2 * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 /* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS
20 * and the service processor on IBM pSeries servers. On these servers, there
21 * are no serial ports under the OS's control, and sometimes there is no other
22 * console available either. However, the service processor has two standard
23 * serial ports, so this over-complicated protocol allows the OS to control
24 * those ports by proxy.
26 * Besides data, the procotol supports the reading/writing of the serial
27 * port's DTR line, and the reading of the CD line. This is to allow the OS to
28 * control a modem attached to the service processor's serial port. Note that
29 * the OS cannot change the speed of the port through this protocol.
34 #include <linux/console.h>
35 #include <linux/ctype.h>
36 #include <linux/delay.h>
37 #include <linux/init.h>
38 #include <linux/interrupt.h>
39 #include <linux/module.h>
40 #include <linux/major.h>
41 #include <linux/kernel.h>
42 #include <linux/sched.h>
43 #include <linux/spinlock.h>
44 #include <linux/sysrq.h>
45 #include <linux/tty.h>
46 #include <linux/tty_flip.h>
47 #include <asm/hvcall.h>
48 #include <asm/hvconsole.h>
50 #include <asm/uaccess.h>
52 #include <asm/param.h>
54 #define HVSI_MAJOR 229
55 #define HVSI_MINOR 128
56 #define MAX_NR_HVSI_CONSOLES 4
58 #define HVSI_TIMEOUT (5*HZ)
59 #define HVSI_VERSION 1
60 #define HVSI_MAX_PACKET 256
61 #define HVSI_MAX_READ 16
62 #define HVSI_MAX_OUTGOING_DATA 12
66 * we pass data via two 8-byte registers, so we would like our char arrays
67 * properly aligned for those loads.
69 #define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
72 struct work_struct writer;
73 struct work_struct handshaker;
74 wait_queue_head_t emptyq; /* woken when outbuf is emptied */
75 wait_queue_head_t stateq; /* woken when HVSI state changes */
78 struct tty_struct *tty;
80 uint8_t throttle_buf[128];
81 uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
82 /* inbuf is for packet reassembly. leave a little room for leftovers. */
83 uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
89 atomic_t seqno; /* HVSI packet sequence number */
91 uint8_t state; /* HVSI protocol state */
93 #ifdef CONFIG_MAGIC_SYSRQ
95 #endif /* CONFIG_MAGIC_SYSRQ */
97 static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
99 static struct tty_driver *hvsi_driver;
100 static int hvsi_count;
101 static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
103 enum HVSI_PROTOCOL_STATE {
105 HVSI_WAIT_FOR_VER_RESPONSE,
106 HVSI_WAIT_FOR_VER_QUERY,
108 HVSI_WAIT_FOR_MCTRL_RESPONSE,
111 #define HVSI_CONSOLE 0x1
113 #define VS_DATA_PACKET_HEADER 0xff
114 #define VS_CONTROL_PACKET_HEADER 0xfe
115 #define VS_QUERY_PACKET_HEADER 0xfd
116 #define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
119 #define VSV_SET_MODEM_CTL 1 /* to service processor only */
120 #define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
121 #define VSV_CLOSE_PROTOCOL 3
124 #define VSV_SEND_VERSION_NUMBER 1
125 #define VSV_SEND_MODEM_CTL_STATUS 2
127 /* yes, these masks are not consecutive. */
128 #define HVSI_TSDTR 0x01
129 #define HVSI_TSCD 0x20
135 } __attribute__((packed));
141 uint8_t data[HVSI_MAX_OUTGOING_DATA];
142 } __attribute__((packed));
144 struct hvsi_control {
149 /* optional depending on verb: */
152 } __attribute__((packed));
159 } __attribute__((packed));
161 struct hvsi_query_response {
166 uint16_t query_seqno;
171 } __attribute__((packed));
175 static inline int is_console(struct hvsi_struct *hp)
177 return hp->flags & HVSI_CONSOLE;
180 static inline int is_open(struct hvsi_struct *hp)
182 /* if we're waiting for an mctrl then we're already open */
183 return (hp->state == HVSI_OPEN)
184 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
187 static inline void print_state(struct hvsi_struct *hp)
190 static const char *state_names[] = {
192 "HVSI_WAIT_FOR_VER_RESPONSE",
193 "HVSI_WAIT_FOR_VER_QUERY",
195 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
198 const char *name = state_names[hp->state];
200 if (hp->state > (sizeof(state_names)/sizeof(char*)))
203 pr_debug("hvsi%i: state = %s\n", hp->index, name);
207 static inline void __set_state(struct hvsi_struct *hp, int state)
211 wake_up_all(&hp->stateq);
214 static inline void set_state(struct hvsi_struct *hp, int state)
218 spin_lock_irqsave(&hp->lock, flags);
219 __set_state(hp, state);
220 spin_unlock_irqrestore(&hp->lock, flags);
223 static inline int len_packet(const uint8_t *packet)
225 return (int)((struct hvsi_header *)packet)->len;
228 static inline int is_header(const uint8_t *packet)
230 struct hvsi_header *header = (struct hvsi_header *)packet;
231 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
234 static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
236 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
237 return 0; /* don't even have the packet header */
239 if (hp->inbuf_end < (packet + len_packet(packet)))
240 return 0; /* don't have the rest of the packet */
245 /* shift remaining bytes in packetbuf down */
246 static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
248 int remaining = (int)(hp->inbuf_end - read_to);
250 pr_debug("%s: %i chars remain\n", __FUNCTION__, remaining);
252 if (read_to != hp->inbuf)
253 memmove(hp->inbuf, read_to, remaining);
255 hp->inbuf_end = hp->inbuf + remaining;
259 #define dbg_dump_packet(packet) dump_packet(packet)
260 #define dbg_dump_hex(data, len) dump_hex(data, len)
262 #define dbg_dump_packet(packet) do { } while (0)
263 #define dbg_dump_hex(data, len) do { } while (0)
266 static void dump_hex(const uint8_t *data, int len)
271 for (i=0; i < len; i++)
272 printk("%.2x", data[i]);
275 for (i=0; i < len; i++) {
276 if (isprint(data[i]))
277 printk("%c", data[i]);
284 static void dump_packet(uint8_t *packet)
286 struct hvsi_header *header = (struct hvsi_header *)packet;
288 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
291 dump_hex(packet, header->len);
294 /* can't use hvc_get_chars because that strips CRs */
295 static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
299 if (plpar_hcall(H_GET_TERM_CHAR, hp->vtermno, 0, 0, 0, &got,
300 (unsigned long *)buf, (unsigned long *)buf+1) == H_Success)
305 static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
306 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
308 struct hvsi_control *header = (struct hvsi_control *)packet;
310 switch (header->verb) {
311 case VSV_MODEM_CTL_UPDATE:
312 if ((header->word & HVSI_TSCD) == 0) {
313 /* CD went away; no more connection */
314 pr_debug("hvsi%i: CD dropped\n", hp->index);
315 hp->mctrl &= TIOCM_CD;
316 if (!(hp->tty->flags & CLOCAL))
317 *to_hangup = hp->tty;
320 case VSV_CLOSE_PROTOCOL:
321 pr_debug("hvsi%i: service processor came back\n", hp->index);
322 if (hp->state != HVSI_CLOSED) {
327 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
334 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
336 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
339 case HVSI_WAIT_FOR_VER_RESPONSE:
340 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
342 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
344 if (resp->u.mctrl_word & HVSI_TSDTR)
345 hp->mctrl |= TIOCM_DTR;
346 if (resp->u.mctrl_word & HVSI_TSCD)
347 hp->mctrl |= TIOCM_CD;
348 __set_state(hp, HVSI_OPEN);
351 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
357 /* respond to service processor's version query */
358 static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
360 struct hvsi_query_response packet __ALIGNED__;
363 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
364 packet.len = sizeof(struct hvsi_query_response);
365 packet.seqno = atomic_inc_return(&hp->seqno);
366 packet.verb = VSV_SEND_VERSION_NUMBER;
367 packet.u.version = HVSI_VERSION;
368 packet.query_seqno = query_seqno+1;
370 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
371 dbg_dump_hex((uint8_t*)&packet, packet.len);
373 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
374 if (wrote != packet.len) {
375 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
383 static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
385 struct hvsi_query *query = (struct hvsi_query *)packet;
388 case HVSI_WAIT_FOR_VER_QUERY:
389 hvsi_version_respond(hp, query->seqno);
390 __set_state(hp, HVSI_OPEN);
393 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
399 static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
403 for (i=0; i < len; i++) {
405 #ifdef CONFIG_MAGIC_SYSRQ
409 } else if (hp->sysrq) {
410 handle_sysrq(c, NULL, hp->tty);
414 #endif /* CONFIG_MAGIC_SYSRQ */
415 tty_insert_flip_char(hp->tty, c, 0);
420 * We could get 252 bytes of data at once here. But the tty layer only
421 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
422 * it. Accordingly we won't send more than 128 bytes at a time to the flip
423 * buffer, which will give the tty buffer a chance to throttle us. Should the
424 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
427 #define TTY_THRESHOLD_THROTTLE 128
428 static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
429 const uint8_t *packet)
431 const struct hvsi_header *header = (const struct hvsi_header *)packet;
432 const uint8_t *data = packet + sizeof(struct hvsi_header);
433 int datalen = header->len - sizeof(struct hvsi_header);
434 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
436 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
442 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __FUNCTION__);
443 datalen = TTY_THRESHOLD_THROTTLE;
446 hvsi_insert_chars(hp, data, datalen);
450 * we still have more data to deliver, so we need to save off the
451 * overflow and send it later
453 pr_debug("%s: deferring overflow\n", __FUNCTION__);
454 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
455 hp->n_throttle = overflow;
462 * Returns true/false indicating data successfully read from hypervisor.
463 * Used both to get packets for tty connections and to advance the state
464 * machine during console handshaking (in which case tty = NULL and we ignore
467 static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
468 struct tty_struct **hangup, struct hvsi_struct **handshake)
470 uint8_t *packet = hp->inbuf;
477 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
479 pr_debug("%s: 0-length read\n", __FUNCTION__);
483 pr_debug("%s: got %i bytes\n", __FUNCTION__, chunklen);
484 dbg_dump_hex(hp->inbuf_end, chunklen);
486 hp->inbuf_end += chunklen;
488 /* handle all completed packets */
489 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
490 struct hvsi_header *header = (struct hvsi_header *)packet;
492 if (!is_header(packet)) {
493 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
494 /* skip bytes until we find a header or run out of data */
495 while ((packet < hp->inbuf_end) && (!is_header(packet)))
500 pr_debug("%s: handling %i-byte packet\n", __FUNCTION__,
502 dbg_dump_packet(packet);
504 switch (header->type) {
505 case VS_DATA_PACKET_HEADER:
509 break; /* no tty buffer to put data in */
510 *flip = hvsi_recv_data(hp, packet);
512 case VS_CONTROL_PACKET_HEADER:
513 hvsi_recv_control(hp, packet, hangup, handshake);
515 case VS_QUERY_RESPONSE_PACKET_HEADER:
516 hvsi_recv_response(hp, packet);
518 case VS_QUERY_PACKET_HEADER:
519 hvsi_recv_query(hp, packet);
522 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
523 hp->index, header->type);
528 packet += len_packet(packet);
530 if (*hangup || *handshake) {
531 pr_debug("%s: hangup or handshake\n", __FUNCTION__);
533 * we need to send the hangup now before receiving any more data.
534 * If we get "data, hangup, data", we can't deliver the second
535 * data before the hangup.
541 compact_inbuf(hp, packet);
546 static void hvsi_send_overflow(struct hvsi_struct *hp)
548 pr_debug("%s: delivering %i bytes overflow\n", __FUNCTION__,
551 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
556 * must get all pending data because we only get an irq on empty->non-empty
559 static irqreturn_t hvsi_interrupt(int irq, void *arg, struct pt_regs *regs)
561 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
562 struct tty_struct *flip;
563 struct tty_struct *hangup;
564 struct hvsi_struct *handshake;
568 pr_debug("%s\n", __FUNCTION__);
571 spin_lock_irqsave(&hp->lock, flags);
572 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
573 spin_unlock_irqrestore(&hp->lock, flags);
576 * we have to call tty_flip_buffer_push() and tty_hangup() outside our
577 * spinlock. But we also have to keep going until we've read all the
582 /* there was data put in the tty flip buffer */
583 tty_flip_buffer_push(flip);
592 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
593 schedule_work(&handshake->handshaker);
597 spin_lock_irqsave(&hp->lock, flags);
598 if (hp->tty && hp->n_throttle
599 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
600 /* we weren't hung up and we weren't throttled, so we can deliver the
603 hvsi_send_overflow(hp);
605 spin_unlock_irqrestore(&hp->lock, flags);
608 tty_flip_buffer_push(flip);
614 /* for boot console, before the irq handler is running */
615 static int __init poll_for_state(struct hvsi_struct *hp, int state)
617 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
620 hvsi_interrupt(hp->virq, (void *)hp, NULL); /* get pending data */
622 if (hp->state == state)
626 if (time_after(jiffies, end_jiffies))
631 /* wait for irq handler to change our state */
632 static int wait_for_state(struct hvsi_struct *hp, int state)
634 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
635 unsigned long timeout;
638 DECLARE_WAITQUEUE(myself, current);
639 set_current_state(TASK_INTERRUPTIBLE);
640 add_wait_queue(&hp->stateq, &myself);
643 set_current_state(TASK_INTERRUPTIBLE);
644 if (hp->state == state)
646 timeout = end_jiffies - jiffies;
647 if (time_after(jiffies, end_jiffies)) {
651 schedule_timeout(timeout);
653 remove_wait_queue(&hp->stateq, &myself);
654 set_current_state(TASK_RUNNING);
659 static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
661 struct hvsi_query packet __ALIGNED__;
664 packet.type = VS_QUERY_PACKET_HEADER;
665 packet.len = sizeof(struct hvsi_query);
666 packet.seqno = atomic_inc_return(&hp->seqno);
669 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
670 dbg_dump_hex((uint8_t*)&packet, packet.len);
672 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
673 if (wrote != packet.len) {
674 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
682 static int hvsi_get_mctrl(struct hvsi_struct *hp)
686 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
687 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
689 ret = hvsi_wait(hp, HVSI_OPEN);
691 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
692 set_state(hp, HVSI_OPEN);
696 pr_debug("%s: mctrl 0x%x\n", __FUNCTION__, hp->mctrl);
701 /* note that we can only set DTR */
702 static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
704 struct hvsi_control packet __ALIGNED__;
707 packet.type = VS_CONTROL_PACKET_HEADER,
708 packet.seqno = atomic_inc_return(&hp->seqno);
709 packet.len = sizeof(struct hvsi_control);
710 packet.verb = VSV_SET_MODEM_CTL;
711 packet.mask = HVSI_TSDTR;
713 if (mctrl & TIOCM_DTR)
714 packet.word = HVSI_TSDTR;
716 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
717 dbg_dump_hex((uint8_t*)&packet, packet.len);
719 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
720 if (wrote != packet.len) {
721 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
728 static void hvsi_drain_input(struct hvsi_struct *hp)
730 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
731 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
733 while (time_before(end_jiffies, jiffies))
734 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
738 static int hvsi_handshake(struct hvsi_struct *hp)
743 * We could have a CLOSE or other data waiting for us before we even try
744 * to open; try to throw it all away so we don't get confused. (CLOSE
745 * is the first message sent up the pipe when the FSP comes online. We
746 * need to distinguish between "it came up a while ago and we're the first
747 * user" and "it was just reset before it saw our handshake packet".)
749 hvsi_drain_input(hp);
751 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
752 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
754 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
758 ret = hvsi_wait(hp, HVSI_OPEN);
765 static void hvsi_handshaker(void *arg)
767 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
769 if (hvsi_handshake(hp) >= 0)
772 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
773 if (is_console(hp)) {
775 * ttys will re-attempt the handshake via hvsi_open, but
776 * the console will not.
778 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
782 static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
784 struct hvsi_data packet __ALIGNED__;
787 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
789 packet.type = VS_DATA_PACKET_HEADER;
790 packet.seqno = atomic_inc_return(&hp->seqno);
791 packet.len = count + sizeof(struct hvsi_header);
792 memcpy(&packet.data, buf, count);
794 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
795 if (ret == packet.len) {
796 /* return the number of chars written, not the packet length */
799 return ret; /* return any errors */
802 static void hvsi_close_protocol(struct hvsi_struct *hp)
804 struct hvsi_control packet __ALIGNED__;
806 packet.type = VS_CONTROL_PACKET_HEADER;
807 packet.seqno = atomic_inc_return(&hp->seqno);
809 packet.verb = VSV_CLOSE_PROTOCOL;
811 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
812 dbg_dump_hex((uint8_t*)&packet, packet.len);
814 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
817 static int hvsi_open(struct tty_struct *tty, struct file *filp)
819 struct hvsi_struct *hp;
821 int line = tty->index;
824 pr_debug("%s\n", __FUNCTION__);
826 if (line < 0 || line >= hvsi_count)
828 hp = &hvsi_ports[line];
830 tty->driver_data = hp;
831 tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */
834 if (hp->state == HVSI_FSP_DIED)
837 spin_lock_irqsave(&hp->lock, flags);
840 atomic_set(&hp->seqno, 0);
841 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
842 spin_unlock_irqrestore(&hp->lock, flags);
845 return 0; /* this has already been handshaked as the console */
847 ret = hvsi_handshake(hp);
849 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
853 ret = hvsi_get_mctrl(hp);
855 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
859 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
861 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
868 /* wait for hvsi_write_worker to empty hp->outbuf */
869 static void hvsi_flush_output(struct hvsi_struct *hp)
871 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
872 unsigned long timeout;
874 DECLARE_WAITQUEUE(myself, current);
875 set_current_state(TASK_UNINTERRUPTIBLE);
876 add_wait_queue(&hp->emptyq, &myself);
879 set_current_state(TASK_UNINTERRUPTIBLE);
880 if (hp->n_outbuf <= 0)
882 timeout = end_jiffies - jiffies;
883 if (time_after(jiffies, end_jiffies))
885 schedule_timeout(timeout);
887 remove_wait_queue(&hp->emptyq, &myself);
888 set_current_state(TASK_RUNNING);
890 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
891 cancel_delayed_work(&hp->writer);
892 flush_scheduled_work();
895 * it's also possible that our timeout expired and hvsi_write_worker
896 * didn't manage to push outbuf. poof.
901 static void hvsi_close(struct tty_struct *tty, struct file *filp)
903 struct hvsi_struct *hp = tty->driver_data;
906 pr_debug("%s\n", __FUNCTION__);
908 if (tty_hung_up_p(filp))
911 spin_lock_irqsave(&hp->lock, flags);
913 if (--hp->count == 0) {
915 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
917 /* only close down connection if it is not the console */
918 if (!is_console(hp)) {
919 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
920 __set_state(hp, HVSI_CLOSED);
922 * any data delivered to the tty layer after this will be
923 * discarded (except for XON/XOFF)
927 spin_unlock_irqrestore(&hp->lock, flags);
929 /* let any existing irq handlers finish. no more will start. */
930 synchronize_irq(hp->virq);
932 /* hvsi_write_worker will re-schedule until outbuf is empty. */
933 hvsi_flush_output(hp);
935 /* tell FSP to stop sending data */
936 hvsi_close_protocol(hp);
939 * drain anything FSP is still in the middle of sending, and let
940 * hvsi_handshake drain the rest on the next open.
942 hvsi_drain_input(hp);
944 spin_lock_irqsave(&hp->lock, flags);
946 } else if (hp->count < 0)
947 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
948 hp - hvsi_ports, hp->count);
950 spin_unlock_irqrestore(&hp->lock, flags);
953 static void hvsi_hangup(struct tty_struct *tty)
955 struct hvsi_struct *hp = tty->driver_data;
958 pr_debug("%s\n", __FUNCTION__);
960 spin_lock_irqsave(&hp->lock, flags);
966 spin_unlock_irqrestore(&hp->lock, flags);
969 /* called with hp->lock held */
970 static void hvsi_push(struct hvsi_struct *hp)
974 if (hp->n_outbuf <= 0)
977 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
980 pr_debug("%s: wrote %i chars\n", __FUNCTION__, n);
982 } else if (n == -EIO) {
983 __set_state(hp, HVSI_FSP_DIED);
984 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
988 /* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
989 static void hvsi_write_worker(void *arg)
991 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
994 static long start_j = 0;
1000 spin_lock_irqsave(&hp->lock, flags);
1002 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
1006 * We could have a non-open connection if the service processor died
1007 * while we were busily scheduling ourselves. In that case, it could
1008 * be minutes before the service processor comes back, so only try
1009 * again once a second.
1011 schedule_delayed_work(&hp->writer, HZ);
1016 if (hp->n_outbuf > 0)
1017 schedule_delayed_work(&hp->writer, 10);
1020 pr_debug("%s: outbuf emptied after %li jiffies\n", __FUNCTION__,
1024 wake_up_all(&hp->emptyq);
1025 if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags)
1026 && hp->tty->ldisc.write_wakeup)
1027 hp->tty->ldisc.write_wakeup(hp->tty);
1028 wake_up_interruptible(&hp->tty->write_wait);
1032 spin_unlock_irqrestore(&hp->lock, flags);
1035 static int hvsi_write_room(struct tty_struct *tty)
1037 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1039 return N_OUTBUF - hp->n_outbuf;
1042 static int hvsi_chars_in_buffer(struct tty_struct *tty)
1044 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1046 return hp->n_outbuf;
1049 static int hvsi_write(struct tty_struct *tty,
1050 const unsigned char *buf, int count)
1052 struct hvsi_struct *hp = tty->driver_data;
1053 const char *source = buf;
1054 unsigned long flags;
1056 int origcount = count;
1058 spin_lock_irqsave(&hp->lock, flags);
1060 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
1063 /* we're either closing or not yet open; don't accept data */
1064 pr_debug("%s: not open\n", __FUNCTION__);
1069 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1070 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1071 * will see there is no room in outbuf and return.
1073 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1074 int chunksize = min(count, hvsi_write_room(hp->tty));
1076 BUG_ON(hp->n_outbuf < 0);
1077 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1078 hp->n_outbuf += chunksize;
1081 source += chunksize;
1086 if (hp->n_outbuf > 0) {
1088 * we weren't able to write it all to the hypervisor.
1089 * schedule another push attempt.
1091 schedule_delayed_work(&hp->writer, 10);
1095 spin_unlock_irqrestore(&hp->lock, flags);
1097 if (total != origcount)
1098 pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount,
1105 * I have never seen throttle or unthrottle called, so this little throttle
1106 * buffering scheme may or may not work.
1108 static void hvsi_throttle(struct tty_struct *tty)
1110 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1112 pr_debug("%s\n", __FUNCTION__);
1114 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1117 static void hvsi_unthrottle(struct tty_struct *tty)
1119 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1120 unsigned long flags;
1123 pr_debug("%s\n", __FUNCTION__);
1125 spin_lock_irqsave(&hp->lock, flags);
1126 if (hp->n_throttle) {
1127 hvsi_send_overflow(hp);
1130 spin_unlock_irqrestore(&hp->lock, flags);
1133 tty_flip_buffer_push(hp->tty);
1135 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1138 static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1140 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1146 static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1147 unsigned int set, unsigned int clear)
1149 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1150 unsigned long flags;
1153 /* we can only alter DTR */
1157 spin_lock_irqsave(&hp->lock, flags);
1159 new_mctrl = (hp->mctrl & ~clear) | set;
1161 if (hp->mctrl != new_mctrl) {
1162 hvsi_set_mctrl(hp, new_mctrl);
1163 hp->mctrl = new_mctrl;
1165 spin_unlock_irqrestore(&hp->lock, flags);
1171 static struct tty_operations hvsi_ops = {
1173 .close = hvsi_close,
1174 .write = hvsi_write,
1175 .hangup = hvsi_hangup,
1176 .write_room = hvsi_write_room,
1177 .chars_in_buffer = hvsi_chars_in_buffer,
1178 .throttle = hvsi_throttle,
1179 .unthrottle = hvsi_unthrottle,
1180 .tiocmget = hvsi_tiocmget,
1181 .tiocmset = hvsi_tiocmset,
1184 static int __init hvsi_init(void)
1188 hvsi_driver = alloc_tty_driver(hvsi_count);
1192 hvsi_driver->owner = THIS_MODULE;
1193 hvsi_driver->devfs_name = "hvsi/";
1194 hvsi_driver->driver_name = "hvsi";
1195 hvsi_driver->name = "hvsi";
1196 hvsi_driver->major = HVSI_MAJOR;
1197 hvsi_driver->minor_start = HVSI_MINOR;
1198 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1199 hvsi_driver->init_termios = tty_std_termios;
1200 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1201 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1202 tty_set_operations(hvsi_driver, &hvsi_ops);
1204 for (i=0; i < hvsi_count; i++) {
1205 struct hvsi_struct *hp = &hvsi_ports[i];
1208 ret = request_irq(hp->virq, hvsi_interrupt, SA_INTERRUPT, "hvsi", hp);
1210 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1213 hvsi_wait = wait_for_state; /* irqs active now */
1215 if (tty_register_driver(hvsi_driver))
1216 panic("Couldn't register hvsi console driver\n");
1218 printk(KERN_INFO "HVSI: registered %i devices\n", hvsi_count);
1222 device_initcall(hvsi_init);
1224 /***** console (not tty) code: *****/
1226 static void hvsi_console_print(struct console *console, const char *buf,
1229 struct hvsi_struct *hp = &hvsi_ports[console->index];
1230 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1231 unsigned int i = 0, n = 0;
1232 int ret, donecr = 0;
1239 * ugh, we have to translate LF -> CRLF ourselves, in place.
1240 * copied from hvc_console.c:
1242 while (count > 0 || i > 0) {
1243 if (count > 0 && i < sizeof(c)) {
1244 if (buf[n] == '\n' && !donecr) {
1253 ret = hvsi_put_chars(hp, c, i);
1261 static struct tty_driver *hvsi_console_device(struct console *console,
1264 *index = console->index;
1268 static int __init hvsi_console_setup(struct console *console, char *options)
1270 struct hvsi_struct *hp = &hvsi_ports[console->index];
1273 if (console->index < 0 || console->index >= hvsi_count)
1276 /* give the FSP a chance to change the baud rate when we re-open */
1277 hvsi_close_protocol(hp);
1279 ret = hvsi_handshake(hp);
1283 ret = hvsi_get_mctrl(hp);
1287 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1291 hp->flags |= HVSI_CONSOLE;
1296 static struct console hvsi_con_driver = {
1298 .write = hvsi_console_print,
1299 .device = hvsi_console_device,
1300 .setup = hvsi_console_setup,
1301 .flags = CON_PRINTBUFFER,
1305 static int __init hvsi_console_init(void)
1307 struct device_node *vty;
1309 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1311 /* search device tree for vty nodes */
1312 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1314 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1315 struct hvsi_struct *hp;
1319 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
1320 irq = (uint32_t *)get_property(vty, "interrupts", NULL);
1321 if (!vtermno || !irq)
1324 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1329 hp = &hvsi_ports[hvsi_count];
1330 INIT_WORK(&hp->writer, hvsi_write_worker, hp);
1331 INIT_WORK(&hp->handshaker, hvsi_handshaker, hp);
1332 init_waitqueue_head(&hp->emptyq);
1333 init_waitqueue_head(&hp->stateq);
1334 spin_lock_init(&hp->lock);
1335 hp->index = hvsi_count;
1336 hp->inbuf_end = hp->inbuf;
1337 hp->state = HVSI_CLOSED;
1338 hp->vtermno = *vtermno;
1339 hp->virq = virt_irq_create_mapping(irq[0]);
1340 if (hp->virq == NO_IRQ) {
1341 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1342 __FUNCTION__, hp->virq);
1345 hp->virq = irq_offset_up(hp->virq);
1351 register_console(&hvsi_con_driver);
1354 console_initcall(hvsi_console_init);