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/spinlock.h>
43 #include <linux/sysrq.h>
44 #include <linux/tty.h>
45 #include <linux/tty_flip.h>
46 #include <asm/hvcall.h>
47 #include <asm/hvconsole.h>
49 #include <asm/uaccess.h>
51 #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 delayed_work 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 static inline int is_console(struct hvsi_struct *hp)
115 return hp->flags & HVSI_CONSOLE;
118 static inline int is_open(struct hvsi_struct *hp)
120 /* if we're waiting for an mctrl then we're already open */
121 return (hp->state == HVSI_OPEN)
122 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
125 static inline void print_state(struct hvsi_struct *hp)
128 static const char *state_names[] = {
130 "HVSI_WAIT_FOR_VER_RESPONSE",
131 "HVSI_WAIT_FOR_VER_QUERY",
133 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
136 const char *name = (hp->state < ARRAY_SIZE(state_names))
137 ? state_names[hp->state] : "UNKNOWN";
139 pr_debug("hvsi%i: state = %s\n", hp->index, name);
143 static inline void __set_state(struct hvsi_struct *hp, int state)
147 wake_up_all(&hp->stateq);
150 static inline void set_state(struct hvsi_struct *hp, int state)
154 spin_lock_irqsave(&hp->lock, flags);
155 __set_state(hp, state);
156 spin_unlock_irqrestore(&hp->lock, flags);
159 static inline int len_packet(const uint8_t *packet)
161 return (int)((struct hvsi_header *)packet)->len;
164 static inline int is_header(const uint8_t *packet)
166 struct hvsi_header *header = (struct hvsi_header *)packet;
167 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
170 static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
172 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
173 return 0; /* don't even have the packet header */
175 if (hp->inbuf_end < (packet + len_packet(packet)))
176 return 0; /* don't have the rest of the packet */
181 /* shift remaining bytes in packetbuf down */
182 static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
184 int remaining = (int)(hp->inbuf_end - read_to);
186 pr_debug("%s: %i chars remain\n", __func__, remaining);
188 if (read_to != hp->inbuf)
189 memmove(hp->inbuf, read_to, remaining);
191 hp->inbuf_end = hp->inbuf + remaining;
195 #define dbg_dump_packet(packet) dump_packet(packet)
196 #define dbg_dump_hex(data, len) dump_hex(data, len)
198 #define dbg_dump_packet(packet) do { } while (0)
199 #define dbg_dump_hex(data, len) do { } while (0)
202 static void dump_hex(const uint8_t *data, int len)
207 for (i=0; i < len; i++)
208 printk("%.2x", data[i]);
211 for (i=0; i < len; i++) {
212 if (isprint(data[i]))
213 printk("%c", data[i]);
220 static void dump_packet(uint8_t *packet)
222 struct hvsi_header *header = (struct hvsi_header *)packet;
224 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
227 dump_hex(packet, header->len);
230 static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
234 got = hvc_get_chars(hp->vtermno, buf, count);
239 static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
240 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
242 struct hvsi_control *header = (struct hvsi_control *)packet;
244 switch (header->verb) {
245 case VSV_MODEM_CTL_UPDATE:
246 if ((header->word & HVSI_TSCD) == 0) {
247 /* CD went away; no more connection */
248 pr_debug("hvsi%i: CD dropped\n", hp->index);
249 hp->mctrl &= TIOCM_CD;
250 /* If userland hasn't done an open(2) yet, hp->tty is NULL. */
251 if (hp->tty && !(hp->tty->flags & CLOCAL))
252 *to_hangup = hp->tty;
255 case VSV_CLOSE_PROTOCOL:
256 pr_debug("hvsi%i: service processor came back\n", hp->index);
257 if (hp->state != HVSI_CLOSED) {
262 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
269 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
271 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
274 case HVSI_WAIT_FOR_VER_RESPONSE:
275 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
277 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
279 if (resp->u.mctrl_word & HVSI_TSDTR)
280 hp->mctrl |= TIOCM_DTR;
281 if (resp->u.mctrl_word & HVSI_TSCD)
282 hp->mctrl |= TIOCM_CD;
283 __set_state(hp, HVSI_OPEN);
286 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
292 /* respond to service processor's version query */
293 static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
295 struct hvsi_query_response packet __ALIGNED__;
298 packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
299 packet.hdr.len = sizeof(struct hvsi_query_response);
300 packet.hdr.seqno = atomic_inc_return(&hp->seqno);
301 packet.verb = VSV_SEND_VERSION_NUMBER;
302 packet.u.version = HVSI_VERSION;
303 packet.query_seqno = query_seqno+1;
305 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
306 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
308 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
309 if (wrote != packet.hdr.len) {
310 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
318 static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
320 struct hvsi_query *query = (struct hvsi_query *)packet;
323 case HVSI_WAIT_FOR_VER_QUERY:
324 hvsi_version_respond(hp, query->hdr.seqno);
325 __set_state(hp, HVSI_OPEN);
328 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
334 static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
338 for (i=0; i < len; i++) {
340 #ifdef CONFIG_MAGIC_SYSRQ
344 } else if (hp->sysrq) {
349 #endif /* CONFIG_MAGIC_SYSRQ */
350 tty_insert_flip_char(hp->tty, c, 0);
355 * We could get 252 bytes of data at once here. But the tty layer only
356 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
357 * it. Accordingly we won't send more than 128 bytes at a time to the flip
358 * buffer, which will give the tty buffer a chance to throttle us. Should the
359 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
362 #define TTY_THRESHOLD_THROTTLE 128
363 static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
364 const uint8_t *packet)
366 const struct hvsi_header *header = (const struct hvsi_header *)packet;
367 const uint8_t *data = packet + sizeof(struct hvsi_header);
368 int datalen = header->len - sizeof(struct hvsi_header);
369 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
371 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
377 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
378 datalen = TTY_THRESHOLD_THROTTLE;
381 hvsi_insert_chars(hp, data, datalen);
385 * we still have more data to deliver, so we need to save off the
386 * overflow and send it later
388 pr_debug("%s: deferring overflow\n", __func__);
389 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
390 hp->n_throttle = overflow;
397 * Returns true/false indicating data successfully read from hypervisor.
398 * Used both to get packets for tty connections and to advance the state
399 * machine during console handshaking (in which case tty = NULL and we ignore
402 static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
403 struct tty_struct **hangup, struct hvsi_struct **handshake)
405 uint8_t *packet = hp->inbuf;
412 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
414 pr_debug("%s: 0-length read\n", __func__);
418 pr_debug("%s: got %i bytes\n", __func__, chunklen);
419 dbg_dump_hex(hp->inbuf_end, chunklen);
421 hp->inbuf_end += chunklen;
423 /* handle all completed packets */
424 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
425 struct hvsi_header *header = (struct hvsi_header *)packet;
427 if (!is_header(packet)) {
428 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
429 /* skip bytes until we find a header or run out of data */
430 while ((packet < hp->inbuf_end) && (!is_header(packet)))
435 pr_debug("%s: handling %i-byte packet\n", __func__,
437 dbg_dump_packet(packet);
439 switch (header->type) {
440 case VS_DATA_PACKET_HEADER:
444 break; /* no tty buffer to put data in */
445 *flip = hvsi_recv_data(hp, packet);
447 case VS_CONTROL_PACKET_HEADER:
448 hvsi_recv_control(hp, packet, hangup, handshake);
450 case VS_QUERY_RESPONSE_PACKET_HEADER:
451 hvsi_recv_response(hp, packet);
453 case VS_QUERY_PACKET_HEADER:
454 hvsi_recv_query(hp, packet);
457 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
458 hp->index, header->type);
463 packet += len_packet(packet);
465 if (*hangup || *handshake) {
466 pr_debug("%s: hangup or handshake\n", __func__);
468 * we need to send the hangup now before receiving any more data.
469 * If we get "data, hangup, data", we can't deliver the second
470 * data before the hangup.
476 compact_inbuf(hp, packet);
481 static void hvsi_send_overflow(struct hvsi_struct *hp)
483 pr_debug("%s: delivering %i bytes overflow\n", __func__,
486 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
491 * must get all pending data because we only get an irq on empty->non-empty
494 static irqreturn_t hvsi_interrupt(int irq, void *arg)
496 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
497 struct tty_struct *flip;
498 struct tty_struct *hangup;
499 struct hvsi_struct *handshake;
503 pr_debug("%s\n", __func__);
506 spin_lock_irqsave(&hp->lock, flags);
507 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
508 spin_unlock_irqrestore(&hp->lock, flags);
511 * we have to call tty_flip_buffer_push() and tty_hangup() outside our
512 * spinlock. But we also have to keep going until we've read all the
517 /* there was data put in the tty flip buffer */
518 tty_flip_buffer_push(flip);
527 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
528 schedule_work(&handshake->handshaker);
532 spin_lock_irqsave(&hp->lock, flags);
533 if (hp->tty && hp->n_throttle
534 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
535 /* we weren't hung up and we weren't throttled, so we can deliver the
538 hvsi_send_overflow(hp);
540 spin_unlock_irqrestore(&hp->lock, flags);
543 tty_flip_buffer_push(flip);
549 /* for boot console, before the irq handler is running */
550 static int __init poll_for_state(struct hvsi_struct *hp, int state)
552 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
555 hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
557 if (hp->state == state)
561 if (time_after(jiffies, end_jiffies))
566 /* wait for irq handler to change our state */
567 static int wait_for_state(struct hvsi_struct *hp, int state)
571 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
577 static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
579 struct hvsi_query packet __ALIGNED__;
582 packet.hdr.type = VS_QUERY_PACKET_HEADER;
583 packet.hdr.len = sizeof(struct hvsi_query);
584 packet.hdr.seqno = atomic_inc_return(&hp->seqno);
587 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
588 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
590 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
591 if (wrote != packet.hdr.len) {
592 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
600 static int hvsi_get_mctrl(struct hvsi_struct *hp)
604 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
605 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
607 ret = hvsi_wait(hp, HVSI_OPEN);
609 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
610 set_state(hp, HVSI_OPEN);
614 pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
619 /* note that we can only set DTR */
620 static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
622 struct hvsi_control packet __ALIGNED__;
625 packet.hdr.type = VS_CONTROL_PACKET_HEADER,
626 packet.hdr.seqno = atomic_inc_return(&hp->seqno);
627 packet.hdr.len = sizeof(struct hvsi_control);
628 packet.verb = VSV_SET_MODEM_CTL;
629 packet.mask = HVSI_TSDTR;
631 if (mctrl & TIOCM_DTR)
632 packet.word = HVSI_TSDTR;
634 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
635 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
637 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
638 if (wrote != packet.hdr.len) {
639 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
646 static void hvsi_drain_input(struct hvsi_struct *hp)
648 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
649 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
651 while (time_before(end_jiffies, jiffies))
652 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
656 static int hvsi_handshake(struct hvsi_struct *hp)
661 * We could have a CLOSE or other data waiting for us before we even try
662 * to open; try to throw it all away so we don't get confused. (CLOSE
663 * is the first message sent up the pipe when the FSP comes online. We
664 * need to distinguish between "it came up a while ago and we're the first
665 * user" and "it was just reset before it saw our handshake packet".)
667 hvsi_drain_input(hp);
669 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
670 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
672 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
676 ret = hvsi_wait(hp, HVSI_OPEN);
683 static void hvsi_handshaker(struct work_struct *work)
685 struct hvsi_struct *hp =
686 container_of(work, struct hvsi_struct, handshaker);
688 if (hvsi_handshake(hp) >= 0)
691 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
692 if (is_console(hp)) {
694 * ttys will re-attempt the handshake via hvsi_open, but
695 * the console will not.
697 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
701 static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
703 struct hvsi_data packet __ALIGNED__;
706 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
708 packet.hdr.type = VS_DATA_PACKET_HEADER;
709 packet.hdr.seqno = atomic_inc_return(&hp->seqno);
710 packet.hdr.len = count + sizeof(struct hvsi_header);
711 memcpy(&packet.data, buf, count);
713 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
714 if (ret == packet.hdr.len) {
715 /* return the number of chars written, not the packet length */
718 return ret; /* return any errors */
721 static void hvsi_close_protocol(struct hvsi_struct *hp)
723 struct hvsi_control packet __ALIGNED__;
725 packet.hdr.type = VS_CONTROL_PACKET_HEADER;
726 packet.hdr.seqno = atomic_inc_return(&hp->seqno);
728 packet.verb = VSV_CLOSE_PROTOCOL;
730 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
731 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
733 hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
736 static int hvsi_open(struct tty_struct *tty, struct file *filp)
738 struct hvsi_struct *hp;
742 pr_debug("%s\n", __func__);
744 hp = &hvsi_ports[tty->index];
746 tty->driver_data = hp;
749 if (hp->state == HVSI_FSP_DIED)
752 spin_lock_irqsave(&hp->lock, flags);
755 atomic_set(&hp->seqno, 0);
756 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
757 spin_unlock_irqrestore(&hp->lock, flags);
760 return 0; /* this has already been handshaked as the console */
762 ret = hvsi_handshake(hp);
764 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
768 ret = hvsi_get_mctrl(hp);
770 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
774 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
776 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
783 /* wait for hvsi_write_worker to empty hp->outbuf */
784 static void hvsi_flush_output(struct hvsi_struct *hp)
786 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
788 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
789 cancel_delayed_work_sync(&hp->writer);
790 flush_work_sync(&hp->handshaker);
793 * it's also possible that our timeout expired and hvsi_write_worker
794 * didn't manage to push outbuf. poof.
799 static void hvsi_close(struct tty_struct *tty, struct file *filp)
801 struct hvsi_struct *hp = tty->driver_data;
804 pr_debug("%s\n", __func__);
806 if (tty_hung_up_p(filp))
809 spin_lock_irqsave(&hp->lock, flags);
811 if (--hp->count == 0) {
813 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
815 /* only close down connection if it is not the console */
816 if (!is_console(hp)) {
817 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
818 __set_state(hp, HVSI_CLOSED);
820 * any data delivered to the tty layer after this will be
821 * discarded (except for XON/XOFF)
825 spin_unlock_irqrestore(&hp->lock, flags);
827 /* let any existing irq handlers finish. no more will start. */
828 synchronize_irq(hp->virq);
830 /* hvsi_write_worker will re-schedule until outbuf is empty. */
831 hvsi_flush_output(hp);
833 /* tell FSP to stop sending data */
834 hvsi_close_protocol(hp);
837 * drain anything FSP is still in the middle of sending, and let
838 * hvsi_handshake drain the rest on the next open.
840 hvsi_drain_input(hp);
842 spin_lock_irqsave(&hp->lock, flags);
844 } else if (hp->count < 0)
845 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
846 hp - hvsi_ports, hp->count);
848 spin_unlock_irqrestore(&hp->lock, flags);
851 static void hvsi_hangup(struct tty_struct *tty)
853 struct hvsi_struct *hp = tty->driver_data;
856 pr_debug("%s\n", __func__);
858 spin_lock_irqsave(&hp->lock, flags);
864 spin_unlock_irqrestore(&hp->lock, flags);
867 /* called with hp->lock held */
868 static void hvsi_push(struct hvsi_struct *hp)
872 if (hp->n_outbuf <= 0)
875 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
878 pr_debug("%s: wrote %i chars\n", __func__, n);
880 } else if (n == -EIO) {
881 __set_state(hp, HVSI_FSP_DIED);
882 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
886 /* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
887 static void hvsi_write_worker(struct work_struct *work)
889 struct hvsi_struct *hp =
890 container_of(work, struct hvsi_struct, writer.work);
893 static long start_j = 0;
899 spin_lock_irqsave(&hp->lock, flags);
901 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
905 * We could have a non-open connection if the service processor died
906 * while we were busily scheduling ourselves. In that case, it could
907 * be minutes before the service processor comes back, so only try
908 * again once a second.
910 schedule_delayed_work(&hp->writer, HZ);
915 if (hp->n_outbuf > 0)
916 schedule_delayed_work(&hp->writer, 10);
919 pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
923 wake_up_all(&hp->emptyq);
928 spin_unlock_irqrestore(&hp->lock, flags);
931 static int hvsi_write_room(struct tty_struct *tty)
933 struct hvsi_struct *hp = tty->driver_data;
935 return N_OUTBUF - hp->n_outbuf;
938 static int hvsi_chars_in_buffer(struct tty_struct *tty)
940 struct hvsi_struct *hp = tty->driver_data;
945 static int hvsi_write(struct tty_struct *tty,
946 const unsigned char *buf, int count)
948 struct hvsi_struct *hp = tty->driver_data;
949 const char *source = buf;
952 int origcount = count;
954 spin_lock_irqsave(&hp->lock, flags);
956 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
959 /* we're either closing or not yet open; don't accept data */
960 pr_debug("%s: not open\n", __func__);
965 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
966 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
967 * will see there is no room in outbuf and return.
969 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
970 int chunksize = min(count, hvsi_write_room(hp->tty));
972 BUG_ON(hp->n_outbuf < 0);
973 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
974 hp->n_outbuf += chunksize;
982 if (hp->n_outbuf > 0) {
984 * we weren't able to write it all to the hypervisor.
985 * schedule another push attempt.
987 schedule_delayed_work(&hp->writer, 10);
991 spin_unlock_irqrestore(&hp->lock, flags);
993 if (total != origcount)
994 pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount,
1001 * I have never seen throttle or unthrottle called, so this little throttle
1002 * buffering scheme may or may not work.
1004 static void hvsi_throttle(struct tty_struct *tty)
1006 struct hvsi_struct *hp = tty->driver_data;
1008 pr_debug("%s\n", __func__);
1010 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1013 static void hvsi_unthrottle(struct tty_struct *tty)
1015 struct hvsi_struct *hp = tty->driver_data;
1016 unsigned long flags;
1019 pr_debug("%s\n", __func__);
1021 spin_lock_irqsave(&hp->lock, flags);
1022 if (hp->n_throttle) {
1023 hvsi_send_overflow(hp);
1026 spin_unlock_irqrestore(&hp->lock, flags);
1029 tty_flip_buffer_push(hp->tty);
1031 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1034 static int hvsi_tiocmget(struct tty_struct *tty)
1036 struct hvsi_struct *hp = tty->driver_data;
1042 static int hvsi_tiocmset(struct tty_struct *tty,
1043 unsigned int set, unsigned int clear)
1045 struct hvsi_struct *hp = tty->driver_data;
1046 unsigned long flags;
1049 /* we can only alter DTR */
1053 spin_lock_irqsave(&hp->lock, flags);
1055 new_mctrl = (hp->mctrl & ~clear) | set;
1057 if (hp->mctrl != new_mctrl) {
1058 hvsi_set_mctrl(hp, new_mctrl);
1059 hp->mctrl = new_mctrl;
1061 spin_unlock_irqrestore(&hp->lock, flags);
1067 static const struct tty_operations hvsi_ops = {
1069 .close = hvsi_close,
1070 .write = hvsi_write,
1071 .hangup = hvsi_hangup,
1072 .write_room = hvsi_write_room,
1073 .chars_in_buffer = hvsi_chars_in_buffer,
1074 .throttle = hvsi_throttle,
1075 .unthrottle = hvsi_unthrottle,
1076 .tiocmget = hvsi_tiocmget,
1077 .tiocmset = hvsi_tiocmset,
1080 static int __init hvsi_init(void)
1084 hvsi_driver = alloc_tty_driver(hvsi_count);
1088 hvsi_driver->driver_name = "hvsi";
1089 hvsi_driver->name = "hvsi";
1090 hvsi_driver->major = HVSI_MAJOR;
1091 hvsi_driver->minor_start = HVSI_MINOR;
1092 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1093 hvsi_driver->init_termios = tty_std_termios;
1094 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1095 hvsi_driver->init_termios.c_ispeed = 9600;
1096 hvsi_driver->init_termios.c_ospeed = 9600;
1097 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1098 tty_set_operations(hvsi_driver, &hvsi_ops);
1100 for (i=0; i < hvsi_count; i++) {
1101 struct hvsi_struct *hp = &hvsi_ports[i];
1104 ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp);
1106 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1109 hvsi_wait = wait_for_state; /* irqs active now */
1111 if (tty_register_driver(hvsi_driver))
1112 panic("Couldn't register hvsi console driver\n");
1114 printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
1118 device_initcall(hvsi_init);
1120 /***** console (not tty) code: *****/
1122 static void hvsi_console_print(struct console *console, const char *buf,
1125 struct hvsi_struct *hp = &hvsi_ports[console->index];
1126 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1127 unsigned int i = 0, n = 0;
1128 int ret, donecr = 0;
1135 * ugh, we have to translate LF -> CRLF ourselves, in place.
1136 * copied from hvc_console.c:
1138 while (count > 0 || i > 0) {
1139 if (count > 0 && i < sizeof(c)) {
1140 if (buf[n] == '\n' && !donecr) {
1149 ret = hvsi_put_chars(hp, c, i);
1157 static struct tty_driver *hvsi_console_device(struct console *console,
1160 *index = console->index;
1164 static int __init hvsi_console_setup(struct console *console, char *options)
1166 struct hvsi_struct *hp;
1169 if (console->index < 0 || console->index >= hvsi_count)
1171 hp = &hvsi_ports[console->index];
1173 /* give the FSP a chance to change the baud rate when we re-open */
1174 hvsi_close_protocol(hp);
1176 ret = hvsi_handshake(hp);
1180 ret = hvsi_get_mctrl(hp);
1184 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1188 hp->flags |= HVSI_CONSOLE;
1193 static struct console hvsi_console = {
1195 .write = hvsi_console_print,
1196 .device = hvsi_console_device,
1197 .setup = hvsi_console_setup,
1198 .flags = CON_PRINTBUFFER,
1202 static int __init hvsi_console_init(void)
1204 struct device_node *vty;
1206 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1208 /* search device tree for vty nodes */
1209 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1211 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1212 struct hvsi_struct *hp;
1213 const uint32_t *vtermno, *irq;
1215 vtermno = of_get_property(vty, "reg", NULL);
1216 irq = of_get_property(vty, "interrupts", NULL);
1217 if (!vtermno || !irq)
1220 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1225 hp = &hvsi_ports[hvsi_count];
1226 INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
1227 INIT_WORK(&hp->handshaker, hvsi_handshaker);
1228 init_waitqueue_head(&hp->emptyq);
1229 init_waitqueue_head(&hp->stateq);
1230 spin_lock_init(&hp->lock);
1231 hp->index = hvsi_count;
1232 hp->inbuf_end = hp->inbuf;
1233 hp->state = HVSI_CLOSED;
1234 hp->vtermno = *vtermno;
1235 hp->virq = irq_create_mapping(NULL, irq[0]);
1236 if (hp->virq == 0) {
1237 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1246 register_console(&hvsi_console);
1249 console_initcall(hvsi_console_init);