diff options
Diffstat (limited to 'drivers/char/hvsi.c')
| -rw-r--r-- | drivers/char/hvsi.c | 1314 |
1 files changed, 0 insertions, 1314 deletions
diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c deleted file mode 100644 index a2bc885ce60a..000000000000 --- a/drivers/char/hvsi.c +++ /dev/null @@ -1,1314 +0,0 @@ -/* - * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS - * and the service processor on IBM pSeries servers. On these servers, there - * are no serial ports under the OS's control, and sometimes there is no other - * console available either. However, the service processor has two standard - * serial ports, so this over-complicated protocol allows the OS to control - * those ports by proxy. - * - * Besides data, the procotol supports the reading/writing of the serial - * port's DTR line, and the reading of the CD line. This is to allow the OS to - * control a modem attached to the service processor's serial port. Note that - * the OS cannot change the speed of the port through this protocol. - */ - -#undef DEBUG - -#include <linux/console.h> -#include <linux/ctype.h> -#include <linux/delay.h> -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/module.h> -#include <linux/major.h> -#include <linux/kernel.h> -#include <linux/spinlock.h> -#include <linux/sysrq.h> -#include <linux/tty.h> -#include <linux/tty_flip.h> -#include <asm/hvcall.h> -#include <asm/hvconsole.h> -#include <asm/prom.h> -#include <asm/uaccess.h> -#include <asm/vio.h> -#include <asm/param.h> - -#define HVSI_MAJOR 229 -#define HVSI_MINOR 128 -#define MAX_NR_HVSI_CONSOLES 4 - -#define HVSI_TIMEOUT (5*HZ) -#define HVSI_VERSION 1 -#define HVSI_MAX_PACKET 256 -#define HVSI_MAX_READ 16 -#define HVSI_MAX_OUTGOING_DATA 12 -#define N_OUTBUF 12 - -/* - * we pass data via two 8-byte registers, so we would like our char arrays - * properly aligned for those loads. - */ -#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) - -struct hvsi_struct { - struct delayed_work writer; - struct work_struct handshaker; - wait_queue_head_t emptyq; /* woken when outbuf is emptied */ - wait_queue_head_t stateq; /* woken when HVSI state changes */ - spinlock_t lock; - int index; - struct tty_struct *tty; - int count; - uint8_t throttle_buf[128]; - uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */ - /* inbuf is for packet reassembly. leave a little room for leftovers. */ - uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ]; - uint8_t *inbuf_end; - int n_throttle; - int n_outbuf; - uint32_t vtermno; - uint32_t virq; - atomic_t seqno; /* HVSI packet sequence number */ - uint16_t mctrl; - uint8_t state; /* HVSI protocol state */ - uint8_t flags; -#ifdef CONFIG_MAGIC_SYSRQ - uint8_t sysrq; -#endif /* CONFIG_MAGIC_SYSRQ */ -}; -static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES]; - -static struct tty_driver *hvsi_driver; -static int hvsi_count; -static int (*hvsi_wait)(struct hvsi_struct *hp, int state); - -enum HVSI_PROTOCOL_STATE { - HVSI_CLOSED, - HVSI_WAIT_FOR_VER_RESPONSE, - HVSI_WAIT_FOR_VER_QUERY, - HVSI_OPEN, - HVSI_WAIT_FOR_MCTRL_RESPONSE, - HVSI_FSP_DIED, -}; -#define HVSI_CONSOLE 0x1 - -#define VS_DATA_PACKET_HEADER 0xff -#define VS_CONTROL_PACKET_HEADER 0xfe -#define VS_QUERY_PACKET_HEADER 0xfd -#define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc - -/* control verbs */ -#define VSV_SET_MODEM_CTL 1 /* to service processor only */ -#define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */ -#define VSV_CLOSE_PROTOCOL 3 - -/* query verbs */ -#define VSV_SEND_VERSION_NUMBER 1 -#define VSV_SEND_MODEM_CTL_STATUS 2 - -/* yes, these masks are not consecutive. */ -#define HVSI_TSDTR 0x01 -#define HVSI_TSCD 0x20 - -struct hvsi_header { - uint8_t type; - uint8_t len; - uint16_t seqno; -} __attribute__((packed)); - -struct hvsi_data { - uint8_t type; - uint8_t len; - uint16_t seqno; - uint8_t data[HVSI_MAX_OUTGOING_DATA]; -} __attribute__((packed)); - -struct hvsi_control { - uint8_t type; - uint8_t len; - uint16_t seqno; - uint16_t verb; - /* optional depending on verb: */ - uint32_t word; - uint32_t mask; -} __attribute__((packed)); - -struct hvsi_query { - uint8_t type; - uint8_t len; - uint16_t seqno; - uint16_t verb; -} __attribute__((packed)); - -struct hvsi_query_response { - uint8_t type; - uint8_t len; - uint16_t seqno; - uint16_t verb; - uint16_t query_seqno; - union { - uint8_t version; - uint32_t mctrl_word; - } u; -} __attribute__((packed)); - - - -static inline int is_console(struct hvsi_struct *hp) -{ - return hp->flags & HVSI_CONSOLE; -} - -static inline int is_open(struct hvsi_struct *hp) -{ - /* if we're waiting for an mctrl then we're already open */ - return (hp->state == HVSI_OPEN) - || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE); -} - -static inline void print_state(struct hvsi_struct *hp) -{ -#ifdef DEBUG - static const char *state_names[] = { - "HVSI_CLOSED", - "HVSI_WAIT_FOR_VER_RESPONSE", - "HVSI_WAIT_FOR_VER_QUERY", - "HVSI_OPEN", - "HVSI_WAIT_FOR_MCTRL_RESPONSE", - "HVSI_FSP_DIED", - }; - const char *name = (hp->state < ARRAY_SIZE(state_names)) - ? state_names[hp->state] : "UNKNOWN"; - - pr_debug("hvsi%i: state = %s\n", hp->index, name); -#endif /* DEBUG */ -} - -static inline void __set_state(struct hvsi_struct *hp, int state) -{ - hp->state = state; - print_state(hp); - wake_up_all(&hp->stateq); -} - -static inline void set_state(struct hvsi_struct *hp, int state) -{ - unsigned long flags; - - spin_lock_irqsave(&hp->lock, flags); - __set_state(hp, state); - spin_unlock_irqrestore(&hp->lock, flags); -} - -static inline int len_packet(const uint8_t *packet) -{ - return (int)((struct hvsi_header *)packet)->len; -} - -static inline int is_header(const uint8_t *packet) -{ - struct hvsi_header *header = (struct hvsi_header *)packet; - return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER; -} - -static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet) -{ - if (hp->inbuf_end < packet + sizeof(struct hvsi_header)) - return 0; /* don't even have the packet header */ - - if (hp->inbuf_end < (packet + len_packet(packet))) - return 0; /* don't have the rest of the packet */ - - return 1; -} - -/* shift remaining bytes in packetbuf down */ -static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to) -{ - int remaining = (int)(hp->inbuf_end - read_to); - - pr_debug("%s: %i chars remain\n", __func__, remaining); - - if (read_to != hp->inbuf) - memmove(hp->inbuf, read_to, remaining); - - hp->inbuf_end = hp->inbuf + remaining; -} - -#ifdef DEBUG -#define dbg_dump_packet(packet) dump_packet(packet) -#define dbg_dump_hex(data, len) dump_hex(data, len) -#else -#define dbg_dump_packet(packet) do { } while (0) -#define dbg_dump_hex(data, len) do { } while (0) -#endif - -static void dump_hex(const uint8_t *data, int len) -{ - int i; - - printk(" "); - for (i=0; i < len; i++) - printk("%.2x", data[i]); - - printk("\n "); - for (i=0; i < len; i++) { - if (isprint(data[i])) - printk("%c", data[i]); - else - printk("."); - } - printk("\n"); -} - -static void dump_packet(uint8_t *packet) -{ - struct hvsi_header *header = (struct hvsi_header *)packet; - - printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len, - header->seqno); - - dump_hex(packet, header->len); -} - -static int hvsi_read(struct hvsi_struct *hp, char *buf, int count) -{ - unsigned long got; - - got = hvc_get_chars(hp->vtermno, buf, count); - - return got; -} - -static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet, - struct tty_struct **to_hangup, struct hvsi_struct **to_handshake) -{ - struct hvsi_control *header = (struct hvsi_control *)packet; - - switch (header->verb) { - case VSV_MODEM_CTL_UPDATE: - if ((header->word & HVSI_TSCD) == 0) { - /* CD went away; no more connection */ - pr_debug("hvsi%i: CD dropped\n", hp->index); - hp->mctrl &= TIOCM_CD; - /* If userland hasn't done an open(2) yet, hp->tty is NULL. */ - if (hp->tty && !(hp->tty->flags & CLOCAL)) - *to_hangup = hp->tty; - } - break; - case VSV_CLOSE_PROTOCOL: - pr_debug("hvsi%i: service processor came back\n", hp->index); - if (hp->state != HVSI_CLOSED) { - *to_handshake = hp; - } - break; - default: - printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ", - hp->index); - dump_packet(packet); - break; - } -} - -static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet) -{ - struct hvsi_query_response *resp = (struct hvsi_query_response *)packet; - - switch (hp->state) { - case HVSI_WAIT_FOR_VER_RESPONSE: - __set_state(hp, HVSI_WAIT_FOR_VER_QUERY); - break; - case HVSI_WAIT_FOR_MCTRL_RESPONSE: - hp->mctrl = 0; - if (resp->u.mctrl_word & HVSI_TSDTR) - hp->mctrl |= TIOCM_DTR; - if (resp->u.mctrl_word & HVSI_TSCD) - hp->mctrl |= TIOCM_CD; - __set_state(hp, HVSI_OPEN); - break; - default: - printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index); - dump_packet(packet); - break; - } -} - -/* respond to service processor's version query */ -static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno) -{ - struct hvsi_query_response packet __ALIGNED__; - int wrote; - - packet.type = VS_QUERY_RESPONSE_PACKET_HEADER; - packet.len = sizeof(struct hvsi_query_response); - packet.seqno = atomic_inc_return(&hp->seqno); - packet.verb = VSV_SEND_VERSION_NUMBER; - packet.u.version = HVSI_VERSION; - packet.query_seqno = query_seqno+1; - - pr_debug("%s: sending %i bytes\n", __func__, packet.len); - dbg_dump_hex((uint8_t*)&packet, packet.len); - - wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); - if (wrote != packet.len) { - printk(KERN_ERR "hvsi%i: couldn't send query response!\n", - hp->index); - return -EIO; - } - - return 0; -} - -static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet) -{ - struct hvsi_query *query = (struct hvsi_query *)packet; - - switch (hp->state) { - case HVSI_WAIT_FOR_VER_QUERY: - hvsi_version_respond(hp, query->seqno); - __set_state(hp, HVSI_OPEN); - break; - default: - printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index); - dump_packet(packet); - break; - } -} - -static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len) -{ - int i; - - for (i=0; i < len; i++) { - char c = buf[i]; -#ifdef CONFIG_MAGIC_SYSRQ - if (c == '\0') { - hp->sysrq = 1; - continue; - } else if (hp->sysrq) { - handle_sysrq(c); - hp->sysrq = 0; - continue; - } -#endif /* CONFIG_MAGIC_SYSRQ */ - tty_insert_flip_char(hp->tty, c, 0); - } -} - -/* - * We could get 252 bytes of data at once here. But the tty layer only - * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow - * it. Accordingly we won't send more than 128 bytes at a time to the flip - * buffer, which will give the tty buffer a chance to throttle us. Should the - * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be - * revisited. - */ -#define TTY_THRESHOLD_THROTTLE 128 -static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp, - const uint8_t *packet) -{ - const struct hvsi_header *header = (const struct hvsi_header *)packet; - const uint8_t *data = packet + sizeof(struct hvsi_header); - int datalen = header->len - sizeof(struct hvsi_header); - int overflow = datalen - TTY_THRESHOLD_THROTTLE; - - pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data); - - if (datalen == 0) - return NULL; - - if (overflow > 0) { - pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__); - datalen = TTY_THRESHOLD_THROTTLE; - } - - hvsi_insert_chars(hp, data, datalen); - - if (overflow > 0) { - /* - * we still have more data to deliver, so we need to save off the - * overflow and send it later - */ - pr_debug("%s: deferring overflow\n", __func__); - memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow); - hp->n_throttle = overflow; - } - - return hp->tty; -} - -/* - * Returns true/false indicating data successfully read from hypervisor. - * Used both to get packets for tty connections and to advance the state - * machine during console handshaking (in which case tty = NULL and we ignore - * incoming data). - */ -static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip, - struct tty_struct **hangup, struct hvsi_struct **handshake) -{ - uint8_t *packet = hp->inbuf; - int chunklen; - - *flip = NULL; - *hangup = NULL; - *handshake = NULL; - - chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ); - if (chunklen == 0) { - pr_debug("%s: 0-length read\n", __func__); - return 0; - } - - pr_debug("%s: got %i bytes\n", __func__, chunklen); - dbg_dump_hex(hp->inbuf_end, chunklen); - - hp->inbuf_end += chunklen; - - /* handle all completed packets */ - while ((packet < hp->inbuf_end) && got_packet(hp, packet)) { - struct hvsi_header *header = (struct hvsi_header *)packet; - - if (!is_header(packet)) { - printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index); - /* skip bytes until we find a header or run out of data */ - while ((packet < hp->inbuf_end) && (!is_header(packet))) - packet++; - continue; - } - - pr_debug("%s: handling %i-byte packet\n", __func__, - len_packet(packet)); - dbg_dump_packet(packet); - - switch (header->type) { - case VS_DATA_PACKET_HEADER: - if (!is_open(hp)) - break; - if (hp->tty == NULL) - break; /* no tty buffer to put data in */ - *flip = hvsi_recv_data(hp, packet); - break; - case VS_CONTROL_PACKET_HEADER: - hvsi_recv_control(hp, packet, hangup, handshake); - break; - case VS_QUERY_RESPONSE_PACKET_HEADER: - hvsi_recv_response(hp, packet); - break; - case VS_QUERY_PACKET_HEADER: - hvsi_recv_query(hp, packet); - break; - default: - printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n", - hp->index, header->type); - dump_packet(packet); - break; - } - - packet += len_packet(packet); - - if (*hangup || *handshake) { - pr_debug("%s: hangup or handshake\n", __func__); - /* - * we need to send the hangup now before receiving any more data. - * If we get "data, hangup, data", we can't deliver the second - * data before the hangup. - */ - break; - } - } - - compact_inbuf(hp, packet); - - return 1; -} - -static void hvsi_send_overflow(struct hvsi_struct *hp) -{ - pr_debug("%s: delivering %i bytes overflow\n", __func__, - hp->n_throttle); - - hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle); - hp->n_throttle = 0; -} - -/* - * must get all pending data because we only get an irq on empty->non-empty - * transition - */ -static irqreturn_t hvsi_interrupt(int irq, void *arg) -{ - struct hvsi_struct *hp = (struct hvsi_struct *)arg; - struct tty_struct *flip; - struct tty_struct *hangup; - struct hvsi_struct *handshake; - unsigned long flags; - int again = 1; - - pr_debug("%s\n", __func__); - - while (again) { - spin_lock_irqsave(&hp->lock, flags); - again = hvsi_load_chunk(hp, &flip, &hangup, &handshake); - spin_unlock_irqrestore(&hp->lock, flags); - - /* - * we have to call tty_flip_buffer_push() and tty_hangup() outside our - * spinlock. But we also have to keep going until we've read all the - * available data. - */ - - if (flip) { - /* there was data put in the tty flip buffer */ - tty_flip_buffer_push(flip); - flip = NULL; - } - - if (hangup) { - tty_hangup(hangup); - } - - if (handshake) { - pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); - schedule_work(&handshake->handshaker); - } - } - - spin_lock_irqsave(&hp->lock, flags); - if (hp->tty && hp->n_throttle - && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) { - /* we weren't hung up and we weren't throttled, so we can deliver the - * rest now */ - flip = hp->tty; - hvsi_send_overflow(hp); - } - spin_unlock_irqrestore(&hp->lock, flags); - - if (flip) { - tty_flip_buffer_push(flip); - } - - return IRQ_HANDLED; -} - -/* for boot console, before the irq handler is running */ -static int __init poll_for_state(struct hvsi_struct *hp, int state) -{ - unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; - - for (;;) { - hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ - - if (hp->state == state) - return 0; - - mdelay(5); - if (time_after(jiffies, end_jiffies)) - return -EIO; - } -} - -/* wait for irq handler to change our state */ -static int wait_for_state(struct hvsi_struct *hp, int state) -{ - int ret = 0; - - if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) - ret = -EIO; - - return ret; -} - -static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) -{ - struct hvsi_query packet __ALIGNED__; - int wrote; - - packet.type = VS_QUERY_PACKET_HEADER; - packet.len = sizeof(struct hvsi_query); - packet.seqno = atomic_inc_return(&hp->seqno); - packet.verb = verb; - - pr_debug("%s: sending %i bytes\n", __func__, packet.len); - dbg_dump_hex((uint8_t*)&packet, packet.len); - - wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); - if (wrote != packet.len) { - printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index, - wrote); - return -EIO; - } - - return 0; -} - -static int hvsi_get_mctrl(struct hvsi_struct *hp) -{ - int ret; - - set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE); - hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS); - - ret = hvsi_wait(hp, HVSI_OPEN); - if (ret < 0) { - printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index); - set_state(hp, HVSI_OPEN); - return ret; - } - - pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl); - - return 0; -} - -/* note that we can only set DTR */ -static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl) -{ - struct hvsi_control packet __ALIGNED__; - int wrote; - - packet.type = VS_CONTROL_PACKET_HEADER, - packet.seqno = atomic_inc_return(&hp->seqno); - packet.len = sizeof(struct hvsi_control); - packet.verb = VSV_SET_MODEM_CTL; - packet.mask = HVSI_TSDTR; - - if (mctrl & TIOCM_DTR) - packet.word = HVSI_TSDTR; - - pr_debug("%s: sending %i bytes\n", __func__, packet.len); - dbg_dump_hex((uint8_t*)&packet, packet.len); - - wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); - if (wrote != packet.len) { - printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index); - return -EIO; - } - - return 0; -} - -static void hvsi_drain_input(struct hvsi_struct *hp) -{ - uint8_t buf[HVSI_MAX_READ] __ALIGNED__; - unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; - - while (time_before(end_jiffies, jiffies)) - if (0 == hvsi_read(hp, buf, HVSI_MAX_READ)) - break; -} - -static int hvsi_handshake(struct hvsi_struct *hp) -{ - int ret; - - /* - * We could have a CLOSE or other data waiting for us before we even try - * to open; try to throw it all away so we don't get confused. (CLOSE - * is the first message sent up the pipe when the FSP comes online. We - * need to distinguish between "it came up a while ago and we're the first - * user" and "it was just reset before it saw our handshake packet".) - */ - hvsi_drain_input(hp); - - set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE); - ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER); - if (ret < 0) { - printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index); - return ret; - } - - ret = hvsi_wait(hp, HVSI_OPEN); - if (ret < 0) - return ret; - - return 0; -} - -static void hvsi_handshaker(struct work_struct *work) -{ - struct hvsi_struct *hp = - container_of(work, struct hvsi_struct, handshaker); - - if (hvsi_handshake(hp) >= 0) - return; - - printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index); - if (is_console(hp)) { - /* - * ttys will re-attempt the handshake via hvsi_open, but - * the console will not. - */ - printk(KERN_ERR "hvsi%i: lost console!\n", hp->index); - } -} - -static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count) -{ - struct hvsi_data packet __ALIGNED__; - int ret; - - BUG_ON(count > HVSI_MAX_OUTGOING_DATA); - - packet.type = VS_DATA_PACKET_HEADER; - packet.seqno = atomic_inc_return(&hp->seqno); - packet.len = count + sizeof(struct hvsi_header); - memcpy(&packet.data, buf, count); - - ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); - if (ret == packet.len) { - /* return the number of chars written, not the packet length */ - return count; - } - return ret; /* return any errors */ -} - -static void hvsi_close_protocol(struct hvsi_struct *hp) -{ - struct hvsi_control packet __ALIGNED__; - - packet.type = VS_CONTROL_PACKET_HEADER; - packet.seqno = atomic_inc_return(&hp->seqno); - packet.len = 6; - packet.verb = VSV_CLOSE_PROTOCOL; - - pr_debug("%s: sending %i bytes\n", __func__, packet.len); - dbg_dump_hex((uint8_t*)&packet, packet.len); - - hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); -} - -static int hvsi_open(struct tty_struct *tty, struct file *filp) -{ - struct hvsi_struct *hp; - unsigned long flags; - int line = tty->index; - int ret; - - pr_debug("%s\n", __func__); - - if (line < 0 || line >= hvsi_count) - return -ENODEV; - hp = &hvsi_ports[line]; - - tty->driver_data = hp; - - mb(); - if (hp->state == HVSI_FSP_DIED) - return -EIO; - - spin_lock_irqsave(&hp->lock, flags); - hp->tty = tty; - hp->count++; - atomic_set(&hp->seqno, 0); - h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); - spin_unlock_irqrestore(&hp->lock, flags); - - if (is_console(hp)) - return 0; /* this has already been handshaked as the console */ - - ret = hvsi_handshake(hp); - if (ret < 0) { - printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name); - return ret; - } - - ret = hvsi_get_mctrl(hp); - if (ret < 0) { - printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name); - return ret; - } - - ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); - if (ret < 0) { - printk(KERN_ERR "%s: couldn't set DTR\n", tty->name); - return ret; - } - - return 0; -} - -/* wait for hvsi_write_worker to empty hp->outbuf */ -static void hvsi_flush_output(struct hvsi_struct *hp) -{ - wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT); - - /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */ - cancel_delayed_work(&hp->writer); - flush_scheduled_work(); - - /* - * it's also possible that our timeout expired and hvsi_write_worker - * didn't manage to push outbuf. poof. - */ - hp->n_outbuf = 0; -} - -static void hvsi_close(struct tty_struct *tty, struct file *filp) -{ - struct hvsi_struct *hp = tty->driver_data; - unsigned long flags; - - pr_debug("%s\n", __func__); - - if (tty_hung_up_p(filp)) - return; - - spin_lock_irqsave(&hp->lock, flags); - - if (--hp->count == 0) { - hp->tty = NULL; - hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */ - - /* only close down connection if it is not the console */ - if (!is_console(hp)) { - h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */ - __set_state(hp, HVSI_CLOSED); - /* - * any data delivered to the tty layer after this will be - * discarded (except for XON/XOFF) - */ - tty->closing = 1; - - spin_unlock_irqrestore(&hp->lock, flags); - - /* let any existing irq handlers finish. no more will start. */ - synchronize_irq(hp->virq); - - /* hvsi_write_worker will re-schedule until outbuf is empty. */ - hvsi_flush_output(hp); - - /* tell FSP to stop sending data */ - hvsi_close_protocol(hp); - - /* - * drain anything FSP is still in the middle of sending, and let - * hvsi_handshake drain the rest on the next open. - */ - hvsi_drain_input(hp); - - spin_lock_irqsave(&hp->lock, flags); - } - } else if (hp->count < 0) - printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", - hp - hvsi_ports, hp->count); - - spin_unlock_irqrestore(&hp->lock, flags); -} - -static void hvsi_hangup(struct tty_struct *tty) -{ - struct hvsi_struct *hp = tty->driver_data; - unsigned long flags; - - pr_debug("%s\n", __func__); - - spin_lock_irqsave(&hp->lock, flags); - - hp->count = 0; - hp->n_outbuf = 0; - hp->tty = NULL; - - spin_unlock_irqrestore(&hp->lock, flags); -} - -/* called with hp->lock held */ -static void hvsi_push(struct hvsi_struct *hp) -{ - int n; - - if (hp->n_outbuf <= 0) - return; - - n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf); - if (n > 0) { - /* success */ - pr_debug("%s: wrote %i chars\n", __func__, n); - hp->n_outbuf = 0; - } else if (n == -EIO) { - __set_state(hp, HVSI_FSP_DIED); - printk(KERN_ERR "hvsi%i: service processor died\n", hp->index); - } -} - -/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */ -static void hvsi_write_worker(struct work_struct *work) -{ - struct hvsi_struct *hp = - container_of(work, struct hvsi_struct, writer.work); - unsigned long flags; -#ifdef DEBUG - static long start_j = 0; - - if (start_j == 0) - start_j = jiffies; -#endif /* DEBUG */ - - spin_lock_irqsave(&hp->lock, flags); - - pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); - - if (!is_open(hp)) { - /* - * We could have a non-open connection if the service processor died - * while we were busily scheduling ourselves. In that case, it could - * be minutes before the service processor comes back, so only try - * again once a second. - */ - schedule_delayed_work(&hp->writer, HZ); - goto out; - } - - hvsi_push(hp); - if (hp->n_outbuf > 0) - schedule_delayed_work(&hp->writer, 10); - else { -#ifdef DEBUG - pr_debug("%s: outbuf emptied after %li jiffies\n", __func__, - jiffies - start_j); - start_j = 0; -#endif /* DEBUG */ - wake_up_all(&hp->emptyq); - tty_wakeup(hp->tty); - } - -out: - spin_unlock_irqrestore(&hp->lock, flags); -} - -static int hvsi_write_room(struct tty_struct *tty) -{ - struct hvsi_struct *hp = tty->driver_data; - - return N_OUTBUF - hp->n_outbuf; -} - -static int hvsi_chars_in_buffer(struct tty_struct *tty) -{ - struct hvsi_struct *hp = tty->driver_data; - - return hp->n_outbuf; -} - -static int hvsi_write(struct tty_struct *tty, - const unsigned char *buf, int count) -{ - struct hvsi_struct *hp = tty->driver_data; - const char *source = buf; - unsigned long flags; - int total = 0; - int origcount = count; - - spin_lock_irqsave(&hp->lock, flags); - - pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); - - if (!is_open(hp)) { - /* we're either closing or not yet open; don't accept data */ - pr_debug("%s: not open\n", __func__); - goto out; - } - - /* - * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf - * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls - * will see there is no room in outbuf and return. - */ - while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) { - int chunksize = min(count, hvsi_write_room(hp->tty)); - - BUG_ON(hp->n_outbuf < 0); - memcpy(hp->outbuf + hp->n_outbuf, source, chunksize); - hp->n_outbuf += chunksize; - - total += chunksize; - source += chunksize; - count -= chunksize; - hvsi_push(hp); - } - - if (hp->n_outbuf > 0) { - /* - * we weren't able to write it all to the hypervisor. - * schedule another push attempt. - */ - schedule_delayed_work(&hp->writer, 10); - } - -out: - spin_unlock_irqrestore(&hp->lock, flags); - - if (total != origcount) - pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount, - total); - - return total; -} - -/* - * I have never seen throttle or unthrottle called, so this little throttle - * buffering scheme may or may not work. - */ -static void hvsi_throttle(struct tty_struct *tty) -{ - struct hvsi_struct *hp = tty->driver_data; - - pr_debug("%s\n", __func__); - - h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); -} - -static void hvsi_unthrottle(struct tty_struct *tty) -{ - struct hvsi_struct *hp = tty->driver_data; - unsigned long flags; - int shouldflip = 0; - - pr_debug("%s\n", __func__); - - spin_lock_irqsave(&hp->lock, flags); - if (hp->n_throttle) { - hvsi_send_overflow(hp); - shouldflip = 1; - } - spin_unlock_irqrestore(&hp->lock, flags); - - if (shouldflip) - tty_flip_buffer_push(hp->tty); - - h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); -} - -static int hvsi_tiocmget(struct tty_struct *tty, struct file *file) -{ - struct hvsi_struct *hp = tty->driver_data; - - hvsi_get_mctrl(hp); - return hp->mctrl; -} - -static int hvsi_tiocmset(struct tty_struct *tty, struct file *file, - unsigned int set, unsigned int clear) -{ - struct hvsi_struct *hp = tty->driver_data; - unsigned long flags; - uint16_t new_mctrl; - - /* we can only alter DTR */ - clear &= TIOCM_DTR; - set &= TIOCM_DTR; - - spin_lock_irqsave(&hp->lock, flags); - - new_mctrl = (hp->mctrl & ~clear) | set; - - if (hp->mctrl != new_mctrl) { - hvsi_set_mctrl(hp, new_mctrl); - hp->mctrl = new_mctrl; - } - spin_unlock_irqrestore(&hp->lock, flags); - - return 0; -} - - -static const struct tty_operations hvsi_ops = { - .open = hvsi_open, - .close = hvsi_close, - .write = hvsi_write, - .hangup = hvsi_hangup, - .write_room = hvsi_write_room, - .chars_in_buffer = hvsi_chars_in_buffer, - .throttle = hvsi_throttle, - .unthrottle = hvsi_unthrottle, - .tiocmget = hvsi_tiocmget, - .tiocmset = hvsi_tiocmset, -}; - -static int __init hvsi_init(void) -{ - int i; - - hvsi_driver = alloc_tty_driver(hvsi_count); - if (!hvsi_driver) - return -ENOMEM; - - hvsi_driver->owner = THIS_MODULE; - hvsi_driver->driver_name = "hvsi"; - hvsi_driver->name = "hvsi"; - hvsi_driver->major = HVSI_MAJOR; - hvsi_driver->minor_start = HVSI_MINOR; - hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM; - hvsi_driver->init_termios = tty_std_termios; - hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; - hvsi_driver->init_termios.c_ispeed = 9600; - hvsi_driver->init_termios.c_ospeed = 9600; - hvsi_driver->flags = TTY_DRIVER_REAL_RAW; - tty_set_operations(hvsi_driver, &hvsi_ops); - - for (i=0; i < hvsi_count; i++) { - struct hvsi_struct *hp = &hvsi_ports[i]; - int ret = 1; - - ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp); - if (ret) - printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n", - hp->virq, ret); - } - hvsi_wait = wait_for_state; /* irqs active now */ - - if (tty_register_driver(hvsi_driver)) - panic("Couldn't register hvsi console driver\n"); - - printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); - - return 0; -} -device_initcall(hvsi_init); - -/***** console (not tty) code: *****/ - -static void hvsi_console_print(struct console *console, const char *buf, - unsigned int count) -{ - struct hvsi_struct *hp = &hvsi_ports[console->index]; - char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__; - unsigned int i = 0, n = 0; - int ret, donecr = 0; - - mb(); - if (!is_open(hp)) - return; - - /* - * ugh, we have to translate LF -> CRLF ourselves, in place. - * copied from hvc_console.c: - */ - while (count > 0 || i > 0) { - if (count > 0 && i < sizeof(c)) { - if (buf[n] == '\n' && !donecr) { - c[i++] = '\r'; - donecr = 1; - } else { - c[i++] = buf[n++]; - donecr = 0; - --count; - } - } else { - ret = hvsi_put_chars(hp, c, i); - if (ret < 0) - i = 0; - i -= ret; - } - } -} - -static struct tty_driver *hvsi_console_device(struct console *console, - int *index) -{ - *index = console->index; - return hvsi_driver; -} - -static int __init hvsi_console_setup(struct console *console, char *options) -{ - struct hvsi_struct *hp; - int ret; - - if (console->index < 0 || console->index >= hvsi_count) - return -1; - hp = &hvsi_ports[console->index]; - - /* give the FSP a chance to change the baud rate when we re-open */ - hvsi_close_protocol(hp); - - ret = hvsi_handshake(hp); - if (ret < 0) - return ret; - - ret = hvsi_get_mctrl(hp); - if (ret < 0) - return ret; - - ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); - if (ret < 0) - return ret; - - hp->flags |= HVSI_CONSOLE; - - return 0; -} - -static struct console hvsi_console = { - .name = "hvsi", - .write = hvsi_console_print, - .device = hvsi_console_device, - .setup = hvsi_console_setup, - .flags = CON_PRINTBUFFER, - .index = -1, -}; - -static int __init hvsi_console_init(void) -{ - struct device_node *vty; - - hvsi_wait = poll_for_state; /* no irqs yet; must poll */ - - /* search device tree for vty nodes */ - for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol"); - vty != NULL; - vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) { - struct hvsi_struct *hp; - const uint32_t *vtermno, *irq; - - vtermno = of_get_property(vty, "reg", NULL); - irq = of_get_property(vty, "interrupts", NULL); - if (!vtermno || !irq) - continue; - - if (hvsi_count >= MAX_NR_HVSI_CONSOLES) { - of_node_put(vty); - break; - } - - hp = &hvsi_ports[hvsi_count]; - INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker); - INIT_WORK(&hp->handshaker, hvsi_handshaker); - init_waitqueue_head(&hp->emptyq); - init_waitqueue_head(&hp->stateq); - spin_lock_init(&hp->lock); - hp->index = hvsi_count; - hp->inbuf_end = hp->inbuf; - hp->state = HVSI_CLOSED; - hp->vtermno = *vtermno; - hp->virq = irq_create_mapping(NULL, irq[0]); - if (hp->virq == NO_IRQ) { - printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n", - __func__, irq[0]); - continue; - } - - hvsi_count++; - } - - if (hvsi_count) - register_console(&hvsi_console); - return 0; -} -console_initcall(hvsi_console_init); |