424 lines
9.6 KiB
C
424 lines
9.6 KiB
C
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#include <linux/types.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/console.h>
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#include <asm/hvsi.h>
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#include "hvc_console.h"
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static int hvsi_send_packet(struct hvsi_priv *pv, struct hvsi_header *packet)
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{
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packet->seqno = cpu_to_be16(atomic_inc_return(&pv->seqno));
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/* Assumes that always succeeds, works in practice */
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return pv->put_chars(pv->termno, (char *)packet, packet->len);
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}
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static void hvsi_start_handshake(struct hvsi_priv *pv)
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{
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struct hvsi_query q;
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/* Reset state */
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pv->established = 0;
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atomic_set(&pv->seqno, 0);
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pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
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/* Send version query */
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q.hdr.type = VS_QUERY_PACKET_HEADER;
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q.hdr.len = sizeof(struct hvsi_query);
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q.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
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hvsi_send_packet(pv, &q.hdr);
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}
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static int hvsi_send_close(struct hvsi_priv *pv)
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{
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struct hvsi_control ctrl;
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pv->established = 0;
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ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
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ctrl.hdr.len = sizeof(struct hvsi_control);
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ctrl.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
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return hvsi_send_packet(pv, &ctrl.hdr);
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}
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static void hvsi_cd_change(struct hvsi_priv *pv, int cd)
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{
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if (cd)
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pv->mctrl |= TIOCM_CD;
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else {
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pv->mctrl &= ~TIOCM_CD;
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/* We copy the existing hvsi driver semantics
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* here which are to trigger a hangup when
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* we get a carrier loss.
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* Closing our connection to the server will
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* do just that.
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*/
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if (!pv->is_console && pv->opened) {
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pr_devel("HVSI@%x Carrier lost, hanging up !\n",
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pv->termno);
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hvsi_send_close(pv);
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}
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}
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}
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static void hvsi_got_control(struct hvsi_priv *pv)
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{
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struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
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switch (be16_to_cpu(pkt->verb)) {
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case VSV_CLOSE_PROTOCOL:
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/* We restart the handshaking */
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hvsi_start_handshake(pv);
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break;
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case VSV_MODEM_CTL_UPDATE:
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/* Transition of carrier detect */
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hvsi_cd_change(pv, be32_to_cpu(pkt->word) & HVSI_TSCD);
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break;
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}
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}
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static void hvsi_got_query(struct hvsi_priv *pv)
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{
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struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
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struct hvsi_query_response r;
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/* We only handle version queries */
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if (be16_to_cpu(pkt->verb) != VSV_SEND_VERSION_NUMBER)
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return;
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pr_devel("HVSI@%x: Got version query, sending response...\n",
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pv->termno);
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/* Send version response */
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r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
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r.hdr.len = sizeof(struct hvsi_query_response);
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r.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
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r.u.version = HVSI_VERSION;
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r.query_seqno = pkt->hdr.seqno;
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hvsi_send_packet(pv, &r.hdr);
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/* Assume protocol is open now */
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pv->established = 1;
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}
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static void hvsi_got_response(struct hvsi_priv *pv)
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{
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struct hvsi_query_response *r =
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(struct hvsi_query_response *)pv->inbuf;
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switch(r->verb) {
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case VSV_SEND_MODEM_CTL_STATUS:
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hvsi_cd_change(pv, be32_to_cpu(r->u.mctrl_word) & HVSI_TSCD);
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pv->mctrl_update = 1;
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break;
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}
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}
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static int hvsi_check_packet(struct hvsi_priv *pv)
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{
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u8 len, type;
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/* Check header validity. If it's invalid, we ditch
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* the whole buffer and hope we eventually resync
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*/
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if (pv->inbuf[0] < 0xfc) {
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pv->inbuf_len = pv->inbuf_pktlen = 0;
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return 0;
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}
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type = pv->inbuf[0];
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len = pv->inbuf[1];
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/* Packet incomplete ? */
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if (pv->inbuf_len < len)
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return 0;
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pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
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pv->termno, type, len);
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/* We have a packet, yay ! Handle it */
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switch(type) {
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case VS_DATA_PACKET_HEADER:
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pv->inbuf_pktlen = len - 4;
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pv->inbuf_cur = 4;
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return 1;
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case VS_CONTROL_PACKET_HEADER:
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hvsi_got_control(pv);
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break;
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case VS_QUERY_PACKET_HEADER:
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hvsi_got_query(pv);
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break;
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case VS_QUERY_RESPONSE_PACKET_HEADER:
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hvsi_got_response(pv);
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break;
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}
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/* Swallow packet and retry */
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pv->inbuf_len -= len;
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memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
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return 1;
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}
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static int hvsi_get_packet(struct hvsi_priv *pv)
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{
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/* If we have room in the buffer, ask HV for more */
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if (pv->inbuf_len < HVSI_INBUF_SIZE)
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pv->inbuf_len += pv->get_chars(pv->termno,
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&pv->inbuf[pv->inbuf_len],
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HVSI_INBUF_SIZE - pv->inbuf_len);
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/*
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* If we have at least 4 bytes in the buffer, check for
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* a full packet and retry
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*/
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if (pv->inbuf_len >= 4)
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return hvsi_check_packet(pv);
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return 0;
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}
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int hvsilib_get_chars(struct hvsi_priv *pv, char *buf, int count)
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{
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unsigned int tries, read = 0;
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if (WARN_ON(!pv))
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return -ENXIO;
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/* If we aren't open, don't do anything in order to avoid races
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* with connection establishment. The hvc core will call this
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* before we have returned from notifier_add(), and we need to
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* avoid multiple users playing with the receive buffer
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*/
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if (!pv->opened)
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return 0;
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/* We try twice, once with what data we have and once more
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* after we try to fetch some more from the hypervisor
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*/
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for (tries = 1; count && tries < 2; tries++) {
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/* Consume existing data packet */
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if (pv->inbuf_pktlen) {
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unsigned int l = min(count, (int)pv->inbuf_pktlen);
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memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
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pv->inbuf_cur += l;
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pv->inbuf_pktlen -= l;
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count -= l;
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read += l;
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}
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if (count == 0)
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break;
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/* Data packet fully consumed, move down remaning data */
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if (pv->inbuf_cur) {
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pv->inbuf_len -= pv->inbuf_cur;
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memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur],
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pv->inbuf_len);
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pv->inbuf_cur = 0;
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}
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/* Try to get another packet */
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if (hvsi_get_packet(pv))
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tries--;
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}
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if (!pv->established) {
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pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
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return -EPIPE;
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}
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return read;
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}
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int hvsilib_put_chars(struct hvsi_priv *pv, const char *buf, int count)
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{
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struct hvsi_data dp;
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int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
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if (WARN_ON(!pv))
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return -ENODEV;
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dp.hdr.type = VS_DATA_PACKET_HEADER;
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dp.hdr.len = adjcount + sizeof(struct hvsi_header);
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memcpy(dp.data, buf, adjcount);
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rc = hvsi_send_packet(pv, &dp.hdr);
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if (rc <= 0)
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return rc;
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return adjcount;
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}
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static void maybe_msleep(unsigned long ms)
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{
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/* During early boot, IRQs are disabled, use mdelay */
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if (irqs_disabled())
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mdelay(ms);
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else
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msleep(ms);
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}
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int hvsilib_read_mctrl(struct hvsi_priv *pv)
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{
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struct hvsi_query q;
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int rc, timeout;
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pr_devel("HVSI@%x: Querying modem control status...\n",
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pv->termno);
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pv->mctrl_update = 0;
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q.hdr.type = VS_QUERY_PACKET_HEADER;
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q.hdr.len = sizeof(struct hvsi_query);
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q.verb = cpu_to_be16(VSV_SEND_MODEM_CTL_STATUS);
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rc = hvsi_send_packet(pv, &q.hdr);
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if (rc <= 0) {
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pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
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return rc;
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}
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/* Try for up to 200ms */
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for (timeout = 0; timeout < 20; timeout++) {
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if (!pv->established)
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return -ENXIO;
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if (pv->mctrl_update)
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return 0;
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if (!hvsi_get_packet(pv))
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maybe_msleep(10);
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}
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return -EIO;
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}
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int hvsilib_write_mctrl(struct hvsi_priv *pv, int dtr)
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{
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struct hvsi_control ctrl;
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unsigned short mctrl;
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mctrl = pv->mctrl;
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if (dtr)
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mctrl |= TIOCM_DTR;
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else
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mctrl &= ~TIOCM_DTR;
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if (mctrl == pv->mctrl)
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return 0;
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pv->mctrl = mctrl;
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pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
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dtr ? "Setting" : "Clearing");
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ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
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ctrl.hdr.len = sizeof(struct hvsi_control);
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ctrl.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
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ctrl.mask = cpu_to_be32(HVSI_TSDTR);
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ctrl.word = cpu_to_be32(dtr ? HVSI_TSDTR : 0);
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return hvsi_send_packet(pv, &ctrl.hdr);
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}
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void hvsilib_establish(struct hvsi_priv *pv)
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{
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int timeout;
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pr_devel("HVSI@%x: Establishing...\n", pv->termno);
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/* Try for up to 200ms, there can be a packet to
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* start the process waiting for us...
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*/
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for (timeout = 0; timeout < 20; timeout++) {
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if (pv->established)
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goto established;
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if (!hvsi_get_packet(pv))
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maybe_msleep(10);
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}
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/* Failed, send a close connection packet just
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* in case
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*/
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pr_devel("HVSI@%x: ... sending close\n", pv->termno);
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hvsi_send_close(pv);
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/* Then restart handshake */
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pr_devel("HVSI@%x: ... restarting handshake\n", pv->termno);
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hvsi_start_handshake(pv);
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pr_devel("HVSI@%x: ... waiting handshake\n", pv->termno);
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/* Try for up to 400ms */
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for (timeout = 0; timeout < 40; timeout++) {
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if (pv->established)
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goto established;
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if (!hvsi_get_packet(pv))
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maybe_msleep(10);
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}
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if (!pv->established) {
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pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
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pv->termno);
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return;
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}
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established:
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/* Query modem control lines */
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pr_devel("HVSI@%x: ... established, reading mctrl\n", pv->termno);
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hvsilib_read_mctrl(pv);
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/* Set our own DTR */
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pr_devel("HVSI@%x: ... setting mctrl\n", pv->termno);
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hvsilib_write_mctrl(pv, 1);
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/* Set the opened flag so reads are allowed */
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wmb();
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pv->opened = 1;
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}
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int hvsilib_open(struct hvsi_priv *pv, struct hvc_struct *hp)
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{
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pr_devel("HVSI@%x: open !\n", pv->termno);
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/* Keep track of the tty data structure */
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pv->tty = tty_port_tty_get(&hp->port);
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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;
|
||
|
|
}
|