1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _FIREWIRE_FWSERIAL_H
3 #define _FIREWIRE_FWSERIAL_H
4
5 #include <linux/kernel.h>
6 #include <linux/tty.h>
7 #include <linux/tty_driver.h>
8 #include <linux/tty_flip.h>
9 #include <linux/list.h>
10 #include <linux/firewire.h>
11 #include <linux/firewire-constants.h>
12 #include <linux/spinlock.h>
13 #include <linux/rcupdate.h>
14 #include <linux/mutex.h>
15 #include <linux/serial.h>
16 #include <linux/serial_reg.h>
17 #include <linux/module.h>
18 #include <linux/seq_file.h>
19 #include <linux/debugfs.h>
20
21 #include "dma_fifo.h"
22
23 #ifdef FWTTY_PROFILING
24 #define DISTRIBUTION_MAX_SIZE 8192
25 #define DISTRIBUTION_MAX_INDEX (ilog2(DISTRIBUTION_MAX_SIZE) + 1)
26 static inline void fwtty_profile_data(unsigned int stat[], unsigned int val)
27 {
28 int n = (val) ? min(ilog2(val) + 1, DISTRIBUTION_MAX_INDEX) : 0;
29 ++stat[n];
30 }
31 #else
32 #define DISTRIBUTION_MAX_INDEX 0
33 #define fwtty_profile_data(st, n)
34 #endif
35
36 /* Parameters for both VIRT_CABLE_PLUG & VIRT_CABLE_PLUG_RSP mgmt codes */
37 struct virt_plug_params {
38 __be32 status_hi;
39 __be32 status_lo;
40 __be32 fifo_hi;
41 __be32 fifo_lo;
42 __be32 fifo_len;
43 };
44
45 struct peer_work_params {
46 union {
47 struct virt_plug_params plug_req;
48 };
49 };
50
51 /**
52 * fwtty_peer: structure representing local & remote unit devices
53 * @unit: unit child device of fw_device node
54 * @serial: back pointer to associated fw_serial aggregate
55 * @guid: unique 64-bit guid for this unit device
56 * @generation: most recent bus generation
57 * @node_id: most recent node_id
58 * @speed: link speed of peer (0 = S100, 2 = S400, ... 5 = S3200)
59 * @mgmt_addr: bus addr region to write mgmt packets to
60 * @status_addr: bus addr register to write line status to
61 * @fifo_addr: bus addr region to write serial output to
62 * @fifo_len: max length for single write to fifo_addr
63 * @list: link for insertion into fw_serial's peer_list
64 * @rcu: for deferring peer reclamation
65 * @lock: spinlock to synchonize changes to state & port fields
66 * @work: only one work item can be queued at any one time
67 * Note: pending work is canceled prior to removal, so this
68 * peer is valid for at least the lifetime of the work function
69 * @work_params: parameter block for work functions
70 * @timer: timer for resetting peer state if remote request times out
71 * @state: current state
72 * @connect: work item for auto-connecting
73 * @connect_retries: # of connections already attempted
74 * @port: associated tty_port (usable if state == FWSC_ATTACHED)
75 */
76 struct fwtty_peer {
77 struct fw_unit *unit;
78 struct fw_serial *serial;
79 u64 guid;
80 int generation;
81 int node_id;
82 unsigned int speed;
83 int max_payload;
84 u64 mgmt_addr;
85
86 /* these are usable only if state == FWSC_ATTACHED */
87 u64 status_addr;
88 u64 fifo_addr;
89 int fifo_len;
90
91 struct list_head list;
92 struct rcu_head rcu;
93
94 spinlock_t lock;
95 work_func_t workfn;
96 struct work_struct work;
97 struct peer_work_params work_params;
98 struct timer_list timer;
99 int state;
100 struct delayed_work connect;
101 int connect_retries;
102
103 struct fwtty_port *port;
104 };
105
106 #define to_peer(ptr, field) (container_of(ptr, struct fwtty_peer, field))
107
108 /* state values for fwtty_peer.state field */
109 enum fwtty_peer_state {
110 FWPS_GONE,
111 FWPS_NOT_ATTACHED,
112 FWPS_ATTACHED,
113 FWPS_PLUG_PENDING,
114 FWPS_PLUG_RESPONDING,
115 FWPS_UNPLUG_PENDING,
116 FWPS_UNPLUG_RESPONDING,
117
118 FWPS_NO_MGMT_ADDR = -1,
119 };
120
121 #define CONNECT_RETRY_DELAY HZ
122 #define MAX_CONNECT_RETRIES 10
123
124 /* must be holding peer lock for these state funclets */
125 static inline void peer_set_state(struct fwtty_peer *peer, int new)
126 {
127 peer->state = new;
128 }
129
130 static inline struct fwtty_port *peer_revert_state(struct fwtty_peer *peer)
131 {
132 struct fwtty_port *port = peer->port;
133
134 peer->port = NULL;
135 peer_set_state(peer, FWPS_NOT_ATTACHED);
136 return port;
137 }
138
139 struct fwserial_mgmt_pkt {
140 struct {
141 __be16 len;
142 __be16 code;
143 } hdr;
144 union {
145 struct virt_plug_params plug_req;
146 struct virt_plug_params plug_rsp;
147 };
148 } __packed;
149
150 /* fwserial_mgmt_packet codes */
151 #define FWSC_RSP_OK 0x0000
152 #define FWSC_RSP_NACK 0x8000
153 #define FWSC_CODE_MASK 0x0fff
154
155 #define FWSC_VIRT_CABLE_PLUG 1
156 #define FWSC_VIRT_CABLE_UNPLUG 2
157 #define FWSC_VIRT_CABLE_PLUG_RSP 3
158 #define FWSC_VIRT_CABLE_UNPLUG_RSP 4
159
160 /* 1 min. plug timeout -- suitable for userland authorization */
161 #define VIRT_CABLE_PLUG_TIMEOUT (60 * HZ)
162
163 struct stats {
164 unsigned int xchars;
165 unsigned int dropped;
166 unsigned int tx_stall;
167 unsigned int fifo_errs;
168 unsigned int sent;
169 unsigned int lost;
170 unsigned int throttled;
171 unsigned int reads[DISTRIBUTION_MAX_INDEX + 1];
172 unsigned int writes[DISTRIBUTION_MAX_INDEX + 1];
173 unsigned int txns[DISTRIBUTION_MAX_INDEX + 1];
174 unsigned int unthrottle[DISTRIBUTION_MAX_INDEX + 1];
175 };
176
177 struct fwconsole_ops {
178 void (*notify)(int code, void *data);
179 void (*stats)(struct stats *stats, void *data);
180 void (*proc_show)(struct seq_file *m, void *data);
181 };
182
183 /* codes for console ops notify */
184 #define FWCON_NOTIFY_ATTACH 1
185 #define FWCON_NOTIFY_DETACH 2
186
187 /**
188 * fwtty_port: structure used to track/represent underlying tty_port
189 * @port: underlying tty_port
190 * @device: tty device
191 * @index: index into port_table for this particular port
192 * note: minor = index + minor_start assigned by tty_alloc_driver()
193 * @serial: back pointer to the containing fw_serial
194 * @rx_handler: bus address handler for unique addr region used by remotes
195 * to communicate with this port. Every port uses
196 * fwtty_port_handler() for per port transactions.
197 * @fwcon_ops: ops for attached fw_console (if any)
198 * @con_data: private data for fw_console
199 * @wait_tx: waitqueue for sleeping until writer/drain completes tx
200 * @emit_breaks: delayed work responsible for generating breaks when the
201 * break line status is active
202 * @cps : characters per second computed from the termios settings
203 * @break_last: timestamp in jiffies from last emit_breaks
204 * @hangup: work responsible for HUPing when carrier is dropped/lost
205 * @mstatus: loose virtualization of LSR/MSR
206 * bits 15..0 correspond to TIOCM_* bits
207 * bits 19..16 reserved for mctrl
208 * bit 20 OOB_TX_THROTTLE
209 * bits 23..21 reserved
210 * bits 31..24 correspond to UART_LSR_* bits
211 * @lock: spinlock for protecting concurrent access to fields below it
212 * @mctrl: loose virtualization of MCR
213 * bits 15..0 correspond to TIOCM_* bits
214 * bit 16 OOB_RX_THROTTLE
215 * bits 19..17 reserved
216 * bits 31..20 reserved for mstatus
217 * @drain: delayed work scheduled to ensure that writes are flushed.
218 * The work can race with the writer but concurrent sending is
219 * prevented with the IN_TX flag. Scheduled under lock to
220 * limit scheduling when fifo has just been drained.
221 * @tx_fifo: fifo used to store & block-up writes for dma to remote
222 * @max_payload: max bytes transmissible per dma (based on peer's max_payload)
223 * @status_mask: UART_LSR_* bitmask significant to rx (based on termios)
224 * @ignore_mask: UART_LSR_* bitmask of states to ignore (also based on termios)
225 * @break_ctl: if set, port is 'sending break' to remote
226 * @write_only: self-explanatory
227 * @overrun: previous rx was lost (partially or completely)
228 * @loopback: if set, port is in loopback mode
229 * @flags: atomic bit flags
230 * bit 0: IN_TX - gate to allow only one cpu to send from the dma fifo
231 * at a time.
232 * bit 1: STOP_TX - force tx to exit while sending
233 * @peer: rcu-pointer to associated fwtty_peer (if attached)
234 * NULL if no peer attached
235 * @icount: predefined statistics reported by the TIOCGICOUNT ioctl
236 * @stats: additional statistics reported in /proc/tty/driver/firewire_serial
237 */
238 struct fwtty_port {
239 struct tty_port port;
240 struct device *device;
241 unsigned int index;
242 struct fw_serial *serial;
243 struct fw_address_handler rx_handler;
244
245 struct fwconsole_ops *fwcon_ops;
246 void *con_data;
247
248 wait_queue_head_t wait_tx;
249 struct delayed_work emit_breaks;
250 unsigned int cps;
251 unsigned long break_last;
252
253 struct work_struct hangup;
254
255 unsigned int mstatus;
256
257 spinlock_t lock;
258 unsigned int mctrl;
259 struct delayed_work drain;
260 struct dma_fifo tx_fifo;
261 int max_payload;
262 unsigned int status_mask;
263 unsigned int ignore_mask;
264 unsigned int break_ctl:1,
265 write_only:1,
266 overrun:1,
267 loopback:1;
268 unsigned long flags;
269
270 struct fwtty_peer __rcu *peer;
271
272 struct async_icount icount;
273 struct stats stats;
274 };
275
276 #define to_port(ptr, field) (container_of(ptr, struct fwtty_port, field))
277
278 /* bit #s for flags field */
279 #define IN_TX 0
280 #define STOP_TX 1
281
282 /* bitmasks for special mctrl/mstatus bits */
283 #define OOB_RX_THROTTLE 0x00010000
284 #define MCTRL_RSRVD 0x000e0000
285 #define OOB_TX_THROTTLE 0x00100000
286 #define MSTATUS_RSRVD 0x00e00000
287
288 #define MCTRL_MASK (TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 | TIOCM_OUT2 | \
289 TIOCM_LOOP | OOB_RX_THROTTLE | MCTRL_RSRVD)
290
291 /* XXX even every 1/50th secs. may be unnecessarily accurate */
292 /* delay in jiffies between brk emits */
293 #define FREQ_BREAKS (HZ / 50)
294
295 /* Ports are allocated in blocks of num_ports for each fw_card */
296 #define MAX_CARD_PORTS CONFIG_FWTTY_MAX_CARD_PORTS
297 #define MAX_TOTAL_PORTS CONFIG_FWTTY_MAX_TOTAL_PORTS
298
299 /* tuning parameters */
300 #define FWTTY_PORT_TXFIFO_LEN 4096
301 #define FWTTY_PORT_MAX_PEND_DMA 8 /* costs a cache line per pend */
302 #define DRAIN_THRESHOLD 1024
303 #define MAX_ASYNC_PAYLOAD 4096 /* ohci-defined limit */
304 #define WRITER_MINIMUM 128
305 /* TODO: how to set watermark to AR context size? see fwtty_rx() */
306 #define HIGH_WATERMARK 32768 /* AR context is 32K */
307
308 /*
309 * Size of bus addr region above 4GB used per port as the recv addr
310 * - must be at least as big as the MAX_ASYNC_PAYLOAD
311 */
312 #define FWTTY_PORT_RXFIFO_LEN MAX_ASYNC_PAYLOAD
313
314 /**
315 * fw_serial: aggregate used to associate tty ports with specific fw_card
316 * @card: fw_card associated with this fw_serial device (1:1 association)
317 * @kref: reference-counted multi-port management allows delayed destroy
318 * @self: local unit device as 'peer'. Not valid until local unit device
319 * is enumerated.
320 * @list: link for insertion into fwserial_list
321 * @peer_list: list of local & remote unit devices attached to this card
322 * @ports: fixed array of tty_ports provided by this serial device
323 */
324 struct fw_serial {
325 struct fw_card *card;
326 struct kref kref;
327
328 struct dentry *debugfs;
329 struct fwtty_peer *self;
330
331 struct list_head list;
332 struct list_head peer_list;
333
334 struct fwtty_port *ports[MAX_CARD_PORTS];
335 };
336
337 #define to_serial(ptr, field) (container_of(ptr, struct fw_serial, field))
338
339 #define TTY_DEV_NAME "fwtty" /* ttyFW was taken */
340 static const char tty_dev_name[] = TTY_DEV_NAME;
341 static const char loop_dev_name[] = "fwloop";
342
343 extern struct tty_driver *fwtty_driver;
344
345 /*
346 * Returns the max send async payload size in bytes based on the unit device
347 * link speed. Self-limiting asynchronous bandwidth (via reducing the payload)
348 * is not necessary and does not work, because
349 * 1) asynchronous traffic will absorb all available bandwidth (less that
350 * being used for isochronous traffic)
351 * 2) isochronous arbitration always wins.
352 */
353 static inline int link_speed_to_max_payload(unsigned int speed)
354 {
355 /* Max async payload is 4096 - see IEEE 1394-2008 tables 6-4, 16-18 */
356 return min(512 << speed, 4096);
357 }
358
359 #endif /* _FIREWIRE_FWSERIAL_H */