[mirror_ubuntu-zesty-kernel.git] / include / linux / virtio_config.h

#ifndef _LINUX_VIRTIO_CONFIG_H
#define _LINUX_VIRTIO_CONFIG_H

#include <linux/err.h>
#include <linux/bug.h>
#include <linux/virtio.h>
#include <uapi/linux/virtio_config.h>

/**
 * virtio_config_ops - operations for configuring a virtio device
 * @get: read the value of a configuration field
 *	vdev: the virtio_device
 *	offset: the offset of the configuration field
 *	buf: the buffer to write the field value into.
 *	len: the length of the buffer
 * @set: write the value of a configuration field
 *	vdev: the virtio_device
 *	offset: the offset of the configuration field
 *	buf: the buffer to read the field value from.
 *	len: the length of the buffer
 * @get_status: read the status byte
 *	vdev: the virtio_device
 *	Returns the status byte
 * @set_status: write the status byte
 *	vdev: the virtio_device
 *	status: the new status byte
 * @reset: reset the device
 *	vdev: the virtio device
 *	After this, status and feature negotiation must be done again
 *	Device must not be reset from its vq/config callbacks, or in
 *	parallel with being added/removed.
 * @find_vqs: find virtqueues and instantiate them.
 *	vdev: the virtio_device
 *	nvqs: the number of virtqueues to find
 *	vqs: on success, includes new virtqueues
 *	callbacks: array of callbacks, for each virtqueue
 *		include a NULL entry for vqs that do not need a callback
 *	names: array of virtqueue names (mainly for debugging)
 *		include a NULL entry for vqs unused by driver
 *	Returns 0 on success or error status
 * @del_vqs: free virtqueues found by find_vqs().
 * @get_features: get the array of feature bits for this device.
 *	vdev: the virtio_device
 *	Returns the first 32 feature bits (all we currently need).
 * @finalize_features: confirm what device features we'll be using.
 *	vdev: the virtio_device
 *	This gives the final feature bits for the device: it can change
 *	the dev->feature bits if it wants.
 * @bus_name: return the bus name associated with the device
 *	vdev: the virtio_device
 *      This returns a pointer to the bus name a la pci_name from which
 *      the caller can then copy.
 * @set_vq_affinity: set the affinity for a virtqueue.
 */
typedef void vq_callback_t(struct virtqueue *);
struct virtio_config_ops {
	void (*get)(struct virtio_device *vdev, unsigned offset,
		    void *buf, unsigned len);
	void (*set)(struct virtio_device *vdev, unsigned offset,
		    const void *buf, unsigned len);
	u8 (*get_status)(struct virtio_device *vdev);
	void (*set_status)(struct virtio_device *vdev, u8 status);
	void (*reset)(struct virtio_device *vdev);
	int (*find_vqs)(struct virtio_device *, unsigned nvqs,
			struct virtqueue *vqs[],
			vq_callback_t *callbacks[],
			const char *names[]);
	void (*del_vqs)(struct virtio_device *);
	u32 (*get_features)(struct virtio_device *vdev);
	void (*finalize_features)(struct virtio_device *vdev);
	const char *(*bus_name)(struct virtio_device *vdev);
	int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
};

/* If driver didn't advertise the feature, it will never appear. */
void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
					 unsigned int fbit);

/**
 * virtio_has_feature - helper to determine if this device has this feature.
 * @vdev: the device
 * @fbit: the feature bit
 */
static inline bool virtio_has_feature(const struct virtio_device *vdev,
				      unsigned int fbit)
{
	/* Did you forget to fix assumptions on max features? */
	if (__builtin_constant_p(fbit))
		BUILD_BUG_ON(fbit >= 32);
	else
		BUG_ON(fbit >= 32);

	if (fbit < VIRTIO_TRANSPORT_F_START)
		virtio_check_driver_offered_feature(vdev, fbit);

	return test_bit(fbit, vdev->features);
}

static inline
struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
					vq_callback_t *c, const char *n)
{
	vq_callback_t *callbacks[] = { c };
	const char *names[] = { n };
	struct virtqueue *vq;
	int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
	if (err < 0)
		return ERR_PTR(err);
	return vq;
}

/**
 * virtio_device_ready - enable vq use in probe function
 * @vdev: the device
 *
 * Driver must call this to use vqs in the probe function.
 *
 * Note: vqs are enabled automatically after probe returns.
 */
static inline
void virtio_device_ready(struct virtio_device *dev)
{
	unsigned status = dev->config->get_status(dev);

	BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
	dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
}

static inline
const char *virtio_bus_name(struct virtio_device *vdev)
{
	if (!vdev->config->bus_name)
		return "virtio";
	return vdev->config->bus_name(vdev);
}

/**
 * virtqueue_set_affinity - setting affinity for a virtqueue
 * @vq: the virtqueue
 * @cpu: the cpu no.
 *
 * Pay attention the function are best-effort: the affinity hint may not be set
 * due to config support, irq type and sharing.
 *
 */
static inline
int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
{
	struct virtio_device *vdev = vq->vdev;
	if (vdev->config->set_vq_affinity)
		return vdev->config->set_vq_affinity(vq, cpu);
	return 0;
}

/* Config space accessors. */
#define virtio_cread(vdev, structname, member, ptr)			\
	do {								\
		/* Must match the member's type, and be integer */	\
		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
			(*ptr) = 1;					\
									\
		switch (sizeof(*ptr)) {					\
		case 1:							\
			*(ptr) = virtio_cread8(vdev,			\
					       offsetof(structname, member)); \
			break;						\
		case 2:							\
			*(ptr) = virtio_cread16(vdev,			\
						offsetof(structname, member)); \
			break;						\
		case 4:							\
			*(ptr) = virtio_cread32(vdev,			\
						offsetof(structname, member)); \
			break;						\
		case 8:							\
			*(ptr) = virtio_cread64(vdev,			\
						offsetof(structname, member)); \
			break;						\
		default:						\
			BUG();						\
		}							\
	} while(0)

/* Config space accessors. */
#define virtio_cwrite(vdev, structname, member, ptr)			\
	do {								\
		/* Must match the member's type, and be integer */	\
		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
			BUG_ON((*ptr) == 1);				\
									\
		switch (sizeof(*ptr)) {					\
		case 1:							\
			virtio_cwrite8(vdev,				\
				       offsetof(structname, member),	\
				       *(ptr));				\
			break;						\
		case 2:							\
			virtio_cwrite16(vdev,				\
					offsetof(structname, member),	\
					*(ptr));			\
			break;						\
		case 4:							\
			virtio_cwrite32(vdev,				\
					offsetof(structname, member),	\
					*(ptr));			\
			break;						\
		case 8:							\
			virtio_cwrite64(vdev,				\
					offsetof(structname, member),	\
					*(ptr));			\
			break;						\
		default:						\
			BUG();						\
		}							\
	} while(0)

static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
{
	u8 ret;
	vdev->config->get(vdev, offset, &ret, sizeof(ret));
	return ret;
}

static inline void virtio_cread_bytes(struct virtio_device *vdev,
				      unsigned int offset,
				      void *buf, size_t len)
{
	vdev->config->get(vdev, offset, buf, len);
}

static inline void virtio_cwrite8(struct virtio_device *vdev,
				  unsigned int offset, u8 val)
{
	vdev->config->set(vdev, offset, &val, sizeof(val));
}

static inline u16 virtio_cread16(struct virtio_device *vdev,
				 unsigned int offset)
{
	u16 ret;
	vdev->config->get(vdev, offset, &ret, sizeof(ret));
	return ret;
}

static inline void virtio_cwrite16(struct virtio_device *vdev,
				   unsigned int offset, u16 val)
{
	vdev->config->set(vdev, offset, &val, sizeof(val));
}

static inline u32 virtio_cread32(struct virtio_device *vdev,
				 unsigned int offset)
{
	u32 ret;
	vdev->config->get(vdev, offset, &ret, sizeof(ret));
	return ret;
}

static inline void virtio_cwrite32(struct virtio_device *vdev,
				   unsigned int offset, u32 val)
{
	vdev->config->set(vdev, offset, &val, sizeof(val));
}

static inline u64 virtio_cread64(struct virtio_device *vdev,
				 unsigned int offset)
{
	u64 ret;
	vdev->config->get(vdev, offset, &ret, sizeof(ret));
	return ret;
}

static inline void virtio_cwrite64(struct virtio_device *vdev,
				   unsigned int offset, u64 val)
{
	vdev->config->set(vdev, offset, &val, sizeof(val));
}

/* Conditional config space accessors. */
#define virtio_cread_feature(vdev, fbit, structname, member, ptr)	\
	({								\
		int _r = 0;						\
		if (!virtio_has_feature(vdev, fbit))			\
			_r = -ENOENT;					\
		else							\
			virtio_cread((vdev), structname, member, ptr);	\
		_r;							\
	})

#endif /* _LINUX_VIRTIO_CONFIG_H */
Commit	Line	Data
ec3d41c4 RR	1	#ifndef _LINUX_VIRTIO_CONFIG_H
ec3d41c4 RR	2	#define _LINUX_VIRTIO_CONFIG_H
b4f68be6	3
d2a7ddda	4	#include <linux/err.h>
187f1882	5	#include <linux/bug.h>
72e61eb4	6	#include <linux/virtio.h>
607ca46e	7	#include <uapi/linux/virtio_config.h>
ec3d41c4 RR	8
	9	/**
	10	* virtio_config_ops - operations for configuring a virtio device
a586d4f6	11	* @get: read the value of a configuration field
ec3d41c4	12	* vdev: the virtio_device
a586d4f6	13	* offset: the offset of the configuration field
ec3d41c4	14	* buf: the buffer to write the field value into.
a586d4f6	15	* len: the length of the buffer
a586d4f6	16	* @set: write the value of a configuration field
ec3d41c4	17	* vdev: the virtio_device
a586d4f6	18	* offset: the offset of the configuration field
ec3d41c4	19	* buf: the buffer to read the field value from.
a586d4f6	20	* len: the length of the buffer
ec3d41c4 RR	21	* @get_status: read the status byte
	22	* vdev: the virtio_device
	23	* Returns the status byte
	24	* @set_status: write the status byte
	25	* vdev: the virtio_device
	26	* status: the new status byte
6e5aa7ef RR	27	* @reset: reset the device
	28	* vdev: the virtio device
	29	* After this, status and feature negotiation must be done again
e6af578c MT	30	* Device must not be reset from its vq/config callbacks, or in
e6af578c MT	31	* parallel with being added/removed.
d2a7ddda	32	* @find_vqs: find virtqueues and instantiate them.
ec3d41c4	33	* vdev: the virtio_device
d2a7ddda MT	34	* nvqs: the number of virtqueues to find
	35	* vqs: on success, includes new virtqueues
	36	* callbacks: array of callbacks, for each virtqueue
6457f126	37	* include a NULL entry for vqs that do not need a callback
d2a7ddda	38	* names: array of virtqueue names (mainly for debugging)
6457f126	39	* include a NULL entry for vqs unused by driver
d2a7ddda MT	40	* Returns 0 on success or error status
d2a7ddda MT	41	* @del_vqs: free virtqueues found by find_vqs().
c45a6816 RR	42	* @get_features: get the array of feature bits for this device.
	43	* vdev: the virtio_device
	44	* Returns the first 32 feature bits (all we currently need).
c624896e	45	* @finalize_features: confirm what device features we'll be using.
c45a6816	46	* vdev: the virtio_device
c624896e RR	47	* This gives the final feature bits for the device: it can change
c624896e RR	48	* the dev->feature bits if it wants.
66846048 RJ	49	* @bus_name: return the bus name associated with the device
	50	* vdev: the virtio_device
	51	* This returns a pointer to the bus name a la pci_name from which
	52	* the caller can then copy.
75a0a52b	53	* @set_vq_affinity: set the affinity for a virtqueue.
ec3d41c4	54	*/
d2a7ddda	55	typedef void vq_callback_t(struct virtqueue *);
1842f23c	56	struct virtio_config_ops {
a586d4f6	57	void (get)(struct virtio_device vdev, unsigned offset,
ec3d41c4	58	void *buf, unsigned len);
a586d4f6	59	void (set)(struct virtio_device vdev, unsigned offset,
ec3d41c4 RR	60	const void *buf, unsigned len);
	61	u8 (get_status)(struct virtio_device vdev);
	62	void (set_status)(struct virtio_device vdev, u8 status);
6e5aa7ef	63	void (reset)(struct virtio_device vdev);
d2a7ddda MT	64	int (find_vqs)(struct virtio_device , unsigned nvqs,
	65	struct virtqueue *vqs[],
	66	vq_callback_t *callbacks[],
	67	const char *names[]);
	68	void (del_vqs)(struct virtio_device );
c45a6816	69	u32 (get_features)(struct virtio_device vdev);
c624896e	70	void (finalize_features)(struct virtio_device vdev);
66846048	71	const char (bus_name)(struct virtio_device *vdev);
75a0a52b	72	int (set_vq_affinity)(struct virtqueue vq, int cpu);
ec3d41c4 RR	73	};
ec3d41c4 RR	74
c45a6816 RR	75	/* If driver didn't advertise the feature, it will never appear. */
	76	void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
	77	unsigned int fbit);
	78
	79	/**
	80	* virtio_has_feature - helper to determine if this device has this feature.
	81	* @vdev: the device
	82	* @fbit: the feature bit
	83	*/
	84	static inline bool virtio_has_feature(const struct virtio_device *vdev,
	85	unsigned int fbit)
	86	{
	87	/* Did you forget to fix assumptions on max features? */
1765e3a4 RR	88	if (__builtin_constant_p(fbit))
	89	BUILD_BUG_ON(fbit >= 32);
	90	else
	91	BUG_ON(fbit >= 32);
c45a6816	92
ee006b35 MM	93	if (fbit < VIRTIO_TRANSPORT_F_START)
	94	virtio_check_driver_offered_feature(vdev, fbit);
	95
c45a6816 RR	96	return test_bit(fbit, vdev->features);
	97	}
	98
d2a7ddda MT	99	static inline
	100	struct virtqueue virtio_find_single_vq(struct virtio_device vdev,
	101	vq_callback_t c, const char n)
	102	{
	103	vq_callback_t *callbacks[] = { c };
	104	const char *names[] = { n };
	105	struct virtqueue *vq;
	106	int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
	107	if (err < 0)
	108	return ERR_PTR(err);
	109	return vq;
	110	}
66846048	111
3569db59 MT	112	/**
	113	* virtio_device_ready - enable vq use in probe function
	114	* @vdev: the device
	115	*
	116	* Driver must call this to use vqs in the probe function.
	117	*
	118	* Note: vqs are enabled automatically after probe returns.
	119	*/
	120	static inline
	121	void virtio_device_ready(struct virtio_device *dev)
	122	{
	123	unsigned status = dev->config->get_status(dev);
	124
	125	BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
	126	dev->config->set_status(dev, status \| VIRTIO_CONFIG_S_DRIVER_OK);
	127	}
	128
66846048 RJ	129	static inline
	130	const char virtio_bus_name(struct virtio_device vdev)
	131	{
	132	if (!vdev->config->bus_name)
	133	return "virtio";
	134	return vdev->config->bus_name(vdev);
	135	}
	136
75a0a52b JW	137	/**
	138	* virtqueue_set_affinity - setting affinity for a virtqueue
	139	* @vq: the virtqueue
	140	* @cpu: the cpu no.
	141	*
	142	* Pay attention the function are best-effort: the affinity hint may not be set
	143	* due to config support, irq type and sharing.
	144	*
	145	*/
	146	static inline
	147	int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
	148	{
	149	struct virtio_device *vdev = vq->vdev;
	150	if (vdev->config->set_vq_affinity)
	151	return vdev->config->set_vq_affinity(vq, cpu);
	152	return 0;
	153	}
	154
0b90d062 RR	155	/* Config space accessors. */
	156	#define virtio_cread(vdev, structname, member, ptr) \
	157	do { \
	158	/* Must match the member's type, and be integer */ \
	159	if (!typecheck(typeof((((structname)0)->member)), (ptr))) \
	160	(*ptr) = 1; \
	161	\
	162	switch (sizeof(*ptr)) { \
	163	case 1: \
	164	*(ptr) = virtio_cread8(vdev, \
	165	offsetof(structname, member)); \
	166	break; \
	167	case 2: \
	168	*(ptr) = virtio_cread16(vdev, \
	169	offsetof(structname, member)); \
	170	break; \
	171	case 4: \
	172	*(ptr) = virtio_cread32(vdev, \
	173	offsetof(structname, member)); \
	174	break; \
	175	case 8: \
	176	*(ptr) = virtio_cread64(vdev, \
	177	offsetof(structname, member)); \
	178	break; \
	179	default: \
	180	BUG(); \
	181	} \
	182	} while(0)
	183
	184	/* Config space accessors. */
	185	#define virtio_cwrite(vdev, structname, member, ptr) \
	186	do { \
	187	/* Must match the member's type, and be integer */ \
	188	if (!typecheck(typeof((((structname)0)->member)), (ptr))) \
	189	BUG_ON((*ptr) == 1); \
	190	\
	191	switch (sizeof(*ptr)) { \
	192	case 1: \
	193	virtio_cwrite8(vdev, \
	194	offsetof(structname, member), \
	195	*(ptr)); \
	196	break; \
	197	case 2: \
	198	virtio_cwrite16(vdev, \
	199	offsetof(structname, member), \
	200	*(ptr)); \
	201	break; \
	202	case 4: \
	203	virtio_cwrite32(vdev, \
	204	offsetof(structname, member), \
	205	*(ptr)); \
	206	break; \
	207	case 8: \
	208	virtio_cwrite64(vdev, \
	209	offsetof(structname, member), \
	210	*(ptr)); \
	211	break; \
	212	default: \
	213	BUG(); \
	214	} \
	215	} while(0)
	216
	217	static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
	218	{
219	u8 ret;
220	vdev->config->get(vdev, offset, &ret, sizeof(ret));
221	return ret;
222	}
223
224	static inline void virtio_cread_bytes(struct virtio_device *vdev,
225	unsigned int offset,
226	void *buf, size_t len)
227	{
228	vdev->config->get(vdev, offset, buf, len);
229	}
230
231	static inline void virtio_cwrite8(struct virtio_device *vdev,
232	unsigned int offset, u8 val)
233	{
234	vdev->config->set(vdev, offset, &val, sizeof(val));
235	}
236
237	static inline u16 virtio_cread16(struct virtio_device *vdev,
238	unsigned int offset)
239	{
240	u16 ret;
241	vdev->config->get(vdev, offset, &ret, sizeof(ret));
242	return ret;
243	}
244
245	static inline void virtio_cwrite16(struct virtio_device *vdev,
246	unsigned int offset, u16 val)
247	{
248	vdev->config->set(vdev, offset, &val, sizeof(val));
249	}
250
251	static inline u32 virtio_cread32(struct virtio_device *vdev,
252	unsigned int offset)
253	{
254	u32 ret;
255	vdev->config->get(vdev, offset, &ret, sizeof(ret));
256	return ret;
257	}
258
259	static inline void virtio_cwrite32(struct virtio_device *vdev,
260	unsigned int offset, u32 val)
261	{
262	vdev->config->set(vdev, offset, &val, sizeof(val));
263	}
264
265	static inline u64 virtio_cread64(struct virtio_device *vdev,
266	unsigned int offset)
267	{
268	u64 ret;
269	vdev->config->get(vdev, offset, &ret, sizeof(ret));
270	return ret;
271	}
272
273	static inline void virtio_cwrite64(struct virtio_device *vdev,
274	unsigned int offset, u64 val)
275	{
276	vdev->config->set(vdev, offset, &val, sizeof(val));
277	}
278
279	/* Conditional config space accessors. */
280	#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
281	({ \
282	int _r = 0; \
283	if (!virtio_has_feature(vdev, fbit)) \
284	_r = -ENOENT; \
285	else \
286	virtio_cread((vdev), structname, member, ptr); \
287	_r; \
288	})
75a0a52b	289
ec3d41c4	290	#endif /* _LINUX_VIRTIO_CONFIG_H */