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>
53 #define HVSI_MAJOR 229
54 #define HVSI_MINOR 128
55 #define MAX_NR_HVSI_CONSOLES 4
57 #define HVSI_TIMEOUT (5*HZ)
58 #define HVSI_VERSION 1
59 #define HVSI_MAX_PACKET 256
60 #define HVSI_MAX_READ 16
61 #define HVSI_MAX_OUTGOING_DATA 12
65 * we pass data via two 8-byte registers, so we would like our char arrays
66 * properly aligned for those loads.
68 #define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
71 struct delayed_work writer;
72 struct work_struct handshaker;
73 wait_queue_head_t emptyq; /* woken when outbuf is emptied */
74 wait_queue_head_t stateq; /* woken when HVSI state changes */
77 struct tty_struct *tty;
79 uint8_t throttle_buf[128];
80 uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
81 /* inbuf is for packet reassembly. leave a little room for leftovers. */
82 uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
88 atomic_t seqno; /* HVSI packet sequence number */
90 uint8_t state; /* HVSI protocol state */
92 #ifdef CONFIG_MAGIC_SYSRQ
94 #endif /* CONFIG_MAGIC_SYSRQ */
96 static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
98 static struct tty_driver *hvsi_driver;
99 static int hvsi_count;
100 static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
102 enum HVSI_PROTOCOL_STATE {
104 HVSI_WAIT_FOR_VER_RESPONSE,
105 HVSI_WAIT_FOR_VER_QUERY,
107 HVSI_WAIT_FOR_MCTRL_RESPONSE,
110 #define HVSI_CONSOLE 0x1
112 #define VS_DATA_PACKET_HEADER 0xff
113 #define VS_CONTROL_PACKET_HEADER 0xfe
114 #define VS_QUERY_PACKET_HEADER 0xfd
115 #define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
118 #define VSV_SET_MODEM_CTL 1 /* to service processor only */
119 #define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
120 #define VSV_CLOSE_PROTOCOL 3
123 #define VSV_SEND_VERSION_NUMBER 1
124 #define VSV_SEND_MODEM_CTL_STATUS 2
126 /* yes, these masks are not consecutive. */
127 #define HVSI_TSDTR 0x01
128 #define HVSI_TSCD 0x20
134 } __attribute__((packed));
140 uint8_t data[HVSI_MAX_OUTGOING_DATA];
141 } __attribute__((packed));
143 struct hvsi_control {
148 /* optional depending on verb: */
151 } __attribute__((packed));
158 } __attribute__((packed));
160 struct hvsi_query_response {
165 uint16_t query_seqno;
170 } __attribute__((packed));
174 static inline int is_console(struct hvsi_struct *hp)
176 return hp->flags & HVSI_CONSOLE;
179 static inline int is_open(struct hvsi_struct *hp)
181 /* if we're waiting for an mctrl then we're already open */
182 return (hp->state == HVSI_OPEN)
183 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
186 static inline void print_state(struct hvsi_struct *hp)
189 static const char *state_names[] = {
191 "HVSI_WAIT_FOR_VER_RESPONSE",
192 "HVSI_WAIT_FOR_VER_QUERY",
194 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
197 const char *name = state_names[hp->state];
199 if (hp->state > ARRAY_SIZE(state_names))
202 pr_debug("hvsi%i: state = %s\n", hp->index, name);
206 static inline void __set_state(struct hvsi_struct *hp, int state)
210 wake_up_all(&hp->stateq);
213 static inline void set_state(struct hvsi_struct *hp, int state)
217 spin_lock_irqsave(&hp->lock, flags);
218 __set_state(hp, state);
219 spin_unlock_irqrestore(&hp->lock, flags);
222 static inline int len_packet(const uint8_t *packet)
224 return (int)((struct hvsi_header *)packet)->len;
227 static inline int is_header(const uint8_t *packet)
229 struct hvsi_header *header = (struct hvsi_header *)packet;
230 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
233 static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
235 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
236 return 0; /* don't even have the packet header */
238 if (hp->inbuf_end < (packet + len_packet(packet)))
239 return 0; /* don't have the rest of the packet */
244 /* shift remaining bytes in packetbuf down */
245 static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
247 int remaining = (int)(hp->inbuf_end - read_to);
249 pr_debug("%s: %i chars remain\n", __func__, remaining);
251 if (read_to != hp->inbuf)
252 memmove(hp->inbuf, read_to, remaining);
254 hp->inbuf_end = hp->inbuf + remaining;
258 #define dbg_dump_packet(packet) dump_packet(packet)
259 #define dbg_dump_hex(data, len) dump_hex(data, len)
261 #define dbg_dump_packet(packet) do { } while (0)
262 #define dbg_dump_hex(data, len) do { } while (0)
265 static void dump_hex(const uint8_t *data, int len)
270 for (i=0; i < len; i++)
271 printk("%.2x", data[i]);
274 for (i=0; i < len; i++) {
275 if (isprint(data[i]))
276 printk("%c", data[i]);
283 static void dump_packet(uint8_t *packet)
285 struct hvsi_header *header = (struct hvsi_header *)packet;
287 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
290 dump_hex(packet, header->len);
293 static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
297 got = hvc_get_chars(hp->vtermno, buf, count);
302 static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
303 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
305 struct hvsi_control *header = (struct hvsi_control *)packet;
307 switch (header->verb) {
308 case VSV_MODEM_CTL_UPDATE:
309 if ((header->word & HVSI_TSCD) == 0) {
310 /* CD went away; no more connection */
311 pr_debug("hvsi%i: CD dropped\n", hp->index);
312 hp->mctrl &= TIOCM_CD;
313 /* If userland hasn't done an open(2) yet, hp->tty is NULL. */
314 if (hp->tty && !(hp->tty->flags & CLOCAL))
315 *to_hangup = hp->tty;
318 case VSV_CLOSE_PROTOCOL:
319 pr_debug("hvsi%i: service processor came back\n", hp->index);
320 if (hp->state != HVSI_CLOSED) {
325 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
332 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
334 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
337 case HVSI_WAIT_FOR_VER_RESPONSE:
338 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
340 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
342 if (resp->u.mctrl_word & HVSI_TSDTR)
343 hp->mctrl |= TIOCM_DTR;
344 if (resp->u.mctrl_word & HVSI_TSCD)
345 hp->mctrl |= TIOCM_CD;
346 __set_state(hp, HVSI_OPEN);
349 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
355 /* respond to service processor's version query */
356 static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
358 struct hvsi_query_response packet __ALIGNED__;
361 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
362 packet.len = sizeof(struct hvsi_query_response);
363 packet.seqno = atomic_inc_return(&hp->seqno);
364 packet.verb = VSV_SEND_VERSION_NUMBER;
365 packet.u.version = HVSI_VERSION;
366 packet.query_seqno = query_seqno+1;
368 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
369 dbg_dump_hex((uint8_t*)&packet, packet.len);
371 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
372 if (wrote != packet.len) {
373 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
381 static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
383 struct hvsi_query *query = (struct hvsi_query *)packet;
386 case HVSI_WAIT_FOR_VER_QUERY:
387 hvsi_version_respond(hp, query->seqno);
388 __set_state(hp, HVSI_OPEN);
391 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
397 static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
401 for (i=0; i < len; i++) {
403 #ifdef CONFIG_MAGIC_SYSRQ
407 } else if (hp->sysrq) {
408 handle_sysrq(c, hp->tty);
412 #endif /* CONFIG_MAGIC_SYSRQ */
413 tty_insert_flip_char(hp->tty, c, 0);
418 * We could get 252 bytes of data at once here. But the tty layer only
419 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
420 * it. Accordingly we won't send more than 128 bytes at a time to the flip
421 * buffer, which will give the tty buffer a chance to throttle us. Should the
422 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
425 #define TTY_THRESHOLD_THROTTLE 128
426 static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
427 const uint8_t *packet)
429 const struct hvsi_header *header = (const struct hvsi_header *)packet;
430 const uint8_t *data = packet + sizeof(struct hvsi_header);
431 int datalen = header->len - sizeof(struct hvsi_header);
432 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
434 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
440 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
441 datalen = TTY_THRESHOLD_THROTTLE;
444 hvsi_insert_chars(hp, data, datalen);
448 * we still have more data to deliver, so we need to save off the
449 * overflow and send it later
451 pr_debug("%s: deferring overflow\n", __func__);
452 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
453 hp->n_throttle = overflow;
460 * Returns true/false indicating data successfully read from hypervisor.
461 * Used both to get packets for tty connections and to advance the state
462 * machine during console handshaking (in which case tty = NULL and we ignore
465 static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
466 struct tty_struct **hangup, struct hvsi_struct **handshake)
468 uint8_t *packet = hp->inbuf;
475 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
477 pr_debug("%s: 0-length read\n", __func__);
481 pr_debug("%s: got %i bytes\n", __func__, chunklen);
482 dbg_dump_hex(hp->inbuf_end, chunklen);
484 hp->inbuf_end += chunklen;
486 /* handle all completed packets */
487 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
488 struct hvsi_header *header = (struct hvsi_header *)packet;
490 if (!is_header(packet)) {
491 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
492 /* skip bytes until we find a header or run out of data */
493 while ((packet < hp->inbuf_end) && (!is_header(packet)))
498 pr_debug("%s: handling %i-byte packet\n", __func__,
500 dbg_dump_packet(packet);
502 switch (header->type) {
503 case VS_DATA_PACKET_HEADER:
507 break; /* no tty buffer to put data in */
508 *flip = hvsi_recv_data(hp, packet);
510 case VS_CONTROL_PACKET_HEADER:
511 hvsi_recv_control(hp, packet, hangup, handshake);
513 case VS_QUERY_RESPONSE_PACKET_HEADER:
514 hvsi_recv_response(hp, packet);
516 case VS_QUERY_PACKET_HEADER:
517 hvsi_recv_query(hp, packet);
520 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
521 hp->index, header->type);
526 packet += len_packet(packet);
528 if (*hangup || *handshake) {
529 pr_debug("%s: hangup or handshake\n", __func__);
531 * we need to send the hangup now before receiving any more data.
532 * If we get "data, hangup, data", we can't deliver the second
533 * data before the hangup.
539 compact_inbuf(hp, packet);
544 static void hvsi_send_overflow(struct hvsi_struct *hp)
546 pr_debug("%s: delivering %i bytes overflow\n", __func__,
549 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
554 * must get all pending data because we only get an irq on empty->non-empty
557 static irqreturn_t hvsi_interrupt(int irq, void *arg)
559 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
560 struct tty_struct *flip;
561 struct tty_struct *hangup;
562 struct hvsi_struct *handshake;
566 pr_debug("%s\n", __func__);
569 spin_lock_irqsave(&hp->lock, flags);
570 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
571 spin_unlock_irqrestore(&hp->lock, flags);
574 * we have to call tty_flip_buffer_push() and tty_hangup() outside our
575 * spinlock. But we also have to keep going until we've read all the
580 /* there was data put in the tty flip buffer */
581 tty_flip_buffer_push(flip);
590 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
591 schedule_work(&handshake->handshaker);
595 spin_lock_irqsave(&hp->lock, flags);
596 if (hp->tty && hp->n_throttle
597 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
598 /* we weren't hung up and we weren't throttled, so we can deliver the
601 hvsi_send_overflow(hp);
603 spin_unlock_irqrestore(&hp->lock, flags);
606 tty_flip_buffer_push(flip);
612 /* for boot console, before the irq handler is running */
613 static int __init poll_for_state(struct hvsi_struct *hp, int state)
615 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
618 hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
620 if (hp->state == state)
624 if (time_after(jiffies, end_jiffies))
629 /* wait for irq handler to change our state */
630 static int wait_for_state(struct hvsi_struct *hp, int state)
634 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
640 static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
642 struct hvsi_query packet __ALIGNED__;
645 packet.type = VS_QUERY_PACKET_HEADER;
646 packet.len = sizeof(struct hvsi_query);
647 packet.seqno = atomic_inc_return(&hp->seqno);
650 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
651 dbg_dump_hex((uint8_t*)&packet, packet.len);
653 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
654 if (wrote != packet.len) {
655 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
663 static int hvsi_get_mctrl(struct hvsi_struct *hp)
667 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
668 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
670 ret = hvsi_wait(hp, HVSI_OPEN);
672 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
673 set_state(hp, HVSI_OPEN);
677 pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
682 /* note that we can only set DTR */
683 static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
685 struct hvsi_control packet __ALIGNED__;
688 packet.type = VS_CONTROL_PACKET_HEADER,
689 packet.seqno = atomic_inc_return(&hp->seqno);
690 packet.len = sizeof(struct hvsi_control);
691 packet.verb = VSV_SET_MODEM_CTL;
692 packet.mask = HVSI_TSDTR;
694 if (mctrl & TIOCM_DTR)
695 packet.word = HVSI_TSDTR;
697 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
698 dbg_dump_hex((uint8_t*)&packet, packet.len);
700 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
701 if (wrote != packet.len) {
702 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
709 static void hvsi_drain_input(struct hvsi_struct *hp)
711 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
712 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
714 while (time_before(end_jiffies, jiffies))
715 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
719 static int hvsi_handshake(struct hvsi_struct *hp)
724 * We could have a CLOSE or other data waiting for us before we even try
725 * to open; try to throw it all away so we don't get confused. (CLOSE
726 * is the first message sent up the pipe when the FSP comes online. We
727 * need to distinguish between "it came up a while ago and we're the first
728 * user" and "it was just reset before it saw our handshake packet".)
730 hvsi_drain_input(hp);
732 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
733 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
735 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
739 ret = hvsi_wait(hp, HVSI_OPEN);
746 static void hvsi_handshaker(struct work_struct *work)
748 struct hvsi_struct *hp =
749 container_of(work, struct hvsi_struct, handshaker);
751 if (hvsi_handshake(hp) >= 0)
754 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
755 if (is_console(hp)) {
757 * ttys will re-attempt the handshake via hvsi_open, but
758 * the console will not.
760 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
764 static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
766 struct hvsi_data packet __ALIGNED__;
769 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
771 packet.type = VS_DATA_PACKET_HEADER;
772 packet.seqno = atomic_inc_return(&hp->seqno);
773 packet.len = count + sizeof(struct hvsi_header);
774 memcpy(&packet.data, buf, count);
776 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
777 if (ret == packet.len) {
778 /* return the number of chars written, not the packet length */
781 return ret; /* return any errors */
784 static void hvsi_close_protocol(struct hvsi_struct *hp)
786 struct hvsi_control packet __ALIGNED__;
788 packet.type = VS_CONTROL_PACKET_HEADER;
789 packet.seqno = atomic_inc_return(&hp->seqno);
791 packet.verb = VSV_CLOSE_PROTOCOL;
793 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
794 dbg_dump_hex((uint8_t*)&packet, packet.len);
796 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
799 static int hvsi_open(struct tty_struct *tty, struct file *filp)
801 struct hvsi_struct *hp;
803 int line = tty->index;
806 pr_debug("%s\n", __func__);
808 if (line < 0 || line >= hvsi_count)
810 hp = &hvsi_ports[line];
812 tty->driver_data = hp;
815 if (hp->state == HVSI_FSP_DIED)
818 spin_lock_irqsave(&hp->lock, flags);
821 atomic_set(&hp->seqno, 0);
822 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
823 spin_unlock_irqrestore(&hp->lock, flags);
826 return 0; /* this has already been handshaked as the console */
828 ret = hvsi_handshake(hp);
830 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
834 ret = hvsi_get_mctrl(hp);
836 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
840 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
842 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
849 /* wait for hvsi_write_worker to empty hp->outbuf */
850 static void hvsi_flush_output(struct hvsi_struct *hp)
852 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
854 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
855 cancel_delayed_work(&hp->writer);
856 flush_scheduled_work();
859 * it's also possible that our timeout expired and hvsi_write_worker
860 * didn't manage to push outbuf. poof.
865 static void hvsi_close(struct tty_struct *tty, struct file *filp)
867 struct hvsi_struct *hp = tty->driver_data;
870 pr_debug("%s\n", __func__);
872 if (tty_hung_up_p(filp))
875 spin_lock_irqsave(&hp->lock, flags);
877 if (--hp->count == 0) {
879 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
881 /* only close down connection if it is not the console */
882 if (!is_console(hp)) {
883 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
884 __set_state(hp, HVSI_CLOSED);
886 * any data delivered to the tty layer after this will be
887 * discarded (except for XON/XOFF)
891 spin_unlock_irqrestore(&hp->lock, flags);
893 /* let any existing irq handlers finish. no more will start. */
894 synchronize_irq(hp->virq);
896 /* hvsi_write_worker will re-schedule until outbuf is empty. */
897 hvsi_flush_output(hp);
899 /* tell FSP to stop sending data */
900 hvsi_close_protocol(hp);
903 * drain anything FSP is still in the middle of sending, and let
904 * hvsi_handshake drain the rest on the next open.
906 hvsi_drain_input(hp);
908 spin_lock_irqsave(&hp->lock, flags);
910 } else if (hp->count < 0)
911 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
912 hp - hvsi_ports, hp->count);
914 spin_unlock_irqrestore(&hp->lock, flags);
917 static void hvsi_hangup(struct tty_struct *tty)
919 struct hvsi_struct *hp = tty->driver_data;
922 pr_debug("%s\n", __func__);
924 spin_lock_irqsave(&hp->lock, flags);
930 spin_unlock_irqrestore(&hp->lock, flags);
933 /* called with hp->lock held */
934 static void hvsi_push(struct hvsi_struct *hp)
938 if (hp->n_outbuf <= 0)
941 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
944 pr_debug("%s: wrote %i chars\n", __func__, n);
946 } else if (n == -EIO) {
947 __set_state(hp, HVSI_FSP_DIED);
948 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
952 /* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
953 static void hvsi_write_worker(struct work_struct *work)
955 struct hvsi_struct *hp =
956 container_of(work, struct hvsi_struct, writer.work);
959 static long start_j = 0;
965 spin_lock_irqsave(&hp->lock, flags);
967 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
971 * We could have a non-open connection if the service processor died
972 * while we were busily scheduling ourselves. In that case, it could
973 * be minutes before the service processor comes back, so only try
974 * again once a second.
976 schedule_delayed_work(&hp->writer, HZ);
981 if (hp->n_outbuf > 0)
982 schedule_delayed_work(&hp->writer, 10);
985 pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
989 wake_up_all(&hp->emptyq);
994 spin_unlock_irqrestore(&hp->lock, flags);
997 static int hvsi_write_room(struct tty_struct *tty)
999 struct hvsi_struct *hp = tty->driver_data;
1001 return N_OUTBUF - hp->n_outbuf;
1004 static int hvsi_chars_in_buffer(struct tty_struct *tty)
1006 struct hvsi_struct *hp = tty->driver_data;
1008 return hp->n_outbuf;
1011 static int hvsi_write(struct tty_struct *tty,
1012 const unsigned char *buf, int count)
1014 struct hvsi_struct *hp = tty->driver_data;
1015 const char *source = buf;
1016 unsigned long flags;
1018 int origcount = count;
1020 spin_lock_irqsave(&hp->lock, flags);
1022 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
1025 /* we're either closing or not yet open; don't accept data */
1026 pr_debug("%s: not open\n", __func__);
1031 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1032 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1033 * will see there is no room in outbuf and return.
1035 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1036 int chunksize = min(count, hvsi_write_room(hp->tty));
1038 BUG_ON(hp->n_outbuf < 0);
1039 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1040 hp->n_outbuf += chunksize;
1043 source += chunksize;
1048 if (hp->n_outbuf > 0) {
1050 * we weren't able to write it all to the hypervisor.
1051 * schedule another push attempt.
1053 schedule_delayed_work(&hp->writer, 10);
1057 spin_unlock_irqrestore(&hp->lock, flags);
1059 if (total != origcount)
1060 pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount,
1067 * I have never seen throttle or unthrottle called, so this little throttle
1068 * buffering scheme may or may not work.
1070 static void hvsi_throttle(struct tty_struct *tty)
1072 struct hvsi_struct *hp = tty->driver_data;
1074 pr_debug("%s\n", __func__);
1076 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1079 static void hvsi_unthrottle(struct tty_struct *tty)
1081 struct hvsi_struct *hp = tty->driver_data;
1082 unsigned long flags;
1085 pr_debug("%s\n", __func__);
1087 spin_lock_irqsave(&hp->lock, flags);
1088 if (hp->n_throttle) {
1089 hvsi_send_overflow(hp);
1092 spin_unlock_irqrestore(&hp->lock, flags);
1095 tty_flip_buffer_push(hp->tty);
1097 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1100 static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1102 struct hvsi_struct *hp = tty->driver_data;
1108 static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1109 unsigned int set, unsigned int clear)
1111 struct hvsi_struct *hp = tty->driver_data;
1112 unsigned long flags;
1115 /* we can only alter DTR */
1119 spin_lock_irqsave(&hp->lock, flags);
1121 new_mctrl = (hp->mctrl & ~clear) | set;
1123 if (hp->mctrl != new_mctrl) {
1124 hvsi_set_mctrl(hp, new_mctrl);
1125 hp->mctrl = new_mctrl;
1127 spin_unlock_irqrestore(&hp->lock, flags);
1133 static const struct tty_operations hvsi_ops = {
1135 .close = hvsi_close,
1136 .write = hvsi_write,
1137 .hangup = hvsi_hangup,
1138 .write_room = hvsi_write_room,
1139 .chars_in_buffer = hvsi_chars_in_buffer,
1140 .throttle = hvsi_throttle,
1141 .unthrottle = hvsi_unthrottle,
1142 .tiocmget = hvsi_tiocmget,
1143 .tiocmset = hvsi_tiocmset,
1146 static int __init hvsi_init(void)
1150 hvsi_driver = alloc_tty_driver(hvsi_count);
1154 hvsi_driver->owner = THIS_MODULE;
1155 hvsi_driver->driver_name = "hvsi";
1156 hvsi_driver->name = "hvsi";
1157 hvsi_driver->major = HVSI_MAJOR;
1158 hvsi_driver->minor_start = HVSI_MINOR;
1159 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1160 hvsi_driver->init_termios = tty_std_termios;
1161 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1162 hvsi_driver->init_termios.c_ispeed = 9600;
1163 hvsi_driver->init_termios.c_ospeed = 9600;
1164 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1165 tty_set_operations(hvsi_driver, &hvsi_ops);
1167 for (i=0; i < hvsi_count; i++) {
1168 struct hvsi_struct *hp = &hvsi_ports[i];
1171 ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp);
1173 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1176 hvsi_wait = wait_for_state; /* irqs active now */
1178 if (tty_register_driver(hvsi_driver))
1179 panic("Couldn't register hvsi console driver\n");
1181 printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
1185 device_initcall(hvsi_init);
1187 /***** console (not tty) code: *****/
1189 static void hvsi_console_print(struct console *console, const char *buf,
1192 struct hvsi_struct *hp = &hvsi_ports[console->index];
1193 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1194 unsigned int i = 0, n = 0;
1195 int ret, donecr = 0;
1202 * ugh, we have to translate LF -> CRLF ourselves, in place.
1203 * copied from hvc_console.c:
1205 while (count > 0 || i > 0) {
1206 if (count > 0 && i < sizeof(c)) {
1207 if (buf[n] == '\n' && !donecr) {
1216 ret = hvsi_put_chars(hp, c, i);
1224 static struct tty_driver *hvsi_console_device(struct console *console,
1227 *index = console->index;
1231 static int __init hvsi_console_setup(struct console *console, char *options)
1233 struct hvsi_struct *hp;
1236 if (console->index < 0 || console->index >= hvsi_count)
1238 hp = &hvsi_ports[console->index];
1240 /* give the FSP a chance to change the baud rate when we re-open */
1241 hvsi_close_protocol(hp);
1243 ret = hvsi_handshake(hp);
1247 ret = hvsi_get_mctrl(hp);
1251 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1255 hp->flags |= HVSI_CONSOLE;
1260 static struct console hvsi_con_driver = {
1262 .write = hvsi_console_print,
1263 .device = hvsi_console_device,
1264 .setup = hvsi_console_setup,
1265 .flags = CON_PRINTBUFFER,
1269 static int __init hvsi_console_init(void)
1271 struct device_node *vty;
1273 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1275 /* search device tree for vty nodes */
1276 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1278 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1279 struct hvsi_struct *hp;
1280 const uint32_t *vtermno, *irq;
1282 vtermno = of_get_property(vty, "reg", NULL);
1283 irq = of_get_property(vty, "interrupts", NULL);
1284 if (!vtermno || !irq)
1287 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1292 hp = &hvsi_ports[hvsi_count];
1293 INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
1294 INIT_WORK(&hp->handshaker, hvsi_handshaker);
1295 init_waitqueue_head(&hp->emptyq);
1296 init_waitqueue_head(&hp->stateq);
1297 spin_lock_init(&hp->lock);
1298 hp->index = hvsi_count;
1299 hp->inbuf_end = hp->inbuf;
1300 hp->state = HVSI_CLOSED;
1301 hp->vtermno = *vtermno;
1302 hp->virq = irq_create_mapping(NULL, irq[0]);
1303 if (hp->virq == NO_IRQ) {
1304 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1313 register_console(&hvsi_con_driver);
1316 console_initcall(hvsi_console_init);