[PATCH 5/5] powerpc/pseries: Move hvsi support into a library
Benjamin Herrenschmidt
benh at kernel.crashing.org
Fri Jun 17 11:08:56 EST 2011
This will allow a different backend to share it
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
arch/powerpc/include/asm/hvsi.h | 34 +++
drivers/tty/hvc/Makefile | 2 +-
drivers/tty/hvc/hvc_vio.c | 405 ++-----------------------------------
drivers/tty/hvc/hvsi_lib.c | 426 +++++++++++++++++++++++++++++++++++++++
4 files changed, 482 insertions(+), 385 deletions(-)
create mode 100644 drivers/tty/hvc/hvsi_lib.c
diff --git a/arch/powerpc/include/asm/hvsi.h b/arch/powerpc/include/asm/hvsi.h
index ab2ddd7..91e0453 100644
--- a/arch/powerpc/include/asm/hvsi.h
+++ b/arch/powerpc/include/asm/hvsi.h
@@ -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 */
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile
index 69a444b..e292053 100644
--- a/drivers/tty/hvc/Makefile
+++ b/drivers/tty/hvc/Makefile
@@ -1,4 +1,4 @@
-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
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index d4e0850..ade73fa 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -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 */
diff --git a/drivers/tty/hvc/hvsi_lib.c b/drivers/tty/hvc/hvsi_lib.c
new file mode 100644
index 0000000..9401fcb
--- /dev/null
+++ b/drivers/tty/hvc/hvsi_lib.c
@@ -0,0 +1,426 @@
+#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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