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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FIREWIRE_FWSERIAL_H
#define _FIREWIRE_FWSERIAL_H
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/list.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/mutex.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include "dma_fifo.h"
#ifdef FWTTY_PROFILING
#define DISTRIBUTION_MAX_SIZE 8192
#define DISTRIBUTION_MAX_INDEX (ilog2(DISTRIBUTION_MAX_SIZE) + 1)
static inline void fwtty_profile_data(unsigned int stat[], unsigned int val)
{
int n = (val) ? min(ilog2(val) + 1, DISTRIBUTION_MAX_INDEX) : 0;
++stat[n];
}
#else
#define DISTRIBUTION_MAX_INDEX 0
#define fwtty_profile_data(st, n)
#endif
/* Parameters for both VIRT_CABLE_PLUG & VIRT_CABLE_PLUG_RSP mgmt codes */
struct virt_plug_params {
__be32 status_hi;
__be32 status_lo;
__be32 fifo_hi;
__be32 fifo_lo;
__be32 fifo_len;
};
struct peer_work_params {
union {
struct virt_plug_params plug_req;
};
};
/**
* fwtty_peer: structure representing local & remote unit devices
* @unit: unit child device of fw_device node
* @serial: back pointer to associated fw_serial aggregate
* @guid: unique 64-bit guid for this unit device
* @generation: most recent bus generation
* @node_id: most recent node_id
* @speed: link speed of peer (0 = S100, 2 = S400, ... 5 = S3200)
* @mgmt_addr: bus addr region to write mgmt packets to
* @status_addr: bus addr register to write line status to
* @fifo_addr: bus addr region to write serial output to
* @fifo_len: max length for single write to fifo_addr
* @list: link for insertion into fw_serial's peer_list
* @rcu: for deferring peer reclamation
* @lock: spinlock to synchonize changes to state & port fields
* @work: only one work item can be queued at any one time
* Note: pending work is canceled prior to removal, so this
* peer is valid for at least the lifetime of the work function
* @work_params: parameter block for work functions
* @timer: timer for resetting peer state if remote request times out
* @state: current state
* @connect: work item for auto-connecting
* @connect_retries: # of connections already attempted
* @port: associated tty_port (usable if state == FWSC_ATTACHED)
*/
struct fwtty_peer {
struct fw_unit *unit;
struct fw_serial *serial;
u64 guid;
int generation;
int node_id;
unsigned int speed;
int max_payload;
u64 mgmt_addr;
/* these are usable only if state == FWSC_ATTACHED */
u64 status_addr;
u64 fifo_addr;
int fifo_len;
struct list_head list;
struct rcu_head rcu;
spinlock_t lock;
work_func_t workfn;
struct work_struct work;
struct peer_work_params work_params;
struct timer_list timer;
int state;
struct delayed_work connect;
int connect_retries;
struct fwtty_port *port;
};
#define to_peer(ptr, field) (container_of(ptr, struct fwtty_peer, field))
/* state values for fwtty_peer.state field */
enum fwtty_peer_state {
FWPS_GONE,
FWPS_NOT_ATTACHED,
FWPS_ATTACHED,
FWPS_PLUG_PENDING,
FWPS_PLUG_RESPONDING,
FWPS_UNPLUG_PENDING,
FWPS_UNPLUG_RESPONDING,
FWPS_NO_MGMT_ADDR = -1,
};
#define CONNECT_RETRY_DELAY HZ
#define MAX_CONNECT_RETRIES 10
/* must be holding peer lock for these state funclets */
static inline void peer_set_state(struct fwtty_peer *peer, int new)
{
peer->state = new;
}
static inline struct fwtty_port *peer_revert_state(struct fwtty_peer *peer)
{
struct fwtty_port *port = peer->port;
peer->port = NULL;
peer_set_state(peer, FWPS_NOT_ATTACHED);
return port;
}
struct fwserial_mgmt_pkt {
struct {
__be16 len;
__be16 code;
} hdr;
union {
struct virt_plug_params plug_req;
struct virt_plug_params plug_rsp;
};
} __packed;
/* fwserial_mgmt_packet codes */
#define FWSC_RSP_OK 0x0000
#define FWSC_RSP_NACK 0x8000
#define FWSC_CODE_MASK 0x0fff
#define FWSC_VIRT_CABLE_PLUG 1
#define FWSC_VIRT_CABLE_UNPLUG 2
#define FWSC_VIRT_CABLE_PLUG_RSP 3
#define FWSC_VIRT_CABLE_UNPLUG_RSP 4
/* 1 min. plug timeout -- suitable for userland authorization */
#define VIRT_CABLE_PLUG_TIMEOUT (60 * HZ)
struct stats {
unsigned int xchars;
unsigned int dropped;
unsigned int tx_stall;
unsigned int fifo_errs;
unsigned int sent;
unsigned int lost;
unsigned int throttled;
unsigned int reads[DISTRIBUTION_MAX_INDEX + 1];
unsigned int writes[DISTRIBUTION_MAX_INDEX + 1];
unsigned int txns[DISTRIBUTION_MAX_INDEX + 1];
unsigned int unthrottle[DISTRIBUTION_MAX_INDEX + 1];
};
struct fwconsole_ops {
void (*notify)(int code, void *data);
void (*stats)(struct stats *stats, void *data);
void (*proc_show)(struct seq_file *m, void *data);
};
/* codes for console ops notify */
#define FWCON_NOTIFY_ATTACH 1
#define FWCON_NOTIFY_DETACH 2
/**
* fwtty_port: structure used to track/represent underlying tty_port
* @port: underlying tty_port
* @device: tty device
* @index: index into port_table for this particular port
* note: minor = index + minor_start assigned by tty_alloc_driver()
* @serial: back pointer to the containing fw_serial
* @rx_handler: bus address handler for unique addr region used by remotes
* to communicate with this port. Every port uses
* fwtty_port_handler() for per port transactions.
* @fwcon_ops: ops for attached fw_console (if any)
* @con_data: private data for fw_console
* @wait_tx: waitqueue for sleeping until writer/drain completes tx
* @emit_breaks: delayed work responsible for generating breaks when the
* break line status is active
* @cps : characters per second computed from the termios settings
* @break_last: timestamp in jiffies from last emit_breaks
* @hangup: work responsible for HUPing when carrier is dropped/lost
* @mstatus: loose virtualization of LSR/MSR
* bits 15..0 correspond to TIOCM_* bits
* bits 19..16 reserved for mctrl
* bit 20 OOB_TX_THROTTLE
* bits 23..21 reserved
* bits 31..24 correspond to UART_LSR_* bits
* @lock: spinlock for protecting concurrent access to fields below it
* @mctrl: loose virtualization of MCR
* bits 15..0 correspond to TIOCM_* bits
* bit 16 OOB_RX_THROTTLE
* bits 19..17 reserved
* bits 31..20 reserved for mstatus
* @drain: delayed work scheduled to ensure that writes are flushed.
* The work can race with the writer but concurrent sending is
* prevented with the IN_TX flag. Scheduled under lock to
* limit scheduling when fifo has just been drained.
* @tx_fifo: fifo used to store & block-up writes for dma to remote
* @max_payload: max bytes transmissible per dma (based on peer's max_payload)
* @status_mask: UART_LSR_* bitmask significant to rx (based on termios)
* @ignore_mask: UART_LSR_* bitmask of states to ignore (also based on termios)
* @break_ctl: if set, port is 'sending break' to remote
* @write_only: self-explanatory
* @overrun: previous rx was lost (partially or completely)
* @loopback: if set, port is in loopback mode
* @flags: atomic bit flags
* bit 0: IN_TX - gate to allow only one cpu to send from the dma fifo
* at a time.
* bit 1: STOP_TX - force tx to exit while sending
* @peer: rcu-pointer to associated fwtty_peer (if attached)
* NULL if no peer attached
* @icount: predefined statistics reported by the TIOCGICOUNT ioctl
* @stats: additional statistics reported in /proc/tty/driver/firewire_serial
*/
struct fwtty_port {
struct tty_port port;
struct device *device;
unsigned int index;
struct fw_serial *serial;
struct fw_address_handler rx_handler;
struct fwconsole_ops *fwcon_ops;
void *con_data;
wait_queue_head_t wait_tx;
struct delayed_work emit_breaks;
unsigned int cps;
unsigned long break_last;
struct work_struct hangup;
unsigned int mstatus;
spinlock_t lock;
unsigned int mctrl;
struct delayed_work drain;
struct dma_fifo tx_fifo;
int max_payload;
unsigned int status_mask;
unsigned int ignore_mask;
unsigned int break_ctl:1,
write_only:1,
overrun:1,
loopback:1;
unsigned long flags;
struct fwtty_peer __rcu *peer;
struct async_icount icount;
struct stats stats;
};
#define to_port(ptr, field) (container_of(ptr, struct fwtty_port, field))
/* bit #s for flags field */
#define IN_TX 0
#define STOP_TX 1
/* bitmasks for special mctrl/mstatus bits */
#define OOB_RX_THROTTLE 0x00010000
#define MCTRL_RSRVD 0x000e0000
#define OOB_TX_THROTTLE 0x00100000
#define MSTATUS_RSRVD 0x00e00000
#define MCTRL_MASK (TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 | TIOCM_OUT2 | \
TIOCM_LOOP | OOB_RX_THROTTLE | MCTRL_RSRVD)
/* XXX even every 1/50th secs. may be unnecessarily accurate */
/* delay in jiffies between brk emits */
#define FREQ_BREAKS (HZ / 50)
/* Ports are allocated in blocks of num_ports for each fw_card */
#define MAX_CARD_PORTS CONFIG_FWTTY_MAX_CARD_PORTS
#define MAX_TOTAL_PORTS CONFIG_FWTTY_MAX_TOTAL_PORTS
/* tuning parameters */
#define FWTTY_PORT_TXFIFO_LEN 4096
#define FWTTY_PORT_MAX_PEND_DMA 8 /* costs a cache line per pend */
#define DRAIN_THRESHOLD 1024
#define MAX_ASYNC_PAYLOAD 4096 /* ohci-defined limit */
#define WRITER_MINIMUM 128
/* TODO: how to set watermark to AR context size? see fwtty_rx() */
#define HIGH_WATERMARK 32768 /* AR context is 32K */
/*
* Size of bus addr region above 4GB used per port as the recv addr
* - must be at least as big as the MAX_ASYNC_PAYLOAD
*/
#define FWTTY_PORT_RXFIFO_LEN MAX_ASYNC_PAYLOAD
/**
* fw_serial: aggregate used to associate tty ports with specific fw_card
* @card: fw_card associated with this fw_serial device (1:1 association)
* @kref: reference-counted multi-port management allows delayed destroy
* @self: local unit device as 'peer'. Not valid until local unit device
* is enumerated.
* @list: link for insertion into fwserial_list
* @peer_list: list of local & remote unit devices attached to this card
* @ports: fixed array of tty_ports provided by this serial device
*/
struct fw_serial {
struct fw_card *card;
struct kref kref;
struct dentry *debugfs;
struct fwtty_peer *self;
struct list_head list;
struct list_head peer_list;
struct fwtty_port *ports[MAX_CARD_PORTS];
};
#define to_serial(ptr, field) (container_of(ptr, struct fw_serial, field))
#define TTY_DEV_NAME "fwtty" /* ttyFW was taken */
static const char tty_dev_name[] = TTY_DEV_NAME;
static const char loop_dev_name[] = "fwloop";
extern struct tty_driver *fwtty_driver;
/*
* Returns the max send async payload size in bytes based on the unit device
* link speed. Self-limiting asynchronous bandwidth (via reducing the payload)
* is not necessary and does not work, because
* 1) asynchronous traffic will absorb all available bandwidth (less that
* being used for isochronous traffic)
* 2) isochronous arbitration always wins.
*/
static inline int link_speed_to_max_payload(unsigned int speed)
{
/* Max async payload is 4096 - see IEEE 1394-2008 tables 6-4, 16-18 */
return min(512 << speed, 4096);
}
#endif /* _FIREWIRE_FWSERIAL_H */