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8fbb3fc9c4
powerpc's asm/prom.h brings some headers that it doesn't need itself. In order to clean it up, first add missing headers in users of asm/prom.h Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/r/8b3dbd25bbeb7949e1b0a2170fee7b9cc5a6f806.1648833418.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1226 lines
30 KiB
C
1226 lines
30 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
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*/
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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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*
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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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*/
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#undef DEBUG
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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/of_irq.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 <linux/uaccess.h>
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#include <asm/vio.h>
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#include <asm/param.h>
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#include <asm/hvsi.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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#define N_OUTBUF 12
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/*
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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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*/
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#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
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struct hvsi_struct {
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struct tty_port port;
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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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spinlock_t lock;
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int index;
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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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uint8_t *inbuf_end;
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int n_throttle;
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int n_outbuf;
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uint32_t vtermno;
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uint32_t virq;
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atomic_t seqno; /* HVSI packet sequence number */
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uint16_t mctrl;
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uint8_t state; /* HVSI protocol state */
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uint8_t flags;
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#ifdef CONFIG_MAGIC_SYSRQ
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uint8_t sysrq;
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#endif /* CONFIG_MAGIC_SYSRQ */
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};
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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_CLOSED,
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HVSI_WAIT_FOR_VER_RESPONSE,
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HVSI_WAIT_FOR_VER_QUERY,
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HVSI_OPEN,
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HVSI_WAIT_FOR_MCTRL_RESPONSE,
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HVSI_FSP_DIED,
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};
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#define HVSI_CONSOLE 0x1
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static inline int is_console(struct hvsi_struct *hp)
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{
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return hp->flags & HVSI_CONSOLE;
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}
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static inline int is_open(struct hvsi_struct *hp)
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{
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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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}
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static inline void print_state(struct hvsi_struct *hp)
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{
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#ifdef DEBUG
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static const char *state_names[] = {
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"HVSI_CLOSED",
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"HVSI_WAIT_FOR_VER_RESPONSE",
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"HVSI_WAIT_FOR_VER_QUERY",
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"HVSI_OPEN",
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"HVSI_WAIT_FOR_MCTRL_RESPONSE",
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"HVSI_FSP_DIED",
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};
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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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#endif /* DEBUG */
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}
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static inline void __set_state(struct hvsi_struct *hp, int state)
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{
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hp->state = state;
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print_state(hp);
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wake_up_all(&hp->stateq);
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}
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static inline void set_state(struct hvsi_struct *hp, int state)
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{
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unsigned long flags;
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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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}
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static inline int len_packet(const uint8_t *packet)
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{
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return (int)((struct hvsi_header *)packet)->len;
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}
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static inline int is_header(const uint8_t *packet)
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{
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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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}
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static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
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{
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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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return 1;
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}
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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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{
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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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}
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#ifdef DEBUG
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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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#else
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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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#endif
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static void dump_hex(const uint8_t *data, int len)
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{
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int i;
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printk(" ");
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for (i=0; i < len; i++)
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printk("%.2x", data[i]);
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printk("\n ");
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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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else
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printk(".");
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}
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printk("\n");
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}
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static void dump_packet(uint8_t *packet)
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{
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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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header->seqno);
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dump_hex(packet, header->len);
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}
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static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
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{
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unsigned long got;
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got = hvc_get_chars(hp->vtermno, buf, count);
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return got;
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}
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static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
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struct tty_struct *tty, struct hvsi_struct **to_handshake)
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{
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struct hvsi_control *header = (struct hvsi_control *)packet;
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switch (be16_to_cpu(header->verb)) {
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case VSV_MODEM_CTL_UPDATE:
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if ((be32_to_cpu(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 (tty && !C_CLOCAL(tty))
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tty_hangup(tty);
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}
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break;
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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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*to_handshake = hp;
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}
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break;
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default:
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printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
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hp->index);
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dump_packet(packet);
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break;
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}
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}
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static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
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{
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struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
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uint32_t mctrl_word;
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switch (hp->state) {
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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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break;
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case HVSI_WAIT_FOR_MCTRL_RESPONSE:
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hp->mctrl = 0;
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mctrl_word = be32_to_cpu(resp->u.mctrl_word);
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if (mctrl_word & HVSI_TSDTR)
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hp->mctrl |= TIOCM_DTR;
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if (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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break;
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default:
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printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
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dump_packet(packet);
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break;
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}
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}
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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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{
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struct hvsi_query_response packet __ALIGNED__;
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int wrote;
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packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
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packet.hdr.len = sizeof(struct hvsi_query_response);
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packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
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packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
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packet.u.version = HVSI_VERSION;
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packet.query_seqno = cpu_to_be16(query_seqno+1);
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pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
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dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
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wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
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if (wrote != packet.hdr.len) {
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printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
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hp->index);
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return -EIO;
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}
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return 0;
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}
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static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
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{
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struct hvsi_query *query = (struct hvsi_query *)packet;
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switch (hp->state) {
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case HVSI_WAIT_FOR_VER_QUERY:
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hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno));
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__set_state(hp, HVSI_OPEN);
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break;
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default:
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printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
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dump_packet(packet);
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break;
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}
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}
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static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
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{
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int i;
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for (i=0; i < len; i++) {
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char c = buf[i];
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#ifdef CONFIG_MAGIC_SYSRQ
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if (c == '\0') {
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hp->sysrq = 1;
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continue;
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} else if (hp->sysrq) {
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handle_sysrq(c);
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hp->sysrq = 0;
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continue;
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}
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#endif /* CONFIG_MAGIC_SYSRQ */
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tty_insert_flip_char(&hp->port, c, 0);
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}
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}
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/*
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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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* revisited.
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*/
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#define TTY_THRESHOLD_THROTTLE 128
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static bool hvsi_recv_data(struct hvsi_struct *hp, const uint8_t *packet)
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{
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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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if (datalen == 0)
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return false;
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if (overflow > 0) {
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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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}
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hvsi_insert_chars(hp, data, datalen);
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if (overflow > 0) {
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/*
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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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*/
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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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}
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return true;
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}
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/*
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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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* incoming data).
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*/
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static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty,
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struct hvsi_struct **handshake)
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{
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uint8_t *packet = hp->inbuf;
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int chunklen;
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bool flip = false;
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*handshake = NULL;
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chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
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if (chunklen == 0) {
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pr_debug("%s: 0-length read\n", __func__);
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return 0;
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}
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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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packet++;
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continue;
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}
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pr_debug("%s: handling %i-byte packet\n", __func__,
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len_packet(packet));
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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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if (!is_open(hp))
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break;
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flip = hvsi_recv_data(hp, packet);
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break;
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case VS_CONTROL_PACKET_HEADER:
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hvsi_recv_control(hp, packet, tty, handshake);
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break;
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case VS_QUERY_RESPONSE_PACKET_HEADER:
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hvsi_recv_response(hp, packet);
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break;
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case VS_QUERY_PACKET_HEADER:
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hvsi_recv_query(hp, packet);
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break;
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default:
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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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dump_packet(packet);
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break;
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}
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packet += len_packet(packet);
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if (*handshake) {
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pr_debug("%s: handshake\n", __func__);
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break;
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}
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}
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compact_inbuf(hp, packet);
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if (flip)
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tty_flip_buffer_push(&hp->port);
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return 1;
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}
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static void hvsi_send_overflow(struct hvsi_struct *hp)
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{
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pr_debug("%s: delivering %i bytes overflow\n", __func__,
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hp->n_throttle);
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hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
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hp->n_throttle = 0;
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}
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/*
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* must get all pending data because we only get an irq on empty->non-empty
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* transition
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*/
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static irqreturn_t hvsi_interrupt(int irq, void *arg)
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{
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struct hvsi_struct *hp = (struct hvsi_struct *)arg;
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struct hvsi_struct *handshake;
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struct tty_struct *tty;
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unsigned long flags;
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int again = 1;
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pr_debug("%s\n", __func__);
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tty = tty_port_tty_get(&hp->port);
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while (again) {
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spin_lock_irqsave(&hp->lock, flags);
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again = hvsi_load_chunk(hp, tty, &handshake);
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spin_unlock_irqrestore(&hp->lock, flags);
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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 && !tty_throttled(tty)) {
|
|
/* we weren't hung up and we weren't throttled, so we can
|
|
* deliver the rest now */
|
|
hvsi_send_overflow(hp);
|
|
tty_flip_buffer_push(&hp->port);
|
|
}
|
|
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 = cpu_to_be16(atomic_inc_return(&hp->seqno));
|
|
packet.verb = cpu_to_be16(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 = cpu_to_be16(atomic_inc_return(&hp->seqno));
|
|
packet.hdr.len = sizeof(struct hvsi_control);
|
|
packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
|
|
packet.mask = cpu_to_be32(HVSI_TSDTR);
|
|
|
|
if (mctrl & TIOCM_DTR)
|
|
packet.word = cpu_to_be32(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 = cpu_to_be16(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 = cpu_to_be16(atomic_inc_return(&hp->seqno));
|
|
packet.hdr.len = 6;
|
|
packet.verb = cpu_to_be16(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(&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);
|
|
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_port_tty_wakeup(&hp->port);
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&hp->lock, flags);
|
|
}
|
|
|
|
static unsigned int hvsi_write_room(struct tty_struct *tty)
|
|
{
|
|
struct hvsi_struct *hp = tty->driver_data;
|
|
|
|
return N_OUTBUF - hp->n_outbuf;
|
|
}
|
|
|
|
static unsigned 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_t(int, 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_flip_buffer_push(&hp->port);
|
|
}
|
|
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)
|
|
{
|
|
struct tty_driver *driver;
|
|
int i, ret;
|
|
|
|
driver = tty_alloc_driver(hvsi_count, TTY_DRIVER_REAL_RAW);
|
|
if (IS_ERR(driver))
|
|
return PTR_ERR(driver);
|
|
|
|
driver->driver_name = "hvsi";
|
|
driver->name = "hvsi";
|
|
driver->major = HVSI_MAJOR;
|
|
driver->minor_start = HVSI_MINOR;
|
|
driver->type = TTY_DRIVER_TYPE_SYSTEM;
|
|
driver->init_termios = tty_std_termios;
|
|
driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
|
|
driver->init_termios.c_ispeed = 9600;
|
|
driver->init_termios.c_ospeed = 9600;
|
|
tty_set_operations(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, 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 */
|
|
|
|
ret = tty_register_driver(driver);
|
|
if (ret) {
|
|
pr_err("Couldn't register hvsi console driver\n");
|
|
goto err_free_irq;
|
|
}
|
|
|
|
hvsi_driver = driver;
|
|
|
|
printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
|
|
|
|
return 0;
|
|
err_free_irq:
|
|
hvsi_wait = poll_for_state;
|
|
for (i = 0; i < hvsi_count; i++) {
|
|
struct hvsi_struct *hp = &hvsi_ports[i];
|
|
|
|
free_irq(hp->virq, hp);
|
|
}
|
|
tty_driver_kref_put(driver);
|
|
|
|
return ret;
|
|
}
|
|
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 -EINVAL;
|
|
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_each_compatible_node(vty, "serial", "hvterm-protocol") {
|
|
struct hvsi_struct *hp;
|
|
const __be32 *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 = be32_to_cpup(vtermno);
|
|
hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq));
|
|
if (hp->virq == 0) {
|
|
printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
|
|
__func__, be32_to_cpup(irq));
|
|
tty_port_destroy(&hp->port);
|
|
continue;
|
|
}
|
|
|
|
hvsi_count++;
|
|
}
|
|
|
|
if (hvsi_count)
|
|
register_console(&hvsi_console);
|
|
return 0;
|
|
}
|
|
console_initcall(hvsi_console_init);
|