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/*****************************************************************************
Copyright(c) 2010 FCI Inc. All Rights Reserved
File name : fci_ringbuffer.c
Description : fci ringbuffer
History :
----------------------------------------------------------------------
2010/11/25 aslan.cho initial
*******************************************************************************/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include "fci_ringbuffer.h"
#define PKT_READY 0
#define PKT_DISPOSED 1
void fci_ringbuffer_init(struct fci_ringbuffer *rbuf, void *data, size_t len)
{
rbuf->pread = rbuf->pwrite = 0;
rbuf->data = data;
rbuf->size = len;
rbuf->error = 0;
init_waitqueue_head(&rbuf->queue);
spin_lock_init(&(rbuf->lock));
}
int fci_ringbuffer_empty(struct fci_ringbuffer *rbuf)
{
return (rbuf->pread == rbuf->pwrite);
}
ssize_t fci_ringbuffer_free(struct fci_ringbuffer *rbuf)
{
ssize_t free;
free = rbuf->pread - rbuf->pwrite;
if (free <= 0)
free += rbuf->size;
return free-1;
}
ssize_t fci_ringbuffer_avail(struct fci_ringbuffer *rbuf)
{
ssize_t avail;
avail = rbuf->pwrite - rbuf->pread;
if (avail < 0)
avail += rbuf->size;
return avail;
}
void fci_ringbuffer_flush(struct fci_ringbuffer *rbuf)
{
rbuf->pread = rbuf->pwrite;
rbuf->error = 0;
}
void fci_ringbuffer_reset(struct fci_ringbuffer *rbuf)
{
rbuf->pread = rbuf->pwrite = 0;
rbuf->error = 0;
}
void fci_ringbuffer_flush_spinlock_wakeup(struct fci_ringbuffer *rbuf)
{
unsigned long flags;
spin_lock_irqsave(&rbuf->lock, flags);
fci_ringbuffer_flush(rbuf);
spin_unlock_irqrestore(&rbuf->lock, flags);
wake_up(&rbuf->queue);
}
ssize_t fci_ringbuffer_read_user(struct fci_ringbuffer *rbuf
, u8 __user *buf, size_t len)
{
size_t todo = len;
size_t split;
split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
if (split > 0) {
if (copy_to_user(buf, rbuf->data+rbuf->pread, split))
return -EFAULT;
buf += split;
todo -= split;
rbuf->pread = 0;
}
if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
return -EFAULT;
rbuf->pread = (rbuf->pread + todo) % rbuf->size;
return len;
}
void fci_ringbuffer_read(struct fci_ringbuffer *rbuf, u8 *buf, size_t len)
{
size_t todo = len;
size_t split;
split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
if (split > 0) {
memcpy(buf, rbuf->data+rbuf->pread, split);
buf += split;
todo -= split;
rbuf->pread = 0;
}
memcpy(buf, rbuf->data+rbuf->pread, todo);
rbuf->pread = (rbuf->pread + todo) % rbuf->size;
}
ssize_t fci_ringbuffer_write(struct fci_ringbuffer *rbuf
, const u8 *buf, size_t len)
{
size_t todo = len;
size_t split;
split = (rbuf->pwrite + len > rbuf->size)
? rbuf->size - rbuf->pwrite : 0;
if (split > 0) {
memcpy(rbuf->data+rbuf->pwrite, buf, split);
buf += split;
todo -= split;
rbuf->pwrite = 0;
}
memcpy(rbuf->data+rbuf->pwrite, buf, todo);
rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
return len;
}
ssize_t fci_ringbuffer_pkt_write(struct fci_ringbuffer *rbuf
, u8 *buf, size_t len)
{
int status;
ssize_t oldpwrite = rbuf->pwrite;
FCI_RINGBUFFER_WRITE_BYTE(rbuf, len >> 8);
FCI_RINGBUFFER_WRITE_BYTE(rbuf, len & 0xff);
FCI_RINGBUFFER_WRITE_BYTE(rbuf, PKT_READY);
status = fci_ringbuffer_write(rbuf, buf, len);
if (status < 0)
rbuf->pwrite = oldpwrite;
return status;
}
ssize_t fci_ringbuffer_pkt_read_user(struct fci_ringbuffer *rbuf, size_t idx,
int offset, u8 __user *buf, size_t len)
{
size_t todo;
size_t split;
size_t pktlen;
pktlen = rbuf->data[idx] << 8;
pktlen |= rbuf->data[(idx + 1) % rbuf->size];
if (offset > pktlen)
return -EINVAL;
if ((offset + len) > pktlen)
len = pktlen - offset;
idx = (idx + FCI_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
todo = len;
split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
if (split > 0) {
if (copy_to_user(buf, rbuf->data+idx, split))
return -EFAULT;
buf += split;
todo -= split;
idx = 0;
}
if (copy_to_user(buf, rbuf->data+idx, todo))
return -EFAULT;
return len;
}
ssize_t fci_ringbuffer_pkt_read(struct fci_ringbuffer *rbuf, size_t idx,
int offset, u8 *buf, size_t len)
{
size_t todo;
size_t split;
size_t pktlen;
pktlen = rbuf->data[idx] << 8;
pktlen |= rbuf->data[(idx + 1) % rbuf->size];
if (offset > pktlen)
return -EINVAL;
if ((offset + len) > pktlen)
len = pktlen - offset;
idx = (idx + FCI_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
todo = len;
split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
if (split > 0) {
memcpy(buf, rbuf->data+idx, split);
buf += split;
todo -= split;
idx = 0;
}
memcpy(buf, rbuf->data+idx, todo);
return len;
}
void fci_ringbuffer_pkt_dispose(struct fci_ringbuffer *rbuf, size_t idx)
{
size_t pktlen;
rbuf->data[(idx + 2) % rbuf->size] = PKT_DISPOSED;
while (fci_ringbuffer_avail(rbuf) > FCI_RINGBUFFER_PKTHDRSIZE) {
if (FCI_RINGBUFFER_PEEK(rbuf, 2) == PKT_DISPOSED) {
pktlen = FCI_RINGBUFFER_PEEK(rbuf, 0) << 8;
pktlen |= FCI_RINGBUFFER_PEEK(rbuf, 1);
FCI_RINGBUFFER_SKIP(rbuf
, pktlen + FCI_RINGBUFFER_PKTHDRSIZE);
} else
break;
}
}
ssize_t fci_ringbuffer_pkt_next(struct fci_ringbuffer *rbuf
, size_t idx, size_t *pktlen)
{
int consumed;
int curpktlen;
int curpktstatus;
if (idx == -1)
idx = rbuf->pread;
else {
curpktlen = rbuf->data[idx] << 8;
curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
idx = (idx + curpktlen + FCI_RINGBUFFER_PKTHDRSIZE)
% rbuf->size;
}
consumed = (idx - rbuf->pread) % rbuf->size;
while ((fci_ringbuffer_avail(rbuf) - consumed)
> FCI_RINGBUFFER_PKTHDRSIZE) {
curpktlen = rbuf->data[idx] << 8;
curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
curpktstatus = rbuf->data[(idx + 2) % rbuf->size];
if (curpktstatus == PKT_READY) {
*pktlen = curpktlen;
return idx;
}
consumed += curpktlen + FCI_RINGBUFFER_PKTHDRSIZE;
idx = (idx + curpktlen + FCI_RINGBUFFER_PKTHDRSIZE)
% rbuf->size;
}
return -1;
}
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