swh:1:snp:3c665ee4f67729f27f2e40193ab88e7298cf0fef
Tip revision: b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce authored by Linus Torvalds on 17 May 2020, 23:48:37 UTC
Linux 5.7-rc6
Linux 5.7-rc6
Tip revision: b9bbe6e
hvc_vio.c
// SPDX-License-Identifier: GPL-2.0+
/*
* vio driver interface to hvc_console.c
*
* This code was moved here to allow the remaining code to be reused as a
* generic polling mode with semi-reliable transport driver core to the
* console and tty subsystems.
*
*
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
* Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
* Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
* Copyright (C) 2004 IBM Corporation
*
* Additional Author(s):
* Ryan S. Arnold <rsa@us.ibm.com>
*
* TODO:
*
* - handle error in sending hvsi protocol packets
* - retry nego on subsequent sends ?
*/
#undef DEBUG
#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/console.h>
#include <asm/hvconsole.h>
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/hvsi.h>
#include <asm/udbg.h>
#include <asm/machdep.h>
#include "hvc_console.h"
static const char hvc_driver_name[] = "hvc_console";
static const struct vio_device_id hvc_driver_table[] = {
{"serial", "hvterm1"},
#ifndef HVC_OLD_HVSI
{"serial", "hvterm-protocol"},
#endif
{ "", "" }
};
typedef enum hv_protocol {
HV_PROTOCOL_RAW,
HV_PROTOCOL_HVSI
} hv_protocol_t;
struct hvterm_priv {
u32 termno; /* HV term number */
hv_protocol_t proto; /* Raw data or HVSI packets */
struct hvsi_priv hvsi; /* HVSI specific data */
spinlock_t buf_lock;
char buf[SIZE_VIO_GET_CHARS];
int left;
int offset;
};
static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
/* For early boot console */
static struct hvterm_priv hvterm_priv0;
static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
{
struct hvterm_priv *pv = hvterm_privs[vtermno];
unsigned long i;
unsigned long flags;
int got;
if (WARN_ON(!pv))
return 0;
spin_lock_irqsave(&pv->buf_lock, flags);
if (pv->left == 0) {
pv->offset = 0;
pv->left = hvc_get_chars(pv->termno, pv->buf, count);
/*
* Work around a HV bug where it gives us a null
* after every \r. -- paulus
*/
for (i = 1; i < pv->left; ++i) {
if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
--pv->left;
if (i < pv->left) {
memmove(&pv->buf[i], &pv->buf[i+1],
pv->left - i);
}
}
}
}
got = min(count, pv->left);
memcpy(buf, &pv->buf[pv->offset], got);
pv->offset += got;
pv->left -= got;
spin_unlock_irqrestore(&pv->buf_lock, flags);
return got;
}
/**
* hvterm_raw_put_chars: send characters to firmware for given vterm adapter
* @vtermno: The virtual terminal number.
* @buf: The characters to send. Because of the underlying hypercall in
* hvc_put_chars(), this buffer must be at least 16 bytes long, even if
* you are sending fewer chars.
* @count: number of chars to send.
*/
static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
{
struct hvterm_priv *pv = hvterm_privs[vtermno];
if (WARN_ON(!pv))
return 0;
return hvc_put_chars(pv->termno, buf, count);
}
static const struct hv_ops hvterm_raw_ops = {
.get_chars = hvterm_raw_get_chars,
.put_chars = hvterm_raw_put_chars,
.notifier_add = notifier_add_irq,
.notifier_del = notifier_del_irq,
.notifier_hangup = notifier_hangup_irq,
};
static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
{
struct hvterm_priv *pv = hvterm_privs[vtermno];
if (WARN_ON(!pv))
return 0;
return hvsilib_get_chars(&pv->hvsi, buf, count);
}
static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
{
struct hvterm_priv *pv = hvterm_privs[vtermno];
if (WARN_ON(!pv))
return 0;
return hvsilib_put_chars(&pv->hvsi, buf, count);
}
static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
int rc;
pr_devel("HVSI@%x: open !\n", pv->termno);
rc = notifier_add_irq(hp, data);
if (rc)
return rc;
return hvsilib_open(&pv->hvsi, hp);
}
static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
pr_devel("HVSI@%x: do close !\n", pv->termno);
hvsilib_close(&pv->hvsi, hp);
notifier_del_irq(hp, data);
}
void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
pr_devel("HVSI@%x: do hangup !\n", pv->termno);
hvsilib_close(&pv->hvsi, hp);
notifier_hangup_irq(hp, data);
}
static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
if (!pv)
return -EINVAL;
return pv->hvsi.mctrl;
}
static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
unsigned int clear)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
pv->termno, set, clear);
if (set & TIOCM_DTR)
hvsilib_write_mctrl(&pv->hvsi, 1);
else if (clear & TIOCM_DTR)
hvsilib_write_mctrl(&pv->hvsi, 0);
return 0;
}
static const struct hv_ops hvterm_hvsi_ops = {
.get_chars = hvterm_hvsi_get_chars,
.put_chars = hvterm_hvsi_put_chars,
.notifier_add = hvterm_hvsi_open,
.notifier_del = hvterm_hvsi_close,
.notifier_hangup = hvterm_hvsi_hangup,
.tiocmget = hvterm_hvsi_tiocmget,
.tiocmset = hvterm_hvsi_tiocmset,
};
static void udbg_hvc_putc(char c)
{
int count = -1;
unsigned char bounce_buffer[16];
if (!hvterm_privs[0])
return;
if (c == '\n')
udbg_hvc_putc('\r');
do {
switch(hvterm_privs[0]->proto) {
case HV_PROTOCOL_RAW:
/*
* hvterm_raw_put_chars requires at least a 16-byte
* buffer, so go via the bounce buffer
*/
bounce_buffer[0] = c;
count = hvterm_raw_put_chars(0, bounce_buffer, 1);
break;
case HV_PROTOCOL_HVSI:
count = hvterm_hvsi_put_chars(0, &c, 1);
break;
}
} while(count == 0);
}
static int udbg_hvc_getc_poll(void)
{
int rc = 0;
char c;
if (!hvterm_privs[0])
return -1;
switch(hvterm_privs[0]->proto) {
case HV_PROTOCOL_RAW:
rc = hvterm_raw_get_chars(0, &c, 1);
break;
case HV_PROTOCOL_HVSI:
rc = hvterm_hvsi_get_chars(0, &c, 1);
break;
}
if (!rc)
return -1;
return c;
}
static int udbg_hvc_getc(void)
{
int ch;
if (!hvterm_privs[0])
return -1;
for (;;) {
ch = udbg_hvc_getc_poll();
if (ch == -1) {
/* This shouldn't be needed...but... */
volatile unsigned long delay;
for (delay=0; delay < 2000000; delay++)
;
} else {
return ch;
}
}
}
static int hvc_vio_probe(struct vio_dev *vdev,
const struct vio_device_id *id)
{
const struct hv_ops *ops;
struct hvc_struct *hp;
struct hvterm_priv *pv;
hv_protocol_t proto;
int i, termno = -1;
/* probed with invalid parameters. */
if (!vdev || !id)
return -EPERM;
if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
proto = HV_PROTOCOL_RAW;
ops = &hvterm_raw_ops;
} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
proto = HV_PROTOCOL_HVSI;
ops = &hvterm_hvsi_ops;
} else {
pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
return -ENXIO;
}
pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
vdev->dev.of_node,
proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
/* Is it our boot one ? */
if (hvterm_privs[0] == &hvterm_priv0 &&
vdev->unit_address == hvterm_priv0.termno) {
pv = hvterm_privs[0];
termno = 0;
pr_devel("->boot console, using termno 0\n");
}
/* nope, allocate a new one */
else {
for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
if (!hvterm_privs[i])
termno = i;
pr_devel("->non-boot console, using termno %d\n", termno);
if (termno < 0)
return -ENODEV;
pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
if (!pv)
return -ENOMEM;
pv->termno = vdev->unit_address;
pv->proto = proto;
spin_lock_init(&pv->buf_lock);
hvterm_privs[termno] = pv;
hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
pv->termno, 0);
}
hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
if (IS_ERR(hp))
return PTR_ERR(hp);
dev_set_drvdata(&vdev->dev, hp);
/* register udbg if it's not there already for console 0 */
if (hp->index == 0 && !udbg_putc) {
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
}
return 0;
}
static struct vio_driver hvc_vio_driver = {
.id_table = hvc_driver_table,
.probe = hvc_vio_probe,
.name = hvc_driver_name,
.driver = {
.suppress_bind_attrs = true,
},
};
static int __init hvc_vio_init(void)
{
int rc;
/* Register as a vio device to receive callbacks */
rc = vio_register_driver(&hvc_vio_driver);
return rc;
}
device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
void __init hvc_vio_init_early(void)
{
const __be32 *termno;
const struct hv_ops *ops;
/* find the boot console from /chosen/stdout */
/* Check if it's a virtual terminal */
if (!of_node_name_prefix(of_stdout, "vty"))
return;
termno = of_get_property(of_stdout, "reg", NULL);
if (termno == NULL)
return;
hvterm_priv0.termno = of_read_number(termno, 1);
spin_lock_init(&hvterm_priv0.buf_lock);
hvterm_privs[0] = &hvterm_priv0;
/* Check the protocol */
if (of_device_is_compatible(of_stdout, "hvterm1")) {
hvterm_priv0.proto = HV_PROTOCOL_RAW;
ops = &hvterm_raw_ops;
}
else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
hvterm_priv0.proto = HV_PROTOCOL_HVSI;
ops = &hvterm_hvsi_ops;
hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
hvterm_priv0.termno, 1);
/* HVSI, perform the handshake now */
hvsilib_establish(&hvterm_priv0.hvsi);
} else
return;
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
#ifdef HVC_OLD_HVSI
/* When using the old HVSI driver don't register the HVC
* backend for HVSI, only do udbg
*/
if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
return;
#endif
/* Check whether the user has requested a different console. */
if (!strstr(boot_command_line, "console="))
add_preferred_console("hvc", 0, NULL);
hvc_instantiate(0, 0, ops);
}
/* call this from early_init() for a working debug console on
* vterm capable LPAR machines
*/
#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
void __init udbg_init_debug_lpar(void)
{
/*
* If we're running as a hypervisor then we definitely can't call the
* hypervisor to print debug output (we *are* the hypervisor), so don't
* register if we detect that MSR_HV=1.
*/
if (mfmsr() & MSR_HV)
return;
hvterm_privs[0] = &hvterm_priv0;
hvterm_priv0.termno = 0;
hvterm_priv0.proto = HV_PROTOCOL_RAW;
spin_lock_init(&hvterm_priv0.buf_lock);
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
}
#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
void __init udbg_init_debug_lpar_hvsi(void)
{
/* See comment above in udbg_init_debug_lpar() */
if (mfmsr() & MSR_HV)
return;
hvterm_privs[0] = &hvterm_priv0;
hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
hvterm_priv0.proto = HV_PROTOCOL_HVSI;
spin_lock_init(&hvterm_priv0.buf_lock);
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
hvterm_priv0.termno, 1);
hvsilib_establish(&hvterm_priv0.hvsi);
}
#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */