diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/hvc/Makefile | 2 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_vio.c | 405 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvsi_lib.c | 426 |
3 files changed, 448 insertions, 385 deletions
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile index 69a444b71c63..e29205316376 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 d4e0850e8051..ade73fae816a 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 000000000000..9401fcb556f0 --- /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; +} |