[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / virtio_ring.h

#ifndef _LINUX_VIRTIO_RING_H
#define _LINUX_VIRTIO_RING_H

#include <linux/irqreturn.h>
#include <uapi/linux/virtio_ring.h>

/*
 * Barriers in virtio are tricky.  Non-SMP virtio guests can't assume
 * they're not on an SMP host system, so they need to assume real
 * barriers.  Non-SMP virtio hosts could skip the barriers, but does
 * anyone care?
 *
 * For virtio_pci on SMP, we don't need to order with respect to MMIO
 * accesses through relaxed memory I/O windows, so smp_mb() et al are
 * sufficient.
 *
 * For using virtio to talk to real devices (eg. other heterogeneous
 * CPUs) we do need real barriers.  In theory, we could be using both
 * kinds of virtio, so it's a runtime decision, and the branch is
 * actually quite cheap.
 */

#ifdef CONFIG_SMP
static inline void virtio_mb(bool weak_barriers)
{
	if (weak_barriers)
		smp_mb();
	else
		mb();
}

static inline void virtio_rmb(bool weak_barriers)
{
	if (weak_barriers)
		smp_rmb();
	else
		rmb();
}

static inline void virtio_wmb(bool weak_barriers)
{
	if (weak_barriers)
		smp_wmb();
	else
		wmb();
}
#else
static inline void virtio_mb(bool weak_barriers)
{
	mb();
}

static inline void virtio_rmb(bool weak_barriers)
{
	rmb();
}

static inline void virtio_wmb(bool weak_barriers)
{
	wmb();
}
#endif

struct virtio_device;
struct virtqueue;

struct virtqueue *vring_new_virtqueue(unsigned int index,
				      unsigned int num,
				      unsigned int vring_align,
				      struct virtio_device *vdev,
				      bool weak_barriers,
				      void *pages,
				      void (*notify)(struct virtqueue *vq),
				      void (*callback)(struct virtqueue *vq),
				      const char *name);
void vring_del_virtqueue(struct virtqueue *vq);
/* Filter out transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev);

irqreturn_t vring_interrupt(int irq, void *_vq);
#endif /* _LINUX_VIRTIO_RING_H */
Commit	Line	Data
0a8a69dd RR	1	#ifndef _LINUX_VIRTIO_RING_H
0a8a69dd RR	2	#define _LINUX_VIRTIO_RING_H
0a8a69dd	3
0a8a69dd	4	#include <linux/irqreturn.h>
607ca46e DH	5	#include <uapi/linux/virtio_ring.h>
607ca46e DH	6
a9a0fef7 RR	7	/*
	8	* Barriers in virtio are tricky. Non-SMP virtio guests can't assume
	9	* they're not on an SMP host system, so they need to assume real
	10	* barriers. Non-SMP virtio hosts could skip the barriers, but does
	11	* anyone care?
	12	*
	13	* For virtio_pci on SMP, we don't need to order with respect to MMIO
	14	* accesses through relaxed memory I/O windows, so smp_mb() et al are
	15	* sufficient.
	16	*
	17	* For using virtio to talk to real devices (eg. other heterogeneous
	18	* CPUs) we do need real barriers. In theory, we could be using both
	19	* kinds of virtio, so it's a runtime decision, and the branch is
	20	* actually quite cheap.
	21	*/
	22
	23	#ifdef CONFIG_SMP
	24	static inline void virtio_mb(bool weak_barriers)
	25	{
	26	if (weak_barriers)
	27	smp_mb();
	28	else
	29	mb();
	30	}
	31
	32	static inline void virtio_rmb(bool weak_barriers)
	33	{
	34	if (weak_barriers)
	35	smp_rmb();
	36	else
	37	rmb();
	38	}
	39
	40	static inline void virtio_wmb(bool weak_barriers)
	41	{
	42	if (weak_barriers)
	43	smp_wmb();
	44	else
	45	wmb();
	46	}
	47	#else
	48	static inline void virtio_mb(bool weak_barriers)
	49	{
	50	mb();
	51	}
	52
	53	static inline void virtio_rmb(bool weak_barriers)
	54	{
	55	rmb();
	56	}
	57
	58	static inline void virtio_wmb(bool weak_barriers)
	59	{
	60	wmb();
	61	}
	62	#endif
	63
0a8a69dd RR	64	struct virtio_device;
	65	struct virtqueue;
	66
17bb6d40 JW	67	struct virtqueue *vring_new_virtqueue(unsigned int index,
17bb6d40 JW	68	unsigned int num,
87c7d57c	69	unsigned int vring_align,
0a8a69dd	70	struct virtio_device *vdev,
7b21e34f	71	bool weak_barriers,
0a8a69dd RR	72	void *pages,
0a8a69dd RR	73	void (notify)(struct virtqueue vq),
9499f5e7 RR	74	void (callback)(struct virtqueue vq),
9499f5e7 RR	75	const char *name);
0a8a69dd	76	void vring_del_virtqueue(struct virtqueue *vq);
e34f8725 RR	77	/* Filter out transport-specific feature bits. */
e34f8725 RR	78	void vring_transport_features(struct virtio_device *vdev);
0a8a69dd RR	79
0a8a69dd RR	80	irqreturn_t vring_interrupt(int irq, void *_vq);
0a8a69dd	81	#endif /* _LINUX_VIRTIO_RING_H */