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#ifndef _VIRTIO_RING_H
#define _VIRTIO_RING_H
#include "types.h" // u64
#include "memmap.h" // PAGE_SIZE
#define PAGE_SHIFT 12
#define PAGE_MASK (PAGE_SIZE-1)
#define virt_to_phys(v) (unsigned long)(v)
#define phys_to_virt(p) (void*)(p)
/* Compiler barrier is enough as an x86 CPU does not reorder reads or writes */
#define smp_rmb() barrier()
#define smp_wmb() barrier()
/* Status byte for guest to report progress, and synchronize features. */
/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
/* We have found a driver for the device. */
#define VIRTIO_CONFIG_S_DRIVER 2
/* Driver has used its parts of the config, and is happy */
#define VIRTIO_CONFIG_S_DRIVER_OK 4
/* We've given up on this device. */
#define VIRTIO_CONFIG_S_FAILED 0x80
#define MAX_QUEUE_NUM (128)
#define VRING_DESC_F_NEXT 1
#define VRING_DESC_F_WRITE 2
#define VRING_AVAIL_F_NO_INTERRUPT 1
#define VRING_USED_F_NO_NOTIFY 1
struct vring_desc
{
u64 addr;
u32 len;
u16 flags;
u16 next;
};
struct vring_avail
{
u16 flags;
u16 idx;
u16 ring[0];
};
struct vring_used_elem
{
u32 id;
u32 len;
};
struct vring_used
{
u16 flags;
u16 idx;
struct vring_used_elem ring[];
};
struct vring {
unsigned int num;
struct vring_desc *desc;
struct vring_avail *avail;
struct vring_used *used;
};
#define vring_size(num) \
(((((sizeof(struct vring_desc) * num) + \
(sizeof(struct vring_avail) + sizeof(u16) * num)) \
+ PAGE_MASK) & ~PAGE_MASK) + \
(sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num))
typedef unsigned char virtio_queue_t[vring_size(MAX_QUEUE_NUM)];
struct vring_virtqueue {
virtio_queue_t queue;
struct vring vring;
u16 free_head;
u16 last_used_idx;
u16 vdata[MAX_QUEUE_NUM];
/* PCI */
int queue_index;
};
struct vring_list {
char *addr;
unsigned int length;
};
static inline void vring_init(struct vring *vr,
unsigned int num, unsigned char *queue)
{
unsigned int i;
unsigned long pa;
ASSERT32FLAT();
vr->num = num;
/* physical address of desc must be page aligned */
pa = virt_to_phys(queue);
pa = (pa + PAGE_MASK) & ~PAGE_MASK;
vr->desc = phys_to_virt(pa);
vr->avail = (struct vring_avail *)&vr->desc[num];
/* disable interrupts */
vr->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
/* physical address of used must be page aligned */
pa = virt_to_phys(&vr->avail->ring[num]);
pa = (pa + PAGE_MASK) & ~PAGE_MASK;
vr->used = phys_to_virt(pa);
for (i = 0; i < num - 1; i++)
vr->desc[i].next = i + 1;
vr->desc[i].next = 0;
}
int vring_more_used(struct vring_virtqueue *vq);
void vring_detach(struct vring_virtqueue *vq, unsigned int head);
int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len);
void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[],
unsigned int out, unsigned int in,
int index, int num_added);
void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added);
#endif /* _VIRTIO_RING_H_ */
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