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Commit 17bdc6c0 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
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powerpc/pseries: Move hvsi support into a library 

This will allow a different backend to share it
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 4d2bb3f5
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Showing with 482 additions and 385 deletions
arch/powerpc/include/asm/hvsi.h
View file @ 17bdc6c0
......@@ -56,5 +56,39 @@ struct hvsi_query_response {
} u;
} __attribute__((packed));
/* hvsi lib struct definitions */
#define HVSI_INBUF_SIZE 255
struct tty_struct;
struct hvsi_priv {
unsigned int inbuf_len; /* data in input buffer */
unsigned char inbuf[HVSI_INBUF_SIZE];
unsigned int inbuf_cur; /* Cursor in input buffer */
unsigned int inbuf_pktlen; /* packet lenght from cursor */
atomic_t seqno; /* packet sequence number */
unsigned int opened:1; /* driver opened */
unsigned int established:1; /* protocol established */
unsigned int is_console:1; /* used as a kernel console device */
unsigned int mctrl_update:1; /* modem control updated */
unsigned short mctrl; /* modem control */
struct tty_struct *tty; /* tty structure */
int (*get_chars)(uint32_t termno, char *buf, int count);
int (*put_chars)(uint32_t termno, const char *buf, int count);
uint32_t termno;
};
/* hvsi lib functions */
struct hvc_struct;
extern void hvsi_init(struct hvsi_priv *pv,
int (*get_chars)(uint32_t termno, char *buf, int count),
int (*put_chars)(uint32_t termno, const char *buf,
int count),
int termno, int is_console);
extern int hvsi_open(struct hvsi_priv *pv, struct hvc_struct *hp);
extern void hvsi_close(struct hvsi_priv *pv, struct hvc_struct *hp);
extern int hvsi_read_mctrl(struct hvsi_priv *pv);
extern int hvsi_write_mctrl(struct hvsi_priv *pv, int dtr);
extern void hvsi_establish(struct hvsi_priv *pv);
extern int hvsi_get_chars(struct hvsi_priv *pv, char *buf, int count);
extern int hvsi_put_chars(struct hvsi_priv *pv, const char *buf, int count);
#endif /* _HVSI_H */
drivers/tty/hvc/Makefile
View file @ 17bdc6c0
obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o
obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi_lib.o
obj-$(CONFIG_HVC_OLD_HVSI) += hvsi.o
obj-$(CONFIG_HVC_ISERIES) += hvc_iseries.o
obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o
......
drivers/tty/hvc/hvc_vio.c
View file @ 17bdc6c0
......@@ -67,22 +67,10 @@ typedef enum hv_protocol {
HV_PROTOCOL_HVSI
} hv_protocol_t;
#define HV_INBUF_SIZE 255
struct hvterm_priv {
u32 termno; /* HV term number */
hv_protocol_t proto; /* Raw data or HVSI packets */
unsigned int inbuf_len; /* Data in input buffer */
unsigned char inbuf[HV_INBUF_SIZE];
unsigned int inbuf_cur; /* Cursor in input buffer */
unsigned int inbuf_pktlen; /* HVSI packet lenght from cursor */
atomic_t seqno; /* HVSI packet sequence number */
unsigned int opened:1; /* HVSI driver opened */
unsigned int established:1; /* HVSI protocol established */
unsigned int is_console:1; /* Used as a kernel console device */
unsigned int mctrl_update:1; /* HVSI modem control updated */
unsigned short mctrl; /* HVSI modem control */
struct tty_struct *tty; /* TTY structure */
u32 termno; /* HV term number */
hv_protocol_t proto; /* Raw data or HVSI packets */
struct hvsi_priv hvsi; /* HVSI specific data */
};
static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
......@@ -139,348 +127,24 @@ static const struct hv_ops hvterm_raw_ops = {
.notifier_hangup = notifier_hangup_irq,
};
static int hvterm_hvsi_send_packet(struct hvterm_priv *pv, struct hvsi_header *packet)
{
packet->seqno = atomic_inc_return(&pv->seqno);
/* Assumes that always succeeds, works in practice */
return hvc_put_chars(pv->termno, (char *)packet, packet->len);
}
static void hvterm_hvsi_start_handshake(struct hvterm_priv *pv)
{
struct hvsi_query q;
/* Reset state */
pv->established = 0;
atomic_set(&pv->seqno, 0);
pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
/* Send version query */
q.hdr.type = VS_QUERY_PACKET_HEADER;
q.hdr.len = sizeof(struct hvsi_query);
q.verb = VSV_SEND_VERSION_NUMBER;
hvterm_hvsi_send_packet(pv, &q.hdr);
}
static int hvterm_hvsi_send_close(struct hvterm_priv *pv)
{
struct hvsi_control ctrl;
pv->established = 0;
ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
ctrl.hdr.len = sizeof(struct hvsi_control);
ctrl.verb = VSV_CLOSE_PROTOCOL;
return hvterm_hvsi_send_packet(pv, &ctrl.hdr);
}
static void hvterm_cd_change(struct hvterm_priv *pv, int cd)
{
if (cd)
pv->mctrl |= TIOCM_CD;
else {
pv->mctrl &= ~TIOCM_CD;
/* We copy the existing hvsi driver semantics
* here which are to trigger a hangup when
* we get a carrier loss.
* Closing our connection to the server will
* do just that.
*/
if (!pv->is_console && pv->opened) {
pr_devel("HVSI@%x Carrier lost, hanging up !\n",
pv->termno);
hvterm_hvsi_send_close(pv);
}
}
}
static void hvterm_hvsi_got_control(struct hvterm_priv *pv)
{
struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
switch (pkt->verb) {
case VSV_CLOSE_PROTOCOL:
/* We restart the handshaking */
hvterm_hvsi_start_handshake(pv);
break;
case VSV_MODEM_CTL_UPDATE:
/* Transition of carrier detect */
hvterm_cd_change(pv, pkt->word & HVSI_TSCD);
break;
}
}
static void hvterm_hvsi_got_query(struct hvterm_priv *pv)
{
struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
struct hvsi_query_response r;
/* We only handle version queries */
if (pkt->verb != VSV_SEND_VERSION_NUMBER)
return;
pr_devel("HVSI@%x: Got version query, sending response...\n",
pv->termno);
/* Send version response */
r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
r.hdr.len = sizeof(struct hvsi_query_response);
r.verb = VSV_SEND_VERSION_NUMBER;
r.u.version = HVSI_VERSION;
r.query_seqno = pkt->hdr.seqno;
hvterm_hvsi_send_packet(pv, &r.hdr);
/* Assume protocol is open now */
pv->established = 1;
}
static void hvterm_hvsi_got_response(struct hvterm_priv *pv)
{
struct hvsi_query_response *r = (struct hvsi_query_response *)pv->inbuf;
switch(r->verb) {
case VSV_SEND_MODEM_CTL_STATUS:
hvterm_cd_change(pv, r->u.mctrl_word & HVSI_TSCD);
pv->mctrl_update = 1;
break;
}
}
static int hvterm_hvsi_check_packet(struct hvterm_priv *pv)
{
u8 len, type;
/* Check header validity. If it's invalid, we ditch
* the whole buffer and hope we eventually resync
*/
if (pv->inbuf[0] < 0xfc) {
pv->inbuf_len = pv->inbuf_pktlen = 0;
return 0;
}
type = pv->inbuf[0];
len = pv->inbuf[1];
/* Packet incomplete ? */
if (pv->inbuf_len < len)
return 0;
pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
pv->termno, type, len);
/* We have a packet, yay ! Handle it */
switch(type) {
case VS_DATA_PACKET_HEADER:
pv->inbuf_pktlen = len - 4;
pv->inbuf_cur = 4;
return 1;
case VS_CONTROL_PACKET_HEADER:
hvterm_hvsi_got_control(pv);
break;
case VS_QUERY_PACKET_HEADER:
hvterm_hvsi_got_query(pv);
break;
case VS_QUERY_RESPONSE_PACKET_HEADER:
hvterm_hvsi_got_response(pv);
break;
}
/* Swallow packet and retry */
pv->inbuf_len -= len;
memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
return 1;
}
static int hvterm_hvsi_get_packet(struct hvterm_priv *pv)
{
/* If we have room in the buffer, ask HV for more */
if (pv->inbuf_len < HV_INBUF_SIZE)
pv->inbuf_len += hvc_get_chars(pv->termno,
&pv->inbuf[pv->inbuf_len],
HV_INBUF_SIZE - pv->inbuf_len);
/*
* If we have at least 4 bytes in the buffer, check for
* a full packet and retry
*/
if (pv->inbuf_len >= 4)
return hvterm_hvsi_check_packet(pv);
return 0;
}
static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
{
struct hvterm_priv *pv = hvterm_privs[vtermno];
unsigned int tries, read = 0;
if (WARN_ON(!pv))
return 0;
/* If we aren't open, dont do anything in order to avoid races
* with connection establishment. The hvc core will call this
* before we have returned from notifier_add(), and we need to
* avoid multiple users playing with the receive buffer
*/
if (!pv->opened)
return 0;
/* We try twice, once with what data we have and once more
* after we try to fetch some more from the hypervisor
*/
for (tries = 1; count && tries < 2; tries++) {
/* Consume existing data packet */
if (pv->inbuf_pktlen) {
unsigned int l = min(count, (int)pv->inbuf_pktlen);
memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
pv->inbuf_cur += l;
pv->inbuf_pktlen -= l;
count -= l;
read += l;
}
if (count == 0)
break;
/* Data packet fully consumed, move down remaning data */
if (pv->inbuf_cur) {
pv->inbuf_len -= pv->inbuf_cur;
memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur], pv->inbuf_len);
pv->inbuf_cur = 0;
}
/* Try to get another packet */
if (hvterm_hvsi_get_packet(pv))
tries--;
}
if (!pv->established) {
pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
return -EPIPE;
}
return read;
return hvsi_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];
struct hvsi_data dp;
int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
if (WARN_ON(!pv))
return 0;
dp.hdr.type = VS_DATA_PACKET_HEADER;
dp.hdr.len = adjcount + sizeof(struct hvsi_header);
memcpy(dp.data, buf, adjcount);
rc = hvterm_hvsi_send_packet(pv, &dp.hdr);
if (rc <= 0)
return rc;
return adjcount;
}
static void maybe_msleep(unsigned long ms)
{
/* During early boot, IRQs are disabled, use mdelay */
if (irqs_disabled())
mdelay(ms);
else
msleep(ms);
}
static int hvterm_hvsi_read_mctrl(struct hvterm_priv *pv)
{
struct hvsi_query q;
int rc, timeout;
pr_devel("HVSI@%x: Querying modem control status...\n",
pv->termno);
pv->mctrl_update = 0;
q.hdr.type = VS_QUERY_PACKET_HEADER;
q.hdr.len = sizeof(struct hvsi_query);
q.hdr.seqno = atomic_inc_return(&pv->seqno);
q.verb = VSV_SEND_MODEM_CTL_STATUS;
rc = hvterm_hvsi_send_packet(pv, &q.hdr);
if (rc <= 0) {
pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
return rc;
}
/* Try for up to 1s */
for (timeout = 0; timeout < 1000; timeout++) {
if (!pv->established)
return -ENXIO;
if (pv->mctrl_update)
return 0;
if (!hvterm_hvsi_get_packet(pv))
maybe_msleep(1);
}
return -EIO;
}
static int hvterm_hvsi_write_mctrl(struct hvterm_priv *pv, int dtr)
{
struct hvsi_control ctrl;
pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
dtr ? "Setting" : "Clearing");
ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
ctrl.hdr.len = sizeof(struct hvsi_control);
ctrl.verb = VSV_SET_MODEM_CTL;
ctrl.mask = HVSI_TSDTR;
ctrl.word = dtr ? HVSI_TSDTR : 0;
if (dtr)
pv->mctrl |= TIOCM_DTR;
else
pv->mctrl &= ~TIOCM_DTR;
return hvterm_hvsi_send_packet(pv, &ctrl.hdr);
}
static void hvterm_hvsi_establish(struct hvterm_priv *pv)
{
int timeout;
/* Try for up to 10ms, there can be a packet to
* start the process waiting for us...
*/
for (timeout = 0; timeout < 10; timeout++) {
if (pv->established)
goto established;
if (!hvterm_hvsi_get_packet(pv))
maybe_msleep(1);
}
/* Failed, send a close connection packet just
* in case
*/
hvterm_hvsi_send_close(pv);
/* Then restart handshake */
hvterm_hvsi_start_handshake(pv);
/* Try for up to 100ms */
for (timeout = 0; timeout < 100; timeout++) {
if (pv->established)
goto established;
if (!hvterm_hvsi_get_packet(pv))
maybe_msleep(1);
}
if (!pv->established) {
pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
pv->termno);
return;
}
established:
/* Query modem control lines */
hvterm_hvsi_read_mctrl(pv);
/* Set our own DTR */
hvterm_hvsi_write_mctrl(pv, 1);
/* Set the opened flag so reads are allowed */
wmb();
pv->opened = 1;
return hvsi_put_chars(&pv->hvsi, buf, count);
}
static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
......@@ -494,46 +158,16 @@ static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
if (rc)
return rc;
/* Keep track of the tty data structure */
pv->tty = tty_kref_get(hp->tty);
hvterm_hvsi_establish(pv);
return 0;
}
static void hvterm_hvsi_shutdown(struct hvc_struct *hp, struct hvterm_priv *pv)
{
unsigned long flags;
if (!pv->is_console) {
pr_devel("HVSI@%x: Not a console, tearing down\n",
pv->termno);
/* Clear opened, synchronize with khvcd */
spin_lock_irqsave(&hp->lock, flags);
pv->opened = 0;
spin_unlock_irqrestore(&hp->lock, flags);
/* Clear our own DTR */
if (!pv->tty || (pv->tty->termios->c_cflag & HUPCL))
hvterm_hvsi_write_mctrl(pv, 0);
/* Tear down the connection */
hvterm_hvsi_send_close(pv);
}
if (pv->tty)
tty_kref_put(pv->tty);
pv->tty = NULL;
return hvsi_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: close !\n", pv->termno);
pr_devel("HVSI@%x: do close !\n", pv->termno);
hvterm_hvsi_shutdown(hp, pv);
hvsi_close(&pv->hvsi, hp);
notifier_del_irq(hp, data);
}
......@@ -542,9 +176,9 @@ void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
{
struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
pr_devel("HVSI@%x: hangup !\n", pv->termno);
pr_devel("HVSI@%x: do hangup !\n", pv->termno);
hvterm_hvsi_shutdown(hp, pv);
hvsi_close(&pv->hvsi, hp);
notifier_hangup_irq(hp, data);
}
......@@ -555,7 +189,7 @@ static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
if (!pv)
return -EINVAL;
return pv->mctrl;
return pv->hvsi.mctrl;
}
static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
......@@ -567,9 +201,9 @@ static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
pv->termno, set, clear);
if (set & TIOCM_DTR)
hvterm_hvsi_write_mctrl(pv, 1);
hvsi_write_mctrl(&pv->hvsi, 1);
else if (clear & TIOCM_DTR)
hvterm_hvsi_write_mctrl(pv, 0);
hvsi_write_mctrl(&pv->hvsi, 0);
return 0;
}
......@@ -633,6 +267,8 @@ static int __devinit hvc_vio_probe(struct vio_dev *vdev,
pv->termno = vdev->unit_address;
pv->proto = proto;
hvterm_privs[termno] = pv;
hvsi_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
pv->termno, 0);
}
hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
......@@ -770,7 +406,6 @@ void __init hvc_vio_init_early(void)
if (termno == NULL)
goto out;
hvterm_priv0.termno = *termno;
hvterm_priv0.is_console = 1;
hvterm_privs[0] = &hvterm_priv0;
/* Check the protocol */
......@@ -781,8 +416,10 @@ void __init hvc_vio_init_early(void)
else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
hvterm_priv0.proto = HV_PROTOCOL_HVSI;
ops = &hvterm_hvsi_ops;
hvsi_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
hvterm_priv0.termno, 1);
/* HVSI, perform the handshake now */
hvterm_hvsi_establish(&hvterm_priv0);
hvsi_establish(&hvterm_priv0.hvsi);
} else
goto out;
udbg_putc = udbg_hvc_putc;
......@@ -810,7 +447,6 @@ void __init udbg_init_debug_lpar(void)
hvterm_privs[0] = &hvterm_priv0;
hvterm_priv0.termno = 0;
hvterm_priv0.proto = HV_PROTOCOL_RAW;
hvterm_priv0.is_console = 1;
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
......@@ -823,10 +459,11 @@ void __init udbg_init_debug_lpar_hvsi(void)
hvterm_privs[0] = &hvterm_priv0;
hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
hvterm_priv0.proto = HV_PROTOCOL_HVSI;
hvterm_priv0.is_console = 1;
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
hvterm_hvsi_establish(&hvterm_priv0);
hvsi_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
hvterm_priv0.termno, 1);
hvsi_establish(&hvterm_priv0.hvsi);
}
#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
drivers/tty/hvc/hvsi_lib.c 0 → 100644
View file @ 17bdc6c0
#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/console.h>
#include <asm/hvsi.h>
#include "hvc_console.h"
static int hvsi_send_packet(struct hvsi_priv *pv, struct hvsi_header *packet)
{
packet->seqno = atomic_inc_return(&pv->seqno);
/* Assumes that always succeeds, works in practice */
return pv->put_chars(pv->termno, (char *)packet, packet->len);
}
static void hvsi_start_handshake(struct hvsi_priv *pv)
{
struct hvsi_query q;
/* Reset state */
pv->established = 0;
atomic_set(&pv->seqno, 0);
pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
/* Send version query */
q.hdr.type = VS_QUERY_PACKET_HEADER;
q.hdr.len = sizeof(struct hvsi_query);
q.verb = VSV_SEND_VERSION_NUMBER;
hvsi_send_packet(pv, &q.hdr);
}
static int hvsi_send_close(struct hvsi_priv *pv)
{
struct hvsi_control ctrl;
pv->established = 0;
ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
ctrl.hdr.len = sizeof(struct hvsi_control);
ctrl.verb = VSV_CLOSE_PROTOCOL;
return hvsi_send_packet(pv, &ctrl.hdr);
}
static void hvsi_cd_change(struct hvsi_priv *pv, int cd)
{
if (cd)
pv->mctrl |= TIOCM_CD;
else {
pv->mctrl &= ~TIOCM_CD;
/* We copy the existing hvsi driver semantics
* here which are to trigger a hangup when
* we get a carrier loss.
* Closing our connection to the server will
* do just that.
*/
if (!pv->is_console && pv->opened) {
pr_devel("HVSI@%x Carrier lost, hanging up !\n",
pv->termno);
hvsi_send_close(pv);
}
}
}
static void hvsi_got_control(struct hvsi_priv *pv)
{
struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
switch (pkt->verb) {
case VSV_CLOSE_PROTOCOL:
/* We restart the handshaking */
hvsi_start_handshake(pv);
break;
case VSV_MODEM_CTL_UPDATE:
/* Transition of carrier detect */
hvsi_cd_change(pv, pkt->word & HVSI_TSCD);
break;
}
}
static void hvsi_got_query(struct hvsi_priv *pv)
{
struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
struct hvsi_query_response r;
/* We only handle version queries */
if (pkt->verb != VSV_SEND_VERSION_NUMBER)
return;
pr_devel("HVSI@%x: Got version query, sending response...\n",
pv->termno);
/* Send version response */
r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
r.hdr.len = sizeof(struct hvsi_query_response);
r.verb = VSV_SEND_VERSION_NUMBER;
r.u.version = HVSI_VERSION;
r.query_seqno = pkt->hdr.seqno;
hvsi_send_packet(pv, &r.hdr);
/* Assume protocol is open now */
pv->established = 1;
}
static void hvsi_got_response(struct hvsi_priv *pv)
{
struct hvsi_query_response *r =
(struct hvsi_query_response *)pv->inbuf;
switch(r->verb) {
case VSV_SEND_MODEM_CTL_STATUS:
hvsi_cd_change(pv, r->u.mctrl_word & HVSI_TSCD);
pv->mctrl_update = 1;
break;
}
}
static int hvsi_check_packet(struct hvsi_priv *pv)
{
u8 len, type;
/* Check header validity. If it's invalid, we ditch
* the whole buffer and hope we eventually resync
*/
if (pv->inbuf[0] < 0xfc) {
pv->inbuf_len = pv->inbuf_pktlen = 0;
return 0;
}
type = pv->inbuf[0];
len = pv->inbuf[1];
/* Packet incomplete ? */
if (pv->inbuf_len < len)
return 0;
pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
pv->termno, type, len);
/* We have a packet, yay ! Handle it */
switch(type) {
case VS_DATA_PACKET_HEADER:
pv->inbuf_pktlen = len - 4;
pv->inbuf_cur = 4;
return 1;
case VS_CONTROL_PACKET_HEADER:
hvsi_got_control(pv);
break;
case VS_QUERY_PACKET_HEADER:
hvsi_got_query(pv);
break;
case VS_QUERY_RESPONSE_PACKET_HEADER:
hvsi_got_response(pv);
break;
}
/* Swallow packet and retry */
pv->inbuf_len -= len;
memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
return 1;
}
static int hvsi_get_packet(struct hvsi_priv *pv)
{
/* If we have room in the buffer, ask HV for more */
if (pv->inbuf_len < HVSI_INBUF_SIZE)
pv->inbuf_len += pv->get_chars(pv->termno,
&pv->inbuf[pv->inbuf_len],
HVSI_INBUF_SIZE - pv->inbuf_len);
/*
* If we have at least 4 bytes in the buffer, check for
* a full packet and retry
*/
if (pv->inbuf_len >= 4)
return hvsi_check_packet(pv);
return 0;
}
int hvsi_get_chars(struct hvsi_priv *pv, char *buf, int count)
{
unsigned int tries, read = 0;
if (WARN_ON(!pv))
return 0;
/* If we aren't open, don't do anything in order to avoid races
* with connection establishment. The hvc core will call this
* before we have returned from notifier_add(), and we need to
* avoid multiple users playing with the receive buffer
*/
if (!pv->opened)
return 0;
/* We try twice, once with what data we have and once more
* after we try to fetch some more from the hypervisor
*/
for (tries = 1; count && tries < 2; tries++) {
/* Consume existing data packet */
if (pv->inbuf_pktlen) {
unsigned int l = min(count, (int)pv->inbuf_pktlen);
memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
pv->inbuf_cur += l;
pv->inbuf_pktlen -= l;
count -= l;
read += l;
}
if (count == 0)
break;
/* Data packet fully consumed, move down remaning data */
if (pv->inbuf_cur) {
pv->inbuf_len -= pv->inbuf_cur;
memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur],
pv->inbuf_len);
pv->inbuf_cur = 0;
}
/* Try to get another packet */
if (hvsi_get_packet(pv))
tries--;
}
if (!pv->established) {
pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
return -EPIPE;
}
return read;
}
int hvsi_put_chars(struct hvsi_priv *pv, const char *buf, int count)
{
struct hvsi_data dp;
int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
if (WARN_ON(!pv))
return 0;
dp.hdr.type = VS_DATA_PACKET_HEADER;
dp.hdr.len = adjcount + sizeof(struct hvsi_header);
memcpy(dp.data, buf, adjcount);
rc = hvsi_send_packet(pv, &dp.hdr);
if (rc <= 0)
return rc;
return adjcount;
}
static void maybe_msleep(unsigned long ms)
{
/* During early boot, IRQs are disabled, use mdelay */
if (irqs_disabled())
mdelay(ms);
else
msleep(ms);
}
int hvsi_read_mctrl(struct hvsi_priv *pv)
{
struct hvsi_query q;
int rc, timeout;
pr_devel("HVSI@%x: Querying modem control status...\n",
pv->termno);
pv->mctrl_update = 0;
q.hdr.type = VS_QUERY_PACKET_HEADER;
q.hdr.len = sizeof(struct hvsi_query);
q.hdr.seqno = atomic_inc_return(&pv->seqno);
q.verb = VSV_SEND_MODEM_CTL_STATUS;
rc = hvsi_send_packet(pv, &q.hdr);
if (rc <= 0) {
pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
return rc;
}
/* Try for up to 200ms */
for (timeout = 0; timeout < 20; timeout++) {
if (!pv->established)
return -ENXIO;
if (pv->mctrl_update)
return 0;
if (!hvsi_get_packet(pv))
maybe_msleep(10);
}
return -EIO;
}
int hvsi_write_mctrl(struct hvsi_priv *pv, int dtr)
{
struct hvsi_control ctrl;
unsigned short mctrl;
mctrl = pv->mctrl;
if (dtr)
mctrl |= TIOCM_DTR;
else
mctrl &= ~TIOCM_DTR;
if (mctrl == pv->mctrl)
return 0;
pv->mctrl = mctrl;
pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
dtr ? "Setting" : "Clearing");
ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
ctrl.hdr.len = sizeof(struct hvsi_control);
ctrl.verb = VSV_SET_MODEM_CTL;
ctrl.mask = HVSI_TSDTR;
ctrl.word = dtr ? HVSI_TSDTR : 0;
return hvsi_send_packet(pv, &ctrl.hdr);
}
void hvsi_establish(struct hvsi_priv *pv)
{
int timeout;
pr_devel("HVSI@%x: Establishing...\n", pv->termno);
/* Try for up to 200ms, there can be a packet to
* start the process waiting for us...
*/
for (timeout = 0; timeout < 20; timeout++) {
if (pv->established)
goto established;
if (!hvsi_get_packet(pv))
maybe_msleep(10);
}
/* Failed, send a close connection packet just
* in case
*/
pr_devel("HVSI@%x: ... sending close\n", pv->termno);
hvsi_send_close(pv);
/* Then restart handshake */
pr_devel("HVSI@%x: ... restarting handshake\n", pv->termno);
hvsi_start_handshake(pv);
pr_devel("HVSI@%x: ... waiting handshake\n", pv->termno);
/* Try for up to 200s */
for (timeout = 0; timeout < 20; timeout++) {
if (pv->established)
goto established;
if (!hvsi_get_packet(pv))
maybe_msleep(10);
}
if (!pv->established) {
pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
pv->termno);
return;
}
established:
/* Query modem control lines */
pr_devel("HVSI@%x: ... established, reading mctrl\n", pv->termno);
hvsi_read_mctrl(pv);
/* Set our own DTR */
pr_devel("HVSI@%x: ... setting mctrl\n", pv->termno);
hvsi_write_mctrl(pv, 1);
/* Set the opened flag so reads are allowed */
wmb();
pv->opened = 1;
}
int hvsi_open(struct hvsi_priv *pv, struct hvc_struct *hp)
{
pr_devel("HVSI@%x: open !\n", pv->termno);
/* Keep track of the tty data structure */
pv->tty = tty_kref_get(hp->tty);
hvsi_establish(pv);
return 0;
}
void hvsi_close(struct hvsi_priv *pv, struct hvc_struct *hp)
{
unsigned long flags;
pr_devel("HVSI@%x: close !\n", pv->termno);
if (!pv->is_console) {
pr_devel("HVSI@%x: Not a console, tearing down\n",
pv->termno);
/* Clear opened, synchronize with khvcd */
spin_lock_irqsave(&hp->lock, flags);
pv->opened = 0;
spin_unlock_irqrestore(&hp->lock, flags);
/* Clear our own DTR */
if (!pv->tty || (pv->tty->termios->c_cflag & HUPCL))
hvsi_write_mctrl(pv, 0);
/* Tear down the connection */
hvsi_send_close(pv);
}
if (pv->tty)
tty_kref_put(pv->tty);
pv->tty = NULL;
}
void hvsi_init(struct hvsi_priv *pv,
int (*get_chars)(uint32_t termno, char *buf, int count),
int (*put_chars)(uint32_t termno, const char *buf,
int count),
int termno, int is_console)
{
memset(pv, 0, sizeof(*pv));
pv->get_chars = get_chars;
pv->put_chars = put_chars;
pv->termno = termno;
pv->is_console = is_console;
}
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