495 lines
12 KiB
C
495 lines
12 KiB
C
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// SPDX-License-Identifier: GPL-2.0 OR MIT
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/*
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* Xen para-virtual sound device
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*
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* Copyright (C) 2016-2018 EPAM Systems Inc.
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*
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* Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
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*/
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#include <xen/events.h>
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#include <xen/grant_table.h>
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#include <xen/xen.h>
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#include <xen/xenbus.h>
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#include "xen_snd_front.h"
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#include "xen_snd_front_alsa.h"
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#include "xen_snd_front_cfg.h"
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#include "xen_snd_front_evtchnl.h"
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static irqreturn_t evtchnl_interrupt_req(int irq, void *dev_id)
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{
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struct xen_snd_front_evtchnl *channel = dev_id;
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struct xen_snd_front_info *front_info = channel->front_info;
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struct xensnd_resp *resp;
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RING_IDX i, rp;
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if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
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return IRQ_HANDLED;
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mutex_lock(&channel->ring_io_lock);
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again:
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rp = channel->u.req.ring.sring->rsp_prod;
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/* Ensure we see queued responses up to rp. */
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rmb();
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/*
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* Assume that the backend is trusted to always write sane values
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* to the ring counters, so no overflow checks on frontend side
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* are required.
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*/
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for (i = channel->u.req.ring.rsp_cons; i != rp; i++) {
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resp = RING_GET_RESPONSE(&channel->u.req.ring, i);
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if (resp->id != channel->evt_id)
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continue;
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switch (resp->operation) {
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case XENSND_OP_OPEN:
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/* fall through */
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case XENSND_OP_CLOSE:
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/* fall through */
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case XENSND_OP_READ:
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/* fall through */
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case XENSND_OP_WRITE:
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/* fall through */
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case XENSND_OP_TRIGGER:
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channel->u.req.resp_status = resp->status;
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complete(&channel->u.req.completion);
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break;
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case XENSND_OP_HW_PARAM_QUERY:
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channel->u.req.resp_status = resp->status;
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channel->u.req.resp.hw_param =
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resp->resp.hw_param;
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complete(&channel->u.req.completion);
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break;
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default:
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dev_err(&front_info->xb_dev->dev,
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"Operation %d is not supported\n",
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resp->operation);
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break;
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}
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}
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channel->u.req.ring.rsp_cons = i;
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if (i != channel->u.req.ring.req_prod_pvt) {
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int more_to_do;
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RING_FINAL_CHECK_FOR_RESPONSES(&channel->u.req.ring,
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more_to_do);
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if (more_to_do)
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goto again;
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} else {
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channel->u.req.ring.sring->rsp_event = i + 1;
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}
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mutex_unlock(&channel->ring_io_lock);
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return IRQ_HANDLED;
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}
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static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)
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{
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struct xen_snd_front_evtchnl *channel = dev_id;
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struct xensnd_event_page *page = channel->u.evt.page;
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u32 cons, prod;
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if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
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return IRQ_HANDLED;
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mutex_lock(&channel->ring_io_lock);
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prod = page->in_prod;
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/* Ensure we see ring contents up to prod. */
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virt_rmb();
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if (prod == page->in_cons)
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goto out;
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/*
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* Assume that the backend is trusted to always write sane values
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* to the ring counters, so no overflow checks on frontend side
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* are required.
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*/
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for (cons = page->in_cons; cons != prod; cons++) {
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struct xensnd_evt *event;
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event = &XENSND_IN_RING_REF(page, cons);
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if (unlikely(event->id != channel->evt_id++))
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continue;
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switch (event->type) {
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case XENSND_EVT_CUR_POS:
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xen_snd_front_alsa_handle_cur_pos(channel,
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event->op.cur_pos.position);
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break;
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}
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}
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page->in_cons = cons;
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/* Ensure ring contents. */
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virt_wmb();
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out:
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mutex_unlock(&channel->ring_io_lock);
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return IRQ_HANDLED;
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}
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void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel)
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{
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int notify;
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channel->u.req.ring.req_prod_pvt++;
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RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&channel->u.req.ring, notify);
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if (notify)
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notify_remote_via_irq(channel->irq);
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}
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static void evtchnl_free(struct xen_snd_front_info *front_info,
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struct xen_snd_front_evtchnl *channel)
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{
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unsigned long page = 0;
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if (channel->type == EVTCHNL_TYPE_REQ)
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page = (unsigned long)channel->u.req.ring.sring;
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else if (channel->type == EVTCHNL_TYPE_EVT)
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page = (unsigned long)channel->u.evt.page;
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if (!page)
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return;
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channel->state = EVTCHNL_STATE_DISCONNECTED;
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if (channel->type == EVTCHNL_TYPE_REQ) {
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/* Release all who still waits for response if any. */
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channel->u.req.resp_status = -EIO;
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complete_all(&channel->u.req.completion);
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}
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if (channel->irq)
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unbind_from_irqhandler(channel->irq, channel);
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if (channel->port)
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xenbus_free_evtchn(front_info->xb_dev, channel->port);
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/* End access and free the page. */
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if (channel->gref != GRANT_INVALID_REF)
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gnttab_end_foreign_access(channel->gref, 0, page);
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else
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free_page(page);
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memset(channel, 0, sizeof(*channel));
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}
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void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info)
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{
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int i;
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if (!front_info->evt_pairs)
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return;
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for (i = 0; i < front_info->num_evt_pairs; i++) {
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evtchnl_free(front_info, &front_info->evt_pairs[i].req);
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evtchnl_free(front_info, &front_info->evt_pairs[i].evt);
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}
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kfree(front_info->evt_pairs);
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front_info->evt_pairs = NULL;
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}
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static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index,
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struct xen_snd_front_evtchnl *channel,
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enum xen_snd_front_evtchnl_type type)
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{
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struct xenbus_device *xb_dev = front_info->xb_dev;
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unsigned long page;
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grant_ref_t gref;
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irq_handler_t handler;
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char *handler_name = NULL;
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int ret;
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memset(channel, 0, sizeof(*channel));
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channel->type = type;
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channel->index = index;
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channel->front_info = front_info;
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channel->state = EVTCHNL_STATE_DISCONNECTED;
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channel->gref = GRANT_INVALID_REF;
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page = get_zeroed_page(GFP_KERNEL);
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if (!page) {
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ret = -ENOMEM;
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goto fail;
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}
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handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME,
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type == EVTCHNL_TYPE_REQ ?
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XENSND_FIELD_RING_REF :
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XENSND_FIELD_EVT_RING_REF);
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if (!handler_name) {
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ret = -ENOMEM;
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goto fail;
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}
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mutex_init(&channel->ring_io_lock);
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if (type == EVTCHNL_TYPE_REQ) {
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struct xen_sndif_sring *sring = (struct xen_sndif_sring *)page;
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init_completion(&channel->u.req.completion);
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mutex_init(&channel->u.req.req_io_lock);
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SHARED_RING_INIT(sring);
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FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE);
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ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
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if (ret < 0) {
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channel->u.req.ring.sring = NULL;
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goto fail;
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}
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handler = evtchnl_interrupt_req;
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} else {
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ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
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virt_to_gfn((void *)page), 0);
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if (ret < 0)
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goto fail;
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channel->u.evt.page = (struct xensnd_event_page *)page;
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gref = ret;
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handler = evtchnl_interrupt_evt;
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}
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channel->gref = gref;
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ret = xenbus_alloc_evtchn(xb_dev, &channel->port);
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if (ret < 0)
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goto fail;
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ret = bind_evtchn_to_irq(channel->port);
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if (ret < 0) {
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dev_err(&xb_dev->dev,
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"Failed to bind IRQ for domid %d port %d: %d\n",
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front_info->xb_dev->otherend_id, channel->port, ret);
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goto fail;
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}
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channel->irq = ret;
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ret = request_threaded_irq(channel->irq, NULL, handler,
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IRQF_ONESHOT, handler_name, channel);
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if (ret < 0) {
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dev_err(&xb_dev->dev, "Failed to request IRQ %d: %d\n",
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channel->irq, ret);
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goto fail;
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}
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kfree(handler_name);
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return 0;
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fail:
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if (page)
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free_page(page);
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kfree(handler_name);
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dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret);
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return ret;
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}
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int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
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int num_streams)
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{
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struct xen_front_cfg_card *cfg = &front_info->cfg;
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struct device *dev = &front_info->xb_dev->dev;
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int d, ret = 0;
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front_info->evt_pairs =
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kcalloc(num_streams,
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sizeof(struct xen_snd_front_evtchnl_pair),
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GFP_KERNEL);
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if (!front_info->evt_pairs)
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return -ENOMEM;
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/* Iterate over devices and their streams and create event channels. */
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for (d = 0; d < cfg->num_pcm_instances; d++) {
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struct xen_front_cfg_pcm_instance *pcm_instance;
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int s, index;
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pcm_instance = &cfg->pcm_instances[d];
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for (s = 0; s < pcm_instance->num_streams_pb; s++) {
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index = pcm_instance->streams_pb[s].index;
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ret = evtchnl_alloc(front_info, index,
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&front_info->evt_pairs[index].req,
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EVTCHNL_TYPE_REQ);
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if (ret < 0) {
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dev_err(dev, "Error allocating control channel\n");
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goto fail;
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}
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ret = evtchnl_alloc(front_info, index,
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&front_info->evt_pairs[index].evt,
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EVTCHNL_TYPE_EVT);
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if (ret < 0) {
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dev_err(dev, "Error allocating in-event channel\n");
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goto fail;
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}
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}
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for (s = 0; s < pcm_instance->num_streams_cap; s++) {
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index = pcm_instance->streams_cap[s].index;
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ret = evtchnl_alloc(front_info, index,
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&front_info->evt_pairs[index].req,
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EVTCHNL_TYPE_REQ);
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if (ret < 0) {
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dev_err(dev, "Error allocating control channel\n");
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goto fail;
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}
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ret = evtchnl_alloc(front_info, index,
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&front_info->evt_pairs[index].evt,
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EVTCHNL_TYPE_EVT);
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if (ret < 0) {
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dev_err(dev, "Error allocating in-event channel\n");
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goto fail;
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}
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}
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}
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front_info->num_evt_pairs = num_streams;
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return 0;
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fail:
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xen_snd_front_evtchnl_free_all(front_info);
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return ret;
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}
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static int evtchnl_publish(struct xenbus_transaction xbt,
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struct xen_snd_front_evtchnl *channel,
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const char *path, const char *node_ring,
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const char *node_chnl)
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{
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struct xenbus_device *xb_dev = channel->front_info->xb_dev;
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int ret;
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/* Write control channel ring reference. */
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ret = xenbus_printf(xbt, path, node_ring, "%u", channel->gref);
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|
|
if (ret < 0) {
|
||
|
|
dev_err(&xb_dev->dev, "Error writing ring-ref: %d\n", ret);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Write event channel ring reference. */
|
||
|
|
ret = xenbus_printf(xbt, path, node_chnl, "%u", channel->port);
|
||
|
|
if (ret < 0) {
|
||
|
|
dev_err(&xb_dev->dev, "Error writing event channel: %d\n", ret);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info)
|
||
|
|
{
|
||
|
|
struct xen_front_cfg_card *cfg = &front_info->cfg;
|
||
|
|
struct xenbus_transaction xbt;
|
||
|
|
int ret, d;
|
||
|
|
|
||
|
|
again:
|
||
|
|
ret = xenbus_transaction_start(&xbt);
|
||
|
|
if (ret < 0) {
|
||
|
|
xenbus_dev_fatal(front_info->xb_dev, ret,
|
||
|
|
"starting transaction");
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (d = 0; d < cfg->num_pcm_instances; d++) {
|
||
|
|
struct xen_front_cfg_pcm_instance *pcm_instance;
|
||
|
|
int s, index;
|
||
|
|
|
||
|
|
pcm_instance = &cfg->pcm_instances[d];
|
||
|
|
|
||
|
|
for (s = 0; s < pcm_instance->num_streams_pb; s++) {
|
||
|
|
index = pcm_instance->streams_pb[s].index;
|
||
|
|
|
||
|
|
ret = evtchnl_publish(xbt,
|
||
|
|
&front_info->evt_pairs[index].req,
|
||
|
|
pcm_instance->streams_pb[s].xenstore_path,
|
||
|
|
XENSND_FIELD_RING_REF,
|
||
|
|
XENSND_FIELD_EVT_CHNL);
|
||
|
|
if (ret < 0)
|
||
|
|
goto fail;
|
||
|
|
|
||
|
|
ret = evtchnl_publish(xbt,
|
||
|
|
&front_info->evt_pairs[index].evt,
|
||
|
|
pcm_instance->streams_pb[s].xenstore_path,
|
||
|
|
XENSND_FIELD_EVT_RING_REF,
|
||
|
|
XENSND_FIELD_EVT_EVT_CHNL);
|
||
|
|
if (ret < 0)
|
||
|
|
goto fail;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (s = 0; s < pcm_instance->num_streams_cap; s++) {
|
||
|
|
index = pcm_instance->streams_cap[s].index;
|
||
|
|
|
||
|
|
ret = evtchnl_publish(xbt,
|
||
|
|
&front_info->evt_pairs[index].req,
|
||
|
|
pcm_instance->streams_cap[s].xenstore_path,
|
||
|
|
XENSND_FIELD_RING_REF,
|
||
|
|
XENSND_FIELD_EVT_CHNL);
|
||
|
|
if (ret < 0)
|
||
|
|
goto fail;
|
||
|
|
|
||
|
|
ret = evtchnl_publish(xbt,
|
||
|
|
&front_info->evt_pairs[index].evt,
|
||
|
|
pcm_instance->streams_cap[s].xenstore_path,
|
||
|
|
XENSND_FIELD_EVT_RING_REF,
|
||
|
|
XENSND_FIELD_EVT_EVT_CHNL);
|
||
|
|
if (ret < 0)
|
||
|
|
goto fail;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ret = xenbus_transaction_end(xbt, 0);
|
||
|
|
if (ret < 0) {
|
||
|
|
if (ret == -EAGAIN)
|
||
|
|
goto again;
|
||
|
|
|
||
|
|
xenbus_dev_fatal(front_info->xb_dev, ret,
|
||
|
|
"completing transaction");
|
||
|
|
goto fail_to_end;
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
fail:
|
||
|
|
xenbus_transaction_end(xbt, 1);
|
||
|
|
fail_to_end:
|
||
|
|
xenbus_dev_fatal(front_info->xb_dev, ret, "writing XenStore");
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
|
||
|
|
bool is_connected)
|
||
|
|
{
|
||
|
|
enum xen_snd_front_evtchnl_state state;
|
||
|
|
|
||
|
|
if (is_connected)
|
||
|
|
state = EVTCHNL_STATE_CONNECTED;
|
||
|
|
else
|
||
|
|
state = EVTCHNL_STATE_DISCONNECTED;
|
||
|
|
|
||
|
|
mutex_lock(&evt_pair->req.ring_io_lock);
|
||
|
|
evt_pair->req.state = state;
|
||
|
|
mutex_unlock(&evt_pair->req.ring_io_lock);
|
||
|
|
|
||
|
|
mutex_lock(&evt_pair->evt.ring_io_lock);
|
||
|
|
evt_pair->evt.state = state;
|
||
|
|
mutex_unlock(&evt_pair->evt.ring_io_lock);
|
||
|
|
}
|
||
|
|
|
||
|
|
void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair)
|
||
|
|
{
|
||
|
|
mutex_lock(&evt_pair->req.ring_io_lock);
|
||
|
|
evt_pair->req.evt_next_id = 0;
|
||
|
|
mutex_unlock(&evt_pair->req.ring_io_lock);
|
||
|
|
|
||
|
|
mutex_lock(&evt_pair->evt.ring_io_lock);
|
||
|
|
evt_pair->evt.evt_next_id = 0;
|
||
|
|
mutex_unlock(&evt_pair->evt.ring_io_lock);
|
||
|
|
}
|
||
|
|
|