diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/tty/hvc/hvsi_lib.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/tty/hvc/hvsi_lib.c')
-rw-r--r-- | kernel/drivers/tty/hvc/hvsi_lib.c | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/kernel/drivers/tty/hvc/hvsi_lib.c b/kernel/drivers/tty/hvc/hvsi_lib.c new file mode 100644 index 000000000..a270f0458 --- /dev/null +++ b/kernel/drivers/tty/hvc/hvsi_lib.c @@ -0,0 +1,423 @@ +#include <linux/types.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 = cpu_to_be16(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 = cpu_to_be16(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 = cpu_to_be16(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 (be16_to_cpu(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, be32_to_cpu(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 (be16_to_cpu(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 = cpu_to_be16(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, be32_to_cpu(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 hvsilib_get_chars(struct hvsi_priv *pv, char *buf, int count) +{ + unsigned int tries, read = 0; + + if (WARN_ON(!pv)) + return -ENXIO; + + /* 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 hvsilib_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 -ENODEV; + + 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 hvsilib_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.verb = cpu_to_be16(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 hvsilib_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 = cpu_to_be16(VSV_SET_MODEM_CTL); + ctrl.mask = cpu_to_be32(HVSI_TSDTR); + ctrl.word = cpu_to_be32(dtr ? HVSI_TSDTR : 0); + return hvsi_send_packet(pv, &ctrl.hdr); +} + +void hvsilib_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 400ms */ + for (timeout = 0; timeout < 40; 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); + + hvsilib_read_mctrl(pv); + + /* Set our own DTR */ + + pr_devel("HVSI@%x: ... setting mctrl\n", pv->termno); + + hvsilib_write_mctrl(pv, 1); + + /* Set the opened flag so reads are allowed */ + wmb(); + pv->opened = 1; +} + +int hvsilib_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_port_tty_get(&hp->port); + + hvsilib_establish(pv); + + return 0; +} + +void hvsilib_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)) + hvsilib_write_mctrl(pv, 0); + + /* Tear down the connection */ + hvsi_send_close(pv); + } + + tty_kref_put(pv->tty); + pv->tty = NULL; +} + +void hvsilib_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; +} |