| /* |
| * 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> |
| #include <asm/hvsi.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 tty_port port; |
| 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; |
| 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 |
| |
| 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 *tty, 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 (tty && !C_CLOCAL(tty)) |
| tty_hangup(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.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER; |
| packet.hdr.len = sizeof(struct hvsi_query_response); |
| packet.hdr.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.hdr.len); |
| dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); |
| |
| wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); |
| if (wrote != packet.hdr.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->hdr.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, struct tty_struct *tty, |
| 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(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 bool hvsi_recv_data(struct hvsi_struct *hp, struct tty_struct *tty, |
| 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 false; |
| |
| if (overflow > 0) { |
| pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__); |
| datalen = TTY_THRESHOLD_THROTTLE; |
| } |
| |
| hvsi_insert_chars(hp, tty, 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 true; |
| } |
| |
| /* |
| * 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 *tty, |
| struct hvsi_struct **handshake) |
| { |
| uint8_t *packet = hp->inbuf; |
| int chunklen; |
| bool flip = false; |
| |
| *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 (tty == NULL) |
| break; /* no tty buffer to put data in */ |
| flip = hvsi_recv_data(hp, tty, packet); |
| break; |
| case VS_CONTROL_PACKET_HEADER: |
| hvsi_recv_control(hp, packet, tty, 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 (*handshake) { |
| pr_debug("%s: handshake\n", __func__); |
| break; |
| } |
| } |
| |
| compact_inbuf(hp, packet); |
| |
| if (flip) |
| tty_flip_buffer_push(tty); |
| |
| return 1; |
| } |
| |
| static void hvsi_send_overflow(struct hvsi_struct *hp, struct tty_struct *tty) |
| { |
| pr_debug("%s: delivering %i bytes overflow\n", __func__, |
| hp->n_throttle); |
| |
| hvsi_insert_chars(hp, tty, 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 hvsi_struct *handshake; |
| struct tty_struct *tty; |
| unsigned long flags; |
| int again = 1; |
| |
| pr_debug("%s\n", __func__); |
| |
| tty = tty_port_tty_get(&hp->port); |
| |
| while (again) { |
| spin_lock_irqsave(&hp->lock, flags); |
| again = hvsi_load_chunk(hp, tty, &handshake); |
| spin_unlock_irqrestore(&hp->lock, flags); |
| |
| if (handshake) { |
| pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); |
| schedule_work(&handshake->handshaker); |
| } |
| } |
| |
| spin_lock_irqsave(&hp->lock, flags); |
| if (tty && hp->n_throttle && !test_bit(TTY_THROTTLED, &tty->flags)) { |
| /* we weren't hung up and we weren't throttled, so we can |
| * deliver the rest now */ |
| hvsi_send_overflow(hp, tty); |
| tty_flip_buffer_push(tty); |
| } |
| spin_unlock_irqrestore(&hp->lock, flags); |
| |
| tty_kref_put(tty); |
| |
| 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.hdr.type = VS_QUERY_PACKET_HEADER; |
| packet.hdr.len = sizeof(struct hvsi_query); |
| packet.hdr.seqno = atomic_inc_return(&hp->seqno); |
| packet.verb = verb; |
| |
| pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); |
| dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); |
| |
| wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); |
| if (wrote != packet.hdr.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.hdr.type = VS_CONTROL_PACKET_HEADER, |
| packet.hdr.seqno = atomic_inc_return(&hp->seqno); |
| packet.hdr.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.hdr.len); |
| dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); |
| |
| wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); |
| if (wrote != packet.hdr.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.hdr.type = VS_DATA_PACKET_HEADER; |
| packet.hdr.seqno = atomic_inc_return(&hp->seqno); |
| packet.hdr.len = count + sizeof(struct hvsi_header); |
| memcpy(&packet.data, buf, count); |
| |
| ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); |
| if (ret == packet.hdr.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.hdr.type = VS_CONTROL_PACKET_HEADER; |
| packet.hdr.seqno = atomic_inc_return(&hp->seqno); |
| packet.hdr.len = 6; |
| packet.verb = VSV_CLOSE_PROTOCOL; |
| |
| pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); |
| dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); |
| |
| hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); |
| } |
| |
| static int hvsi_open(struct tty_struct *tty, struct file *filp) |
| { |
| struct hvsi_struct *hp; |
| unsigned long flags; |
| int ret; |
| |
| pr_debug("%s\n", __func__); |
| |
| hp = &hvsi_ports[tty->index]; |
| |
| tty->driver_data = hp; |
| |
| mb(); |
| if (hp->state == HVSI_FSP_DIED) |
| return -EIO; |
| |
| tty_port_tty_set(&hp->port, tty); |
| spin_lock_irqsave(&hp->lock, flags); |
| hp->port.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_sync(&hp->writer); |
| flush_work_sync(&hp->handshaker); |
| |
| /* |
| * 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->port.count == 0) { |
| tty_port_tty_set(&hp->port, 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->port.count < 0) |
| printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", |
| hp - hvsi_ports, hp->port.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__); |
| |
| tty_port_tty_set(&hp->port, NULL); |
| |
| spin_lock_irqsave(&hp->lock, flags); |
| hp->port.count = 0; |
| hp->n_outbuf = 0; |
| 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); |
| struct tty_struct *tty; |
| 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 = tty_port_tty_get(&hp->port); |
| if (tty) { |
| tty_wakeup(tty); |
| tty_kref_put(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(tty) > 0)) { |
| int chunksize = min(count, hvsi_write_room(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; |
| |
| pr_debug("%s\n", __func__); |
| |
| spin_lock_irqsave(&hp->lock, flags); |
| if (hp->n_throttle) { |
| hvsi_send_overflow(hp, tty); |
| tty_flip_buffer_push(tty); |
| } |
| spin_unlock_irqrestore(&hp->lock, flags); |
| |
| |
| h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); |
| } |
| |
| static int hvsi_tiocmget(struct tty_struct *tty) |
| { |
| struct hvsi_struct *hp = tty->driver_data; |
| |
| hvsi_get_mctrl(hp); |
| return hp->mctrl; |
| } |
| |
| static int hvsi_tiocmset(struct tty_struct *tty, |
| 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->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; |
| |
| tty_port_link_device(&hp->port, hvsi_driver, i); |
| |
| ret = request_irq(hp->virq, hvsi_interrupt, 0, "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); |
| tty_port_init(&hp->port); |
| 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 == 0) { |
| 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); |