underscore at the end ensures a compile-time error if someone
108      * assigns to dc->props instead of using device_class_set_props.
109      */
110     Property *props_;
111 
112     /*
113      * Can this device be instantiated with -device / device_add?
114      * All devices should support instantiation with device_add, and
115      * this flag should not exist.  But we're not there, yet.  Some
116      * devices fail to instantiate with cryptic error messages.
117      * Others instantiate, but don't work.  Exposing users to such
118      * behavior would be cruel; clearing this flag will protect them.
119      * It should never be cleared without a comment explaining why it
120      * is cleared.
121      * TODO remove once we're there
122      */
123     bool user_creatable;
124     bool hotpluggable;
125 
126     /* callbacks */
127     /*
128      * Reset method here is deprecated and replaced by methods in the
129      * resettable class interface to implement a multi-phase reset.
130      * TODO: remove once every reset callback is unused
131      */
132     DeviceReset reset;
133     DeviceRealize realize;
134     DeviceUnrealize unrealize;
135 
136     /* device state */
137     const VMStateDescription *vmsd;
138 
139     /* Private to qdev / bus.  */
140     const char *bus_type;
141 };
142 
143 typedef struct NamedGPIOList NamedGPIOList;
144 
145 struct NamedGPIOList {
146     char *name;
147     qemu_irq *in;
148     int num_in;
149     int num_out;
150     QLIST_ENTRY(NamedGPIOList) node;
151 };
152 
153 typedef struct Clock Clock;
154 typedef struct NamedClockList NamedClockList;
155 
156 struct NamedClockList {
157     char *name;
158     Clock *clock;
159     bool output;
160     bool alias;
161     QLIST_ENTRY(NamedClockList) node;
162 };
163 
164 /**
165  * DeviceState:
166  * @realized: Indicates whether the device has been fully constructed.
167  *            When accessed outside big qemu lock, must be accessed with
168  *            qatomic_load_acquire()
169  * @reset: ResettableState for the device; handled by Resettable interface.
170  *
171  * This structure should not be accessed directly.  We declare it here
172  * so that it can be embedded in individual device state structures.
173  */
174 struct DeviceState {
175     /*< private >*/
176     Object parent_obj;
177     /*< public >*/
178 
179     const char *id;
180     char *canonical_path;
181     bool realized;
182     bool pending_deleted_event;
183     QemuOpts *opts;
184     int hotplugged;
185     bool allow_unplug_during_migration;
186     BusState *parent_bus;
187     QLIST_HEAD(, NamedGPIOList) gpios;
188     QLIST_HEAD(, NamedClockList) clocks;
189     QLIST_HEAD(, BusState) child_bus;
190     int num_child_bus;
191     int instance_id_alias;
192     int alias_required_for_version;
193     ResettableState reset;
194 };
195 
196 struct DeviceListener {
197     void (*realize)(DeviceListener *listener, DeviceState *dev);
198     void (*unrealize)(DeviceListener *listener, DeviceState *dev);
199     /*
200      * This callback is called upon init of the DeviceState and
201      * informs qdev if a device should be visible or hidden.  We can
202      * hide a failover device depending for example on the device
203      * opts.
204      */
205     bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts);
206     QTAILQ_ENTRY(DeviceListener) link;
207 };
208 
209 #define TYPE_BUS "bus"
210 DECLARE_OBJ_CHECKERS(BusState, BusClass,
211                      BUS, TYPE_BUS)
212 
213 struct BusClass {
214     ObjectClass parent_class;
215 
216     /* FIXME first arg should be BusState */
217     void (*print_dev)(Monitor *mon, DeviceState *dev, int indent);
218     char *(*get_dev_path)(DeviceState *dev);
219 
220     /*
221      * This callback is used to create Open Firmware device path in accordance
222      * with OF spec http://forthworks.com/standards/of1275.pdf. Individual bus
223      * bindings can be found at http://playground.sun.com/1275/bindings/.
224      */
225     char *(*get_fw_dev_path)(DeviceState *dev);
226 
227     void (*reset)(BusState *bus);
228 
229     /*
230      * Return whether the device can be added to @bus,
231      * based on the address that was set (via device properties)
232      * before realize.  If not, on return @errp contains the
233      * human-readable error message.
234      */
235     bool (*check_address)(BusState *bus, DeviceState *dev, Error **errp);
236 
237     BusRealize realize;
238     BusUnrealize unrealize;
239 
240     /* maximum devices allowed on the bus, 0: no limit. */
241     int max_dev;
242     /* number of automatically allocated bus ids (e.g. ide.0) */
243     int automatic_ids;
244 };
245 
246 typedef struct BusChild {
247     struct rcu_head rcu;
248     DeviceState *child;
249     int index;
250     QTAILQ_ENTRY(BusChild) sibling;
251 } BusChild;
252 
253 #define QDEV_HOTPLUG_HANDLER_PROPERTY "hotplug-handler"
254 
255 /**
256  * BusState:
257  * @hotplug_handler: link to a hotplug handler associated with bus.
258  * @reset: ResettableState for the bus; handled by Resettable interface.
259  */
260 struct BusState {
261     Object obj;
262     DeviceState *parent;
263     char *name;
264     HotplugHandler *hotplug_handler;
265     int max_index;
266     bool realized;
267     int num_children;
268 
269     /*
270      * children is a RCU QTAILQ, thus readers must use RCU to access it,
271      * and writers must hold the big qemu lock
272      */
273 
274     QTAILQ_HEAD(, BusChild) children;
275     QLIST_ENTRY(BusState) sibling;
276     ResettableState reset;
277 };
278 
279 /**
280  * Property:
281  * @set_default: true if the default value should be set from @defval,
282  *    in which case @info->set_default_value must not be NULL
283  *    (if false then no default value is set by the property system
284  *     and the field retains whatever value it was given by instance_init).
285  * @defval: default value for the property. This is used only if @set_default
286  *     is true.
287  */
288 struct Property {
289     const char   *name;
290     const PropertyInfo *info;
291     ptrdiff_t    offset;
292     uint8_t      bitnr;
293     bool         set_default;
294     union {
295         int64_t i;
296         uint64_t u;
297     } defval;
298     int          arrayoffset;
299     const PropertyInfo *arrayinfo;
300     int          arrayfieldsize;
301     const char   *link_type;
302 };
303 
304 struct PropertyInfo {
305     const char *name;
306     const char *description;
307     const QEnumLookup *enum_table;
308     int (*print)(DeviceState *dev, Property *prop, char *dest, size_t len);
309     void (*set_default_value)(ObjectProperty *op, const Property *prop);
310     void (*create)(ObjectClass *oc, Property *prop);
311     ObjectPropertyAccessor *get;
312     ObjectPropertyAccessor *set;
313     ObjectPropertyRelease *release;
314 };
315 
316 /**
317  * GlobalProperty:
318  * @used: Set to true if property was used when initializing a device.
319  * @optional: If set to true, GlobalProperty will be skipped without errors
320  *            if the property doesn't exist.
321  *
322  * An error is fatal for non-hotplugged devices, when the global is applied.
323  */
324 typedef struct GlobalProperty {
325     const char *driver;
326     const char *property;
327     const char *value;
328     bool used;
329     bool optional;
330 } GlobalProperty;
331 
332 static inline void
333 compat_props_add(GPtrArray *arr,
334                  GlobalProperty props[], size_t nelem)
335 {
336     int i;
337     for (i = 0; i < nelem; i++) {
338         g_ptr_array_add(arr, (void *)&props[i]);
339     }
340 }
341 
342 /*** Board API.  This should go away once we have a machine config file.  ***/
343 
344 /**
345  * qdev_new: Create a device on the heap
346  * @name: device type to create (we assert() that this type exists)
347  *
348  * This only allocates the memory and initializes the device state
349  * structure, ready for the caller to set properties if they wish.
350  * The device still needs to be realized.
351  * The returned object has a reference count of 1.
352  */
353 DeviceState *qdev_new(const char *name);
354 /**
355  * qdev_try_new: Try to create a device on the heap
356  * @name: device type to create
357  *
358  * This is like qdev_new(), except it returns %NULL when type @name
359  * does not exist, rather than asserting.
360  */
361 DeviceState *qdev_try_new(const char *name);
362 /**
363  * qdev_realize: Realize @dev.
364  * @dev: device to realize
365  * @bus: bus to plug it into (may be NULL)
366  * @errp: pointer to error object
367  *
368  * "Realize" the device, i.e. perform the second phase of device
369  * initialization.
370  * @dev must not be plugged into a bus already.
371  * If @bus, plug @dev into @bus.  This takes a reference to @dev.
372  * If @dev has no QOM parent, make one up, taking another reference.
373  * On success, return true.
374  * On failure, store an error through @errp and return false.
375  *
376  * If you created @dev using qdev_new(), you probably want to use
377  * qdev_realize_and_unref() instead.
378  */
379 bool qdev_realize(DeviceState *dev, BusState *bus, Error **errp);
380 /**
381  * qdev_realize_and_unref: Realize @dev and drop a reference
382  * @dev: device to realize
383  * @bus: bus to plug it into (may be NULL)
384  * @errp: pointer to error object
385  *
386  * Realize @dev and drop a reference.
387  * This is like qdev_realize(), except the caller must hold a
388  * (private) reference, which is dropped on return regardless of
389  * success or failure.  Intended use::
390  *
391  *     dev = qdev_new();
392  *     [...]
393  *     qdev_realize_and_unref(dev, bus, errp);
394  *
395  * Now @dev can go away without further ado.
396  *
397  * If you are embedding the device into some other QOM device and
398  * initialized it via some variant on object_initialize_child() then
399  * do not use this function, because that family of functions arrange
400  * for the only reference to the child device to be held by the parent
401  * via the child<> property, and so the reference-count-drop done here
402  * would be incorrect. For that use case you want qdev_realize().
403  */
404 bool qdev_realize_and_unref(DeviceState *dev, BusState *bus, Error **errp);
405 /**
406  * qdev_unrealize: Unrealize a device
407  * @dev: device to unrealize
408  *
409  * This function will "unrealize" a device, which is the first phase
410  * of correctly destroying a device that has been realized. It will:
411  *
412  *  - unrealize any child buses by calling qbus_unrealize()
413  *    (this will recursively unrealize any devices on those buses)
414  *  - call the the unrealize method of @dev
415  *
416  * The device can then be freed by causing its reference count to go
417  * to zero.
418  *
419  * Warning: most devices in QEMU do not expect to be unrealized.  Only
420  * devices which are hot-unpluggable should be unrealized (as part of
421  * the unplugging process); all other devices are expected to last for
422  * the life of the simulation and should not be unrealized and freed.
423  */
424 void qdev_unrealize(DeviceState *dev);
425 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
426                                  int required_for_version);
427 HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev);
428 HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev);
429 bool qdev_hotplug_allowed(DeviceState *dev, Error **errp);
430 /**
431  * qdev_get_hotplug_handler: Get handler responsible for device wiring
432  *
433  * Find HOTPLUG_HANDLER for @dev that provides [pre|un]plug callbacks for it.
434  *
435  * Note: in case @dev has a parent bus, it will be returned as handler unless
436  * machine handler overrides it.
437  *
438  * Returns: pointer to object that implements TYPE_HOTPLUG_HANDLER interface
439  *          or NULL if there aren't any.
440  */
441 HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev);
442 void qdev_unplug(DeviceState *dev, Error **errp);
443 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,
444                                   DeviceState *dev, Error **errp);
445 void qdev_machine_creation_done(void);
446 bool qdev_machine_modified(void);
447 
448 /**
449  * GpioPolarity: Polarity of a GPIO line
450  *
451  * GPIO lines use either positive (active-high) logic,
452  * or negative (active-low) logic.
453  *
454  * In active-high logic (%GPIO_POLARITY_ACTIVE_HIGH), a pin is
455  * active when the voltage on the pin is high (relative to ground);
456  * whereas in active-low logic (%GPIO_POLARITY_ACTIVE_LOW), a pin
457  * is active when the voltage on the pin is low (or grounded).
458  */
459 typedef enum {
460     GPIO_POLARITY_ACTIVE_LOW,
461     GPIO_POLARITY_ACTIVE_HIGH
462 } GpioPolarity;
463 
464 /**
465  * qdev_get_gpio_in: Get one of a device's anonymous input GPIO lines
466  * @dev: Device whose GPIO we want
467  * @n: Number of the anonymous GPIO line (which must be in range)
468  *
469  * Returns the qemu_irq corresponding to an anonymous input GPIO line
470  * (which the device has set up with qdev_init_gpio_in()). The index
471  * @n of the GPIO line must be valid (i.e. be at least 0 and less than
472  * the total number of anonymous input GPIOs the device has); this
473  * function will assert() if passed an invalid index.
474  *
475  * This function is intended to be used by board code or SoC "container"
476  * device models to wire up the GPIO lines; usually the return value
477  * will be passed to qdev_connect_gpio_out() or a similar function to
478  * connect another device's output GPIO line to this input.
479  *
480  * For named input GPIO lines, use qdev_get_gpio_in_named().
481  */
482 qemu_irq qdev_get_gpio_in(DeviceState *dev, int n);
483 /**
484  * qdev_get_gpio_in_named: Get one of a device's named input GPIO lines
485  * @dev: Device whose GPIO we want
486  * @name: Name of the input GPIO array
487  * @n: Number of the GPIO line in that array (which must be in range)
488  *
489  * Returns the qemu_irq corresponding to a named input GPIO line
490  * (which the device has set up with qdev_init_gpio_in_named()).
491  * The @name string must correspond to an input GPIO array which exists on
492  * the device, and the index @n of the GPIO line must be valid (i.e.
493  * be at least 0 and less than the total number of input GPIOs in that
494  * array); this function will assert() if passed an invalid name or index.
495  *
496  * For anonymous input GPIO lines, use qdev_get_gpio_in().
497  */
498 qemu_irq qdev_get_gpio_in_named(DeviceState *dev, const char *name, int n);
499 
500 /**
501  * qdev_connect_gpio_out: Connect one of a device's anonymous output GPIO lines
502  * @dev: Device whose GPIO to connect
503  * @n: Number of the anonymous output GPIO line (which must be in range)
504  * @pin: qemu_irq to connect the output line to
505  *
506  * This function connects an anonymous output GPIO line on a device
507  * up to an arbitrary qemu_irq, so that when the device asserts that
508  * output GPIO line, the qemu_irq's callback is invoked.
509  * The index @n of the GPIO line must be valid (i.e. be at least 0 and
510  * less than the total number of anonymous output GPIOs the device has
511  * created with qdev_init_gpio_out()); otherwise this function will assert().
512  *
513  * Outbound GPIO lines can be connected to any qemu_irq, but the common
514  * case is connecting them to another device's inbound GPIO line, using
515  * the qemu_irq returned by qdev_get_gpio_in() or qdev_get_gpio_in_named().
516  *
517  * It is not valid to try to connect one outbound GPIO to multiple
518  * qemu_irqs at once, or to connect multiple outbound GPIOs to the
519  * same qemu_irq. (Warning: there is no assertion or other guard to
520  * catch this error: the model will just not do the right thing.)
521  * Instead, for fan-out you can use the TYPE_IRQ_SPLIT device: connect
522  * a device's outbound GPIO to the splitter's input, and connect each
523  * of the splitter's outputs to a different device.  For fan-in you
524  * can use the TYPE_OR_IRQ device, which is a model of a logical OR
525  * gate with multiple inputs and one output.
526  *
527  * For named output GPIO lines, use qdev_connect_gpio_out_named().
528  */
529 void qdev_connect_gpio_out(DeviceState *dev, int n, qemu_irq pin);
530 /**
531  * qdev_connect_gpio_out: Connect one of a device's anonymous output GPIO lines
532  * @dev: Device whose GPIO to connect
533  * @name: Name of the output GPIO array
534  * @n: Number of the anonymous output GPIO line (which must be in range)
535  * @pin: qemu_irq to connect the output line to
536  *
537  * This function connects an anonymous output GPIO line on a device
538  * up to an arbitrary qemu_irq, so that when the device asserts that
539  * output GPIO line, the qemu_irq's callback is invoked.
540  * The @name string must correspond to an output GPIO array which exists on
541  * the device, and the index @n of the GPIO line must be valid (i.e.
542  * be at least 0 and less than the total number of input GPIOs in that
543  * array); this function will assert() if passed an invalid name or index.
544  *
545  * Outbound GPIO lines can be connected to any qemu_irq, but the common
546  * case is connecting them to another device's inbound GPIO line, using
547  * the qemu_irq returned by qdev_get_gpio_in() or qdev_get_gpio_in_named().
548  *
549  * It is not valid to try to connect one outbound GPIO to multiple
550  * qemu_irqs at once, or to connect multiple outbound GPIOs to the
551  * same qemu_irq; see qdev_connect_gpio_out() for details.
552  *
553  * For named output GPIO lines, use qdev_connect_gpio_out_named().
554  */
555 void qdev_connect_gpio_out_named(DeviceState *dev, const char *name, int n,
556                                  qemu_irq pin);
557 /**
558  * qdev_get_gpio_out_connector: Get the qemu_irq connected to an output GPIO
559  * @dev: Device whose output GPIO we are interested in
560  * @name: Name of the output GPIO array
561  * @n: Number of the output GPIO line within that array
562  *
563  * Returns whatever qemu_irq is currently connected to the specified
564  * output GPIO line of @dev. This will be NULL if the output GPIO line
565  * has never been wired up to the anything.  Note that the qemu_irq
566  * returned does not belong to @dev -- it will be the input GPIO or
567  * IRQ of whichever device the board code has connected up to @dev's
568  * output GPIO.
569  *
570  * You probably don't need to use this function -- it is used only
571  * by the platform-bus subsystem.
572  */
573 qemu_irq qdev_get_gpio_out_connector(DeviceState *dev, const char *name, int n);
574 /**
575  * qdev_intercept_gpio_out: Intercept an existing GPIO connection
576  * @dev: Device to intercept the outbound GPIO line from
577  * @icpt: New qemu_irq to connect instead
578  * @name: Name of the output GPIO array
579  * @n: Number of the GPIO line in the array
580  *
581  * This function is provided only for use by the qtest testing framework
582  * and is not suitable for use in non-testing parts of QEMU.
583  *
584  * This function breaks an existing connection of an outbound GPIO
585  * line from @dev, and replaces it with the new qemu_irq @icpt, as if
586  * ``qdev_connect_gpio_out_named(dev, icpt, name, n)`` had been called.
587  * The previously connected qemu_irq is returned, so it can be restored
588  * by a second call to qdev_intercept_gpio_out() if desired.
589  */
590 qemu_irq qdev_intercept_gpio_out(DeviceState *dev, qemu_irq icpt,
591                                  const char *name, int n);
592 
593 BusState *qdev_get_child_bus(DeviceState *dev, const char *name);
594 
595 /*** Device API.  ***/
596 
597 /**
598  * qdev_init_gpio_in: create an array of anonymous input GPIO lines
599  * @dev: Device to create input GPIOs for
600  * @handler: Function to call when GPIO line value is set
601  * @n: Number of GPIO lines to create
602  *
603  * Devices should use functions in the qdev_init_gpio_in* family in
604  * their instance_init or realize methods to create any input GPIO
605  * lines they need. There is no functional difference between
606  * anonymous and named GPIO lines. Stylistically, named GPIOs are
607  * preferable (easier to understand at callsites) unless a device
608  * has exactly one uniform kind of GPIO input whose purpose is obvious.
609  * Note that input GPIO lines can serve as 'sinks' for IRQ lines.
610  *
611  * See qdev_get_gpio_in() for how code that uses such a device can get
612  * hold of an input GPIO line to manipulate it.
613  */
614 void qdev_init_gpio_in(DeviceState *dev, qemu_irq_handler handler, int n);
615 /**
616  * qdev_init_gpio_out: create an array of anonymous output GPIO lines
617  * @dev: Device to create output GPIOs for
618  * @pins: Pointer to qemu_irq or qemu_irq array for the GPIO lines
619  * @n: Number of GPIO lines to create
620  *
621  * Devices should use functions in the qdev_init_gpio_out* family
622  * in their instance_init or realize methods to create any output
623  * GPIO lines they need. There is no functional difference between
624  * anonymous and named GPIO lines. Stylistically, named GPIOs are
625  * preferable (easier to understand at callsites) unless a device
626  * has exactly one uniform kind of GPIO output whose purpose is obvious.
627  *
628  * The @pins argument should be a pointer to either a "qemu_irq"
629  * (if @n == 1) or a "qemu_irq []" array (if @n > 1) in the device's
630  * state structure. The device implementation can then raise and
631  * lower the GPIO line by calling qemu_set_irq(). (If anything is
632  * connected to the other end of the GPIO this will cause the handler
633  * function for that input GPIO to be called.)
634  *
635  * See qdev_connect_gpio_out() for how code that uses such a device
636  * can connect to one of its output GPIO lines.
637  */
638 void qdev_init_gpio_out(DeviceState *dev, qemu_irq *pins, int n);
639 /**
640  * qdev_init_gpio_out: create an array of named output GPIO lines
641  * @dev: Device to create output GPIOs for
642  * @pins: Pointer to qemu_irq or qemu_irq array for the GPIO lines
643  * @name: Name to give this array of GPIO lines
644  * @n: Number of GPIO lines to create
645  *
646  * Like qdev_init_gpio_out(), but creates an array of GPIO output lines
647  * with a name. Code using the device can then connect these GPIO lines
648  * using qdev_connect_gpio_out_named().
649  */
650 void qdev_init_gpio_out_named(DeviceState *dev, qemu_irq *pins,
651                               const char *name, int n);
652 /**
653  * qdev_init_gpio_in_named_with_opaque: create an array of input GPIO lines
654  *   for the specified device
655  *
656  * @dev: Device to create input GPIOs for
657  * @handler: Function to call when GPIO line value is set
658  * @opaque: Opaque data pointer to pass to @handler
659  * @name: Name of the GPIO input (must be unique for this device)
660  * @n: Number of GPIO lines in this input set
661  */
662 void qdev_init_gpio_in_named_with_opaque(DeviceState *dev,
663                                          qemu_irq_handler handler,
664                                          void *opaque,
665                                          const char *name, int n);
666 
667 /**
668  * qdev_init_gpio_in_named: create an array of input GPIO lines
669  *   for the specified device
670  *
671  * Like qdev_init_gpio_in_named_with_opaque(), but the opaque pointer
672  * passed to the handler is @dev (which is the most commonly desired behaviour).
673  */
674 static inline void qdev_init_gpio_in_named(DeviceState *dev,
675                                            qemu_irq_handler handler,
676                                            const char *name, int n)
677 {
678     qdev_init_gpio_in_named_with_opaque(dev, handler, dev, name, n);
679 }
680 
681 /**
682  * qdev_pass_gpios: create GPIO lines on container which pass through to device
683  * @dev: Device which has GPIO lines
684  * @container: Container device which needs to expose them
685  * @name: Name of GPIO array to pass through (NULL for the anonymous GPIO array)
686  *
687  * In QEMU, complicated devices like SoCs are often modelled with a
688  * "container" QOM device which itself contains other QOM devices and
689  * which wires them up appropriately. This function allows the container
690  * to create GPIO arrays on itself which simply pass through to a GPIO
691  * array of one of its internal devices.
692  *
693  * If @dev has both input and output GPIOs named @name then both will
694  * be passed through. It is not possible to pass a subset of the array
695  * with this function.
696  *
697  * To users of the container device, the GPIO array created on @container
698  * behaves exactly like any other.
699  */
700 void qdev_pass_gpios(DeviceState *dev, DeviceState *container,
701                      const char *name);
702 
703 BusState *qdev_get_parent_bus(DeviceState *dev);
704 
705 /*** BUS API. ***/
706 
707 DeviceState *qdev_find_recursive(BusState *bus, const char *id);
708 
709 /* Returns 0 to walk children, > 0 to skip walk, < 0 to terminate walk. */
710 typedef int (qbus_walkerfn)(BusState *bus, void *opaque);
711 typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);
712 
713 void qbus_create_inplace(void *bus, size_t size, const char *typename,
714                          DeviceState *parent, const char *name);
715 BusState *qbus_create(const char *typename, DeviceState *parent, const char *name);
716 bool qbus_realize(BusState *bus, Error **errp);
717 void qbus_unrealize(BusState *bus);
718 
719 /* Returns > 0 if either devfn or busfn skip walk somewhere in cursion,
720  *         < 0 if either devfn or busfn terminate walk somewhere in cursion,
721  *           0 otherwise. */
722 int qbus_walk_children(BusState *bus,
723                        qdev_walkerfn *pre_devfn, qbus_walkerfn *pre_busfn,
724                        qdev_walkerfn *post_devfn, qbus_walkerfn *post_busfn,
725                        void *opaque);
726 int qdev_walk_children(DeviceState *dev,
727                        qdev_walkerfn *pre_devfn, qbus_walkerfn *pre_busfn,
728                        qdev_walkerfn *post_devfn, qbus_walkerfn *post_busfn,
729                        void *opaque);
730 
731 /**
732  * @qdev_reset_all:
733  * Reset @dev. See @qbus_reset_all() for more details.
734  *
735  * Note: This function is deprecated and will be removed when it becomes unused.
736  * Please use device_cold_reset() now.
737  */
738 void qdev_reset_all(DeviceState *dev);
739 void qdev_reset_all_fn(void *opaque);
740 
741 /**
742  * @qbus_reset_all:
743  * @bus: Bus to be reset.
744  *
745  * Reset @bus and perform a bus-level ("hard") reset of all devices connected
746  * to it, including recursive processing of all buses below @bus itself.  A
747  * hard reset means that qbus_reset_all will reset all state of the device.
748  * For PCI devices, for example, this will include the base address registers
749  * or configuration space.
750  *
751  * Note: This function is deprecated and will be removed when it becomes unused.
752  * Please use bus_cold_reset() now.
753  */
754 void qbus_reset_all(BusState *bus);
755 void qbus_reset_all_fn(void *opaque);
756 
757 /**
758  * device_cold_reset:
759  * Reset device @dev and perform a recursive processing using the resettable
760  * interface. It triggers a RESET_TYPE_COLD.
761  */
762 void device_cold_reset(DeviceState *dev);
763 
764 /**
765  * bus_cold_reset:
766  *
767  * Reset bus @bus and perform a recursive processing using the resettable
768  * interface. It triggers a RESET_TYPE_COLD.
769  */
770 void bus_cold_reset(BusState *bus);
771 
772 /**
773  * device_is_in_reset:
774  * Return true if the device @dev is currently being reset.
775  */
776 bool device_is_in_reset(DeviceState *dev);
777 
778 /**
779  * bus_is_in_reset:
780  * Return true if the bus @bus is currently being reset.
781  */
782 bool bus_is_in_reset(BusState *bus);
783 
784 /* This should go away once we get rid of the NULL bus hack */
785 BusState *sysbus_get_default(void);
786 
787 char *qdev_get_fw_dev_path(DeviceState *dev);
788 char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, DeviceState *dev);
789 
790 /**
791  * @qdev_machine_init
792  *
793  * Initialize platform devices before machine init.  This is a hack until full
794  * support for composition is added.
795  */
796 void qdev_machine_init(void);
797 
798 /**
799  * device_legacy_reset:
800  *
801  * Reset a single device (by calling the reset method).
802  * Note: This function is deprecated and will be removed when it becomes unused.
803  * Please use device_cold_reset() now.
804  */
805 void device_legacy_reset(DeviceState *dev);
806 
807 void device_class_set_props(DeviceClass *dc, Property *props);
808 
809 /**
810  * device_class_set_parent_reset:
811  * TODO: remove the function when DeviceClass's reset method
812  * is not used anymore.
813  */
814 void device_class_set_parent_reset(DeviceClass *dc,
815                                    DeviceReset dev_reset,
816                                    DeviceReset *parent_reset);
817 void device_class_set_parent_realize(DeviceClass *dc,
818                                      DeviceRealize dev_realize,
819                                      DeviceRealize *parent_realize);
820 void device_class_set_parent_unrealize(DeviceClass *dc,
821                                        DeviceUnrealize dev_unrealize,
822                                        DeviceUnrealize *parent_unrealize);
823 
824 const VMStateDescription *qdev_get_vmsd(DeviceState *dev);
825 
826 const char *qdev_fw_name(DeviceState *dev);
827 
828 Object *qdev_get_machine(void);
829 
830 /* FIXME: make this a link<> */
831 bool qdev_set_parent_bus(DeviceState *dev, BusState *bus, Error **errp);
832 
833 extern bool qdev_hotplug;
834 extern bool qdev_hot_removed;
835 
836 char *qdev_get_dev_path(DeviceState *dev);
837 
838 void qbus_set_hotplug_handler(BusState *bus, Object *handler);
839 void qbus_set_bus_hotplug_handler(BusState *bus);
840 
841 static inline bool qbus_is_hotpluggable(BusState *bus)
842 {
843    return bus->hotplug_handler;
844 }
845 
846 void device_listener_register(DeviceListener *listener);
847 void device_listener_unregister(DeviceListener *listener);
848 
849 /**
850  * @qdev_should_hide_device:
851  * @opts: QemuOpts as passed on cmdline.
852  *
853  * Check if a device should be added.
854  * When a device is added via qdev_device_add() this will be called,
855  * and return if the device should be added now or not.
856  */
857 bool qdev_should_hide_device(QemuOpts *opts);
858 
859 #endif
860