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/* -----------------------------------------------------------------------------
* Copyright (c) 2011 Ozmo Inc
* Released under the GNU General Public License Version 2 (GPLv2).
* -----------------------------------------------------------------------------
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include "ozdbg.h"
#include "ozprotocol.h"
#include "ozeltbuf.h"
#include "ozpd.h"
#define OZ_ELT_INFO_MAGIC_USED 0x35791057
#define OZ_ELT_INFO_MAGIC_FREE 0x78940102
/*
* Context: softirq-serialized
*/
int 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);
buf->max_free_elts = 32;
spin_lock_init(&buf->lock);
return 0;
}
/*
* Context: softirq or process
*/
void oz_elt_buf_term(struct oz_elt_buf *buf)
{
struct list_head *e;
int i;
/* Free any elements in the order or isoc lists. */
for (i = 0; i < 2; i++) {
struct list_head *list;
if (i)
list = &buf->order_list;
else
list = &buf->isoc_list;
e = list->next;
while (e != list) {
struct oz_elt_info *ei =
container_of(e, struct oz_elt_info, link_order);
e = e->next;
kfree(ei);
}
}
/* Free any elelment in the pool. */
while (buf->elt_pool) {
struct oz_elt_info *ei =
container_of(buf->elt_pool, struct oz_elt_info, link);
buf->elt_pool = buf->elt_pool->next;
kfree(ei);
}
buf->free_elts = 0;
}
/*
* Context: softirq or process
*/
struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
{
struct oz_elt_info *ei;
spin_lock_bh(&buf->lock);
if (buf->free_elts && buf->elt_pool) {
ei = container_of(buf->elt_pool, struct oz_elt_info, link);
buf->elt_pool = ei->link.next;
buf->free_elts--;
spin_unlock_bh(&buf->lock);
if (ei->magic != OZ_ELT_INFO_MAGIC_FREE) {
oz_dbg(ON, "%s: ei with bad magic: 0x%x\n",
__func__, ei->magic);
}
} else {
spin_unlock_bh(&buf->lock);
ei = kmalloc(sizeof(struct oz_elt_info), GFP_ATOMIC);
}
if (ei) {
ei->flags = 0;
ei->app_id = 0;
ei->callback = NULL;
ei->context = 0;
ei->stream = NULL;
ei->magic = OZ_ELT_INFO_MAGIC_USED;
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) {
if (ei->magic == OZ_ELT_INFO_MAGIC_USED) {
buf->free_elts++;
ei->link.next = buf->elt_pool;
buf->elt_pool = &ei->link;
ei->magic = OZ_ELT_INFO_MAGIC_FREE;
} else {
oz_dbg(ON, "%s: bad magic ei: %p magic: 0x%x\n",
__func__, ei, ei->magic);
}
}
}
/*------------------------------------------------------------------------------
* Context: softirq
*/
void oz_elt_info_free_chain(struct oz_elt_buf *buf, struct list_head *list)
{
struct list_head *e;
e = list->next;
spin_lock_bh(&buf->lock);
while (e != list) {
struct oz_elt_info *ei;
ei = container_of(e, struct oz_elt_info, link);
e = e->next;
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 | __GFP_ZERO);
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;
struct oz_elt_stream *st = NULL;
oz_dbg(ON, "%s: (0x%x)\n", __func__, id);
spin_lock_bh(&buf->lock);
e = buf->stream_list.next;
while (e != &buf->stream_list) {
st = container_of(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;
}
e = st->elt_list.next;
while (e != &st->elt_list) {
struct oz_elt_info *ei =
container_of(e, struct oz_elt_info, link);
e = e->next;
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 = container_of(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 >
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