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 * add udbg support for xmon/kdb
39 #include <linux/console.h>
40 #include <linux/ctype.h>
41 #include <linux/delay.h>
42 #include <linux/init.h>
43 #include <linux/interrupt.h>
44 #include <linux/module.h>
45 #include <linux/major.h>
46 #include <linux/kernel.h>
47 #include <linux/sched.h>
48 #include <linux/spinlock.h>
49 #include <linux/sysrq.h>
50 #include <linux/tty.h>
51 #include <linux/tty_flip.h>
52 #include <asm/hvcall.h>
53 #include <asm/hvconsole.h>
55 #include <asm/uaccess.h>
58 #define HVSI_MAJOR 229
59 #define HVSI_MINOR 128
60 #define MAX_NR_HVSI_CONSOLES 4
62 #define HVSI_TIMEOUT (5*HZ)
63 #define HVSI_VERSION 1
64 #define HVSI_MAX_PACKET 256
65 #define HVSI_MAX_READ 16
66 #define HVSI_MAX_OUTGOING_DATA 12
70 * we pass data via two 8-byte registers, so we would like our char arrays
71 * properly aligned for those loads.
73 #define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
76 struct work_struct writer;
77 wait_queue_head_t emptyq; /* woken when outbuf is emptied */
78 wait_queue_head_t stateq; /* woken when HVSI state changes */
81 struct tty_struct *tty;
83 uint8_t throttle_buf[128];
84 uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
85 /* inbuf is for packet reassembly. leave a little room for leftovers. */
86 uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
92 atomic_t seqno; /* HVSI packet sequence number */
94 uint8_t state; /* HVSI protocol state */
96 #ifdef CONFIG_MAGIC_SYSRQ
98 #endif /* CONFIG_MAGIC_SYSRQ */
100 static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
102 static struct tty_driver *hvsi_driver;
103 static int hvsi_count;
104 static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
106 enum HVSI_PROTOCOL_STATE {
108 HVSI_WAIT_FOR_VER_RESPONSE,
109 HVSI_WAIT_FOR_VER_QUERY,
111 HVSI_WAIT_FOR_MCTRL_RESPONSE,
113 #define HVSI_CONSOLE 0x1
115 #define VS_DATA_PACKET_HEADER 0xff
116 #define VS_CONTROL_PACKET_HEADER 0xfe
117 #define VS_QUERY_PACKET_HEADER 0xfd
118 #define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
121 #define VSV_SET_MODEM_CTL 1 /* to service processor only */
122 #define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
123 #define VSV_CLOSE_PROTOCOL 3
126 #define VSV_SEND_VERSION_NUMBER 1
127 #define VSV_SEND_MODEM_CTL_STATUS 2
129 /* yes, these masks are not consecutive. */
130 #define HVSI_TSDTR 0x01
131 #define HVSI_TSCD 0x20
137 } __attribute__((packed));
143 uint8_t data[HVSI_MAX_OUTGOING_DATA];
144 } __attribute__((packed));
146 struct hvsi_control {
151 /* optional depending on verb: */
154 } __attribute__((packed));
161 } __attribute__((packed));
163 struct hvsi_query_response {
168 uint16_t query_seqno;
173 } __attribute__((packed));
175 static inline int is_open(struct hvsi_struct *hp)
177 /* if we're waiting for an mctrl then we're already open */
178 return (hp->state == HVSI_OPEN)
179 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
182 static inline void print_state(struct hvsi_struct *hp)
185 static const char *state_names[] = {
187 "HVSI_WAIT_FOR_VER_RESPONSE",
188 "HVSI_WAIT_FOR_VER_QUERY",
190 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
192 const char *name = state_names[hp->state];
194 if (hp->state > (sizeof(state_names)/sizeof(char*)))
197 pr_debug("hvsi%i: state = %s\n", hp->index, name);
201 static inline void __set_state(struct hvsi_struct *hp, int state)
205 wake_up_all(&hp->stateq);
208 static inline void set_state(struct hvsi_struct *hp, int state)
212 spin_lock_irqsave(&hp->lock, flags);
213 __set_state(hp, state);
214 spin_unlock_irqrestore(&hp->lock, flags);
217 static inline int len_packet(const uint8_t *packet)
219 return (int)((struct hvsi_header *)packet)->len;
222 static inline int is_header(const uint8_t *packet)
224 struct hvsi_header *header = (struct hvsi_header *)packet;
225 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
228 static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
230 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
231 return 0; /* don't even have the packet header */
233 if (hp->inbuf_end < (packet + len_packet(packet)))
234 return 0; /* don't have the rest of the packet */
239 /* shift remaining bytes in packetbuf down */
240 static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
242 int remaining = (int)(hp->inbuf_end - read_to);
244 pr_debug("%s: %i chars remain\n", __FUNCTION__, remaining);
246 if (read_to != hp->inbuf)
247 memmove(hp->inbuf, read_to, remaining);
249 hp->inbuf_end = hp->inbuf + remaining;
253 #define dbg_dump_packet(packet) dump_packet(packet)
254 #define dbg_dump_hex(data, len) dump_hex(data, len)
256 #define dbg_dump_packet(packet) do { } while (0)
257 #define dbg_dump_hex(data, len) do { } while (0)
260 static void dump_hex(const uint8_t *data, int len)
265 for (i=0; i < len; i++)
266 printk("%.2x", data[i]);
269 for (i=0; i < len; i++) {
270 if (isprint(data[i]))
271 printk("%c", data[i]);
278 static void dump_packet(uint8_t *packet)
280 struct hvsi_header *header = (struct hvsi_header *)packet;
282 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
285 dump_hex(packet, header->len);
288 /* can't use hvc_get_chars because that strips CRs */
289 static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
293 if (plpar_hcall(H_GET_TERM_CHAR, hp->vtermno, 0, 0, 0, &got,
294 (unsigned long *)buf, (unsigned long *)buf+1) == H_Success)
300 * we can't call tty_hangup() directly here because we need to call that
301 * outside of our lock
303 static struct tty_struct *hvsi_recv_control(struct hvsi_struct *hp,
306 struct tty_struct *to_hangup = NULL;
307 struct hvsi_control *header = (struct hvsi_control *)packet;
309 switch (header->verb) {
310 case VSV_MODEM_CTL_UPDATE:
311 if ((header->word & HVSI_TSCD) == 0) {
312 /* CD went away; no more connection */
313 pr_debug("hvsi%i: CD dropped\n", hp->index);
314 hp->mctrl &= TIOCM_CD;
315 if (!(hp->tty->flags & CLOCAL))
319 case VSV_CLOSE_PROTOCOL:
321 "hvsi%i: service processor closed connection!\n", hp->index);
322 __set_state(hp, HVSI_CLOSED);
327 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
336 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
338 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
341 case HVSI_WAIT_FOR_VER_RESPONSE:
342 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
344 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
346 if (resp->u.mctrl_word & HVSI_TSDTR)
347 hp->mctrl |= TIOCM_DTR;
348 if (resp->u.mctrl_word & HVSI_TSCD)
349 hp->mctrl |= TIOCM_CD;
350 __set_state(hp, HVSI_OPEN);
353 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
359 /* respond to service processor's version query */
360 static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
362 struct hvsi_query_response packet __ALIGNED__;
365 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
366 packet.len = sizeof(struct hvsi_query_response);
367 packet.seqno = atomic_inc_return(&hp->seqno);
368 packet.verb = VSV_SEND_VERSION_NUMBER;
369 packet.u.version = HVSI_VERSION;
370 packet.query_seqno = query_seqno+1;
372 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
373 dbg_dump_hex((uint8_t*)&packet, packet.len);
375 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
376 if (wrote != packet.len) {
377 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
385 static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
387 struct hvsi_query *query = (struct hvsi_query *)packet;
390 case HVSI_WAIT_FOR_VER_QUERY:
391 __set_state(hp, HVSI_OPEN);
392 hvsi_version_respond(hp, query->seqno);
395 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
401 static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
405 for (i=0; i < len; i++) {
407 #ifdef CONFIG_MAGIC_SYSRQ
411 } else if (hp->sysrq) {
412 handle_sysrq(c, NULL, hp->tty);
416 #endif /* CONFIG_MAGIC_SYSRQ */
417 tty_insert_flip_char(hp->tty, c, 0);
422 * We could get 252 bytes of data at once here. But the tty layer only
423 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
424 * it. Accordingly we won't send more than 128 bytes at a time to the flip
425 * buffer, which will give the tty buffer a chance to throttle us. Should the
426 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
429 #define TTY_THRESHOLD_THROTTLE 128
430 static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
431 const uint8_t *packet)
433 const struct hvsi_header *header = (const struct hvsi_header *)packet;
434 const uint8_t *data = packet + sizeof(struct hvsi_header);
435 int datalen = header->len - sizeof(struct hvsi_header);
436 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
438 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
444 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __FUNCTION__);
445 datalen = TTY_THRESHOLD_THROTTLE;
448 hvsi_insert_chars(hp, data, datalen);
452 * we still have more data to deliver, so we need to save off the
453 * overflow and send it later
455 pr_debug("%s: deferring overflow\n", __FUNCTION__);
456 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
457 hp->n_throttle = overflow;
464 * Returns true/false indicating data successfully read from hypervisor.
465 * Used both to get packets for tty connections and to advance the state
466 * machine during console handshaking (in which case tty = NULL and we ignore
469 static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
470 struct tty_struct **hangup)
472 uint8_t *packet = hp->inbuf;
478 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
482 pr_debug("%s: got %i bytes\n", __FUNCTION__, chunklen);
483 dbg_dump_hex(hp->inbuf_end, chunklen);
485 hp->inbuf_end += chunklen;
487 /* handle all completed packets */
488 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
489 struct hvsi_header *header = (struct hvsi_header *)packet;
491 if (!is_header(packet)) {
492 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
493 /* skip bytes until we find a header or run out of data */
494 while ((packet < hp->inbuf_end) && (!is_header(packet)))
499 pr_debug("%s: handling %i-byte packet\n", __FUNCTION__,
501 dbg_dump_packet(packet);
503 switch (header->type) {
504 case VS_DATA_PACKET_HEADER:
508 break; /* no tty buffer to put data in */
509 *flip = hvsi_recv_data(hp, packet);
511 case VS_CONTROL_PACKET_HEADER:
512 *hangup = hvsi_recv_control(hp, packet);
514 case VS_QUERY_RESPONSE_PACKET_HEADER:
515 hvsi_recv_response(hp, packet);
517 case VS_QUERY_PACKET_HEADER:
518 hvsi_recv_query(hp, packet);
521 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
522 hp->index, header->type);
527 packet += len_packet(packet);
530 pr_debug("%s: hangup\n", __FUNCTION__);
532 * we need to send the hangup now before receiving any more data.
533 * If we get "data, hangup, data", we can't deliver the second
534 * data before the hangup.
540 compact_inbuf(hp, packet);
545 static void hvsi_send_overflow(struct hvsi_struct *hp)
547 pr_debug("%s: delivering %i bytes overflow\n", __FUNCTION__,
550 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
555 * must get all pending data because we only get an irq on empty->non-empty
558 static irqreturn_t hvsi_interrupt(int irq, void *arg, struct pt_regs *regs)
560 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
561 struct tty_struct *flip;
562 struct tty_struct *hangup;
564 irqreturn_t handled = IRQ_NONE;
567 pr_debug("%s\n", __FUNCTION__);
570 spin_lock_irqsave(&hp->lock, flags);
571 again = hvsi_load_chunk(hp, &flip, &hangup);
572 handled = IRQ_HANDLED;
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 spin_lock_irqsave(&hp->lock, flags);
593 if (hp->tty && hp->n_throttle
594 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
595 /* we weren't hung up and we weren't throttled, so we can deliver the
598 hvsi_send_overflow(hp);
600 spin_unlock_irqrestore(&hp->lock, flags);
603 tty_flip_buffer_push(flip);
609 /* for boot console, before the irq handler is running */
610 static int __init poll_for_state(struct hvsi_struct *hp, int state)
612 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
615 hvsi_interrupt(hp->virq, (void *)hp, NULL); /* get pending data */
617 if (hp->state == state)
621 if (time_after(jiffies, end_jiffies))
626 /* wait for irq handler to change our state */
627 static int wait_for_state(struct hvsi_struct *hp, int state)
629 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
630 unsigned long timeout;
633 DECLARE_WAITQUEUE(myself, current);
634 set_current_state(TASK_INTERRUPTIBLE);
635 add_wait_queue(&hp->stateq, &myself);
638 set_current_state(TASK_INTERRUPTIBLE);
639 if (hp->state == state)
641 timeout = end_jiffies - jiffies;
642 if (time_after(jiffies, end_jiffies)) {
646 schedule_timeout(timeout);
648 remove_wait_queue(&hp->stateq, &myself);
649 set_current_state(TASK_RUNNING);
654 static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
656 struct hvsi_query packet __ALIGNED__;
659 packet.type = VS_QUERY_PACKET_HEADER;
660 packet.len = sizeof(struct hvsi_query);
661 packet.seqno = atomic_inc_return(&hp->seqno);
664 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
665 dbg_dump_hex((uint8_t*)&packet, packet.len);
667 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
668 if (wrote != packet.len) {
669 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
677 static int hvsi_get_mctrl(struct hvsi_struct *hp)
681 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
682 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
684 ret = hvsi_wait(hp, HVSI_OPEN);
686 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
687 set_state(hp, HVSI_OPEN);
691 pr_debug("%s: mctrl 0x%x\n", __FUNCTION__, hp->mctrl);
696 /* note that we can only set DTR */
697 static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
699 struct hvsi_control packet __ALIGNED__;
702 packet.type = VS_CONTROL_PACKET_HEADER,
703 packet.seqno = atomic_inc_return(&hp->seqno);
704 packet.len = sizeof(struct hvsi_control);
705 packet.verb = VSV_SET_MODEM_CTL;
706 packet.mask = HVSI_TSDTR;
708 if (mctrl & TIOCM_DTR)
709 packet.word = HVSI_TSDTR;
711 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
712 dbg_dump_hex((uint8_t*)&packet, packet.len);
714 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
715 if (wrote != packet.len) {
716 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
723 static void hvsi_drain_input(struct hvsi_struct *hp)
725 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
726 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
728 while (time_before(end_jiffies, jiffies))
729 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
733 static int hvsi_handshake(struct hvsi_struct *hp)
738 * We could have a CLOSE or other data waiting for us before we even try
739 * to open; try to throw it all away so we don't get confused. (CLOSE
740 * is the first message sent up the pipe when the FSP comes online. We
741 * need to distinguish between "it came up a while ago and we're the first
742 * user" and "it was just reset before it saw our handshake packet".)
744 hvsi_drain_input(hp);
746 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
747 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
749 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
753 ret = hvsi_wait(hp, HVSI_OPEN);
760 static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
762 struct hvsi_data packet __ALIGNED__;
765 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
767 packet.type = VS_DATA_PACKET_HEADER;
768 packet.seqno = atomic_inc_return(&hp->seqno);
769 packet.len = count + sizeof(struct hvsi_header);
770 memcpy(&packet.data, buf, count);
772 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
773 if (ret == packet.len) {
774 /* return the number of chars written, not the packet length */
777 return ret; /* return any errors */
780 static void hvsi_close_protocol(struct hvsi_struct *hp)
782 struct hvsi_control packet __ALIGNED__;
784 packet.type = VS_CONTROL_PACKET_HEADER;
785 packet.seqno = atomic_inc_return(&hp->seqno);
787 packet.verb = VSV_CLOSE_PROTOCOL;
789 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
790 dbg_dump_hex((uint8_t*)&packet, packet.len);
792 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
795 static int hvsi_open(struct tty_struct *tty, struct file *filp)
797 struct hvsi_struct *hp;
799 int line = tty->index;
802 pr_debug("%s\n", __FUNCTION__);
804 if (line < 0 || line >= hvsi_count)
806 hp = &hvsi_ports[line];
808 tty->driver_data = hp;
809 tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */
811 spin_lock_irqsave(&hp->lock, flags);
814 atomic_set(&hp->seqno, 0);
815 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
816 spin_unlock_irqrestore(&hp->lock, flags);
818 if (hp->flags & HVSI_CONSOLE)
819 return 0; /* this has already been handshaked as the console */
821 ret = hvsi_handshake(hp);
823 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
827 ret = hvsi_get_mctrl(hp);
829 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
833 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
835 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
842 /* wait for hvsi_write_worker to empty hp->outbuf */
843 static void hvsi_flush_output(struct hvsi_struct *hp)
845 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
846 unsigned long timeout;
848 DECLARE_WAITQUEUE(myself, current);
849 set_current_state(TASK_UNINTERRUPTIBLE);
850 add_wait_queue(&hp->emptyq, &myself);
853 set_current_state(TASK_UNINTERRUPTIBLE);
854 if (hp->n_outbuf <= 0)
856 timeout = end_jiffies - jiffies;
857 if (time_after(jiffies, end_jiffies))
859 schedule_timeout(timeout);
861 remove_wait_queue(&hp->emptyq, &myself);
862 set_current_state(TASK_RUNNING);
864 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
865 cancel_delayed_work(&hp->writer);
866 flush_scheduled_work();
869 * it's also possible that our timeout expired and hvsi_write_worker
870 * didn't manage to push outbuf. poof.
875 static void hvsi_close(struct tty_struct *tty, struct file *filp)
877 struct hvsi_struct *hp = tty->driver_data;
880 pr_debug("%s\n", __FUNCTION__);
882 if (tty_hung_up_p(filp))
885 spin_lock_irqsave(&hp->lock, flags);
887 if (--hp->count == 0) {
889 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
891 /* only close down connection if it is not the console */
892 if (!(hp->flags & HVSI_CONSOLE)) {
893 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
894 __set_state(hp, HVSI_CLOSED);
896 * any data delivered to the tty layer after this will be
897 * discarded (except for XON/XOFF)
901 spin_unlock_irqrestore(&hp->lock, flags);
903 /* let any existing irq handlers finish. no more will start. */
904 synchronize_irq(hp->virq);
906 /* hvsi_write_worker will re-schedule until outbuf is empty. */
907 hvsi_flush_output(hp);
909 /* tell FSP to stop sending data */
910 hvsi_close_protocol(hp);
913 * drain anything FSP is still in the middle of sending, and let
914 * hvsi_handshake drain the rest on the next open.
916 hvsi_drain_input(hp);
918 spin_lock_irqsave(&hp->lock, flags);
920 } else if (hp->count < 0)
921 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
922 hp - hvsi_ports, hp->count);
924 spin_unlock_irqrestore(&hp->lock, flags);
927 static void hvsi_hangup(struct tty_struct *tty)
929 struct hvsi_struct *hp = tty->driver_data;
931 pr_debug("%s\n", __FUNCTION__);
937 /* called with hp->lock held */
938 static void hvsi_push(struct hvsi_struct *hp)
942 if (hp->n_outbuf <= 0)
945 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
948 * either all data was sent or there was an error, and we throw away
955 /* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
956 static void hvsi_write_worker(void *arg)
958 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
961 static long start_j = 0;
967 spin_lock_irqsave(&hp->lock, flags);
970 if (hp->n_outbuf > 0)
971 schedule_delayed_work(&hp->writer, 10);
974 pr_debug("%s: outbuf emptied after %li jiffies\n", __FUNCTION__,
978 wake_up_all(&hp->emptyq);
979 if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags)
980 && hp->tty->ldisc.write_wakeup)
981 hp->tty->ldisc.write_wakeup(hp->tty);
982 wake_up_interruptible(&hp->tty->write_wait);
985 spin_unlock_irqrestore(&hp->lock, flags);
988 static int hvsi_write_room(struct tty_struct *tty)
990 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
992 return N_OUTBUF - hp->n_outbuf;
995 static int hvsi_chars_in_buffer(struct tty_struct *tty)
997 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1002 static int hvsi_write(struct tty_struct *tty, int from_user,
1003 const unsigned char *buf, int count)
1005 struct hvsi_struct *hp = tty->driver_data;
1006 const char *source = buf;
1008 unsigned long flags;
1010 int origcount = count;
1013 kbuf = kmalloc(count, GFP_KERNEL);
1016 if (copy_from_user(kbuf, buf, count)) {
1023 spin_lock_irqsave(&hp->lock, flags);
1026 /* we're either closing or not yet open; don't accept data */
1027 pr_debug("%s: not open\n", __FUNCTION__);
1032 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1033 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1034 * will see there is no room in outbuf and return.
1036 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1037 int chunksize = min(count, hvsi_write_room(hp->tty));
1039 BUG_ON(hp->n_outbuf < 0);
1040 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1041 hp->n_outbuf += chunksize;
1044 source += chunksize;
1049 if (hp->n_outbuf > 0) {
1051 * we weren't able to write it all to the hypervisor.
1052 * schedule another push attempt.
1054 schedule_delayed_work(&hp->writer, 10);
1058 spin_unlock_irqrestore(&hp->lock, flags);
1063 if (total != origcount)
1064 pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount,
1071 * I have never seen throttle or unthrottle called, so this little throttle
1072 * buffering scheme may or may not work.
1074 static void hvsi_throttle(struct tty_struct *tty)
1076 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1078 pr_debug("%s\n", __FUNCTION__);
1080 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1083 static void hvsi_unthrottle(struct tty_struct *tty)
1085 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1086 unsigned long flags;
1089 pr_debug("%s\n", __FUNCTION__);
1091 spin_lock_irqsave(&hp->lock, flags);
1092 if (hp->n_throttle) {
1093 hvsi_send_overflow(hp);
1096 spin_unlock_irqrestore(&hp->lock, flags);
1099 tty_flip_buffer_push(hp->tty);
1101 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1104 static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1106 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1112 static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1113 unsigned int set, unsigned int clear)
1115 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1116 unsigned long flags;
1119 /* we can only alter DTR */
1123 spin_lock_irqsave(&hp->lock, flags);
1125 new_mctrl = (hp->mctrl & ~clear) | set;
1127 if (hp->mctrl != new_mctrl) {
1128 hvsi_set_mctrl(hp, new_mctrl);
1129 hp->mctrl = new_mctrl;
1131 spin_unlock_irqrestore(&hp->lock, flags);
1137 static struct tty_operations hvsi_ops = {
1139 .close = hvsi_close,
1140 .write = hvsi_write,
1141 .hangup = hvsi_hangup,
1142 .write_room = hvsi_write_room,
1143 .chars_in_buffer = hvsi_chars_in_buffer,
1144 .throttle = hvsi_throttle,
1145 .unthrottle = hvsi_unthrottle,
1146 .tiocmget = hvsi_tiocmget,
1147 .tiocmset = hvsi_tiocmset,
1150 static int __init hvsi_init(void)
1154 hvsi_driver = alloc_tty_driver(hvsi_count);
1158 hvsi_driver->owner = THIS_MODULE;
1159 hvsi_driver->devfs_name = "hvsi/";
1160 hvsi_driver->driver_name = "hvsi";
1161 hvsi_driver->name = "hvsi";
1162 hvsi_driver->major = HVSI_MAJOR;
1163 hvsi_driver->minor_start = HVSI_MINOR;
1164 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1165 hvsi_driver->init_termios = tty_std_termios;
1166 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1167 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1168 tty_set_operations(hvsi_driver, &hvsi_ops);
1170 for (i=0; i < hvsi_count; i++) {
1171 struct hvsi_struct *hp = &hvsi_ports[i];
1174 ret = request_irq(hp->virq, hvsi_interrupt, SA_INTERRUPT, "hvsi", hp);
1176 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1179 hvsi_wait = wait_for_state; /* irqs active now */
1181 if (tty_register_driver(hvsi_driver))
1182 panic("Couldn't register hvsi console driver\n");
1184 printk(KERN_INFO "HVSI: registered %i devices\n", hvsi_count);
1188 device_initcall(hvsi_init);
1190 /***** console (not tty) code: *****/
1192 static void hvsi_console_print(struct console *console, const char *buf,
1195 struct hvsi_struct *hp = &hvsi_ports[console->index];
1196 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1197 unsigned int i = 0, n = 0;
1198 int ret, donecr = 0;
1205 * ugh, we have to translate LF -> CRLF ourselves, in place.
1206 * copied from hvc_console.c:
1208 while (count > 0 || i > 0) {
1209 if (count > 0 && i < sizeof(c)) {
1210 if (buf[n] == '\n' && !donecr) {
1219 ret = hvsi_put_chars(hp, c, i);
1227 static struct tty_driver *hvsi_console_device(struct console *console,
1230 *index = console->index;
1234 static int __init hvsi_console_setup(struct console *console, char *options)
1236 struct hvsi_struct *hp = &hvsi_ports[console->index];
1239 if (console->index < 0 || console->index >= hvsi_count)
1242 /* give the FSP a chance to change the baud rate when we re-open */
1243 hvsi_close_protocol(hp);
1245 ret = hvsi_handshake(hp);
1249 ret = hvsi_get_mctrl(hp);
1253 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1257 hp->flags |= HVSI_CONSOLE;
1262 static struct console hvsi_con_driver = {
1264 .write = hvsi_console_print,
1265 .device = hvsi_console_device,
1266 .setup = hvsi_console_setup,
1267 .flags = CON_PRINTBUFFER,
1271 static int __init hvsi_console_init(void)
1273 struct device_node *vty;
1275 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1277 /* search device tree for vty nodes */
1278 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1280 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1281 struct hvsi_struct *hp;
1285 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
1286 irq = (uint32_t *)get_property(vty, "interrupts", NULL);
1287 if (!vtermno || !irq)
1290 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1295 hp = &hvsi_ports[hvsi_count];
1296 INIT_WORK(&hp->writer, hvsi_write_worker, hp);
1297 init_waitqueue_head(&hp->emptyq);
1298 init_waitqueue_head(&hp->stateq);
1299 hp->lock = SPIN_LOCK_UNLOCKED;
1300 hp->index = hvsi_count;
1301 hp->inbuf_end = hp->inbuf;
1302 hp->state = HVSI_CLOSED;
1303 hp->vtermno = *vtermno;
1304 hp->virq = virt_irq_create_mapping(irq[0]);
1305 if (hp->virq == NO_IRQ) {
1306 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1307 __FUNCTION__, hp->virq);
1310 hp->virq = irq_offset_up(hp->virq);
1316 register_console(&hvsi_con_driver);
1319 console_initcall(hvsi_console_init);