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1225 lines
30 KiB
1225 lines
30 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Copyright (C) 2004 Hollis Blanchard <[email protected]>, IBM |
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*/ |
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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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|
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#undef DEBUG |
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|
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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/prom.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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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if (flip) |
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tty_flip_buffer_push(&hp->port); |
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|
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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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/* |
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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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|
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tty = tty_port_tty_get(&hp->port); |
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|
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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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|
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if (handshake) { |
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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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} |
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} |
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|
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spin_lock_irqsave(&hp->lock, flags); |
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if (tty && hp->n_throttle && !tty_throttled(tty)) { |
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/* we weren't hung up and we weren't throttled, so we can |
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* deliver the rest now */ |
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hvsi_send_overflow(hp); |
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tty_flip_buffer_push(&hp->port); |
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} |
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spin_unlock_irqrestore(&hp->lock, flags); |
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|
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tty_kref_put(tty); |
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|
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return IRQ_HANDLED; |
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} |
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|
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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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{ |
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unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; |
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|
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for (;;) { |
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hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ |
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|
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if (hp->state == state) |
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return 0; |
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mdelay(5); |
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if (time_after(jiffies, end_jiffies)) |
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return -EIO; |
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} |
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} |
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|
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/* wait for irq handler to change our state */ |
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static int wait_for_state(struct hvsi_struct *hp, int state) |
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{ |
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int ret = 0; |
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|
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if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) |
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ret = -EIO; |
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|
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return ret; |
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} |
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|
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static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) |
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{ |
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struct hvsi_query packet __ALIGNED__; |
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int wrote; |
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|
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packet.hdr.type = VS_QUERY_PACKET_HEADER; |
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packet.hdr.len = sizeof(struct hvsi_query); |
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packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); |
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packet.verb = cpu_to_be16(verb); |
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|
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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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|
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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 (%i)!\n", hp->index, |
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wrote); |
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return -EIO; |
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} |
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|
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return 0; |
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} |
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|
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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);
|
|
|