[deliverable/linux.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 <linux/virtio_byteorder.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 *);
	u64 (*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_test_bit - helper to test feature bits. For use by transports.
 *                     Devices should normally use virtio_has_feature,
 *                     which includes more checks.
 * @vdev: the device
 * @fbit: the feature bit
 */
static inline bool __virtio_test_bit(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 >= 64);
	else
		BUG_ON(fbit >= 64);

	return vdev->features & BIT_ULL(fbit);
}

/**
 * __virtio_set_bit - helper to set feature bits. For use by transports.
 * @vdev: the device
 * @fbit: the feature bit
 */
static inline void __virtio_set_bit(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 >= 64);
	else
		BUG_ON(fbit >= 64);

	vdev->features |= BIT_ULL(fbit);
}

/**
 * __virtio_clear_bit - helper to clear feature bits. For use by transports.
 * @vdev: the device
 * @fbit: the feature bit
 */
static inline void __virtio_clear_bit(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 >= 64);
	else
		BUG_ON(fbit >= 64);

	vdev->features &= ~BIT_ULL(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)
{
	if (fbit < VIRTIO_TRANSPORT_F_START)
		virtio_check_driver_offered_feature(vdev, fbit);

	return __virtio_test_bit(vdev, fbit);
}

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;
}

/* Memory accessors */
static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
{
	return __virtio16_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
{
	return __cpu_to_virtio16(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
{
	return __virtio32_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
{
	return __cpu_to_virtio32(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
{
	return __virtio64_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
{
	return __cpu_to_virtio64(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
}

/* 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>
eef960a0	7	#include <linux/virtio_byteorder.h>
607ca46e	8	#include <uapi/linux/virtio_config.h>
ec3d41c4 RR	9
	10	/**
	11	* virtio_config_ops - operations for configuring a virtio device
a586d4f6	12	* @get: read the value of a configuration field
ec3d41c4	13	* vdev: the virtio_device
a586d4f6	14	* offset: the offset of the configuration field
ec3d41c4	15	* buf: the buffer to write the field value into.
a586d4f6	16	* len: the length of the buffer
a586d4f6	17	* @set: write the value of a configuration field
ec3d41c4	18	* vdev: the virtio_device
a586d4f6	19	* offset: the offset of the configuration field
ec3d41c4	20	* buf: the buffer to read the field value from.
a586d4f6	21	* len: the length of the buffer
ec3d41c4 RR	22	* @get_status: read the status byte
	23	* vdev: the virtio_device
	24	* Returns the status byte
	25	* @set_status: write the status byte
	26	* vdev: the virtio_device
	27	* status: the new status byte
6e5aa7ef RR	28	* @reset: reset the device
	29	* vdev: the virtio device
	30	* After this, status and feature negotiation must be done again
e6af578c MT	31	* Device must not be reset from its vq/config callbacks, or in
e6af578c MT	32	* parallel with being added/removed.
d2a7ddda	33	* @find_vqs: find virtqueues and instantiate them.
ec3d41c4	34	* vdev: the virtio_device
d2a7ddda MT	35	* nvqs: the number of virtqueues to find
	36	* vqs: on success, includes new virtqueues
	37	* callbacks: array of callbacks, for each virtqueue
6457f126	38	* include a NULL entry for vqs that do not need a callback
d2a7ddda	39	* names: array of virtqueue names (mainly for debugging)
6457f126	40	* include a NULL entry for vqs unused by driver
d2a7ddda MT	41	* Returns 0 on success or error status
d2a7ddda MT	42	* @del_vqs: free virtqueues found by find_vqs().
c45a6816 RR	43	* @get_features: get the array of feature bits for this device.
	44	* vdev: the virtio_device
	45	* Returns the first 32 feature bits (all we currently need).
c624896e	46	* @finalize_features: confirm what device features we'll be using.
c45a6816	47	* vdev: the virtio_device
c624896e RR	48	* This gives the final feature bits for the device: it can change
c624896e RR	49	* the dev->feature bits if it wants.
66846048 RJ	50	* @bus_name: return the bus name associated with the device
	51	* vdev: the virtio_device
	52	* This returns a pointer to the bus name a la pci_name from which
	53	* the caller can then copy.
75a0a52b	54	* @set_vq_affinity: set the affinity for a virtqueue.
ec3d41c4	55	*/
d2a7ddda	56	typedef void vq_callback_t(struct virtqueue *);
1842f23c	57	struct virtio_config_ops {
a586d4f6	58	void (get)(struct virtio_device vdev, unsigned offset,
ec3d41c4	59	void *buf, unsigned len);
a586d4f6	60	void (set)(struct virtio_device vdev, unsigned offset,
ec3d41c4 RR	61	const void *buf, unsigned len);
	62	u8 (get_status)(struct virtio_device vdev);
	63	void (set_status)(struct virtio_device vdev, u8 status);
6e5aa7ef	64	void (reset)(struct virtio_device vdev);
d2a7ddda MT	65	int (find_vqs)(struct virtio_device , unsigned nvqs,
	66	struct virtqueue *vqs[],
	67	vq_callback_t *callbacks[],
	68	const char *names[]);
	69	void (del_vqs)(struct virtio_device );
d0254773	70	u64 (get_features)(struct virtio_device vdev);
c624896e	71	void (finalize_features)(struct virtio_device vdev);
66846048	72	const char (bus_name)(struct virtio_device *vdev);
75a0a52b	73	int (set_vq_affinity)(struct virtqueue vq, int cpu);
ec3d41c4 RR	74	};
ec3d41c4 RR	75
c45a6816 RR	76	/* If driver didn't advertise the feature, it will never appear. */
	77	void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
	78	unsigned int fbit);
	79
	80	/**
d4024af5 MT	81	* __virtio_test_bit - helper to test feature bits. For use by transports.
	82	* Devices should normally use virtio_has_feature,
	83	* which includes more checks.
c45a6816 RR	84	* @vdev: the device
	85	* @fbit: the feature bit
	86	*/
d4024af5 MT	87	static inline bool __virtio_test_bit(const struct virtio_device *vdev,
	88	unsigned int fbit)
	89	{
	90	/* Did you forget to fix assumptions on max features? */
	91	if (__builtin_constant_p(fbit))
d0254773	92	BUILD_BUG_ON(fbit >= 64);
d4024af5	93	else
d0254773	94	BUG_ON(fbit >= 64);
d4024af5	95
d0254773	96	return vdev->features & BIT_ULL(fbit);
d4024af5 MT	97	}
	98
	99	/**
	100	* __virtio_set_bit - helper to set feature bits. For use by transports.
	101	* @vdev: the device
	102	* @fbit: the feature bit
	103	*/
	104	static inline void __virtio_set_bit(struct virtio_device *vdev,
	105	unsigned int fbit)
	106	{
	107	/* Did you forget to fix assumptions on max features? */
	108	if (__builtin_constant_p(fbit))
d0254773	109	BUILD_BUG_ON(fbit >= 64);
d4024af5	110	else
d0254773	111	BUG_ON(fbit >= 64);
d4024af5	112
d0254773	113	vdev->features \|= BIT_ULL(fbit);
d4024af5 MT	114	}
	115
	116	/**
	117	* __virtio_clear_bit - helper to clear feature bits. For use by transports.
	118	* @vdev: the device
	119	* @fbit: the feature bit
	120	*/
	121	static inline void __virtio_clear_bit(struct virtio_device *vdev,
c45a6816 RR	122	unsigned int fbit)
	123	{
	124	/* Did you forget to fix assumptions on max features? */
1765e3a4	125	if (__builtin_constant_p(fbit))
d0254773	126	BUILD_BUG_ON(fbit >= 64);
1765e3a4	127	else
d0254773	128	BUG_ON(fbit >= 64);
c45a6816	129
d0254773	130	vdev->features &= ~BIT_ULL(fbit);
d4024af5 MT	131	}
	132
	133	/**
	134	* virtio_has_feature - helper to determine if this device has this feature.
	135	* @vdev: the device
	136	* @fbit: the feature bit
	137	*/
	138	static inline bool virtio_has_feature(const struct virtio_device *vdev,
	139	unsigned int fbit)
	140	{
ee006b35 MM	141	if (fbit < VIRTIO_TRANSPORT_F_START)
	142	virtio_check_driver_offered_feature(vdev, fbit);
	143
d4024af5	144	return __virtio_test_bit(vdev, fbit);
c45a6816 RR	145	}
c45a6816 RR	146
d2a7ddda MT	147	static inline
	148	struct virtqueue virtio_find_single_vq(struct virtio_device vdev,
	149	vq_callback_t c, const char n)
	150	{
	151	vq_callback_t *callbacks[] = { c };
	152	const char *names[] = { n };
	153	struct virtqueue *vq;
	154	int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
	155	if (err < 0)
	156	return ERR_PTR(err);
	157	return vq;
	158	}
66846048	159
3569db59 MT	160	/**
	161	* virtio_device_ready - enable vq use in probe function
	162	* @vdev: the device
	163	*
	164	* Driver must call this to use vqs in the probe function.
	165	*
	166	* Note: vqs are enabled automatically after probe returns.
	167	*/
	168	static inline
	169	void virtio_device_ready(struct virtio_device *dev)
	170	{
	171	unsigned status = dev->config->get_status(dev);
	172
	173	BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
	174	dev->config->set_status(dev, status \| VIRTIO_CONFIG_S_DRIVER_OK);
	175	}
	176
66846048 RJ	177	static inline
	178	const char virtio_bus_name(struct virtio_device vdev)
	179	{
	180	if (!vdev->config->bus_name)
	181	return "virtio";
	182	return vdev->config->bus_name(vdev);
	183	}
	184
75a0a52b JW	185	/**
	186	* virtqueue_set_affinity - setting affinity for a virtqueue
	187	* @vq: the virtqueue
	188	* @cpu: the cpu no.
	189	*
	190	* Pay attention the function are best-effort: the affinity hint may not be set
	191	* due to config support, irq type and sharing.
	192	*
	193	*/
	194	static inline
	195	int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
	196	{
	197	struct virtio_device *vdev = vq->vdev;
	198	if (vdev->config->set_vq_affinity)
	199	return vdev->config->set_vq_affinity(vq, cpu);
	200	return 0;
	201	}
	202
eef960a0 MT	203	/* Memory accessors */
	204	static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
	205	{
	206	return __virtio16_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	207	}
	208
	209	static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
	210	{
	211	return __cpu_to_virtio16(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	212	}
	213
	214	static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
	215	{
	216	return __virtio32_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	217	}
	218
	219	static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
	220	{
	221	return __cpu_to_virtio32(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	222	}
	223
	224	static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
	225	{
	226	return __virtio64_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	227	}
	228
	229	static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
	230	{
	231	return __cpu_to_virtio64(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
	232	}
	233
0b90d062 RR	234	/* Config space accessors. */
	235	#define virtio_cread(vdev, structname, member, ptr) \
	236	do { \
	237	/* Must match the member's type, and be integer */ \
	238	if (!typecheck(typeof((((structname)0)->member)), (ptr))) \
	239	(*ptr) = 1; \
	240	\
	241	switch (sizeof(*ptr)) { \
	242	case 1: \
	243	*(ptr) = virtio_cread8(vdev, \
	244	offsetof(structname, member)); \
	245	break; \
	246	case 2: \
	247	*(ptr) = virtio_cread16(vdev, \
	248	offsetof(structname, member)); \
	249	break; \
	250	case 4: \
	251	*(ptr) = virtio_cread32(vdev, \
	252	offsetof(structname, member)); \
	253	break; \
	254	case 8: \
	255	*(ptr) = virtio_cread64(vdev, \
	256	offsetof(structname, member)); \
	257	break; \
	258	default: \
	259	BUG(); \
	260	} \
	261	} while(0)
	262
	263	/* Config space accessors. */
	264	#define virtio_cwrite(vdev, structname, member, ptr) \
	265	do { \
	266	/* Must match the member's type, and be integer */ \
	267	if (!typecheck(typeof((((structname)0)->member)), (ptr))) \
	268	BUG_ON((*ptr) == 1); \
	269	\
	270	switch (sizeof(*ptr)) { \
	271	case 1: \
	272	virtio_cwrite8(vdev, \
	273	offsetof(structname, member), \
	274	*(ptr)); \
	275	break; \
	276	case 2: \
	277	virtio_cwrite16(vdev, \
	278	offsetof(structname, member), \
	279	*(ptr)); \
	280	break; \
	281	case 4: \
	282	virtio_cwrite32(vdev, \
	283	offsetof(structname, member), \
	284	*(ptr)); \
	285	break; \
	286	case 8: \
	287	virtio_cwrite64(vdev, \
	288	offsetof(structname, member), \
	289	*(ptr)); \
	290	break; \
	291	default: \
	292	BUG(); \
	293	} \
	294	} while(0)
	295
	296	static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
	297	{
298	u8 ret;
299	vdev->config->get(vdev, offset, &ret, sizeof(ret));
300	return ret;
301	}
302
303	static inline void virtio_cread_bytes(struct virtio_device *vdev,
304	unsigned int offset,
305	void *buf, size_t len)
306	{
307	vdev->config->get(vdev, offset, buf, len);
308	}
309
310	static inline void virtio_cwrite8(struct virtio_device *vdev,
311	unsigned int offset, u8 val)
312	{
313	vdev->config->set(vdev, offset, &val, sizeof(val));
314	}
315
316	static inline u16 virtio_cread16(struct virtio_device *vdev,
317	unsigned int offset)
318	{
319	u16 ret;
320	vdev->config->get(vdev, offset, &ret, sizeof(ret));
321	return ret;
322	}
323
324	static inline void virtio_cwrite16(struct virtio_device *vdev,
325	unsigned int offset, u16 val)
326	{
327	vdev->config->set(vdev, offset, &val, sizeof(val));
328	}
329
330	static inline u32 virtio_cread32(struct virtio_device *vdev,
331	unsigned int offset)
332	{
333	u32 ret;
334	vdev->config->get(vdev, offset, &ret, sizeof(ret));
335	return ret;
336	}
337
338	static inline void virtio_cwrite32(struct virtio_device *vdev,
339	unsigned int offset, u32 val)
340	{
341	vdev->config->set(vdev, offset, &val, sizeof(val));
342	}
343
344	static inline u64 virtio_cread64(struct virtio_device *vdev,
345	unsigned int offset)
346	{
347	u64 ret;
348	vdev->config->get(vdev, offset, &ret, sizeof(ret));
349	return ret;
350	}
351
352	static inline void virtio_cwrite64(struct virtio_device *vdev,
353	unsigned int offset, u64 val)
354	{
355	vdev->config->set(vdev, offset, &val, sizeof(val));
356	}
357
358	/* Conditional config space accessors. */
359	#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
360	({ \
361	int _r = 0; \
362	if (!virtio_has_feature(vdev, fbit)) \
363	_r = -ENOENT; \
364	else \
365	virtio_cread((vdev), structname, member, ptr); \
366	_r; \
367	})
75a0a52b	368
ec3d41c4	369	#endif /* _LINUX_VIRTIO_CONFIG_H */