- 根目录:
- drivers
- staging
- ozwpan
- ozeltbuf.c
/* -----------------------------------------------------------------------------
* Copyright (c) 2011 Ozmo Inc
* Released under the GNU General Public License Version 2 (GPLv2).
* -----------------------------------------------------------------------------
*/
#include <linux/module.h>
#include <linux/netdevice.h>
#include "ozdbg.h"
#include "ozprotocol.h"
#include "ozeltbuf.h"
#include "ozpd.h"
/*
* Context: softirq-serialized
*/
void oz_elt_buf_init(struct oz_elt_buf *buf)
{
memset(buf, 0, sizeof(struct oz_elt_buf));
INIT_LIST_HEAD(&buf->stream_list);
INIT_LIST_HEAD(&buf->order_list);
INIT_LIST_HEAD(&buf->isoc_list);
spin_lock_init(&buf->lock);
}
/*
* Context: softirq or process
*/
void oz_elt_buf_term(struct oz_elt_buf *buf)
{
struct oz_elt_info *ei, *n;
list_for_each_entry_safe(ei, n, &buf->isoc_list, link_order)
kfree(ei);
list_for_each_entry_safe(ei, n, &buf->order_list, link_order)
kfree(ei);
}
/*
* Context: softirq or process
*/
struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
{
struct oz_elt_info *ei;
ei = kmem_cache_zalloc(oz_elt_info_cache, GFP_ATOMIC);
if (ei) {
INIT_LIST_HEAD(&ei->link);
INIT_LIST_HEAD(&ei->link_order);
}
return ei;
}
/*
* Precondition: oz_elt_buf.lock must be held.
* Context: softirq or process
*/
void oz_elt_info_free(struct oz_elt_buf *buf, struct oz_elt_info *ei)
{
if (ei)
kmem_cache_free(oz_elt_info_cache, ei);
}
/*------------------------------------------------------------------------------
* Context: softirq
*/
void oz_elt_info_free_chain(struct oz_elt_buf *buf, struct list_head *list)
{
struct oz_elt_info *ei, *n;
spin_lock_bh(&buf->lock);
list_for_each_entry_safe(ei, n, list->next, link)
oz_elt_info_free(buf, ei);
spin_unlock_bh(&buf->lock);
}
int oz_elt_stream_create(struct oz_elt_buf *buf, u8 id, int max_buf_count)
{
struct oz_elt_stream *st;
oz_dbg(ON, "%s: (0x%x)\n", __func__, id);
st = kzalloc(sizeof(struct oz_elt_stream), GFP_ATOMIC);
if (st == NULL)
return -ENOMEM;
atomic_set(&st->ref_count, 1);
st->id = id;
st->max_buf_count = max_buf_count;
INIT_LIST_HEAD(&st->elt_list);
spin_lock_bh(&buf->lock);
list_add_tail(&st->link, &buf->stream_list);
spin_unlock_bh(&buf->lock);
return 0;
}
int oz_elt_stream_delete(struct oz_elt_buf *buf, u8 id)
{
struct list_head *e, *n;
struct oz_elt_stream *st = NULL;
oz_dbg(ON, "%s: (0x%x)\n", __func__, id);
spin_lock_bh(&buf->lock);
list_for_each(e, &buf->stream_list) {
st = list_entry(e, struct oz_elt_stream, link);
if (st->id == id) {
list_del(e);
break;
}
st = NULL;
}
if (!st) {
spin_unlock_bh(&buf->lock);
return -1;
}
list_for_each_safe(e, n, &st->elt_list) {
struct oz_elt_info *ei =
list_entry(e, struct oz_elt_info, link);
list_del_init(&ei->link);
list_del_init(&ei->link_order);
st->buf_count -= ei->length;
oz_dbg(STREAM, "Stream down: %d %d %d\n",
st->buf_count, ei->length, atomic_read(&st->ref_count));
oz_elt_stream_put(st);
oz_elt_info_free(buf, ei);
}
spin_unlock_bh(&buf->lock);
oz_elt_stream_put(st);
return 0;
}
void oz_elt_stream_get(struct oz_elt_stream *st)
{
atomic_inc(&st->ref_count);
}
void oz_elt_stream_put(struct oz_elt_stream *st)
{
if (atomic_dec_and_test(&st->ref_count)) {
oz_dbg(ON, "Stream destroyed\n");
kfree(st);
}
}
/*
* Precondition: Element buffer lock must be held.
* If this function fails the caller is responsible for deallocating the elt
* info structure.
*/
int oz_queue_elt_info(struct oz_elt_buf *buf, u8 isoc, u8 id,
struct oz_elt_info *ei)
{
struct oz_elt_stream *st = NULL;
struct list_head *e;
if (id) {
list_for_each(e, &buf->stream_list) {
st = list_entry(e, struct oz_elt_stream, link);
if (st->id == id)
break;
}
if (e == &buf->stream_list) {
/* Stream specified but stream not known so fail.
* Caller deallocates element info. */
return -1;
}
}
if (st) {
/* If this is an ISOC fixed element that needs a frame number
* then insert that now. Earlier we stored the unit count in
* this field.
*/
struct oz_isoc_fixed *body = (struct oz_isoc_fixed *)
&ei->data[sizeof(struct oz_elt)];
if ((body->app_id == OZ_APPID_USB) && (body->type
== OZ_USB_ENDPOINT_DATA) &&
(body->format == OZ_DATA_F_ISOC_FIXED)) {
u8 unit_count = body->frame_number;
body->frame_number = st->frame_number;
st->frame_number += unit_count;
}
/* Claim stream and update accounts */
oz_elt_stream_get(st);
ei->stream = st;
st->buf_count += ei->length;
/* Add to list in stream. */
list_add_tail(&ei->link, &st->elt_list);
oz_dbg(STREAM, "Stream up: %d %d\n", st->buf_count, ei->length);
/* Check if we have too much buffered for this stream. If so
* start dropping elements until we are back in bounds.
*/
while ((st->buf_count > st->max_buf_count) &&
!list_empty(&st->elt_list)) {
struct oz_elt_info *ei2 =
list_first_entry(&st->elt_list,
struct oz_elt_info, link);
list_del_init(&ei2->link);
list_del_init(&ei2->link_order);
st->buf_count -= ei2->length;
oz_elt_info_free(buf, ei2);
oz_elt_stream_put(st);
}
}
list_add_tail(&ei->link_order, isoc ?
&buf->isoc_list : &buf->order_list);
return 0;
}
int oz_select_elts_for_tx(struct oz_elt_buf *buf, u8 isoc, unsigned *len,
unsigned max_len, struct list_head *list)
{
int count = 0;
struct list_head *el;
struct oz_elt_info *ei, *n;
spin_lock_bh(&buf->lock);
if (isoc)
el = &buf->isoc_list;
else
el = &buf->order_list;
list_for_each_entry_safe(ei, n, el, link_order) {
if ((*len + ei->length) <= max_len) {
struct oz_app_hdr *app_hdr = (struct oz_app_hdr *)
&ei->data[sizeof(struct oz_elt)];
app_hdr->elt_seq_num = buf->tx_seq_num[ei->app_id]++;
if (buf->tx_seq_num[ei->app_id] == 0)
buf->tx_seq_num[ei->app_id] = 1;
*len += ei->length;
list_del(&ei->link);
list_del(&ei->link_order);
if (ei->stream) {
ei->stream->buf_count -= ei->length;
oz_dbg(STREAM, "Stream down: %d %d\n",
ei->stream->buf_count, ei->length);
oz_elt_stream_put(ei->stream);
ei->stream = NULL;
}
INIT_LIST_HEAD(&ei->link_order);
list_add_tail(&ei->link, list);
count++;
} else {
break;
}
}
spin_unlock_bh(&buf->lock);
return count;
}
int oz_are_elts_available(struct oz_elt_buf *buf)
{
return !list_empty(&buf->order_list);
}