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* Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS
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* and the service processor on IBM pSeries servers. On these servers, there
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* are no serial ports under the OS's control, and sometimes there is no other
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* console available either. However, the service processor has two standard
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* serial ports, so this over-complicated protocol allows the OS to control
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* those ports by proxy.
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* Besides data, the procotol supports the reading/writing of the serial
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* port's DTR line, and the reading of the CD line. This is to allow the OS to
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* control a modem attached to the service processor's serial port. Note that
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* the OS cannot change the speed of the port through this protocol.
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#include <linux/console.h>
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#include <linux/ctype.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/major.h>
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/sysrq.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <asm/hvcall.h>
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#include <asm/hvconsole.h>
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#include <asm/uaccess.h>
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#include <asm/param.h>
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#define HVSI_MAJOR 229
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#define HVSI_MINOR 128
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#define MAX_NR_HVSI_CONSOLES 4
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#define HVSI_TIMEOUT (5*HZ)
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#define HVSI_VERSION 1
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#define HVSI_MAX_PACKET 256
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#define HVSI_MAX_READ 16
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#define HVSI_MAX_OUTGOING_DATA 12
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* we pass data via two 8-byte registers, so we would like our char arrays
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* properly aligned for those loads.
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#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
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struct delayed_work writer;
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struct work_struct handshaker;
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wait_queue_head_t emptyq; /* woken when outbuf is emptied */
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wait_queue_head_t stateq; /* woken when HVSI state changes */
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struct tty_struct *tty;
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uint8_t throttle_buf[128];
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uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
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/* inbuf is for packet reassembly. leave a little room for leftovers. */
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uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
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atomic_t seqno; /* HVSI packet sequence number */
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uint8_t state; /* HVSI protocol state */
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#ifdef CONFIG_MAGIC_SYSRQ
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#endif /* CONFIG_MAGIC_SYSRQ */
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static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
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static struct tty_driver *hvsi_driver;
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static int hvsi_count;
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static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
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enum HVSI_PROTOCOL_STATE {
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HVSI_WAIT_FOR_VER_RESPONSE,
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HVSI_WAIT_FOR_VER_QUERY,
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HVSI_WAIT_FOR_MCTRL_RESPONSE,
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#define HVSI_CONSOLE 0x1
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#define VS_DATA_PACKET_HEADER 0xff
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#define VS_CONTROL_PACKET_HEADER 0xfe
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#define VS_QUERY_PACKET_HEADER 0xfd
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#define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
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#define VSV_SET_MODEM_CTL 1 /* to service processor only */
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#define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
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#define VSV_CLOSE_PROTOCOL 3
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#define VSV_SEND_VERSION_NUMBER 1
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#define VSV_SEND_MODEM_CTL_STATUS 2
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/* yes, these masks are not consecutive. */
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#define HVSI_TSDTR 0x01
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#define HVSI_TSCD 0x20
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} __attribute__((packed));
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uint8_t data[HVSI_MAX_OUTGOING_DATA];
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} __attribute__((packed));
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struct hvsi_control {
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/* optional depending on verb: */
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} __attribute__((packed));
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} __attribute__((packed));
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struct hvsi_query_response {
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uint16_t query_seqno;
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} __attribute__((packed));
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static inline int is_console(struct hvsi_struct *hp)
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return hp->flags & HVSI_CONSOLE;
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static inline int is_open(struct hvsi_struct *hp)
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/* if we're waiting for an mctrl then we're already open */
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return (hp->state == HVSI_OPEN)
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|| (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
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static inline void print_state(struct hvsi_struct *hp)
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static const char *state_names[] = {
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"HVSI_WAIT_FOR_VER_RESPONSE",
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"HVSI_WAIT_FOR_VER_QUERY",
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"HVSI_WAIT_FOR_MCTRL_RESPONSE",
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const char *name = (hp->state < ARRAY_SIZE(state_names))
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? state_names[hp->state] : "UNKNOWN";
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pr_debug("hvsi%i: state = %s\n", hp->index, name);
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static inline void __set_state(struct hvsi_struct *hp, int state)
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wake_up_all(&hp->stateq);
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static inline void set_state(struct hvsi_struct *hp, int state)
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spin_lock_irqsave(&hp->lock, flags);
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__set_state(hp, state);
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spin_unlock_irqrestore(&hp->lock, flags);
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static inline int len_packet(const uint8_t *packet)
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return (int)((struct hvsi_header *)packet)->len;
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static inline int is_header(const uint8_t *packet)
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struct hvsi_header *header = (struct hvsi_header *)packet;
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return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
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static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
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if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
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return 0; /* don't even have the packet header */
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if (hp->inbuf_end < (packet + len_packet(packet)))
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return 0; /* don't have the rest of the packet */
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/* shift remaining bytes in packetbuf down */
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static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
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int remaining = (int)(hp->inbuf_end - read_to);
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pr_debug("%s: %i chars remain\n", __func__, remaining);
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if (read_to != hp->inbuf)
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memmove(hp->inbuf, read_to, remaining);
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hp->inbuf_end = hp->inbuf + remaining;
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#define dbg_dump_packet(packet) dump_packet(packet)
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#define dbg_dump_hex(data, len) dump_hex(data, len)
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#define dbg_dump_packet(packet) do { } while (0)
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#define dbg_dump_hex(data, len) do { } while (0)
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static void dump_hex(const uint8_t *data, int len)
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for (i=0; i < len; i++)
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printk("%.2x", data[i]);
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for (i=0; i < len; i++) {
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if (isprint(data[i]))
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printk("%c", data[i]);
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static void dump_packet(uint8_t *packet)
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struct hvsi_header *header = (struct hvsi_header *)packet;
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printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
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dump_hex(packet, header->len);
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static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
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got = hvc_get_chars(hp->vtermno, buf, count);
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static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
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struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
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struct hvsi_control *header = (struct hvsi_control *)packet;
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switch (header->verb) {
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case VSV_MODEM_CTL_UPDATE:
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if ((header->word & HVSI_TSCD) == 0) {
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/* CD went away; no more connection */
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pr_debug("hvsi%i: CD dropped\n", hp->index);
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hp->mctrl &= TIOCM_CD;
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/* If userland hasn't done an open(2) yet, hp->tty is NULL. */
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if (hp->tty && !(hp->tty->flags & CLOCAL))
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*to_hangup = hp->tty;
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case VSV_CLOSE_PROTOCOL:
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pr_debug("hvsi%i: service processor came back\n", hp->index);
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if (hp->state != HVSI_CLOSED) {
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printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
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static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
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struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
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case HVSI_WAIT_FOR_VER_RESPONSE:
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__set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
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case HVSI_WAIT_FOR_MCTRL_RESPONSE:
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if (resp->u.mctrl_word & HVSI_TSDTR)
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hp->mctrl |= TIOCM_DTR;
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if (resp->u.mctrl_word & HVSI_TSCD)
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hp->mctrl |= TIOCM_CD;
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__set_state(hp, HVSI_OPEN);
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printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
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/* respond to service processor's version query */
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static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
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struct hvsi_query_response packet __ALIGNED__;
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packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
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packet.len = sizeof(struct hvsi_query_response);
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packet.seqno = atomic_inc_return(&hp->seqno);
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packet.verb = VSV_SEND_VERSION_NUMBER;
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packet.u.version = HVSI_VERSION;
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packet.query_seqno = query_seqno+1;
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pr_debug("%s: sending %i bytes\n", __func__, packet.len);
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dbg_dump_hex((uint8_t*)&packet, packet.len);
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wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
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if (wrote != packet.len) {
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printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
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static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
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struct hvsi_query *query = (struct hvsi_query *)packet;
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case HVSI_WAIT_FOR_VER_QUERY:
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hvsi_version_respond(hp, query->seqno);
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__set_state(hp, HVSI_OPEN);
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printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
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static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
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for (i=0; i < len; i++) {
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#ifdef CONFIG_MAGIC_SYSRQ
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} else if (hp->sysrq) {
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#endif /* CONFIG_MAGIC_SYSRQ */
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tty_insert_flip_char(hp->tty, c, 0);
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* We could get 252 bytes of data at once here. But the tty layer only
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* throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
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* it. Accordingly we won't send more than 128 bytes at a time to the flip
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* buffer, which will give the tty buffer a chance to throttle us. Should the
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* value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
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#define TTY_THRESHOLD_THROTTLE 128
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static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
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const uint8_t *packet)
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const struct hvsi_header *header = (const struct hvsi_header *)packet;
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const uint8_t *data = packet + sizeof(struct hvsi_header);
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int datalen = header->len - sizeof(struct hvsi_header);
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int overflow = datalen - TTY_THRESHOLD_THROTTLE;
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pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
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pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
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datalen = TTY_THRESHOLD_THROTTLE;
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hvsi_insert_chars(hp, data, datalen);
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* we still have more data to deliver, so we need to save off the
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* overflow and send it later
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pr_debug("%s: deferring overflow\n", __func__);
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memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
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hp->n_throttle = overflow;
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* Returns true/false indicating data successfully read from hypervisor.
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* Used both to get packets for tty connections and to advance the state
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* machine during console handshaking (in which case tty = NULL and we ignore
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static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
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struct tty_struct **hangup, struct hvsi_struct **handshake)
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uint8_t *packet = hp->inbuf;
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chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
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pr_debug("%s: 0-length read\n", __func__);
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pr_debug("%s: got %i bytes\n", __func__, chunklen);
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dbg_dump_hex(hp->inbuf_end, chunklen);
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hp->inbuf_end += chunklen;
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/* handle all completed packets */
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while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
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struct hvsi_header *header = (struct hvsi_header *)packet;
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if (!is_header(packet)) {
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printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
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/* skip bytes until we find a header or run out of data */
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while ((packet < hp->inbuf_end) && (!is_header(packet)))
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pr_debug("%s: handling %i-byte packet\n", __func__,
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dbg_dump_packet(packet);
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switch (header->type) {
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case VS_DATA_PACKET_HEADER:
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break; /* no tty buffer to put data in */
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*flip = hvsi_recv_data(hp, packet);
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case VS_CONTROL_PACKET_HEADER:
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hvsi_recv_control(hp, packet, hangup, handshake);
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case VS_QUERY_RESPONSE_PACKET_HEADER:
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hvsi_recv_response(hp, packet);
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case VS_QUERY_PACKET_HEADER:
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hvsi_recv_query(hp, packet);
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printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
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hp->index, header->type);
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packet += len_packet(packet);
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if (*hangup || *handshake) {
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pr_debug("%s: hangup or handshake\n", __func__);
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* we need to send the hangup now before receiving any more data.
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* If we get "data, hangup, data", we can't deliver the second
531
* data before the hangup.
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compact_inbuf(hp, packet);
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static void hvsi_send_overflow(struct hvsi_struct *hp)
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pr_debug("%s: delivering %i bytes overflow\n", __func__,
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hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
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* must get all pending data because we only get an irq on empty->non-empty
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static irqreturn_t hvsi_interrupt(int irq, void *arg)
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struct hvsi_struct *hp = (struct hvsi_struct *)arg;
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struct tty_struct *flip;
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struct tty_struct *hangup;
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struct hvsi_struct *handshake;
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pr_debug("%s\n", __func__);
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spin_lock_irqsave(&hp->lock, flags);
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again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
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spin_unlock_irqrestore(&hp->lock, flags);
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* we have to call tty_flip_buffer_push() and tty_hangup() outside our
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* spinlock. But we also have to keep going until we've read all the
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/* there was data put in the tty flip buffer */
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tty_flip_buffer_push(flip);
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pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
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schedule_work(&handshake->handshaker);
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spin_lock_irqsave(&hp->lock, flags);
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if (hp->tty && hp->n_throttle
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&& (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
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/* we weren't hung up and we weren't throttled, so we can deliver the
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hvsi_send_overflow(hp);
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spin_unlock_irqrestore(&hp->lock, flags);
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tty_flip_buffer_push(flip);
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/* for boot console, before the irq handler is running */
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static int __init poll_for_state(struct hvsi_struct *hp, int state)
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unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
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hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
618
if (hp->state == state)
622
if (time_after(jiffies, end_jiffies))
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/* wait for irq handler to change our state */
628
static int wait_for_state(struct hvsi_struct *hp, int state)
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if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
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static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
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struct hvsi_query packet __ALIGNED__;
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packet.type = VS_QUERY_PACKET_HEADER;
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packet.len = sizeof(struct hvsi_query);
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packet.seqno = atomic_inc_return(&hp->seqno);
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pr_debug("%s: sending %i bytes\n", __func__, packet.len);
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dbg_dump_hex((uint8_t*)&packet, packet.len);
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wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
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if (wrote != packet.len) {
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printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
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static int hvsi_get_mctrl(struct hvsi_struct *hp)
665
set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
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hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
668
ret = hvsi_wait(hp, HVSI_OPEN);
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printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
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set_state(hp, HVSI_OPEN);
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pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
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/* note that we can only set DTR */
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static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
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struct hvsi_control packet __ALIGNED__;
686
packet.type = VS_CONTROL_PACKET_HEADER,
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packet.seqno = atomic_inc_return(&hp->seqno);
688
packet.len = sizeof(struct hvsi_control);
689
packet.verb = VSV_SET_MODEM_CTL;
690
packet.mask = HVSI_TSDTR;
692
if (mctrl & TIOCM_DTR)
693
packet.word = HVSI_TSDTR;
695
pr_debug("%s: sending %i bytes\n", __func__, packet.len);
696
dbg_dump_hex((uint8_t*)&packet, packet.len);
698
wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
699
if (wrote != packet.len) {
700
printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
707
static void hvsi_drain_input(struct hvsi_struct *hp)
709
uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
710
unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
712
while (time_before(end_jiffies, jiffies))
713
if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
717
static int hvsi_handshake(struct hvsi_struct *hp)
722
* We could have a CLOSE or other data waiting for us before we even try
723
* to open; try to throw it all away so we don't get confused. (CLOSE
724
* is the first message sent up the pipe when the FSP comes online. We
725
* need to distinguish between "it came up a while ago and we're the first
726
* user" and "it was just reset before it saw our handshake packet".)
728
hvsi_drain_input(hp);
730
set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
731
ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
733
printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
737
ret = hvsi_wait(hp, HVSI_OPEN);
744
static void hvsi_handshaker(struct work_struct *work)
746
struct hvsi_struct *hp =
747
container_of(work, struct hvsi_struct, handshaker);
749
if (hvsi_handshake(hp) >= 0)
752
printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
753
if (is_console(hp)) {
755
* ttys will re-attempt the handshake via hvsi_open, but
756
* the console will not.
758
printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
762
static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
764
struct hvsi_data packet __ALIGNED__;
767
BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
769
packet.type = VS_DATA_PACKET_HEADER;
770
packet.seqno = atomic_inc_return(&hp->seqno);
771
packet.len = count + sizeof(struct hvsi_header);
772
memcpy(&packet.data, buf, count);
774
ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
775
if (ret == packet.len) {
776
/* return the number of chars written, not the packet length */
779
return ret; /* return any errors */
782
static void hvsi_close_protocol(struct hvsi_struct *hp)
784
struct hvsi_control packet __ALIGNED__;
786
packet.type = VS_CONTROL_PACKET_HEADER;
787
packet.seqno = atomic_inc_return(&hp->seqno);
789
packet.verb = VSV_CLOSE_PROTOCOL;
791
pr_debug("%s: sending %i bytes\n", __func__, packet.len);
792
dbg_dump_hex((uint8_t*)&packet, packet.len);
794
hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
797
static int hvsi_open(struct tty_struct *tty, struct file *filp)
799
struct hvsi_struct *hp;
801
int line = tty->index;
804
pr_debug("%s\n", __func__);
806
if (line < 0 || line >= hvsi_count)
808
hp = &hvsi_ports[line];
810
tty->driver_data = hp;
813
if (hp->state == HVSI_FSP_DIED)
816
spin_lock_irqsave(&hp->lock, flags);
819
atomic_set(&hp->seqno, 0);
820
h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
821
spin_unlock_irqrestore(&hp->lock, flags);
824
return 0; /* this has already been handshaked as the console */
826
ret = hvsi_handshake(hp);
828
printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
832
ret = hvsi_get_mctrl(hp);
834
printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
838
ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
840
printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
847
/* wait for hvsi_write_worker to empty hp->outbuf */
848
static void hvsi_flush_output(struct hvsi_struct *hp)
850
wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
852
/* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
853
cancel_delayed_work_sync(&hp->writer);
854
flush_work_sync(&hp->handshaker);
857
* it's also possible that our timeout expired and hvsi_write_worker
858
* didn't manage to push outbuf. poof.
863
static void hvsi_close(struct tty_struct *tty, struct file *filp)
865
struct hvsi_struct *hp = tty->driver_data;
868
pr_debug("%s\n", __func__);
870
if (tty_hung_up_p(filp))
873
spin_lock_irqsave(&hp->lock, flags);
875
if (--hp->count == 0) {
877
hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
879
/* only close down connection if it is not the console */
880
if (!is_console(hp)) {
881
h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
882
__set_state(hp, HVSI_CLOSED);
884
* any data delivered to the tty layer after this will be
885
* discarded (except for XON/XOFF)
889
spin_unlock_irqrestore(&hp->lock, flags);
891
/* let any existing irq handlers finish. no more will start. */
892
synchronize_irq(hp->virq);
894
/* hvsi_write_worker will re-schedule until outbuf is empty. */
895
hvsi_flush_output(hp);
897
/* tell FSP to stop sending data */
898
hvsi_close_protocol(hp);
901
* drain anything FSP is still in the middle of sending, and let
902
* hvsi_handshake drain the rest on the next open.
904
hvsi_drain_input(hp);
906
spin_lock_irqsave(&hp->lock, flags);
908
} else if (hp->count < 0)
909
printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
910
hp - hvsi_ports, hp->count);
912
spin_unlock_irqrestore(&hp->lock, flags);
915
static void hvsi_hangup(struct tty_struct *tty)
917
struct hvsi_struct *hp = tty->driver_data;
920
pr_debug("%s\n", __func__);
922
spin_lock_irqsave(&hp->lock, flags);
928
spin_unlock_irqrestore(&hp->lock, flags);
931
/* called with hp->lock held */
932
static void hvsi_push(struct hvsi_struct *hp)
936
if (hp->n_outbuf <= 0)
939
n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
942
pr_debug("%s: wrote %i chars\n", __func__, n);
944
} else if (n == -EIO) {
945
__set_state(hp, HVSI_FSP_DIED);
946
printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
950
/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
951
static void hvsi_write_worker(struct work_struct *work)
953
struct hvsi_struct *hp =
954
container_of(work, struct hvsi_struct, writer.work);
957
static long start_j = 0;
963
spin_lock_irqsave(&hp->lock, flags);
965
pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
969
* We could have a non-open connection if the service processor died
970
* while we were busily scheduling ourselves. In that case, it could
971
* be minutes before the service processor comes back, so only try
972
* again once a second.
974
schedule_delayed_work(&hp->writer, HZ);
979
if (hp->n_outbuf > 0)
980
schedule_delayed_work(&hp->writer, 10);
983
pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
987
wake_up_all(&hp->emptyq);
992
spin_unlock_irqrestore(&hp->lock, flags);
995
static int hvsi_write_room(struct tty_struct *tty)
997
struct hvsi_struct *hp = tty->driver_data;
999
return N_OUTBUF - hp->n_outbuf;
1002
static int hvsi_chars_in_buffer(struct tty_struct *tty)
1004
struct hvsi_struct *hp = tty->driver_data;
1006
return hp->n_outbuf;
1009
static int hvsi_write(struct tty_struct *tty,
1010
const unsigned char *buf, int count)
1012
struct hvsi_struct *hp = tty->driver_data;
1013
const char *source = buf;
1014
unsigned long flags;
1016
int origcount = count;
1018
spin_lock_irqsave(&hp->lock, flags);
1020
pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
1023
/* we're either closing or not yet open; don't accept data */
1024
pr_debug("%s: not open\n", __func__);
1029
* when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1030
* and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1031
* will see there is no room in outbuf and return.
1033
while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1034
int chunksize = min(count, hvsi_write_room(hp->tty));
1036
BUG_ON(hp->n_outbuf < 0);
1037
memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1038
hp->n_outbuf += chunksize;
1041
source += chunksize;
1046
if (hp->n_outbuf > 0) {
1048
* we weren't able to write it all to the hypervisor.
1049
* schedule another push attempt.
1051
schedule_delayed_work(&hp->writer, 10);
1055
spin_unlock_irqrestore(&hp->lock, flags);
1057
if (total != origcount)
1058
pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount,
1065
* I have never seen throttle or unthrottle called, so this little throttle
1066
* buffering scheme may or may not work.
1068
static void hvsi_throttle(struct tty_struct *tty)
1070
struct hvsi_struct *hp = tty->driver_data;
1072
pr_debug("%s\n", __func__);
1074
h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1077
static void hvsi_unthrottle(struct tty_struct *tty)
1079
struct hvsi_struct *hp = tty->driver_data;
1080
unsigned long flags;
1083
pr_debug("%s\n", __func__);
1085
spin_lock_irqsave(&hp->lock, flags);
1086
if (hp->n_throttle) {
1087
hvsi_send_overflow(hp);
1090
spin_unlock_irqrestore(&hp->lock, flags);
1093
tty_flip_buffer_push(hp->tty);
1095
h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1098
static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1100
struct hvsi_struct *hp = tty->driver_data;
1106
static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1107
unsigned int set, unsigned int clear)
1109
struct hvsi_struct *hp = tty->driver_data;
1110
unsigned long flags;
1113
/* we can only alter DTR */
1117
spin_lock_irqsave(&hp->lock, flags);
1119
new_mctrl = (hp->mctrl & ~clear) | set;
1121
if (hp->mctrl != new_mctrl) {
1122
hvsi_set_mctrl(hp, new_mctrl);
1123
hp->mctrl = new_mctrl;
1125
spin_unlock_irqrestore(&hp->lock, flags);
1131
static const struct tty_operations hvsi_ops = {
1133
.close = hvsi_close,
1134
.write = hvsi_write,
1135
.hangup = hvsi_hangup,
1136
.write_room = hvsi_write_room,
1137
.chars_in_buffer = hvsi_chars_in_buffer,
1138
.throttle = hvsi_throttle,
1139
.unthrottle = hvsi_unthrottle,
1140
.tiocmget = hvsi_tiocmget,
1141
.tiocmset = hvsi_tiocmset,
1144
static int __init hvsi_init(void)
1148
hvsi_driver = alloc_tty_driver(hvsi_count);
1152
hvsi_driver->owner = THIS_MODULE;
1153
hvsi_driver->driver_name = "hvsi";
1154
hvsi_driver->name = "hvsi";
1155
hvsi_driver->major = HVSI_MAJOR;
1156
hvsi_driver->minor_start = HVSI_MINOR;
1157
hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1158
hvsi_driver->init_termios = tty_std_termios;
1159
hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1160
hvsi_driver->init_termios.c_ispeed = 9600;
1161
hvsi_driver->init_termios.c_ospeed = 9600;
1162
hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1163
tty_set_operations(hvsi_driver, &hvsi_ops);
1165
for (i=0; i < hvsi_count; i++) {
1166
struct hvsi_struct *hp = &hvsi_ports[i];
1169
ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp);
1171
printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1174
hvsi_wait = wait_for_state; /* irqs active now */
1176
if (tty_register_driver(hvsi_driver))
1177
panic("Couldn't register hvsi console driver\n");
1179
printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
1183
device_initcall(hvsi_init);
1185
/***** console (not tty) code: *****/
1187
static void hvsi_console_print(struct console *console, const char *buf,
1190
struct hvsi_struct *hp = &hvsi_ports[console->index];
1191
char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1192
unsigned int i = 0, n = 0;
1193
int ret, donecr = 0;
1200
* ugh, we have to translate LF -> CRLF ourselves, in place.
1201
* copied from hvc_console.c:
1203
while (count > 0 || i > 0) {
1204
if (count > 0 && i < sizeof(c)) {
1205
if (buf[n] == '\n' && !donecr) {
1214
ret = hvsi_put_chars(hp, c, i);
1222
static struct tty_driver *hvsi_console_device(struct console *console,
1225
*index = console->index;
1229
static int __init hvsi_console_setup(struct console *console, char *options)
1231
struct hvsi_struct *hp;
1234
if (console->index < 0 || console->index >= hvsi_count)
1236
hp = &hvsi_ports[console->index];
1238
/* give the FSP a chance to change the baud rate when we re-open */
1239
hvsi_close_protocol(hp);
1241
ret = hvsi_handshake(hp);
1245
ret = hvsi_get_mctrl(hp);
1249
ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1253
hp->flags |= HVSI_CONSOLE;
1258
static struct console hvsi_console = {
1260
.write = hvsi_console_print,
1261
.device = hvsi_console_device,
1262
.setup = hvsi_console_setup,
1263
.flags = CON_PRINTBUFFER,
1267
static int __init hvsi_console_init(void)
1269
struct device_node *vty;
1271
hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1273
/* search device tree for vty nodes */
1274
for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1276
vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1277
struct hvsi_struct *hp;
1278
const uint32_t *vtermno, *irq;
1280
vtermno = of_get_property(vty, "reg", NULL);
1281
irq = of_get_property(vty, "interrupts", NULL);
1282
if (!vtermno || !irq)
1285
if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1290
hp = &hvsi_ports[hvsi_count];
1291
INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
1292
INIT_WORK(&hp->handshaker, hvsi_handshaker);
1293
init_waitqueue_head(&hp->emptyq);
1294
init_waitqueue_head(&hp->stateq);
1295
spin_lock_init(&hp->lock);
1296
hp->index = hvsi_count;
1297
hp->inbuf_end = hp->inbuf;
1298
hp->state = HVSI_CLOSED;
1299
hp->vtermno = *vtermno;
1300
hp->virq = irq_create_mapping(NULL, irq[0]);
1301
if (hp->virq == NO_IRQ) {
1302
printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1311
register_console(&hvsi_console);
1314
console_initcall(hvsi_console_init);