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rio_cm.c
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/*
* rio_cm - RapidIO Channelized Messaging Driver
*
* Copyright 2013-2016 Integrated Device Technology, Inc.
* Copyright (c) 2015, Prodrive Technologies
* Copyright (c) 2015, RapidIO Trade Association
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* THIS PROGRAM IS DISTRIBUTED IN THE HOPE THAT IT WILL BE USEFUL,
* BUT WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. SEE THE
* GNU GENERAL PUBLIC LICENSE FOR MORE DETAILS.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include "include/rio.h"
#include "include/rio_drv.h"
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/reboot.h>
#include <linux/bitops.h>
#include <linux/printk.h>
#include "include/rio_cm_cdev.h"
#define DRV_NAME "rio_cm"
#define DRV_VERSION "1.0.0"
#define DRV_AUTHOR "Alexandre Bounine <[email protected]>"
#define DRV_DESC "RapidIO Channelized Messaging Driver"
#define DEV_NAME "rio_cm"
/* Debug output filtering masks */
enum {
DBG_NONE = 0,
DBG_INIT = BIT(0), /* driver init */
DBG_EXIT = BIT(1), /* driver exit */
DBG_MPORT = BIT(2), /* mport add/remove */
DBG_RDEV = BIT(3), /* RapidIO device add/remove */
DBG_CHOP = BIT(4), /* channel operations */
DBG_WAIT = BIT(5), /* waiting for events */
DBG_TX = BIT(6), /* message TX */
DBG_TX_EVENT = BIT(7), /* message TX event */
DBG_RX_DATA = BIT(8), /* inbound data messages */
DBG_RX_CMD = BIT(9), /* inbound REQ/ACK/NACK messages */
DBG_ALL = ~0,
};
#ifdef DEBUG
#define riocm_debug(level, fmt, arg...) \
do { \
if (DBG_##level & dbg_level) \
pr_debug(DRV_NAME ": %s " fmt "\n", \
__func__, ##arg); \
} while (0)
#else
#define riocm_debug(level, fmt, arg...) \
no_printk(KERN_DEBUG pr_fmt(DRV_NAME fmt "\n"), ##arg)
#endif
#define riocm_warn(fmt, arg...) \
pr_warn(DRV_NAME ": %s WARNING " fmt "\n", __func__, ##arg)
#define riocm_error(fmt, arg...) \
pr_err(DRV_NAME ": %s ERROR " fmt "\n", __func__, ##arg)
static int cmbox = 1;
module_param(cmbox, int, S_IRUGO);
MODULE_PARM_DESC(cmbox, "RapidIO Mailbox number (default 1)");
static int chstart = 256;
module_param(chstart, int, S_IRUGO);
MODULE_PARM_DESC(chstart,
"Start channel number for dynamic allocation (default 256)");
#ifdef DEBUG
static u32 dbg_level = DBG_NONE;
module_param(dbg_level, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(dbg_level, "Debugging output level (default 0 = none)");
#endif
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
#define RIOCM_TX_RING_SIZE 128
#define RIOCM_RX_RING_SIZE 128
#define RIOCM_CONNECT_TO 3 /* connect response TO (in sec) */
#define RIOCM_MAX_CHNUM 0xffff /* Use full range of u16 field */
#define RIOCM_CHNUM_AUTO 0
#define RIOCM_MAX_EP_COUNT 0x10000 /* Max number of endpoints */
enum rio_cm_state {
RIO_CM_IDLE,
RIO_CM_CONNECT,
RIO_CM_CONNECTED,
RIO_CM_DISCONNECT,
RIO_CM_CHAN_BOUND,
RIO_CM_LISTEN,
RIO_CM_DESTROYING,
};
enum rio_cm_pkt_type {
RIO_CM_SYS = 0xaa,
RIO_CM_CHAN = 0x55,
};
enum rio_cm_chop {
CM_CONN_REQ,
CM_CONN_ACK,
CM_CONN_CLOSE,
CM_DATA_MSG,
};
struct rio_ch_base_bhdr {
u32 src_id;
u32 dst_id;
#define RIO_HDR_LETTER_MASK 0xffff0000
#define RIO_HDR_MBOX_MASK 0x0000ffff
u8 src_mbox;
u8 dst_mbox;
u8 type;
} __attribute__((__packed__));
struct rio_ch_chan_hdr {
struct rio_ch_base_bhdr bhdr;
u8 ch_op;
u16 dst_ch;
u16 src_ch;
u16 msg_len;
u16 rsrvd;
} __attribute__((__packed__));
struct tx_req {
struct list_head node;
struct rio_dev *rdev;
void *buffer;
size_t len;
};
struct cm_dev {
struct list_head list;
struct rio_mport *mport;
void *rx_buf[RIOCM_RX_RING_SIZE];
int rx_slots;
struct mutex rx_lock;
void *tx_buf[RIOCM_TX_RING_SIZE];
int tx_slot;
int tx_cnt;
int tx_ack_slot;
struct list_head tx_reqs;
spinlock_t tx_lock;
struct list_head peers;
u32 npeers;
struct workqueue_struct *rx_wq;
struct work_struct rx_work;
};
struct chan_rx_ring {
void *buf[RIOCM_RX_RING_SIZE];
int head;
int tail;
int count;
/* Tracking RX buffers reported to upper level */
void *inuse[RIOCM_RX_RING_SIZE];
int inuse_cnt;
};
struct rio_channel {
u16 id; /* local channel ID */
struct kref ref; /* channel refcount */
struct file *filp;
struct cm_dev *cmdev; /* associated CM device object */
struct rio_dev *rdev; /* remote RapidIO device */
enum rio_cm_state state;
int error;
spinlock_t lock;
void *context;
u32 loc_destid; /* local destID */
u32 rem_destid; /* remote destID */
u16 rem_channel; /* remote channel ID */
struct list_head accept_queue;
struct list_head ch_node;
struct completion comp;
struct completion comp_close;
struct chan_rx_ring rx_ring;
};
struct cm_peer {
struct list_head node;
struct rio_dev *rdev;
};
struct rio_cm_work {
struct work_struct work;
struct cm_dev *cm;
void *data;
};
struct conn_req {
struct list_head node;
u32 destid; /* requester destID */
u16 chan; /* requester channel ID */
struct cm_dev *cmdev;
};
/*
* A channel_dev structure represents a CM_CDEV
* @cdev Character device
* @dev Associated device object
*/
struct channel_dev {
struct cdev cdev;
struct device *dev;
};
static struct rio_channel *riocm_ch_alloc(u16 ch_num);
static void riocm_ch_free(struct kref *ref);
static int riocm_post_send(struct cm_dev *cm, struct rio_dev *rdev,
void *buffer, size_t len);
static int riocm_ch_close(struct rio_channel *ch);
static DEFINE_SPINLOCK(idr_lock);
static DEFINE_IDR(ch_idr);
static LIST_HEAD(cm_dev_list);
static DECLARE_RWSEM(rdev_sem);
static struct class *dev_class;
static unsigned int dev_major;
static unsigned int dev_minor_base;
static dev_t dev_number;
static struct channel_dev riocm_cdev;
#define is_msg_capable(src_ops, dst_ops) \
((src_ops & RIO_SRC_OPS_DATA_MSG) && \
(dst_ops & RIO_DST_OPS_DATA_MSG))
#define dev_cm_capable(dev) \
is_msg_capable(dev->src_ops, dev->dst_ops)
static int riocm_cmp(struct rio_channel *ch, enum rio_cm_state cmp)
{
int ret;
spin_lock_bh(&ch->lock);
ret = (ch->state == cmp);
spin_unlock_bh(&ch->lock);
return ret;
}
static int riocm_cmp_exch(struct rio_channel *ch,
enum rio_cm_state cmp, enum rio_cm_state exch)
{
int ret;
spin_lock_bh(&ch->lock);
ret = (ch->state == cmp);
if (ret)
ch->state = exch;
spin_unlock_bh(&ch->lock);
return ret;
}
static enum rio_cm_state riocm_exch(struct rio_channel *ch,
enum rio_cm_state exch)
{
enum rio_cm_state old;
spin_lock_bh(&ch->lock);
old = ch->state;
ch->state = exch;
spin_unlock_bh(&ch->lock);
return old;
}
static struct rio_channel *riocm_get_channel(u16 nr)
{
struct rio_channel *ch;
spin_lock_bh(&idr_lock);
ch = idr_find(&ch_idr, nr);
if (ch)
kref_get(&ch->ref);
spin_unlock_bh(&idr_lock);
return ch;
}
static void riocm_put_channel(struct rio_channel *ch)
{
kref_put(&ch->ref, riocm_ch_free);
}
static void *riocm_rx_get_msg(struct cm_dev *cm)
{
void *msg;
int i;
msg = rio_get_inb_message(cm->mport, cmbox);
if (msg) {
for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
if (cm->rx_buf[i] == msg) {
cm->rx_buf[i] = NULL;
cm->rx_slots++;
break;
}
}
if (i == RIOCM_RX_RING_SIZE)
riocm_warn("no record for buffer 0x%p", msg);
}
return msg;
}
/*
* riocm_rx_fill - fills a ring of receive buffers for given cm device
* @cm: cm_dev object
* @nent: max number of entries to fill
*
* Returns: none
*/
static void riocm_rx_fill(struct cm_dev *cm, int nent)
{
int i;
if (cm->rx_slots == 0)
return;
for (i = 0; i < RIOCM_RX_RING_SIZE && cm->rx_slots && nent; i++) {
if (cm->rx_buf[i] == NULL) {
cm->rx_buf[i] = kmalloc(RIO_MAX_MSG_SIZE, GFP_KERNEL);
if (cm->rx_buf[i] == NULL)
break;
rio_add_inb_buffer(cm->mport, cmbox, cm->rx_buf[i]);
cm->rx_slots--;
nent--;
}
}
}
/*
* riocm_rx_free - frees all receive buffers associated with given cm device
* @cm: cm_dev object
*
* Returns: none
*/
static void riocm_rx_free(struct cm_dev *cm)
{
int i;
for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
if (cm->rx_buf[i] != NULL) {
kfree(cm->rx_buf[i]);
cm->rx_buf[i] = NULL;
}
}
}
/*
* riocm_req_handler - connection request handler
* @cm: cm_dev object
* @req_data: pointer to the request packet
*
* Returns: 0 if success, or
* -EINVAL if channel is not in correct state,
* -ENODEV if cannot find a channel with specified ID,
* -ENOMEM if unable to allocate memory to store the request
*/
static int riocm_req_handler(struct cm_dev *cm, void *req_data)
{
struct rio_channel *ch;
struct conn_req *req;
struct rio_ch_chan_hdr *hh = req_data;
u16 chnum;
chnum = ntohs(hh->dst_ch);
ch = riocm_get_channel(chnum);
if (!ch)
return -ENODEV;
if (ch->state != RIO_CM_LISTEN) {
riocm_debug(RX_CMD, "channel %d is not in listen state", chnum);
riocm_put_channel(ch);
return -EINVAL;
}
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req) {
riocm_put_channel(ch);
return -ENOMEM;
}
req->destid = ntohl(hh->bhdr.src_id);
req->chan = ntohs(hh->src_ch);
req->cmdev = cm;
spin_lock_bh(&ch->lock);
list_add_tail(&req->node, &ch->accept_queue);
spin_unlock_bh(&ch->lock);
complete(&ch->comp);
riocm_put_channel(ch);
return 0;
}
/*
* riocm_resp_handler - response to connection request handler
* @resp_data: pointer to the response packet
*
* Returns: 0 if success, or
* -EINVAL if channel is not in correct state,
* -ENODEV if cannot find a channel with specified ID,
*/
static int riocm_resp_handler(void *resp_data)
{
struct rio_channel *ch;
struct rio_ch_chan_hdr *hh = resp_data;
u16 chnum;
chnum = ntohs(hh->dst_ch);
ch = riocm_get_channel(chnum);
if (!ch)
return -ENODEV;
if (ch->state != RIO_CM_CONNECT) {
riocm_put_channel(ch);
return -EINVAL;
}
riocm_exch(ch, RIO_CM_CONNECTED);
ch->rem_channel = ntohs(hh->src_ch);
complete(&ch->comp);
riocm_put_channel(ch);
return 0;
}
/*
* riocm_close_handler - channel close request handler
* @req_data: pointer to the request packet
*
* Returns: 0 if success, or
* -ENODEV if cannot find a channel with specified ID,
* + error codes returned by riocm_ch_close.
*/
static int riocm_close_handler(void *data)
{
struct rio_channel *ch;
struct rio_ch_chan_hdr *hh = data;
int ret;
riocm_debug(RX_CMD, "for ch=%d", ntohs(hh->dst_ch));
spin_lock_bh(&idr_lock);
ch = idr_find(&ch_idr, ntohs(hh->dst_ch));
if (!ch) {
spin_unlock_bh(&idr_lock);
return -ENODEV;
}
idr_remove(&ch_idr, ch->id);
spin_unlock_bh(&idr_lock);
riocm_exch(ch, RIO_CM_DISCONNECT);
ret = riocm_ch_close(ch);
if (ret)
riocm_debug(RX_CMD, "riocm_ch_close() returned %d", ret);
return 0;
}
/*
* rio_cm_handler - function that services request (non-data) packets
* @cm: cm_dev object
* @data: pointer to the packet
*/
static void rio_cm_handler(struct cm_dev *cm, void *data)
{
struct rio_ch_chan_hdr *hdr;
if (!rio_mport_is_running(cm->mport))
goto out;
hdr = data;
riocm_debug(RX_CMD, "OP=%x for ch=%d from %d",
hdr->ch_op, ntohs(hdr->dst_ch), ntohs(hdr->src_ch));
switch (hdr->ch_op) {
case CM_CONN_REQ:
riocm_req_handler(cm, data);
break;
case CM_CONN_ACK:
riocm_resp_handler(data);
break;
case CM_CONN_CLOSE:
riocm_close_handler(data);
break;
default:
riocm_error("Invalid packet header");
break;
}
out:
kfree(data);
}
/*
* rio_rx_data_handler - received data packet handler
* @cm: cm_dev object
* @buf: data packet
*
* Returns: 0 if success, or
* -ENODEV if cannot find a channel with specified ID,
* -EIO if channel is not in CONNECTED state,
* -ENOMEM if channel RX queue is full (packet discarded)
*/
static int rio_rx_data_handler(struct cm_dev *cm, void *buf)
{
struct rio_ch_chan_hdr *hdr;
struct rio_channel *ch;
hdr = buf;
riocm_debug(RX_DATA, "for ch=%d", ntohs(hdr->dst_ch));
ch = riocm_get_channel(ntohs(hdr->dst_ch));
if (!ch) {
/* Discard data message for non-existing channel */
kfree(buf);
return -ENODEV;
}
/* Place pointer to the buffer into channel's RX queue */
spin_lock(&ch->lock);
if (ch->state != RIO_CM_CONNECTED) {
/* Channel is not ready to receive data, discard a packet */
riocm_debug(RX_DATA, "ch=%d is in wrong state=%d",
ch->id, ch->state);
spin_unlock(&ch->lock);
kfree(buf);
riocm_put_channel(ch);
return -EIO;
}
if (ch->rx_ring.count == RIOCM_RX_RING_SIZE) {
/* If RX ring is full, discard a packet */
riocm_debug(RX_DATA, "ch=%d is full", ch->id);
spin_unlock(&ch->lock);
kfree(buf);
riocm_put_channel(ch);
return -ENOMEM;
}
ch->rx_ring.buf[ch->rx_ring.head] = buf;
ch->rx_ring.head++;
ch->rx_ring.count++;
ch->rx_ring.head %= RIOCM_RX_RING_SIZE;
complete(&ch->comp);
spin_unlock(&ch->lock);
riocm_put_channel(ch);
return 0;
}
/*
* rio_ibmsg_handler - inbound message packet handler
*/
static void rio_ibmsg_handler(struct work_struct *work)
{
struct cm_dev *cm = container_of(work, struct cm_dev, rx_work);
void *data;
struct rio_ch_chan_hdr *hdr;
if (!rio_mport_is_running(cm->mport))
return;
while (1) {
mutex_lock(&cm->rx_lock);
data = riocm_rx_get_msg(cm);
if (data)
riocm_rx_fill(cm, 1);
mutex_unlock(&cm->rx_lock);
if (data == NULL)
break;
hdr = data;
if (hdr->bhdr.type != RIO_CM_CHAN) {
/* For now simply discard packets other than channel */
riocm_error("Unsupported TYPE code (0x%x). Msg dropped",
hdr->bhdr.type);
kfree(data);
continue;
}
/* Process a channel message */
if (hdr->ch_op == CM_DATA_MSG)
rio_rx_data_handler(cm, data);
else
rio_cm_handler(cm, data);
}
}
static void riocm_inb_msg_event(struct rio_mport *mport, void *dev_id,
int mbox, int slot)
{
struct cm_dev *cm = dev_id;
if (rio_mport_is_running(cm->mport) && !work_pending(&cm->rx_work))
queue_work(cm->rx_wq, &cm->rx_work);
}
/*
* rio_txcq_handler - TX completion handler
* @cm: cm_dev object
* @slot: TX queue slot
*
* TX completion handler also ensures that pending request packets are placed
* into transmit queue as soon as a free slot becomes available. This is done
* to give higher priority to request packets during high intensity data flow.
*/
static void rio_txcq_handler(struct cm_dev *cm, int slot)
{
int ack_slot;
/* ATTN: Add TX completion notification if/when direct buffer
* transfer is implemented. At this moment only correct tracking
* of tx_count is important.
*/
riocm_debug(TX_EVENT, "for mport_%d slot %d tx_cnt %d",
cm->mport->id, slot, cm->tx_cnt);
spin_lock(&cm->tx_lock);
ack_slot = cm->tx_ack_slot;
if (ack_slot == slot)
riocm_debug(TX_EVENT, "slot == ack_slot");
while (cm->tx_cnt && ((ack_slot != slot) ||
(cm->tx_cnt == RIOCM_TX_RING_SIZE))) {
cm->tx_buf[ack_slot] = NULL;
++ack_slot;
ack_slot &= (RIOCM_TX_RING_SIZE - 1);
cm->tx_cnt--;
}
if (cm->tx_cnt < 0 || cm->tx_cnt > RIOCM_TX_RING_SIZE)
riocm_error("tx_cnt %d out of sync", cm->tx_cnt);
WARN_ON((cm->tx_cnt < 0) || (cm->tx_cnt > RIOCM_TX_RING_SIZE));
cm->tx_ack_slot = ack_slot;
/*
* If there are pending requests, insert them into transmit queue
*/
if (!list_empty(&cm->tx_reqs) && (cm->tx_cnt < RIOCM_TX_RING_SIZE)) {
struct tx_req *req, *_req;
int rc;
list_for_each_entry_safe(req, _req, &cm->tx_reqs, node) {
list_del(&req->node);
cm->tx_buf[cm->tx_slot] = req->buffer;
rc = rio_add_outb_message(cm->mport, req->rdev, cmbox,
req->buffer, req->len);
kfree(req->buffer);
kfree(req);
++cm->tx_cnt;
++cm->tx_slot;
cm->tx_slot &= (RIOCM_TX_RING_SIZE - 1);
if (cm->tx_cnt == RIOCM_TX_RING_SIZE)
break;
}
}
spin_unlock(&cm->tx_lock);
}
static void riocm_outb_msg_event(struct rio_mport *mport, void *dev_id,
int mbox, int slot)
{
struct cm_dev *cm = dev_id;
if (cm && rio_mport_is_running(cm->mport))
rio_txcq_handler(cm, slot);
}
static int riocm_queue_req(struct cm_dev *cm, struct rio_dev *rdev,
void *buffer, size_t len)
{
unsigned long flags;
struct tx_req *treq;
treq = kzalloc(sizeof(*treq), GFP_KERNEL);
if (treq == NULL)
return -ENOMEM;
treq->rdev = rdev;
treq->buffer = buffer;
treq->len = len;
spin_lock_irqsave(&cm->tx_lock, flags);
list_add_tail(&treq->node, &cm->tx_reqs);
spin_unlock_irqrestore(&cm->tx_lock, flags);
return 0;
}
/*
* riocm_post_send - helper function that places packet into msg TX queue
* @cm: cm_dev object
* @rdev: target RapidIO device object (required by outbound msg interface)
* @buffer: pointer to a packet buffer to send
* @len: length of data to transfer
* @req: request priority flag
*
* Returns: 0 if success, or error code otherwise.
*/
static int riocm_post_send(struct cm_dev *cm, struct rio_dev *rdev,
void *buffer, size_t len)
{
int rc;
unsigned long flags;
spin_lock_irqsave(&cm->tx_lock, flags);
if (cm->mport == NULL) {
rc = -ENODEV;
goto err_out;
}
if (cm->tx_cnt == RIOCM_TX_RING_SIZE) {
riocm_debug(TX, "Tx Queue is full");
rc = -EBUSY;
goto err_out;
}
cm->tx_buf[cm->tx_slot] = buffer;
rc = rio_add_outb_message(cm->mport, rdev, cmbox, buffer, len);
riocm_debug(TX, "Add buf@%p destid=%x tx_slot=%d tx_cnt=%d",
buffer, rdev->destid, cm->tx_slot, cm->tx_cnt);
++cm->tx_cnt;
++cm->tx_slot;
cm->tx_slot &= (RIOCM_TX_RING_SIZE - 1);
err_out:
spin_unlock_irqrestore(&cm->tx_lock, flags);
return rc;
}
/*
* riocm_ch_send - sends a data packet to a remote device
* @ch_id: local channel ID
* @buf: pointer to a data buffer to send (including CM header)
* @len: length of data to transfer (including CM header)
*
* ATTN: ASSUMES THAT THE HEADER SPACE IS RESERVED PART OF THE DATA PACKET
*
* Returns: 0 if success, or
* -EINVAL if one or more input parameters is/are not valid,
* -ENODEV if cannot find a channel with specified ID,
* -EAGAIN if a channel is not in CONNECTED state,
* + error codes returned by HW send routine.
*/
static int riocm_ch_send(u16 ch_id, void *buf, int len)
{
struct rio_channel *ch;
struct rio_ch_chan_hdr *hdr;
int ret;
if (buf == NULL || ch_id == 0 || len == 0 || len > RIO_MAX_MSG_SIZE)
return -EINVAL;
ch = riocm_get_channel(ch_id);
if (!ch) {
riocm_error("%s(%d) ch_%d not found", current->comm,
task_pid_nr(current), ch_id);
return -ENODEV;
}
if (!riocm_cmp(ch, RIO_CM_CONNECTED)) {
ret = -EAGAIN;
goto err_out;
}
/*
* Fill buffer header section with corresponding channel data
*/
hdr = buf;
hdr->bhdr.src_id = htonl(ch->loc_destid);
hdr->bhdr.dst_id = htonl(ch->rem_destid);
hdr->bhdr.src_mbox = cmbox;
hdr->bhdr.dst_mbox = cmbox;
hdr->bhdr.type = RIO_CM_CHAN;
hdr->ch_op = CM_DATA_MSG;
hdr->dst_ch = htons(ch->rem_channel);
hdr->src_ch = htons(ch->id);
hdr->msg_len = htons((u16)len);
/* ATTN: the function call below relies on the fact that underlying
* HW-specific add_outb_message() routine copies TX data into its own
* internal transfer buffer (true for all RIONET compatible mport
* drivers). Must be reviewed if mport driver uses the buffer directly.
*/
ret = riocm_post_send(ch->cmdev, ch->rdev, buf, len);
if (ret)
riocm_debug(TX, "ch %d send_err=%d", ch->id, ret);
err_out:
riocm_put_channel(ch);
return ret;
}
static int riocm_ch_free_rxbuf(struct rio_channel *ch, void *buf)
{
int i, ret = -EINVAL;
spin_lock_bh(&ch->lock);
for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
if (ch->rx_ring.inuse[i] == buf) {
ch->rx_ring.inuse[i] = NULL;
ch->rx_ring.inuse_cnt--;
ret = 0;
break;
}
}
spin_unlock_bh(&ch->lock);
if (!ret)
kfree(buf);
return ret;
}
/*
* riocm_ch_receive - fetch a data packet received for the specified channel
* @ch: local channel ID
* @buf: pointer to a packet buffer
* @timeout: timeout to wait for incoming packet (in jiffies)
*
* Returns: 0 and valid buffer pointer if success, or NULL pointer and one of:
* -EAGAIN if a channel is not in CONNECTED state,
* -ENOMEM if in-use tracking queue is full,
* -ETIME if wait timeout expired,
* -EINTR if wait was interrupted.
*/
static int riocm_ch_receive(struct rio_channel *ch, void **buf, long timeout)
{
void *rxmsg = NULL;
int i, ret = 0;
long wret;
if (!riocm_cmp(ch, RIO_CM_CONNECTED)) {
ret = -EAGAIN;
goto out;
}
if (ch->rx_ring.inuse_cnt == RIOCM_RX_RING_SIZE) {
/* If we do not have entries to track buffers given to upper
* layer, reject request.
*/
ret = -ENOMEM;
goto out;
}
wret = wait_for_completion_interruptible_timeout(&ch->comp, timeout);
riocm_debug(WAIT, "wait on %d returned %ld", ch->id, wret);
if (!wret)
ret = -ETIME;
else if (wret == -ERESTARTSYS)
ret = -EINTR;
else
ret = riocm_cmp(ch, RIO_CM_CONNECTED) ? 0 : -ECONNRESET;
if (ret)
goto out;
spin_lock_bh(&ch->lock);
rxmsg = ch->rx_ring.buf[ch->rx_ring.tail];
ch->rx_ring.buf[ch->rx_ring.tail] = NULL;
ch->rx_ring.count--;
ch->rx_ring.tail++;
ch->rx_ring.tail %= RIOCM_RX_RING_SIZE;
ret = -ENOMEM;
for (i = 0; i < RIOCM_RX_RING_SIZE; i++) {
if (ch->rx_ring.inuse[i] == NULL) {
ch->rx_ring.inuse[i] = rxmsg;
ch->rx_ring.inuse_cnt++;
ret = 0;
break;
}
}
if (ret) {
/* We have no entry to store pending message: drop it */
kfree(rxmsg);
rxmsg = NULL;
}
spin_unlock_bh(&ch->lock);
out:
*buf = rxmsg;
return ret;
}
/*
* riocm_ch_connect - sends a connect request to a remote device
* @loc_ch: local channel ID
* @cm: CM device to send connect request
* @peer: target RapidIO device
* @rem_ch: remote channel ID
*
* Returns: 0 if success, or
* -EINVAL if the channel is not in IDLE state,
* -EAGAIN if no connection request available immediately,
* -ETIME if ACK response timeout expired,
* -EINTR if wait for response was interrupted.
*/
static int riocm_ch_connect(u16 loc_ch, struct cm_dev *cm,
struct cm_peer *peer, u16 rem_ch)
{
struct rio_channel *ch = NULL;
struct rio_ch_chan_hdr *hdr;
int ret;
long wret;
ch = riocm_get_channel(loc_ch);
if (!ch)
return -ENODEV;
if (!riocm_cmp_exch(ch, RIO_CM_IDLE, RIO_CM_CONNECT)) {
ret = -EINVAL;
goto conn_done;
}
ch->cmdev = cm;
ch->rdev = peer->rdev;
ch->context = NULL;
ch->loc_destid = cm->mport->host_deviceid;
ch->rem_channel = rem_ch;
/*
* Send connect request to the remote RapidIO device
*/
hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
if (hdr == NULL) {
ret = -ENOMEM;
goto conn_done;
}
hdr->bhdr.src_id = htonl(ch->loc_destid);
hdr->bhdr.dst_id = htonl(peer->rdev->destid);
hdr->bhdr.src_mbox = cmbox;
hdr->bhdr.dst_mbox = cmbox;
hdr->bhdr.type = RIO_CM_CHAN;
hdr->ch_op = CM_CONN_REQ;
hdr->dst_ch = htons(rem_ch);
hdr->src_ch = htons(loc_ch);
/* ATTN: the function call below relies on the fact that underlying
* HW-specific add_outb_message() routine copies TX data into its
* internal transfer buffer. Must be reviewed if mport driver uses
* this buffer directly.
*/
ret = riocm_post_send(cm, peer->rdev, hdr, sizeof(*hdr));