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android-kvm / linux / 8b402c929d21a18e9a228d4ad6f0a076577cd63c / . / drivers / staging / fwserial / fwserial.c
blob: 73deae3cd9ebf6178c73c6309aa7ca125e0d2184 [file] [log] [blame]
/*
* FireWire Serial driver
*
* Copyright (C) 2012 Peter Hurley <peter@hurleysoftware.com>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/rculist.h>
#include <linux/workqueue.h>
#include <linux/ratelimit.h>
#include <linux/bug.h>
#include <linux/uaccess.h>
#include "fwserial.h"
#define be32_to_u64(hi, lo) ((u64)be32_to_cpu(hi) << 32 | be32_to_cpu(lo))
#define LINUX_VENDOR_ID 0xd00d1eU /* same id used in card root directory */
#define FWSERIAL_VERSION 0x00e81cU /* must be unique within LINUX_VENDOR_ID */
/* configurable options */
static int num_ttys = 4; /* # of std ttys to create per fw_card */
/* - doubles as loopback port index */
static bool auto_connect = true; /* try to VIRT_CABLE to every peer */
static bool create_loop_dev = true; /* create a loopback device for each card */
module_param_named(ttys, num_ttys, int, S_IRUGO | S_IWUSR);
module_param_named(auto, auto_connect, bool, S_IRUGO | S_IWUSR);
module_param_named(loop, create_loop_dev, bool, S_IRUGO | S_IWUSR);
/*
* Threshold below which the tty is woken for writing
* - should be equal to WAKEUP_CHARS in drivers/tty/n_tty.c because
* even if the writer is woken, n_tty_poll() won't set POLLOUT until
* our fifo is below this level
*/
#define WAKEUP_CHARS 256
/**
* fwserial_list: list of every fw_serial created for each fw_card
* See discussion in fwserial_probe.
*/
static LIST_HEAD(fwserial_list);
static DEFINE_MUTEX(fwserial_list_mutex);
/**
* port_table: array of tty ports allocated to each fw_card
*
* tty ports are allocated during probe when an fw_serial is first
* created for a given fw_card. Ports are allocated in a contiguous block,
* each block consisting of 'num_ports' ports.
*/
static struct fwtty_port *port_table[MAX_TOTAL_PORTS];
static DEFINE_MUTEX(port_table_lock);
static bool port_table_corrupt;
#define FWTTY_INVALID_INDEX MAX_TOTAL_PORTS
#define loop_idx(port) (((port)->index) / num_ports)
#define table_idx(loop) ((loop) * num_ports + num_ttys)
/* total # of tty ports created per fw_card */
static int num_ports;
/* slab used as pool for struct fwtty_transactions */
static struct kmem_cache *fwtty_txn_cache;
struct tty_driver *fwtty_driver;
static struct tty_driver *fwloop_driver;
static struct dentry *fwserial_debugfs;
struct fwtty_transaction;
typedef void (*fwtty_transaction_cb)(struct fw_card *card, int rcode,
void *data, size_t length,
struct fwtty_transaction *txn);
struct fwtty_transaction {
struct fw_transaction fw_txn;
fwtty_transaction_cb callback;
struct fwtty_port *port;
union {
struct dma_pending dma_pended;
};
};
#define to_device(a, b) (a->b)
#define fwtty_err(p, fmt, ...) \
dev_err(to_device(p, device), fmt, ##__VA_ARGS__)
#define fwtty_info(p, fmt, ...) \
dev_info(to_device(p, device), fmt, ##__VA_ARGS__)
#define fwtty_notice(p, fmt, ...) \
dev_notice(to_device(p, device), fmt, ##__VA_ARGS__)
#define fwtty_dbg(p, fmt, ...) \
dev_dbg(to_device(p, device), "%s: " fmt, __func__, ##__VA_ARGS__)
#define fwtty_err_ratelimited(p, fmt, ...) \
dev_err_ratelimited(to_device(p, device), fmt, ##__VA_ARGS__)
#ifdef DEBUG
static inline void debug_short_write(struct fwtty_port *port, int c, int n)
{
int avail;
if (n < c) {
spin_lock_bh(&port->lock);
avail = dma_fifo_avail(&port->tx_fifo);
spin_unlock_bh(&port->lock);
fwtty_dbg(port, "short write: avail:%d req:%d wrote:%d\n",
avail, c, n);
}
}
#else
#define debug_short_write(port, c, n)
#endif
static struct fwtty_peer *__fwserial_peer_by_node_id(struct fw_card *card,
int generation, int id);
#ifdef FWTTY_PROFILING
static void fwtty_profile_fifo(struct fwtty_port *port, unsigned *stat)
{
spin_lock_bh(&port->lock);
fwtty_profile_data(stat, dma_fifo_avail(&port->tx_fifo));
spin_unlock_bh(&port->lock);
}
static void fwtty_dump_profile(struct seq_file *m, struct stats *stats)
{
/* for each stat, print sum of 0 to 2^k, then individually */
int k = 4;
unsigned sum;
int j;
char t[10];
snprintf(t, 10, "< %d", 1 << k);
seq_printf(m, "\n%14s %6s", " ", t);
for (j = k + 1; j < DISTRIBUTION_MAX_INDEX; ++j)
seq_printf(m, "%6d", 1 << j);
++k;
for (j = 0, sum = 0; j <= k; ++j)
sum += stats->reads[j];
seq_printf(m, "\n%14s: %6d", "reads", sum);
for (j = k + 1; j <= DISTRIBUTION_MAX_INDEX; ++j)
seq_printf(m, "%6d", stats->reads[j]);
for (j = 0, sum = 0; j <= k; ++j)
sum += stats->writes[j];
seq_printf(m, "\n%14s: %6d", "writes", sum);
for (j = k + 1; j <= DISTRIBUTION_MAX_INDEX; ++j)
seq_printf(m, "%6d", stats->writes[j]);
for (j = 0, sum = 0; j <= k; ++j)
sum += stats->txns[j];
seq_printf(m, "\n%14s: %6d", "txns", sum);
for (j = k + 1; j <= DISTRIBUTION_MAX_INDEX; ++j)
seq_printf(m, "%6d", stats->txns[j]);
for (j = 0, sum = 0; j <= k; ++j)
sum += stats->unthrottle[j];
seq_printf(m, "\n%14s: %6d", "avail @ unthr", sum);
for (j = k + 1; j <= DISTRIBUTION_MAX_INDEX; ++j)
seq_printf(m, "%6d", stats->unthrottle[j]);
}
#else
#define fwtty_profile_fifo(port, stat)
#define fwtty_dump_profile(m, stats)
#endif
/*
* Returns the max receive packet size for the given node
* Devices which are OHCI v1.0/ v1.1/ v1.2-draft or RFC 2734 compliant
* are required by specification to support max_rec of 8 (512 bytes) or more.
*/
static inline int device_max_receive(struct fw_device *fw_device)
{
/* see IEEE 1394-2008 table 8-8 */
return min(2 << fw_device->max_rec, 4096);
}
static void fwtty_log_tx_error(struct fwtty_port *port, int rcode)
{
switch (rcode) {
case RCODE_SEND_ERROR:
fwtty_err_ratelimited(port, "card busy\n");
break;
case RCODE_ADDRESS_ERROR:
fwtty_err_ratelimited(port, "bad unit addr or write length\n");
break;
case RCODE_DATA_ERROR:
fwtty_err_ratelimited(port, "failed rx\n");
break;
case RCODE_NO_ACK:
fwtty_err_ratelimited(port, "missing ack\n");
break;
case RCODE_BUSY:
fwtty_err_ratelimited(port, "remote busy\n");
break;
default:
fwtty_err_ratelimited(port, "failed tx: %d\n", rcode);
}
}
static void fwtty_txn_constructor(void *this)
{
struct fwtty_transaction *txn = this;
init_timer(&txn->fw_txn.split_timeout_timer);
}
static void fwtty_common_callback(struct fw_card *card, int rcode,
void *payload, size_t len, void *cb_data)
{
struct fwtty_transaction *txn = cb_data;
struct fwtty_port *port = txn->port;
if (port && rcode != RCODE_COMPLETE)
fwtty_log_tx_error(port, rcode);
if (txn->callback)
txn->callback(card, rcode, payload, len, txn);
kmem_cache_free(fwtty_txn_cache, txn);
}
static int fwtty_send_data_async(struct fwtty_peer *peer, int tcode,
unsigned long long addr, void *payload,
size_t len, fwtty_transaction_cb callback,
struct fwtty_port *port)
{
struct fwtty_transaction *txn;
int generation;
txn = kmem_cache_alloc(fwtty_txn_cache, GFP_ATOMIC);
if (!txn)
return -ENOMEM;
txn->callback = callback;
txn->port = port;
generation = peer->generation;
smp_rmb();
fw_send_request(peer->serial->card, &txn->fw_txn, tcode,
peer->node_id, generation, peer->speed, addr, payload,
len, fwtty_common_callback, txn);
return 0;
}
static void fwtty_send_txn_async(struct fwtty_peer *peer,
struct fwtty_transaction *txn, int tcode,
unsigned long long addr, void *payload,
size_t len, fwtty_transaction_cb callback,
struct fwtty_port *port)
{
int generation;
txn->callback = callback;
txn->port = port;
generation = peer->generation;
smp_rmb();
fw_send_request(peer->serial->card, &txn->fw_txn, tcode,
peer->node_id, generation, peer->speed, addr, payload,
len, fwtty_common_callback, txn);
}
static void __fwtty_restart_tx(struct fwtty_port *port)
{
int len, avail;
len = dma_fifo_out_level(&port->tx_fifo);
if (len)
schedule_delayed_work(&port->drain, 0);
avail = dma_fifo_avail(&port->tx_fifo);
fwtty_dbg(port, "fifo len: %d avail: %d\n", len, avail);
}
static void fwtty_restart_tx(struct fwtty_port *port)
{
spin_lock_bh(&port->lock);
__fwtty_restart_tx(port);
spin_unlock_bh(&port->lock);
}
/**
* fwtty_update_port_status - decodes & dispatches line status changes
*
* Note: in loopback, the port->lock is being held. Only use functions that
* don't attempt to reclaim the port->lock.
*/
static void fwtty_update_port_status(struct fwtty_port *port, unsigned status)
{
unsigned delta;
struct tty_struct *tty;
/* simulated LSR/MSR status from remote */
status &= ~MCTRL_MASK;
delta = (port->mstatus ^ status) & ~MCTRL_MASK;
delta &= ~(status & TIOCM_RNG);
port->mstatus = status;
if (delta & TIOCM_RNG)
++port->icount.rng;
if (delta & TIOCM_DSR)
++port->icount.dsr;
if (delta & TIOCM_CAR)
++port->icount.dcd;
if (delta & TIOCM_CTS)
++port->icount.cts;
fwtty_dbg(port, "status: %x delta: %x\n", status, delta);
if (delta & TIOCM_CAR) {
tty = tty_port_tty_get(&port->port);
if (tty && !C_CLOCAL(tty)) {
if (status & TIOCM_CAR)
wake_up_interruptible(&port->port.open_wait);
else
schedule_work(&port->hangup);
}
tty_kref_put(tty);
}
if (delta & TIOCM_CTS) {
tty = tty_port_tty_get(&port->port);
if (tty && C_CRTSCTS(tty)) {
if (tty->hw_stopped) {
if (status & TIOCM_CTS) {
tty->hw_stopped = 0;
if (port->loopback)
__fwtty_restart_tx(port);
else
fwtty_restart_tx(port);
}
} else {
if (~status & TIOCM_CTS)
tty->hw_stopped = 1;
}
}
tty_kref_put(tty);
} else if (delta & OOB_TX_THROTTLE) {
tty = tty_port_tty_get(&port->port);
if (tty) {
if (tty->hw_stopped) {
if (~status & OOB_TX_THROTTLE) {
tty->hw_stopped = 0;
if (port->loopback)
__fwtty_restart_tx(port);
else
fwtty_restart_tx(port);
}
} else {
if (status & OOB_TX_THROTTLE)
tty->hw_stopped = 1;
}
}
tty_kref_put(tty);
}
if (delta & (UART_LSR_BI << 24)) {
if (status & (UART_LSR_BI << 24)) {
port->break_last = jiffies;
schedule_delayed_work(&port->emit_breaks, 0);
} else {
/* run emit_breaks one last time (if pending) */
mod_delayed_work(system_wq, &port->emit_breaks, 0);
}
}
if (delta & (TIOCM_DSR | TIOCM_CAR | TIOCM_CTS | TIOCM_RNG))
wake_up_interruptible(&port->port.delta_msr_wait);
}
/**
* __fwtty_port_line_status - generate 'line status' for indicated port
*
* This function returns a remote 'MSR' state based on the local 'MCR' state,
* as if a null modem cable was attached. The actual status is a mangling
* of TIOCM_* bits suitable for sending to a peer's status_addr.
*
* Note: caller must be holding port lock
*/
static unsigned __fwtty_port_line_status(struct fwtty_port *port)
{
unsigned status = 0;
/* TODO: add module param to tie RNG to DTR as well */
if (port->mctrl & TIOCM_DTR)
status |= TIOCM_DSR | TIOCM_CAR;
if (port->mctrl & TIOCM_RTS)
status |= TIOCM_CTS;
if (port->mctrl & OOB_RX_THROTTLE)
status |= OOB_TX_THROTTLE;
/* emulate BRK as add'l line status */
if (port->break_ctl)
status |= UART_LSR_BI << 24;
return status;
}
/**
* __fwtty_write_port_status - send the port line status to peer
*
* Note: caller must be holding the port lock.
*/
static int __fwtty_write_port_status(struct fwtty_port *port)
{
struct fwtty_peer *peer;
int err = -ENOENT;
unsigned status = __fwtty_port_line_status(port);
rcu_read_lock();
peer = rcu_dereference(port->peer);
if (peer) {
err = fwtty_send_data_async(peer, TCODE_WRITE_QUADLET_REQUEST,
peer->status_addr, &status,
sizeof(status), NULL, port);
}
rcu_read_unlock();
return err;
}
/**
* fwtty_write_port_status - same as above but locked by port lock
*/
static int fwtty_write_port_status(struct fwtty_port *port)
{
int err;
spin_lock_bh(&port->lock);
err = __fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
return err;
}
static void fwtty_throttle_port(struct fwtty_port *port)
{
struct tty_struct *tty;
unsigned old;
tty = tty_port_tty_get(&port->port);
if (!tty)
return;
spin_lock_bh(&port->lock);
old = port->mctrl;
port->mctrl |= OOB_RX_THROTTLE;
if (C_CRTSCTS(tty))
port->mctrl &= ~TIOCM_RTS;
if (~old & OOB_RX_THROTTLE)
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
tty_kref_put(tty);
}
/**
* fwtty_do_hangup - wait for ldisc to deliver all pending rx; only then hangup
*
* When the remote has finished tx, and all in-flight rx has been received and
* and pushed to the flip buffer, the remote may close its device. This will
* drop DTR on the remote which will drop carrier here. Typically, the tty is
* hung up when carrier is dropped or lost.
*
* However, there is a race between the hang up and the line discipline
* delivering its data to the reader. A hangup will cause the ldisc to flush
* (ie., clear) the read buffer and flip buffer. Because of firewire's
* relatively high throughput, the ldisc frequently lags well behind the driver,
* resulting in lost data (which has already been received and written to
* the flip buffer) when the remote closes its end.
*
* Unfortunately, since the flip buffer offers no direct method for determining
* if it holds data, ensuring the ldisc has delivered all data is problematic.
*/
/* FIXME: drop this workaround when __tty_hangup waits for ldisc completion */
static void fwtty_do_hangup(struct work_struct *work)
{
struct fwtty_port *port = to_port(work, hangup);
struct tty_struct *tty;
schedule_timeout_uninterruptible(msecs_to_jiffies(50));
tty = tty_port_tty_get(&port->port);
if (tty)
tty_vhangup(tty);
tty_kref_put(tty);
}
static void fwtty_emit_breaks(struct work_struct *work)
{
struct fwtty_port *port = to_port(to_delayed_work(work), emit_breaks);
static const char buf[16];
unsigned long now = jiffies;
unsigned long elapsed = now - port->break_last;
int n, t, c, brk = 0;
/* generate breaks at the line rate (but at least 1) */
n = (elapsed * port->cps) / HZ + 1;
port->break_last = now;
fwtty_dbg(port, "sending %d brks\n", n);
while (n) {
t = min(n, 16);
c = tty_insert_flip_string_fixed_flag(&port->port, buf,
TTY_BREAK, t);
n -= c;
brk += c;
if (c < t)
break;
}
tty_flip_buffer_push(&port->port);
if (port->mstatus & (UART_LSR_BI << 24))
schedule_delayed_work(&port->emit_breaks, FREQ_BREAKS);
port->icount.brk += brk;
}
static int fwtty_rx(struct fwtty_port *port, unsigned char *data, size_t len)
{
int c, n = len;
unsigned lsr;
int err = 0;
fwtty_dbg(port, "%d\n", n);
fwtty_profile_data(port->stats.reads, n);
if (port->write_only) {
n = 0;
goto out;
}
/* disregard break status; breaks are generated by emit_breaks work */
lsr = (port->mstatus >> 24) & ~UART_LSR_BI;
if (port->overrun)
lsr |= UART_LSR_OE;
if (lsr & UART_LSR_OE)
++port->icount.overrun;
lsr &= port->status_mask;
if (lsr & ~port->ignore_mask & UART_LSR_OE) {
if (!tty_insert_flip_char(&port->port, 0, TTY_OVERRUN)) {
err = -EIO;
goto out;
}
}
port->overrun = false;
if (lsr & port->ignore_mask & ~UART_LSR_OE) {
/* TODO: don't drop SAK and Magic SysRq here */
n = 0;
goto out;
}
c = tty_insert_flip_string_fixed_flag(&port->port, data, TTY_NORMAL, n);
if (c > 0)
tty_flip_buffer_push(&port->port);
n -= c;
if (n) {
port->overrun = true;
err = -EIO;
fwtty_err_ratelimited(port, "flip buffer overrun\n");
} else {
/* throttle the sender if remaining flip buffer space has
* reached high watermark to avoid losing data which may be
* in-flight. Since the AR request context is 32k, that much
* data may have _already_ been acked.
*/
if (tty_buffer_space_avail(&port->port) < HIGH_WATERMARK)
fwtty_throttle_port(port);
}
out:
port->icount.rx += len;
port->stats.lost += n;
return err;
}
/**
* fwtty_port_handler - bus address handler for port reads/writes
* @parameters: fw_address_callback_t as specified by firewire core interface
*
* This handler is responsible for handling inbound read/write dma from remotes.
*/
static void fwtty_port_handler(struct fw_card *card,
struct fw_request *request,
int tcode, int destination, int source,
int generation,
unsigned long long addr,
void *data, size_t len,
void *callback_data)
{
struct fwtty_port *port = callback_data;
struct fwtty_peer *peer;
int err;
int rcode;
/* Only accept rx from the peer virtual-cabled to this port */
rcu_read_lock();
peer = __fwserial_peer_by_node_id(card, generation, source);
rcu_read_unlock();
if (!peer || peer != rcu_access_pointer(port->peer)) {
rcode = RCODE_ADDRESS_ERROR;
fwtty_err_ratelimited(port, "ignoring unauthenticated data\n");
goto respond;
}
switch (tcode) {
case TCODE_WRITE_QUADLET_REQUEST:
if (addr != port->rx_handler.offset || len != 4) {
rcode = RCODE_ADDRESS_ERROR;
} else {
fwtty_update_port_status(port, *(unsigned *)data);
rcode = RCODE_COMPLETE;
}
break;
case TCODE_WRITE_BLOCK_REQUEST:
if (addr != port->rx_handler.offset + 4 ||
len > port->rx_handler.length - 4) {
rcode = RCODE_ADDRESS_ERROR;
} else {
err = fwtty_rx(port, data, len);
switch (err) {
case 0:
rcode = RCODE_COMPLETE;
break;
case -EIO:
rcode = RCODE_DATA_ERROR;
break;
default:
rcode = RCODE_CONFLICT_ERROR;
break;
}
}
break;
default:
rcode = RCODE_TYPE_ERROR;
}
respond:
fw_send_response(card, request, rcode);
}
/**
* fwtty_tx_complete - callback for tx dma
* @data: ignored, has no meaning for write txns
* @length: ignored, has no meaning for write txns
*
* The writer must be woken here if the fifo has been emptied because it
* may have slept if chars_in_buffer was != 0
*/
static void fwtty_tx_complete(struct fw_card *card, int rcode,
void *data, size_t length,
struct fwtty_transaction *txn)
{
struct fwtty_port *port = txn->port;
int len;
fwtty_dbg(port, "rcode: %d\n", rcode);
switch (rcode) {
case RCODE_COMPLETE:
spin_lock_bh(&port->lock);
dma_fifo_out_complete(&port->tx_fifo, &txn->dma_pended);
len = dma_fifo_level(&port->tx_fifo);
spin_unlock_bh(&port->lock);
port->icount.tx += txn->dma_pended.len;
break;
default:
/* TODO: implement retries */
spin_lock_bh(&port->lock);
dma_fifo_out_complete(&port->tx_fifo, &txn->dma_pended);
len = dma_fifo_level(&port->tx_fifo);
spin_unlock_bh(&port->lock);
port->stats.dropped += txn->dma_pended.len;
}
if (len < WAKEUP_CHARS)
tty_port_tty_wakeup(&port->port);
}
static int fwtty_tx(struct fwtty_port *port, bool drain)
{
struct fwtty_peer *peer;
struct fwtty_transaction *txn;
struct tty_struct *tty;
int n, len;
tty = tty_port_tty_get(&port->port);
if (!tty)
return -ENOENT;
rcu_read_lock();
peer = rcu_dereference(port->peer);
if (!peer) {
n = -EIO;
goto out;
}
if (test_and_set_bit(IN_TX, &port->flags)) {
n = -EALREADY;
goto out;
}
/* try to write as many dma transactions out as possible */
n = -EAGAIN;
while (!tty->stopped && !tty->hw_stopped &&
!test_bit(STOP_TX, &port->flags)) {
txn = kmem_cache_alloc(fwtty_txn_cache, GFP_ATOMIC);
if (!txn) {
n = -ENOMEM;
break;
}
spin_lock_bh(&port->lock);
n = dma_fifo_out_pend(&port->tx_fifo, &txn->dma_pended);
spin_unlock_bh(&port->lock);
fwtty_dbg(port, "out: %u rem: %d\n", txn->dma_pended.len, n);
if (n < 0) {
kmem_cache_free(fwtty_txn_cache, txn);
if (n == -EAGAIN) {
++port->stats.tx_stall;
} else if (n == -ENODATA) {
fwtty_profile_data(port->stats.txns, 0);
} else {
++port->stats.fifo_errs;
fwtty_err_ratelimited(port, "fifo err: %d\n",
n);
}
break;
}
fwtty_profile_data(port->stats.txns, txn->dma_pended.len);
fwtty_send_txn_async(peer, txn, TCODE_WRITE_BLOCK_REQUEST,
peer->fifo_addr, txn->dma_pended.data,
txn->dma_pended.len, fwtty_tx_complete,
port);
++port->stats.sent;
/*
* Stop tx if the 'last view' of the fifo is empty or if
* this is the writer and there's not enough data to bother
*/
if (n == 0 || (!drain && n < WRITER_MINIMUM))
break;
}
if (n >= 0 || n == -EAGAIN || n == -ENOMEM || n == -ENODATA) {
spin_lock_bh(&port->lock);
len = dma_fifo_out_level(&port->tx_fifo);
if (len) {
unsigned long delay = (n == -ENOMEM) ? HZ : 1;
schedule_delayed_work(&port->drain, delay);
}
len = dma_fifo_level(&port->tx_fifo);
spin_unlock_bh(&port->lock);
/* wakeup the writer */
if (drain && len < WAKEUP_CHARS)
tty_wakeup(tty);
}
clear_bit(IN_TX, &port->flags);
wake_up_interruptible(&port->wait_tx);
out:
rcu_read_unlock();
tty_kref_put(tty);
return n;
}
static void fwtty_drain_tx(struct work_struct *work)
{
struct fwtty_port *port = to_port(to_delayed_work(work), drain);
fwtty_tx(port, true);
}
static void fwtty_write_xchar(struct fwtty_port *port, char ch)
{
struct fwtty_peer *peer;
++port->stats.xchars;
fwtty_dbg(port, "%02x\n", ch);
rcu_read_lock();
peer = rcu_dereference(port->peer);
if (peer) {
fwtty_send_data_async(peer, TCODE_WRITE_BLOCK_REQUEST,
peer->fifo_addr, &ch, sizeof(ch),
NULL, port);
}
rcu_read_unlock();
}
struct fwtty_port *fwtty_port_get(unsigned index)
{
struct fwtty_port *port;
if (index >= MAX_TOTAL_PORTS)
return NULL;
mutex_lock(&port_table_lock);
port = port_table[index];
if (port)
kref_get(&port->serial->kref);
mutex_unlock(&port_table_lock);
return port;
}
EXPORT_SYMBOL(fwtty_port_get);
static int fwtty_ports_add(struct fw_serial *serial)
{
int err = -EBUSY;
int i, j;
if (port_table_corrupt)
return err;
mutex_lock(&port_table_lock);
for (i = 0; i + num_ports <= MAX_TOTAL_PORTS; i += num_ports) {
if (!port_table[i]) {
for (j = 0; j < num_ports; ++i, ++j) {
serial->ports[j]->index = i;
port_table[i] = serial->ports[j];
}
err = 0;
break;
}
}
mutex_unlock(&port_table_lock);
return err;
}
static void fwserial_destroy(struct kref *kref)
{
struct fw_serial *serial = to_serial(kref, kref);
struct fwtty_port **ports = serial->ports;
int j, i = ports[0]->index;
synchronize_rcu();
mutex_lock(&port_table_lock);
for (j = 0; j < num_ports; ++i, ++j) {
port_table_corrupt |= port_table[i] != ports[j];
WARN_ONCE(port_table_corrupt, "port_table[%d]: %p != ports[%d]: %p",
i, port_table[i], j, ports[j]);
port_table[i] = NULL;
}
mutex_unlock(&port_table_lock);
for (j = 0; j < num_ports; ++j) {
fw_core_remove_address_handler(&ports[j]->rx_handler);
tty_port_destroy(&ports[j]->port);
kfree(ports[j]);
}
kfree(serial);
}
void fwtty_port_put(struct fwtty_port *port)
{
kref_put(&port->serial->kref, fwserial_destroy);
}
EXPORT_SYMBOL(fwtty_port_put);
static void fwtty_port_dtr_rts(struct tty_port *tty_port, int on)
{
struct fwtty_port *port = to_port(tty_port, port);
fwtty_dbg(port, "on/off: %d\n", on);
spin_lock_bh(&port->lock);
/* Don't change carrier state if this is a console */
if (!port->port.console) {
if (on)
port->mctrl |= TIOCM_DTR | TIOCM_RTS;
else
port->mctrl &= ~(TIOCM_DTR | TIOCM_RTS);
}
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
}
/**
* fwtty_port_carrier_raised: required tty_port operation
*
* This port operation is polled after a tty has been opened and is waiting for
* carrier detect -- see drivers/tty/tty_port:tty_port_block_til_ready().
*/
static int fwtty_port_carrier_raised(struct tty_port *tty_port)
{
struct fwtty_port *port = to_port(tty_port, port);
int rc;
rc = (port->mstatus & TIOCM_CAR);
fwtty_dbg(port, "%d\n", rc);
return rc;
}
static unsigned set_termios(struct fwtty_port *port, struct tty_struct *tty)
{
unsigned baud, frame;
baud = tty_termios_baud_rate(&tty->termios);
tty_termios_encode_baud_rate(&tty->termios, baud, baud);
/* compute bit count of 2 frames */
frame = 12 + ((C_CSTOPB(tty)) ? 4 : 2) + ((C_PARENB(tty)) ? 2 : 0);
switch (C_CSIZE(tty)) {
case CS5:
frame -= (C_CSTOPB(tty)) ? 1 : 0;
break;
case CS6:
frame += 2;
break;
case CS7:
frame += 4;
break;
case CS8:
frame += 6;
break;
}
port->cps = (baud << 1) / frame;
port->status_mask = UART_LSR_OE;
if (_I_FLAG(tty, BRKINT | PARMRK))
port->status_mask |= UART_LSR_BI;
port->ignore_mask = 0;
if (I_IGNBRK(tty)) {
port->ignore_mask |= UART_LSR_BI;
if (I_IGNPAR(tty))
port->ignore_mask |= UART_LSR_OE;
}
port->write_only = !C_CREAD(tty);
/* turn off echo and newline xlat if loopback */
if (port->loopback) {
tty->termios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHOKE |
ECHONL | ECHOPRT | ECHOCTL);
tty->termios.c_oflag &= ~ONLCR;
}
return baud;
}
static int fwtty_port_activate(struct tty_port *tty_port,
struct tty_struct *tty)
{
struct fwtty_port *port = to_port(tty_port, port);
unsigned baud;
int err;
set_bit(TTY_IO_ERROR, &tty->flags);
err = dma_fifo_alloc(&port->tx_fifo, FWTTY_PORT_TXFIFO_LEN,
cache_line_size(),
port->max_payload,
FWTTY_PORT_MAX_PEND_DMA,
GFP_KERNEL);
if (err)
return err;
spin_lock_bh(&port->lock);
baud = set_termios(port, tty);
/* if console, don't change carrier state */
if (!port->port.console) {
port->mctrl = 0;
if (baud != 0)
port->mctrl = TIOCM_DTR | TIOCM_RTS;
}
if (C_CRTSCTS(tty) && ~port->mstatus & TIOCM_CTS)
tty->hw_stopped = 1;
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
clear_bit(TTY_IO_ERROR, &tty->flags);
return 0;
}
/**
* fwtty_port_shutdown
*
* Note: the tty port core ensures this is not the console and
* manages TTY_IO_ERROR properly
*/
static void fwtty_port_shutdown(struct tty_port *tty_port)
{
struct fwtty_port *port = to_port(tty_port, port);
/* TODO: cancel outstanding transactions */
cancel_delayed_work_sync(&port->emit_breaks);
cancel_delayed_work_sync(&port->drain);
spin_lock_bh(&port->lock);
port->flags = 0;
port->break_ctl = 0;
port->overrun = 0;
__fwtty_write_port_status(port);
dma_fifo_free(&port->tx_fifo);
spin_unlock_bh(&port->lock);
}
static int fwtty_open(struct tty_struct *tty, struct file *fp)
{
struct fwtty_port *port = tty->driver_data;
return tty_port_open(&port->port, tty, fp);
}
static void fwtty_close(struct tty_struct *tty, struct file *fp)
{
struct fwtty_port *port = tty->driver_data;
tty_port_close(&port->port, tty, fp);
}
static void fwtty_hangup(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
tty_port_hangup(&port->port);
}
static void fwtty_cleanup(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
tty->driver_data = NULL;
fwtty_port_put(port);
}
static int fwtty_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct fwtty_port *port = fwtty_port_get(tty->index);
int err;
err = tty_standard_install(driver, tty);
if (!err)
tty->driver_data = port;
else
fwtty_port_put(port);
return err;
}
static int fwloop_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct fwtty_port *port = fwtty_port_get(table_idx(tty->index));
int err;
err = tty_standard_install(driver, tty);
if (!err)
tty->driver_data = port;
else
fwtty_port_put(port);
return err;
}
static int fwtty_write(struct tty_struct *tty, const unsigned char *buf, int c)
{
struct fwtty_port *port = tty->driver_data;
int n, len;
fwtty_dbg(port, "%d\n", c);
fwtty_profile_data(port->stats.writes, c);
spin_lock_bh(&port->lock);
n = dma_fifo_in(&port->tx_fifo, buf, c);
len = dma_fifo_out_level(&port->tx_fifo);
if (len < DRAIN_THRESHOLD)
schedule_delayed_work(&port->drain, 1);
spin_unlock_bh(&port->lock);
if (len >= DRAIN_THRESHOLD)
fwtty_tx(port, false);
debug_short_write(port, c, n);
return (n < 0) ? 0 : n;
}
static int fwtty_write_room(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
int n;
spin_lock_bh(&port->lock);
n = dma_fifo_avail(&port->tx_fifo);
spin_unlock_bh(&port->lock);
fwtty_dbg(port, "%d\n", n);
return n;
}
static int fwtty_chars_in_buffer(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
int n;
spin_lock_bh(&port->lock);
n = dma_fifo_level(&port->tx_fifo);
spin_unlock_bh(&port->lock);
fwtty_dbg(port, "%d\n", n);
return n;
}
static void fwtty_send_xchar(struct tty_struct *tty, char ch)
{
struct fwtty_port *port = tty->driver_data;
fwtty_dbg(port, "%02x\n", ch);
fwtty_write_xchar(port, ch);
}
static void fwtty_throttle(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
/*
* Ignore throttling (but not unthrottling).
* It only makes sense to throttle when data will no longer be
* accepted by the tty flip buffer. For example, it is
* possible for received data to overflow the tty buffer long
* before the line discipline ever has a chance to throttle the driver.
* Additionally, the driver may have already completed the I/O
* but the tty buffer is still emptying, so the line discipline is
* throttling and unthrottling nothing.
*/
++port->stats.throttled;
}
static void fwtty_unthrottle(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
fwtty_dbg(port, "CRTSCTS: %d\n", (C_CRTSCTS(tty) != 0));
fwtty_profile_fifo(port, port->stats.unthrottle);
spin_lock_bh(&port->lock);
port->mctrl &= ~OOB_RX_THROTTLE;
if (C_CRTSCTS(tty))
port->mctrl |= TIOCM_RTS;
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
}
static int check_msr_delta(struct fwtty_port *port, unsigned long mask,
struct async_icount *prev)
{
struct async_icount now;
int delta;
now = port->icount;
delta = ((mask & TIOCM_RNG && prev->rng != now.rng) ||
(mask & TIOCM_DSR && prev->dsr != now.dsr) ||
(mask & TIOCM_CAR && prev->dcd != now.dcd) ||
(mask & TIOCM_CTS && prev->cts != now.cts));
*prev = now;
return delta;
}
static int wait_msr_change(struct fwtty_port *port, unsigned long mask)
{
struct async_icount prev;
prev = port->icount;
return wait_event_interruptible(port->port.delta_msr_wait,
check_msr_delta(port, mask, &prev));
}
static int get_serial_info(struct fwtty_port *port,
struct serial_struct __user *info)
{
struct serial_struct tmp;
memset(&tmp, 0, sizeof(tmp));
tmp.type = PORT_UNKNOWN;
tmp.line = port->port.tty->index;
tmp.flags = port->port.flags;
tmp.xmit_fifo_size = FWTTY_PORT_TXFIFO_LEN;
tmp.baud_base = 400000000;
tmp.close_delay = port->port.close_delay;
return (copy_to_user(info, &tmp, sizeof(*info))) ? -EFAULT : 0;
}
static int set_serial_info(struct fwtty_port *port,
struct serial_struct __user *info)
{
struct serial_struct tmp;
if (copy_from_user(&tmp, info, sizeof(tmp)))
return -EFAULT;
if (tmp.irq != 0 || tmp.port != 0 || tmp.custom_divisor != 0 ||
tmp.baud_base != 400000000)
return -EPERM;
if (!capable(CAP_SYS_ADMIN)) {
if (((tmp.flags & ~ASYNC_USR_MASK) !=
(port->port.flags & ~ASYNC_USR_MASK)))
return -EPERM;
} else {
port->port.close_delay = tmp.close_delay * HZ / 100;
}
return 0;
}
static int fwtty_ioctl(struct tty_struct *tty, unsigned cmd,
unsigned long arg)
{
struct fwtty_port *port = tty->driver_data;
int err;
switch (cmd) {
case TIOCGSERIAL:
mutex_lock(&port->port.mutex);
err = get_serial_info(port, (void __user *)arg);
mutex_unlock(&port->port.mutex);
break;
case TIOCSSERIAL:
mutex_lock(&port->port.mutex);
err = set_serial_info(port, (void __user *)arg);
mutex_unlock(&port->port.mutex);
break;
case TIOCMIWAIT:
err = wait_msr_change(port, arg);
break;
default:
err = -ENOIOCTLCMD;
}
return err;
}
static void fwtty_set_termios(struct tty_struct *tty, struct ktermios *old)
{
struct fwtty_port *port = tty->driver_data;
unsigned baud;
spin_lock_bh(&port->lock);
baud = set_termios(port, tty);
if ((baud == 0) && (old->c_cflag & CBAUD)) {
port->mctrl &= ~(TIOCM_DTR | TIOCM_RTS);
} else if ((baud != 0) && !(old->c_cflag & CBAUD)) {
if (C_CRTSCTS(tty) || !test_bit(TTY_THROTTLED, &tty->flags))
port->mctrl |= TIOCM_DTR | TIOCM_RTS;
else
port->mctrl |= TIOCM_DTR;
}
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
if (old->c_cflag & CRTSCTS) {
if (!C_CRTSCTS(tty)) {
tty->hw_stopped = 0;
fwtty_restart_tx(port);
}
} else if (C_CRTSCTS(tty) && ~port->mstatus & TIOCM_CTS) {
tty->hw_stopped = 1;
}
}
/**
* fwtty_break_ctl - start/stop sending breaks
*
* Signals the remote to start or stop generating simulated breaks.
* First, stop dequeueing from the fifo and wait for writer/drain to leave tx
* before signalling the break line status. This guarantees any pending rx will
* be queued to the line discipline before break is simulated on the remote.
* Conversely, turning off break_ctl requires signalling the line status change,
* then enabling tx.
*/
static int fwtty_break_ctl(struct tty_struct *tty, int state)
{
struct fwtty_port *port = tty->driver_data;
long ret;
fwtty_dbg(port, "%d\n", state);
if (state == -1) {
set_bit(STOP_TX, &port->flags);
ret = wait_event_interruptible_timeout(port->wait_tx,
!test_bit(IN_TX, &port->flags),
10);
if (ret == 0 || ret == -ERESTARTSYS) {
clear_bit(STOP_TX, &port->flags);
fwtty_restart_tx(port);
return -EINTR;
}
}
spin_lock_bh(&port->lock);
port->break_ctl = (state == -1);
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
if (state == 0) {
spin_lock_bh(&port->lock);
dma_fifo_reset(&port->tx_fifo);
clear_bit(STOP_TX, &port->flags);
spin_unlock_bh(&port->lock);
}
return 0;
}
static int fwtty_tiocmget(struct tty_struct *tty)
{
struct fwtty_port *port = tty->driver_data;
unsigned tiocm;
spin_lock_bh(&port->lock);
tiocm = (port->mctrl & MCTRL_MASK) | (port->mstatus & ~MCTRL_MASK);
spin_unlock_bh(&port->lock);
fwtty_dbg(port, "%x\n", tiocm);
return tiocm;
}
static int fwtty_tiocmset(struct tty_struct *tty, unsigned set, unsigned clear)
{
struct fwtty_port *port = tty->driver_data;
fwtty_dbg(port, "set: %x clear: %x\n", set, clear);
/* TODO: simulate loopback if TIOCM_LOOP set */
spin_lock_bh(&port->lock);
port->mctrl &= ~(clear & MCTRL_MASK & 0xffff);
port->mctrl |= set & MCTRL_MASK & 0xffff;
__fwtty_write_port_status(port);
spin_unlock_bh(&port->lock);
return 0;
}
static int fwtty_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct fwtty_port *port = tty->driver_data;
struct stats stats;
memcpy(&stats, &port->stats, sizeof(stats));
if (port->port.console)
(*port->fwcon_ops->stats)(&stats, port->con_data);
icount->cts = port->icount.cts;
icount->dsr = port->icount.dsr;
icount->rng = port->icount.rng;
icount->dcd = port->icount.dcd;
icount->rx = port->icount.rx;
icount->tx = port->icount.tx + stats.xchars;
icount->frame = port->icount.frame;
icount->overrun = port->icount.overrun;
icount->parity = port->icount.parity;
icount->brk = port->icount.brk;
icount->buf_overrun = port->icount.overrun;
return 0;
}
static void fwtty_proc_show_port(struct seq_file *m, struct fwtty_port *port)
{
struct stats stats;
memcpy(&stats, &port->stats, sizeof(stats));
if (port->port.console)
(*port->fwcon_ops->stats)(&stats, port->con_data);
seq_printf(m, " addr:%012llx tx:%d rx:%d", port->rx_handler.offset,
port->icount.tx + stats.xchars, port->icount.rx);
seq_printf(m, " cts:%d dsr:%d rng:%d dcd:%d", port->icount.cts,
port->icount.dsr, port->icount.rng, port->icount.dcd);
seq_printf(m, " fe:%d oe:%d pe:%d brk:%d", port->icount.frame,
port->icount.overrun, port->icount.parity, port->icount.brk);
}
static void fwtty_debugfs_show_port(struct seq_file *m, struct fwtty_port *port)
{
struct stats stats;
memcpy(&stats, &port->stats, sizeof(stats));
if (port->port.console)
(*port->fwcon_ops->stats)(&stats, port->con_data);
seq_printf(m, " dr:%d st:%d err:%d lost:%d", stats.dropped,
stats.tx_stall, stats.fifo_errs, stats.lost);
seq_printf(m, " pkts:%d thr:%d", stats.sent, stats.throttled);
if (port->port.console) {
seq_puts(m, "\n ");
(*port->fwcon_ops->proc_show)(m, port->con_data);
}
fwtty_dump_profile(m, &port->stats);
}
static void fwtty_debugfs_show_peer(struct seq_file *m, struct fwtty_peer *peer)
{
int generation = peer->generation;
smp_rmb();
seq_printf(m, " %s:", dev_name(&peer->unit->device));
seq_printf(m, " node:%04x gen:%d", peer->node_id, generation);
seq_printf(m, " sp:%d max:%d guid:%016llx", peer->speed,
peer->max_payload, (unsigned long long) peer->guid);
seq_printf(m, " mgmt:%012llx", (unsigned long long) peer->mgmt_addr);
seq_printf(m, " addr:%012llx", (unsigned long long) peer->status_addr);
seq_putc(m, '\n');
}
static int fwtty_proc_show(struct seq_file *m, void *v)
{
struct fwtty_port *port;
int i;
seq_puts(m, "fwserinfo: 1.0 driver: 1.0\n");
for (i = 0; i < MAX_TOTAL_PORTS && (port = fwtty_port_get(i)); ++i) {
seq_printf(m, "%2d:", i);
if (capable(CAP_SYS_ADMIN))
fwtty_proc_show_port(m, port);
fwtty_port_put(port);
seq_puts(m, "\n");
}
return 0;
}
static int fwtty_debugfs_stats_show(struct seq_file *m, void *v)
{
struct fw_serial *serial = m->private;
struct fwtty_port *port;
int i;
for (i = 0; i < num_ports; ++i) {
port = fwtty_port_get(serial->ports[i]->index);
if (port) {
seq_printf(m, "%2d:", port->index);
fwtty_proc_show_port(m, port);
fwtty_debugfs_show_port(m, port);
fwtty_port_put(port);
seq_puts(m, "\n");
}
}
return 0;
}
static int fwtty_debugfs_peers_show(struct seq_file *m, void *v)
{
struct fw_serial *serial = m->private;
struct fwtty_peer *peer;
rcu_read_lock();
seq_printf(m, "card: %s guid: %016llx\n",
dev_name(serial->card->device),
(unsigned long long) serial->card->guid);
list_for_each_entry_rcu(peer, &serial->peer_list, list)
fwtty_debugfs_show_peer(m, peer);
rcu_read_unlock();
return 0;
}
static int fwtty_proc_open(struct inode *inode, struct file *fp)
{
return single_open(fp, fwtty_proc_show, NULL);
}
static int fwtty_stats_open(struct inode *inode, struct file *fp)
{
return single_open(fp, fwtty_debugfs_stats_show, inode->i_private);
}
static int fwtty_peers_open(struct inode *inode, struct file *fp)
{
return single_open(fp, fwtty_debugfs_peers_show, inode->i_private);
}
static const struct file_operations fwtty_stats_fops = {
.owner = THIS_MODULE,
.open = fwtty_stats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations fwtty_peers_fops = {
.owner = THIS_MODULE,
.open = fwtty_peers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations fwtty_proc_fops = {
.owner = THIS_MODULE,
.open = fwtty_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct tty_port_operations fwtty_port_ops = {
.dtr_rts = fwtty_port_dtr_rts,
.carrier_raised = fwtty_port_carrier_raised,
.shutdown = fwtty_port_shutdown,
.activate = fwtty_port_activate,
};
static const struct tty_operations fwtty_ops = {
.open = fwtty_open,
.close = fwtty_close,
.hangup = fwtty_hangup,
.cleanup = fwtty_cleanup,
.install = fwtty_install,
.write = fwtty_write,
.write_room = fwtty_write_room,
.chars_in_buffer = fwtty_chars_in_buffer,
.send_xchar = fwtty_send_xchar,
.throttle = fwtty_throttle,
.unthrottle = fwtty_unthrottle,
.ioctl = fwtty_ioctl,
.set_termios = fwtty_set_termios,
.break_ctl = fwtty_break_ctl,
.tiocmget = fwtty_tiocmget,
.tiocmset = fwtty_tiocmset,
.get_icount = fwtty_get_icount,
.proc_fops = &fwtty_proc_fops,
};
static const struct tty_operations fwloop_ops = {
.open = fwtty_open,
.close = fwtty_close,
.hangup = fwtty_hangup,
.cleanup = fwtty_cleanup,
.install = fwloop_install,
.write = fwtty_write,
.write_room = fwtty_write_room,
.chars_in_buffer = fwtty_chars_in_buffer,
.send_xchar = fwtty_send_xchar,
.throttle = fwtty_throttle,
.unthrottle = fwtty_unthrottle,
.ioctl = fwtty_ioctl,
.set_termios = fwtty_set_termios,
.break_ctl = fwtty_break_ctl,
.tiocmget = fwtty_tiocmget,
.tiocmset = fwtty_tiocmset,
.get_icount = fwtty_get_icount,
};
static inline int mgmt_pkt_expected_len(__be16 code)
{
static const struct fwserial_mgmt_pkt pkt;
switch (be16_to_cpu(code)) {
case FWSC_VIRT_CABLE_PLUG:
return sizeof(pkt.hdr) + sizeof(pkt.plug_req);
case FWSC_VIRT_CABLE_PLUG_RSP: /* | FWSC_RSP_OK */
return sizeof(pkt.hdr) + sizeof(pkt.plug_rsp);
case FWSC_VIRT_CABLE_UNPLUG:
case FWSC_VIRT_CABLE_UNPLUG_RSP:
case FWSC_VIRT_CABLE_PLUG_RSP | FWSC_RSP_NACK:
case FWSC_VIRT_CABLE_UNPLUG_RSP | FWSC_RSP_NACK:
return sizeof(pkt.hdr);
default:
return -1;
}
}
static inline void fill_plug_params(struct virt_plug_params *params,
struct fwtty_port *port)
{
u64 status_addr = port->rx_handler.offset;
u64 fifo_addr = port->rx_handler.offset + 4;
size_t fifo_len = port->rx_handler.length - 4;
params->status_hi = cpu_to_be32(status_addr >> 32);
params->status_lo = cpu_to_be32(status_addr);
params->fifo_hi = cpu_to_be32(fifo_addr >> 32);
params->fifo_lo = cpu_to_be32(fifo_addr);
params->fifo_len = cpu_to_be32(fifo_len);
}
static inline void fill_plug_req(struct fwserial_mgmt_pkt *pkt,
struct fwtty_port *port)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_PLUG);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
fill_plug_params(&pkt->plug_req, port);
}
static inline void fill_plug_rsp_ok(struct fwserial_mgmt_pkt *pkt,
struct fwtty_port *port)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_PLUG_RSP);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
fill_plug_params(&pkt->plug_rsp, port);
}
static inline void fill_plug_rsp_nack(struct fwserial_mgmt_pkt *pkt)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_PLUG_RSP | FWSC_RSP_NACK);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
}
static inline void fill_unplug_req(struct fwserial_mgmt_pkt *pkt)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_UNPLUG);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
}
static inline void fill_unplug_rsp_nack(struct fwserial_mgmt_pkt *pkt)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_UNPLUG_RSP | FWSC_RSP_NACK);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
}
static inline void fill_unplug_rsp_ok(struct fwserial_mgmt_pkt *pkt)
{
pkt->hdr.code = cpu_to_be16(FWSC_VIRT_CABLE_UNPLUG_RSP);
pkt->hdr.len = cpu_to_be16(mgmt_pkt_expected_len(pkt->hdr.code));
}
static void fwserial_virt_plug_complete(struct fwtty_peer *peer,
struct virt_plug_params *params)
{
struct fwtty_port *port = peer->port;
peer->status_addr = be32_to_u64(params->status_hi, params->status_lo);
peer->fifo_addr = be32_to_u64(params->fifo_hi, params->fifo_lo);
peer->fifo_len = be32_to_cpu(params->fifo_len);
peer_set_state(peer, FWPS_ATTACHED);
/* reconfigure tx_fifo optimally for this peer */
spin_lock_bh(&port->lock);
port->max_payload = min(peer->max_payload, peer->fifo_len);
dma_fifo_change_tx_limit(&port->tx_fifo, port->max_payload);
spin_unlock_bh(&peer->port->lock);
if (port->port.console && port->fwcon_ops->notify != NULL)
(*port->fwcon_ops->notify)(FWCON_NOTIFY_ATTACH, port->con_data);
fwtty_info(&peer->unit, "peer (guid:%016llx) connected on %s\n",
(unsigned long long)peer->guid, dev_name(port->device));
}
static inline int fwserial_send_mgmt_sync(struct fwtty_peer *peer,
struct fwserial_mgmt_pkt *pkt)
{
int generation;
int rcode, tries = 5;
do {
generation = peer->generation;
smp_rmb();
rcode = fw_run_transaction(peer->serial->card,
TCODE_WRITE_BLOCK_REQUEST,
peer->node_id,
generation, peer->speed,
peer->mgmt_addr,
pkt, be16_to_cpu(pkt->hdr.len));
if (rcode == RCODE_BUSY || rcode == RCODE_SEND_ERROR ||
rcode == RCODE_GENERATION) {
fwtty_dbg(&peer->unit, "mgmt write error: %d\n", rcode);
continue;
} else {
break;
}
} while (--tries > 0);
return rcode;
}
/**
* fwserial_claim_port - attempt to claim port @ index for peer
*
* Returns ptr to claimed port or error code (as ERR_PTR())
* Can sleep - must be called from process context
*/
static struct fwtty_port *fwserial_claim_port(struct fwtty_peer *peer,
int index)
{
struct fwtty_port *port;
if (index < 0 || index >= num_ports)
return ERR_PTR(-EINVAL);
/* must guarantee that previous port releases have completed */
synchronize_rcu();
port = peer->serial->ports[index];
spin_lock_bh(&port->lock);
if (!rcu_access_pointer(port->peer))
rcu_assign_pointer(port->peer, peer);
else
port = ERR_PTR(-EBUSY);
spin_unlock_bh(&port->lock);
return port;
}
/**
* fwserial_find_port - find avail port and claim for peer
*
* Returns ptr to claimed port or NULL if none avail
* Can sleep - must be called from process context
*/
static struct fwtty_port *fwserial_find_port(struct fwtty_peer *peer)
{
struct fwtty_port **ports = peer->serial->ports;
int i;
/* must guarantee that previous port releases have completed */
synchronize_rcu();
/* TODO: implement optional GUID-to-specific port # matching */
/* find an unattached port (but not the loopback port, if present) */
for (i = 0; i < num_ttys; ++i) {
spin_lock_bh(&ports[i]->lock);
if (!ports[i]->peer) {
/* claim port */
rcu_assign_pointer(ports[i]->peer, peer);
spin_unlock_bh(&ports[i]->lock);
return ports[i];
}
spin_unlock_bh(&ports[i]->lock);
}
return NULL;
}
static void fwserial_release_port(struct fwtty_port *port, bool reset)
{
/* drop carrier (and all other line status) */
if (reset)
fwtty_update_port_status(port, 0);
spin_lock_bh(&port->lock);
/* reset dma fifo max transmission size back to S100 */
port->max_payload = link_speed_to_max_payload(SCODE_100);
dma_fifo_change_tx_limit(&port->tx_fifo, port->max_payload);
RCU_INIT_POINTER(port->peer, NULL);
spin_unlock_bh(&port->lock);
if (port->port.console && port->fwcon_ops->notify != NULL)
(*port->fwcon_ops->notify)(FWCON_NOTIFY_DETACH, port->con_data);
}
static void fwserial_plug_timeout(unsigned long data)
{
struct fwtty_peer *peer = (struct fwtty_peer *)data;
struct fwtty_port *port;
spin_lock_bh(&peer->lock);
if (peer->state != FWPS_PLUG_PENDING) {
spin_unlock_bh(&peer->lock);
return;
}
port = peer_revert_state(peer);
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, false);
}
/**
* fwserial_connect_peer - initiate virtual cable with peer
*
* Returns 0 if VIRT_CABLE_PLUG request was successfully sent,
* otherwise error code. Must be called from process context.
*/
static int fwserial_connect_peer(struct fwtty_peer *peer)
{
struct fwtty_port *port;
struct fwserial_mgmt_pkt *pkt;
int err, rcode;
pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
port = fwserial_find_port(peer);
if (!port) {
fwtty_err(&peer->unit, "avail ports in use\n");
err = -EBUSY;
goto free_pkt;
}
spin_lock_bh(&peer->lock);
/* only initiate VIRT_CABLE_PLUG if peer is currently not attached */
if (peer->state != FWPS_NOT_ATTACHED) {
err = -EBUSY;
goto release_port;
}
peer->port = port;
peer_set_state(peer, FWPS_PLUG_PENDING);
fill_plug_req(pkt, peer->port);
setup_timer(&peer->timer, fwserial_plug_timeout, (unsigned long)peer);
mod_timer(&peer->timer, jiffies + VIRT_CABLE_PLUG_TIMEOUT);
spin_unlock_bh(&peer->lock);
rcode = fwserial_send_mgmt_sync(peer, pkt);
spin_lock_bh(&peer->lock);
if (peer->state == FWPS_PLUG_PENDING && rcode != RCODE_COMPLETE) {
if (rcode == RCODE_CONFLICT_ERROR)
err = -EAGAIN;
else
err = -EIO;
goto cancel_timer;
}
spin_unlock_bh(&peer->lock);
kfree(pkt);
return 0;
cancel_timer:
del_timer(&peer->timer);
peer_revert_state(peer);
release_port:
spin_unlock_bh(&peer->lock);
fwserial_release_port(port, false);
free_pkt:
kfree(pkt);
return err;
}
/**
* fwserial_close_port -
* HUP the tty (if the tty exists) and unregister the tty device.
* Only used by the unit driver upon unit removal to disconnect and
* cleanup all attached ports
*
* The port reference is put by fwtty_cleanup (if a reference was
* ever taken).
*/
static void fwserial_close_port(struct tty_driver *driver,
struct fwtty_port *port)
{
struct tty_struct *tty;
mutex_lock(&port->port.mutex);
tty = tty_port_tty_get(&port->port);
if (tty) {
tty_vhangup(tty);
tty_kref_put(tty);
}
mutex_unlock(&port->port.mutex);
if (driver == fwloop_driver)
tty_unregister_device(driver, loop_idx(port));
else
tty_unregister_device(driver, port->index);
}
/**
* fwserial_lookup - finds first fw_serial associated with card
* @card: fw_card to match
*
* NB: caller must be holding fwserial_list_mutex
*/
static struct fw_serial *fwserial_lookup(struct fw_card *card)
{
struct fw_serial *serial;
list_for_each_entry(serial, &fwserial_list, list) {
if (card == serial->card)
return serial;
}
return NULL;
}
/**
* __fwserial_lookup_rcu - finds first fw_serial associated with card
* @card: fw_card to match
*
* NB: caller must be inside rcu_read_lock() section
*/
static struct fw_serial *__fwserial_lookup_rcu(struct fw_card *card)
{
struct fw_serial *serial;
list_for_each_entry_rcu(serial, &fwserial_list, list) {
if (card == serial->card)
return serial;
}
return NULL;
}
/**
* __fwserial_peer_by_node_id - finds a peer matching the given generation + id
*
* If a matching peer could not be found for the specified generation/node id,
* this could be because:
* a) the generation has changed and one of the nodes hasn't updated yet
* b) the remote node has created its remote unit device before this
* local node has created its corresponding remote unit device
* In either case, the remote node should retry
*
* Note: caller must be in rcu_read_lock() section
*/
static struct fwtty_peer *__fwserial_peer_by_node_id(struct fw_card *card,
int generation, int id)
{
struct fw_serial *serial;
struct fwtty_peer *peer;
serial = __fwserial_lookup_rcu(card);
if (!serial) {
/*
* Something is very wrong - there should be a matching
* fw_serial structure for every fw_card. Maybe the remote node
* has created its remote unit device before this driver has
* been probed for any unit devices...
*/
fwtty_err(card, "unknown card (guid %016llx)\n",
(unsigned long long) card->guid);
return NULL;
}
list_for_each_entry_rcu(peer, &serial->peer_list, list) {
int g = peer->generation;
smp_rmb();
if (generation == g && id == peer->node_id)
return peer;
}
return NULL;
}
#ifdef DEBUG
static void __dump_peer_list(struct fw_card *card)
{
struct fw_serial *serial;
struct fwtty_peer *peer;
serial = __fwserial_lookup_rcu(card);
if (!serial)
return;
list_for_each_entry_rcu(peer, &serial->peer_list, list) {
int g = peer->generation;
smp_rmb();
fwtty_dbg(card, "peer(%d:%x) guid: %016llx\n",
g, peer->node_id, (unsigned long long) peer->guid);
}
}
#else
#define __dump_peer_list(s)
#endif
static void fwserial_auto_connect(struct work_struct *work)
{
struct fwtty_peer *peer = to_peer(to_delayed_work(work), connect);
int err;
err = fwserial_connect_peer(peer);
if (err == -EAGAIN && ++peer->connect_retries < MAX_CONNECT_RETRIES)
schedule_delayed_work(&peer->connect, CONNECT_RETRY_DELAY);
}
static void fwserial_peer_workfn(struct work_struct *work)
{
struct fwtty_peer *peer = to_peer(work, work);
peer->workfn(work);
}
/**
* fwserial_add_peer - add a newly probed 'serial' unit device as a 'peer'
* @serial: aggregate representing the specific fw_card to add the peer to
* @unit: 'peer' to create and add to peer_list of serial
*
* Adds a 'peer' (ie, a local or remote 'serial' unit device) to the list of
* peers for a specific fw_card. Optionally, auto-attach this peer to an
* available tty port. This function is called either directly or indirectly
* as a result of a 'serial' unit device being created & probed.
*
* Note: this function is serialized with fwserial_remove_peer() by the
* fwserial_list_mutex held in fwserial_probe().
*
* A 1:1 correspondence between an fw_unit and an fwtty_peer is maintained
* via the dev_set_drvdata() for the device of the fw_unit.
*/
static int fwserial_add_peer(struct fw_serial *serial, struct fw_unit *unit)
{
struct device *dev = &unit->device;
struct fw_device *parent = fw_parent_device(unit);
struct fwtty_peer *peer;
struct fw_csr_iterator ci;
int key, val;
int generation;
peer = kzalloc(sizeof(*peer), GFP_KERNEL);
if (!peer)
return -ENOMEM;
peer_set_state(peer, FWPS_NOT_ATTACHED);
dev_set_drvdata(dev, peer);
peer->unit = unit;
peer->guid = (u64)parent->config_rom[3] << 32 | parent->config_rom[4];
peer->speed = parent->max_speed;
peer->max_payload = min(device_max_receive(parent),
link_speed_to_max_payload(peer->speed));
generation = parent->generation;
smp_rmb();
peer->node_id = parent->node_id;
smp_wmb();
peer->generation = generation;
/* retrieve the mgmt bus addr from the unit directory */
fw_csr_iterator_init(&ci, unit->directory);
while (fw_csr_iterator_next(&ci, &key, &val)) {
if (key == (CSR_OFFSET | CSR_DEPENDENT_INFO)) {
peer->mgmt_addr = CSR_REGISTER_BASE + 4 * val;
break;
}
}
if (peer->mgmt_addr == 0ULL) {
/*
* No mgmt address effectively disables VIRT_CABLE_PLUG -
* this peer will not be able to attach to a remote
*/
peer_set_state(peer, FWPS_NO_MGMT_ADDR);
}
spin_lock_init(&peer->lock);
peer->port = NULL;
init_timer(&peer->timer);
INIT_WORK(&peer->work, fwserial_peer_workfn);
INIT_DELAYED_WORK(&peer->connect, fwserial_auto_connect);
/* associate peer with specific fw_card */
peer->serial = serial;
list_add_rcu(&peer->list, &serial->peer_list);
fwtty_info(&peer->unit, "peer added (guid:%016llx)\n",
(unsigned long long)peer->guid);
/* identify the local unit & virt cable to loopback port */
if (parent->is_local) {
serial->self = peer;
if (create_loop_dev) {
struct fwtty_port *port;
port = fwserial_claim_port(peer, num_ttys);
if (!IS_ERR(port)) {
struct virt_plug_params params;
spin_lock_bh(&peer->lock);
peer->port = port;
fill_plug_params(&params, port);
fwserial_virt_plug_complete(peer, &params);
spin_unlock_bh(&peer->lock);
fwtty_write_port_status(port);
}
}
} else if (auto_connect) {
/* auto-attach to remote units only (if policy allows) */
schedule_delayed_work(&peer->connect, 1);
}
return 0;
}
/**
* fwserial_remove_peer - remove a 'serial' unit device as a 'peer'
*
* Remove a 'peer' from its list of peers. This function is only
* called by fwserial_remove() on bus removal of the unit device.
*
* Note: this function is serialized with fwserial_add_peer() by the
* fwserial_list_mutex held in fwserial_remove().
*/
static void fwserial_remove_peer(struct fwtty_peer *peer)
{
struct fwtty_port *port;
spin_lock_bh(&peer->lock);
peer_set_state(peer, FWPS_GONE);
spin_unlock_bh(&peer->lock);
cancel_delayed_work_sync(&peer->connect);
cancel_work_sync(&peer->work);
spin_lock_bh(&peer->lock);
/* if this unit is the local unit, clear link */
if (peer == peer->serial->self)
peer->serial->self = NULL;
/* cancel the request timeout timer (if running) */
del_timer(&peer->timer);
port = peer->port;
peer->port = NULL;
list_del_rcu(&peer->list);
fwtty_info(&peer->unit, "peer removed (guid:%016llx)\n",
(unsigned long long)peer->guid);
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, true);
synchronize_rcu();
kfree(peer);
}
/**
* fwserial_create - init everything to create TTYs for a specific fw_card
* @unit: fw_unit for first 'serial' unit device probed for this fw_card
*
* This function inits the aggregate structure (an fw_serial instance)
* used to manage the TTY ports registered by a specific fw_card. Also, the
* unit device is added as the first 'peer'.
*
* This unit device may represent a local unit device (as specified by the
* config ROM unit directory) or it may represent a remote unit device
* (as specified by the reading of the remote node's config ROM).
*
* Returns 0 to indicate "ownership" of the unit device, or a negative errno
* value to indicate which error.
*/
static int fwserial_create(struct fw_unit *unit)
{
struct fw_device *parent = fw_parent_device(unit);
struct fw_card *card = parent->card;
struct fw_serial *serial;
struct fwtty_port *port;
struct device *tty_dev;
int i, j;
int err;
serial = kzalloc(sizeof(*serial), GFP_KERNEL);
if (!serial)
return -ENOMEM;
kref_init(&serial->kref);
serial->card = card;
INIT_LIST_HEAD(&serial->peer_list);
for (i = 0; i < num_ports; ++i) {
port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port) {
err = -ENOMEM;
goto free_ports;
}
tty_port_init(&port->port);
port->index = FWTTY_INVALID_INDEX;
port->port.ops = &fwtty_port_ops;
port->serial = serial;
tty_buffer_set_limit(&port->port, 128 * 1024);
spin_lock_init(&port->lock);
INIT_DELAYED_WORK(&port->drain, fwtty_drain_tx);
INIT_DELAYED_WORK(&port->emit_breaks, fwtty_emit_breaks);
INIT_WORK(&port->hangup, fwtty_do_hangup);
init_waitqueue_head(&port->wait_tx);
port->max_payload = link_speed_to_max_payload(SCODE_100);
dma_fifo_init(&port->tx_fifo);
RCU_INIT_POINTER(port->peer, NULL);
serial->ports[i] = port;
/* get unique bus addr region for port's status & recv fifo */
port->rx_handler.length = FWTTY_PORT_RXFIFO_LEN + 4;
port->rx_handler.address_callback = fwtty_port_handler;
port->rx_handler.callback_data = port;
/*
* XXX: use custom memory region above cpu physical memory addrs
* this will ease porting to 64-bit firewire adapters
*/
err = fw_core_add_address_handler(&port->rx_handler,
&fw_high_memory_region);
if (err) {
kfree(port);
goto free_ports;
}
}
/* preserve i for error cleanup */
err = fwtty_ports_add(serial);
if (err) {
fwtty_err(&unit, "no space in port table\n");
goto free_ports;
}
for (j = 0; j < num_ttys; ++j) {
tty_dev = tty_port_register_device(&serial->ports[j]->port,
fwtty_driver,
serial->ports[j]->index,
card->device);
if (IS_ERR(tty_dev)) {
err = PTR_ERR(tty_dev);
fwtty_err(&unit, "register tty device error (%d)\n",
err);
goto unregister_ttys;
}
serial->ports[j]->device = tty_dev;
}
/* preserve j for error cleanup */
if (create_loop_dev) {
struct device *loop_dev;
loop_dev = tty_port_register_device(&serial->ports[j]->port,
fwloop_driver,
loop_idx(serial->ports[j]),
card->device);
if (IS_ERR(loop_dev)) {
err = PTR_ERR(loop_dev);
fwtty_err(&unit, "create loop device failed (%d)\n",
err);
goto unregister_ttys;
}
serial->ports[j]->device = loop_dev;
serial->ports[j]->loopback = true;
}
if (!IS_ERR_OR_NULL(fwserial_debugfs)) {
serial->debugfs = debugfs_create_dir(dev_name(&unit->device),
fwserial_debugfs);
if (!IS_ERR_OR_NULL(serial->debugfs)) {
debugfs_create_file("peers", 0444, serial->debugfs,
serial, &fwtty_peers_fops);
debugfs_create_file("stats", 0444, serial->debugfs,
serial, &fwtty_stats_fops);
}
}
list_add_rcu(&serial->list, &fwserial_list);
fwtty_notice(&unit, "TTY over FireWire on device %s (guid %016llx)\n",
dev_name(card->device), (unsigned long long) card->guid);
err = fwserial_add_peer(serial, unit);
if (!err)
return 0;
fwtty_err(&unit, "unable to add peer unit device (%d)\n", err);
/* fall-through to error processing */
debugfs_remove_recursive(serial->debugfs);
list_del_rcu(&serial->list);
if (create_loop_dev)
tty_unregister_device(fwloop_driver,
loop_idx(serial->ports[j]));
unregister_ttys:
for (--j; j >= 0; --j)
tty_unregister_device(fwtty_driver, serial->ports[j]->index);
kref_put(&serial->kref, fwserial_destroy);
return err;
free_ports:
for (--i; i >= 0; --i) {
tty_port_destroy(&serial->ports[i]->port);
kfree(serial->ports[i]);
}
kfree(serial);
return err;
}
/**
* fwserial_probe: bus probe function for firewire 'serial' unit devices
*
* A 'serial' unit device is created and probed as a result of:
* - declaring a ieee1394 bus id table for 'devices' matching a fabricated
* 'serial' unit specifier id
* - adding a unit directory to the config ROM(s) for a 'serial' unit
*
* The firewire core registers unit devices by enumerating unit directories
* of a node's config ROM after reading the config ROM when a new node is
* added to the bus topology after a bus reset.
*
* The practical implications of this are:
* - this probe is called for both local and remote nodes that have a 'serial'
* unit directory in their config ROM (that matches the specifiers in
* fwserial_id_table).
* - no specific order is enforced for local vs. remote unit devices
*
* This unit driver copes with the lack of specific order in the same way the
* firewire net driver does -- each probe, for either a local or remote unit
* device, is treated as a 'peer' (has a struct fwtty_peer instance) and the
* first peer created for a given fw_card (tracked by the global fwserial_list)
* creates the underlying TTYs (aggregated in a fw_serial instance).
*
* NB: an early attempt to differentiate local & remote unit devices by creating
* peers only for remote units and fw_serial instances (with their
* associated TTY devices) only for local units was discarded. Managing
* the peer lifetimes on device removal proved too complicated.
*
* fwserial_probe/fwserial_remove are effectively serialized by the
* fwserial_list_mutex. This is necessary because the addition of the first peer
* for a given fw_card will trigger the creation of the fw_serial for that
* fw_card, which must not simultaneously contend with the removal of the
* last peer for a given fw_card triggering the destruction of the same
* fw_serial for the same fw_card.
*/
static int fwserial_probe(struct fw_unit *unit,
const struct ieee1394_device_id *id)
{
struct fw_serial *serial;
int err;
mutex_lock(&fwserial_list_mutex);
serial = fwserial_lookup(fw_parent_device(unit)->card);
if (!serial)
err = fwserial_create(unit);
else
err = fwserial_add_peer(serial, unit);
mutex_unlock(&fwserial_list_mutex);
return err;
}
/**
* fwserial_remove: bus removal function for firewire 'serial' unit devices
*
* The corresponding 'peer' for this unit device is removed from the list of
* peers for the associated fw_serial (which has a 1:1 correspondence with a
* specific fw_card). If this is the last peer being removed, then trigger
* the destruction of the underlying TTYs.
*/
static void fwserial_remove(struct fw_unit *unit)
{
struct fwtty_peer *peer = dev_get_drvdata(&unit->device);
struct fw_serial *serial = peer->serial;
int i;
mutex_lock(&fwserial_list_mutex);
fwserial_remove_peer(peer);
if (list_empty(&serial->peer_list)) {
/* unlink from the fwserial_list here */
list_del_rcu(&serial->list);
debugfs_remove_recursive(serial->debugfs);
for (i = 0; i < num_ttys; ++i)
fwserial_close_port(fwtty_driver, serial->ports[i]);
if (create_loop_dev)
fwserial_close_port(fwloop_driver, serial->ports[i]);
kref_put(&serial->kref, fwserial_destroy);
}
mutex_unlock(&fwserial_list_mutex);
}
/**
* fwserial_update: bus update function for 'firewire' serial unit devices
*
* Updates the new node_id and bus generation for this peer. Note that locking
* is unnecessary; but careful memory barrier usage is important to enforce the
* load and store order of generation & node_id.
*
* The fw-core orders the write of node_id before generation in the parent
* fw_device to ensure that a stale node_id cannot be used with a current
* bus generation. So the generation value must be read before the node_id.
*
* In turn, this orders the write of node_id before generation in the peer to
* also ensure a stale node_id cannot be used with a current bus generation.
*/
static void fwserial_update(struct fw_unit *unit)
{
struct fw_device *parent = fw_parent_device(unit);
struct fwtty_peer *peer = dev_get_drvdata(&unit->device);
int generation;
generation = parent->generation;
smp_rmb();
peer->node_id = parent->node_id;
smp_wmb();
peer->generation = generation;
}
static const struct ieee1394_device_id fwserial_id_table[] = {
{
.match_flags = IEEE1394_MATCH_SPECIFIER_ID |
IEEE1394_MATCH_VERSION,
.specifier_id = LINUX_VENDOR_ID,
.version = FWSERIAL_VERSION,
},
{ }
};
static struct fw_driver fwserial_driver = {
.driver = {
.owner = THIS_MODULE,
.name = KBUILD_MODNAME,
.bus = &fw_bus_type,
},
.probe = fwserial_probe,
.update = fwserial_update,
.remove = fwserial_remove,
.id_table = fwserial_id_table,
};
#define FW_UNIT_SPECIFIER(id) ((CSR_SPECIFIER_ID << 24) | (id))
#define FW_UNIT_VERSION(ver) ((CSR_VERSION << 24) | (ver))
#define FW_UNIT_ADDRESS(ofs) (((CSR_OFFSET | CSR_DEPENDENT_INFO) << 24) \
| (((ofs) - CSR_REGISTER_BASE) >> 2))
/* XXX: config ROM definitons could be improved with semi-automated offset
* and length calculation
*/
#define FW_ROM_LEN(quads) ((quads) << 16)
#define FW_ROM_DESCRIPTOR(ofs) (((CSR_LEAF | CSR_DESCRIPTOR) << 24) | (ofs))
struct fwserial_unit_directory_data {
u32 len_crc;
u32 unit_specifier;
u32 unit_sw_version;
u32 unit_addr_offset;
u32 desc1_ofs;
u32 desc1_len_crc;
u32 desc1_data[5];
} __packed;
static struct fwserial_unit_directory_data fwserial_unit_directory_data = {
.len_crc = FW_ROM_LEN(4),
.unit_specifier = FW_UNIT_SPECIFIER(LINUX_VENDOR_ID),
.unit_sw_version = FW_UNIT_VERSION(FWSERIAL_VERSION),
.desc1_ofs = FW_ROM_DESCRIPTOR(1),
.desc1_len_crc = FW_ROM_LEN(5),
.desc1_data = {
0x00000000, /* type = text */
0x00000000, /* enc = ASCII, lang EN */
0x4c696e75, /* 'Linux TTY' */
0x78205454,
0x59000000,
},
};
static struct fw_descriptor fwserial_unit_directory = {
.length = sizeof(fwserial_unit_directory_data) / sizeof(u32),
.key = (CSR_DIRECTORY | CSR_UNIT) << 24,
.data = (u32 *)&fwserial_unit_directory_data,
};
/*
* The management address is in the unit space region but above other known
* address users (to keep wild writes from causing havoc)
*/
static const struct fw_address_region fwserial_mgmt_addr_region = {
.start = CSR_REGISTER_BASE + 0x1e0000ULL,
.end = 0x1000000000000ULL,
};
static struct fw_address_handler fwserial_mgmt_addr_handler;
/**
* fwserial_handle_plug_req - handle VIRT_CABLE_PLUG request work
* @work: ptr to peer->work
*
* Attempts to complete the VIRT_CABLE_PLUG handshake sequence for this peer.
*
* This checks for a collided request-- ie, that a VIRT_CABLE_PLUG request was
* already sent to this peer. If so, the collision is resolved by comparing
* guid values; the loser sends the plug response.
*
* Note: if an error prevents a response, don't do anything -- the
* remote will timeout its request.
*/
static void fwserial_handle_plug_req(struct work_struct *work)
{
struct fwtty_peer *peer = to_peer(work, work);
struct virt_plug_params *plug_req = &peer->work_params.plug_req;
struct fwtty_port *port;
struct fwserial_mgmt_pkt *pkt;
int rcode;
pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return;
port = fwserial_find_port(peer);
spin_lock_bh(&peer->lock);
switch (peer->state) {
case FWPS_NOT_ATTACHED:
if (!port) {
fwtty_err(&peer->unit, "no more ports avail\n");
fill_plug_rsp_nack(pkt);
} else {
peer->port = port;
fill_plug_rsp_ok(pkt, peer->port);
peer_set_state(peer, FWPS_PLUG_RESPONDING);
/* don't release claimed port */
port = NULL;
}
break;
case FWPS_PLUG_PENDING:
if (peer->serial->card->guid > peer->guid)
goto cleanup;
/* We lost - hijack the already-claimed port and send ok */
del_timer(&peer->timer);
fill_plug_rsp_ok(pkt, peer->port);
peer_set_state(peer, FWPS_PLUG_RESPONDING);
break;
default:
fill_plug_rsp_nack(pkt);
}
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, false);
rcode = fwserial_send_mgmt_sync(peer, pkt);
spin_lock_bh(&peer->lock);
if (peer->state == FWPS_PLUG_RESPONDING) {
if (rcode == RCODE_COMPLETE) {
struct fwtty_port *tmp = peer->port;
fwserial_virt_plug_complete(peer, plug_req);
spin_unlock_bh(&peer->lock);
fwtty_write_port_status(tmp);
spin_lock_bh(&peer->lock);
} else {
fwtty_err(&peer->unit, "PLUG_RSP error (%d)\n", rcode);
port = peer_revert_state(peer);
}
}
cleanup:
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, false);
kfree(pkt);
}
static void fwserial_handle_unplug_req(struct work_struct *work)
{
struct fwtty_peer *peer = to_peer(work, work);
struct fwtty_port *port = NULL;
struct fwserial_mgmt_pkt *pkt;
int rcode;
pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return;
spin_lock_bh(&peer->lock);
switch (peer->state) {
case FWPS_ATTACHED:
fill_unplug_rsp_ok(pkt);
peer_set_state(peer, FWPS_UNPLUG_RESPONDING);
break;
case FWPS_UNPLUG_PENDING:
if (peer->serial->card->guid > peer->guid)
goto cleanup;
/* We lost - send unplug rsp */
del_timer(&peer->timer);
fill_unplug_rsp_ok(pkt);
peer_set_state(peer, FWPS_UNPLUG_RESPONDING);
break;
default:
fill_unplug_rsp_nack(pkt);
}
spin_unlock_bh(&peer->lock);
rcode = fwserial_send_mgmt_sync(peer, pkt);
spin_lock_bh(&peer->lock);
if (peer->state == FWPS_UNPLUG_RESPONDING) {
if (rcode != RCODE_COMPLETE)
fwtty_err(&peer->unit, "UNPLUG_RSP error (%d)\n",
rcode);
port = peer_revert_state(peer);
}
cleanup:
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, true);
kfree(pkt);
}
static int fwserial_parse_mgmt_write(struct fwtty_peer *peer,
struct fwserial_mgmt_pkt *pkt,
unsigned long long addr,
size_t len)
{
struct fwtty_port *port = NULL;
bool reset = false;
int rcode;
if (addr != fwserial_mgmt_addr_handler.offset || len < sizeof(pkt->hdr))
return RCODE_ADDRESS_ERROR;
if (len != be16_to_cpu(pkt->hdr.len) ||
len != mgmt_pkt_expected_len(pkt->hdr.code))
return RCODE_DATA_ERROR;
spin_lock_bh(&peer->lock);
if (peer->state == FWPS_GONE) {
/*
* This should never happen - it would mean that the
* remote unit that just wrote this transaction was
* already removed from the bus -- and the removal was
* processed before we rec'd this transaction
*/
fwtty_err(&peer->unit, "peer already removed\n");
spin_unlock_bh(&peer->lock);
return RCODE_ADDRESS_ERROR;
}
rcode = RCODE_COMPLETE;
fwtty_dbg(&peer->unit, "mgmt: hdr.code: %04hx\n", pkt->hdr.code);
switch (be16_to_cpu(pkt->hdr.code) & FWSC_CODE_MASK) {
case FWSC_VIRT_CABLE_PLUG:
if (work_pending(&peer->work)) {
fwtty_err(&peer->unit, "plug req: busy\n");
rcode = RCODE_CONFLICT_ERROR;
} else {
peer->work_params.plug_req = pkt->plug_req;
peer->workfn = fwserial_handle_plug_req;
queue_work(system_unbound_wq, &peer->work);
}
break;
case FWSC_VIRT_CABLE_PLUG_RSP:
if (peer->state != FWPS_PLUG_PENDING) {
rcode = RCODE_CONFLICT_ERROR;
} else if (be16_to_cpu(pkt->hdr.code) & FWSC_RSP_NACK) {
fwtty_notice(&peer->unit, "NACK plug rsp\n");
port = peer_revert_state(peer);
} else {
struct fwtty_port *tmp = peer->port;
fwserial_virt_plug_complete(peer, &pkt->plug_rsp);
spin_unlock_bh(&peer->lock);
fwtty_write_port_status(tmp);
spin_lock_bh(&peer->lock);
}
break;
case FWSC_VIRT_CABLE_UNPLUG:
if (work_pending(&peer->work)) {
fwtty_err(&peer->unit, "unplug req: busy\n");
rcode = RCODE_CONFLICT_ERROR;
} else {
peer->workfn = fwserial_handle_unplug_req;
queue_work(system_unbound_wq, &peer->work);
}
break;
case FWSC_VIRT_CABLE_UNPLUG_RSP:
if (peer->state != FWPS_UNPLUG_PENDING) {
rcode = RCODE_CONFLICT_ERROR;
} else {
if (be16_to_cpu(pkt->hdr.code) & FWSC_RSP_NACK)
fwtty_notice(&peer->unit, "NACK unplug?\n");
port = peer_revert_state(peer);
reset = true;
}
break;
default:
fwtty_err(&peer->unit, "unknown mgmt code %d\n",
be16_to_cpu(pkt->hdr.code));
rcode = RCODE_DATA_ERROR;
}
spin_unlock_bh(&peer->lock);
if (port)
fwserial_release_port(port, reset);
return rcode;
}
/**
* fwserial_mgmt_handler: bus address handler for mgmt requests
* @parameters: fw_address_callback_t as specified by firewire core interface
*
* This handler is responsible for handling virtual cable requests from remotes
* for all cards.
*/
static void fwserial_mgmt_handler(struct fw_card *card,
struct fw_request *request,
int tcode, int destination, int source,
int generation,
unsigned long long addr,
void *data, size_t len,
void *callback_data)
{
struct fwserial_mgmt_pkt *pkt = data;
struct fwtty_peer *peer;
int rcode;
rcu_read_lock();
peer = __fwserial_peer_by_node_id(card, generation, source);
if (!peer) {
fwtty_dbg(card, "peer(%d:%x) not found\n", generation, source);
__dump_peer_list(card);
rcode = RCODE_CONFLICT_ERROR;
} else {
switch (tcode) {
case TCODE_WRITE_BLOCK_REQUEST:
rcode = fwserial_parse_mgmt_write(peer, pkt, addr, len);
break;
default:
rcode = RCODE_TYPE_ERROR;
}
}
rcu_read_unlock();
fw_send_response(card, request, rcode);
}
static int __init fwserial_init(void)
{
int err, num_loops = !!(create_loop_dev);
/* XXX: placeholder for a "firewire" debugfs node */
fwserial_debugfs = debugfs_create_dir(KBUILD_MODNAME, NULL);
/* num_ttys/num_ports must not be set above the static alloc avail */
if (num_ttys + num_loops > MAX_CARD_PORTS)
num_ttys = MAX_CARD_PORTS - num_loops;
num_ports = num_ttys + num_loops;
fwtty_driver = tty_alloc_driver(MAX_TOTAL_PORTS, TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV);
if (IS_ERR(fwtty_driver)) {
err = PTR_ERR(fwtty_driver);
return err;
}
fwtty_driver->driver_name = KBUILD_MODNAME;
fwtty_driver->name = tty_dev_name;
fwtty_driver->major = 0;
fwtty_driver->minor_start = 0;
fwtty_driver->type = TTY_DRIVER_TYPE_SERIAL;
fwtty_driver->subtype = SERIAL_TYPE_NORMAL;
fwtty_driver->init_termios = tty_std_termios;
fwtty_driver->init_termios.c_cflag |= CLOCAL;
tty_set_operations(fwtty_driver, &fwtty_ops);
err = tty_register_driver(fwtty_driver);
if (err) {
pr_err("register tty driver failed (%d)\n", err);
goto put_tty;
}
if (create_loop_dev) {
fwloop_driver = tty_alloc_driver(MAX_TOTAL_PORTS / num_ports,
TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV);
if (IS_ERR(fwloop_driver)) {
err = PTR_ERR(fwloop_driver);
goto unregister_driver;
}
fwloop_driver->driver_name = KBUILD_MODNAME "_loop";
fwloop_driver->name = loop_dev_name;
fwloop_driver->major = 0;
fwloop_driver->minor_start = 0;
fwloop_driver->type = TTY_DRIVER_TYPE_SERIAL;
fwloop_driver->subtype = SERIAL_TYPE_NORMAL;
fwloop_driver->init_termios = tty_std_termios;
fwloop_driver->init_termios.c_cflag |= CLOCAL;
tty_set_operations(fwloop_driver, &fwloop_ops);
err = tty_register_driver(fwloop_driver);
if (err) {
pr_err("register loop driver failed (%d)\n", err);
goto put_loop;
}
}
fwtty_txn_cache = kmem_cache_create("fwtty_txn_cache",
sizeof(struct fwtty_transaction),
0, 0, fwtty_txn_constructor);
if (!fwtty_txn_cache) {
err = -ENOMEM;
goto unregister_loop;
}
/*
* Ideally, this address handler would be registered per local node
* (rather than the same handler for all local nodes). However,
* since the firewire core requires the config rom descriptor *before*
* the local unit device(s) are created, a single management handler
* must suffice for all local serial units.
*/
fwserial_mgmt_addr_handler.length = sizeof(struct fwserial_mgmt_pkt);
fwserial_mgmt_addr_handler.address_callback = fwserial_mgmt_handler;
err = fw_core_add_address_handler(&fwserial_mgmt_addr_handler,
&fwserial_mgmt_addr_region);
if (err) {
pr_err("add management handler failed (%d)\n", err);
goto destroy_cache;
}
fwserial_unit_directory_data.unit_addr_offset =
FW_UNIT_ADDRESS(fwserial_mgmt_addr_handler.offset);
err = fw_core_add_descriptor(&fwserial_unit_directory);
if (err) {
pr_err("add unit descriptor failed (%d)\n", err);
goto remove_handler;
}
err = driver_register(&fwserial_driver.driver);
if (err) {
pr_err("register fwserial driver failed (%d)\n", err);
goto remove_descriptor;
}
return 0;
remove_descriptor:
fw_core_remove_descriptor(&fwserial_unit_directory);
remove_handler:
fw_core_remove_address_handler(&fwserial_mgmt_addr_handler);
destroy_cache:
kmem_cache_destroy(fwtty_txn_cache);
unregister_loop:
if (create_loop_dev)
tty_unregister_driver(fwloop_driver);
put_loop:
if (create_loop_dev)
put_tty_driver(fwloop_driver);
unregister_driver:
tty_unregister_driver(fwtty_driver);
put_tty:
put_tty_driver(fwtty_driver);
debugfs_remove_recursive(fwserial_debugfs);
return err;
}
static void __exit fwserial_exit(void)
{
driver_unregister(&fwserial_driver.driver);
fw_core_remove_descriptor(&fwserial_unit_directory);
fw_core_remove_address_handler(&fwserial_mgmt_addr_handler);
kmem_cache_destroy(fwtty_txn_cache);
if (create_loop_dev) {
tty_unregister_driver(fwloop_driver);
put_tty_driver(fwloop_driver);
}
tty_unregister_driver(fwtty_driver);
put_tty_driver(fwtty_driver);
debugfs_remove_recursive(fwserial_debugfs);
}
module_init(fwserial_init);
module_exit(fwserial_exit);
MODULE_AUTHOR("Peter Hurley (peter@hurleysoftware.com)");
MODULE_DESCRIPTION("FireWire Serial TTY Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(ieee1394, fwserial_id_table);
MODULE_PARM_DESC(ttys, "Number of ttys to create for each local firewire node");
MODULE_PARM_DESC(auto, "Auto-connect a tty to each firewire node discovered");
MODULE_PARM_DESC(loop, "Create a loopback device, fwloop<n>, with ttys");