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6417f03132
MODULE_SUPPORTED_DEVICE was added in pre-git era and never was implemented. We can safely remove it, because the kernel has grown to have many more reliable mechanisms to determine if device is supported or not. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
394 lines
9.5 KiB
C
394 lines
9.5 KiB
C
// 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 <linux/delay.h>
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#include <linux/module.h>
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#include <xen/page.h>
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#include <xen/platform_pci.h>
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#include <xen/xen.h>
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#include <xen/xenbus.h>
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#include <xen/xen-front-pgdir-shbuf.h>
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#include <xen/interface/io/sndif.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_evtchnl.h"
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static struct xensnd_req *
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be_stream_prepare_req(struct xen_snd_front_evtchnl *evtchnl, u8 operation)
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{
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struct xensnd_req *req;
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req = RING_GET_REQUEST(&evtchnl->u.req.ring,
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evtchnl->u.req.ring.req_prod_pvt);
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req->operation = operation;
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req->id = evtchnl->evt_next_id++;
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evtchnl->evt_id = req->id;
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return req;
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}
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static int be_stream_do_io(struct xen_snd_front_evtchnl *evtchnl)
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{
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if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED))
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return -EIO;
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reinit_completion(&evtchnl->u.req.completion);
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xen_snd_front_evtchnl_flush(evtchnl);
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return 0;
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}
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static int be_stream_wait_io(struct xen_snd_front_evtchnl *evtchnl)
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{
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if (wait_for_completion_timeout(&evtchnl->u.req.completion,
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msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0)
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return -ETIMEDOUT;
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return evtchnl->u.req.resp_status;
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}
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int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl,
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struct xensnd_query_hw_param *hw_param_req,
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struct xensnd_query_hw_param *hw_param_resp)
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{
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struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_HW_PARAM_QUERY);
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req->op.hw_param = *hw_param_req;
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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if (ret == 0)
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*hw_param_resp = evtchnl->u.req.resp.hw_param;
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl,
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struct xen_front_pgdir_shbuf *shbuf,
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u8 format, unsigned int channels,
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unsigned int rate, u32 buffer_sz,
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u32 period_sz)
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{
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struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_OPEN);
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req->op.open.pcm_format = format;
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req->op.open.pcm_channels = channels;
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req->op.open.pcm_rate = rate;
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req->op.open.buffer_sz = buffer_sz;
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req->op.open.period_sz = period_sz;
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req->op.open.gref_directory =
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xen_front_pgdir_shbuf_get_dir_start(shbuf);
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl)
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{
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__always_unused struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_CLOSE);
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl,
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unsigned long pos, unsigned long count)
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{
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struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_WRITE);
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req->op.rw.length = count;
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req->op.rw.offset = pos;
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl,
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unsigned long pos, unsigned long count)
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{
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struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_READ);
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req->op.rw.length = count;
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req->op.rw.offset = pos;
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl,
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int type)
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{
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struct xensnd_req *req;
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int ret;
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mutex_lock(&evtchnl->u.req.req_io_lock);
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mutex_lock(&evtchnl->ring_io_lock);
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req = be_stream_prepare_req(evtchnl, XENSND_OP_TRIGGER);
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req->op.trigger.type = type;
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mutex_unlock(&evtchnl->ring_io_lock);
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ret = be_stream_do_io(evtchnl);
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if (ret == 0)
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ret = be_stream_wait_io(evtchnl);
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mutex_unlock(&evtchnl->u.req.req_io_lock);
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return ret;
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}
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static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
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{
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xen_snd_front_alsa_fini(front_info);
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xen_snd_front_evtchnl_free_all(front_info);
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}
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static int sndback_initwait(struct xen_snd_front_info *front_info)
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{
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int num_streams;
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int ret;
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ret = xen_snd_front_cfg_card(front_info, &num_streams);
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if (ret < 0)
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return ret;
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/* create event channels for all streams and publish */
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ret = xen_snd_front_evtchnl_create_all(front_info, num_streams);
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if (ret < 0)
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return ret;
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return xen_snd_front_evtchnl_publish_all(front_info);
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}
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static int sndback_connect(struct xen_snd_front_info *front_info)
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{
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return xen_snd_front_alsa_init(front_info);
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}
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static void sndback_disconnect(struct xen_snd_front_info *front_info)
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{
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xen_snd_drv_fini(front_info);
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xenbus_switch_state(front_info->xb_dev, XenbusStateInitialising);
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}
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static void sndback_changed(struct xenbus_device *xb_dev,
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enum xenbus_state backend_state)
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{
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struct xen_snd_front_info *front_info = dev_get_drvdata(&xb_dev->dev);
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int ret;
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dev_dbg(&xb_dev->dev, "Backend state is %s, front is %s\n",
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xenbus_strstate(backend_state),
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xenbus_strstate(xb_dev->state));
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switch (backend_state) {
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case XenbusStateReconfiguring:
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case XenbusStateReconfigured:
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case XenbusStateInitialised:
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break;
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case XenbusStateInitialising:
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/* Recovering after backend unexpected closure. */
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sndback_disconnect(front_info);
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break;
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case XenbusStateInitWait:
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/* Recovering after backend unexpected closure. */
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sndback_disconnect(front_info);
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ret = sndback_initwait(front_info);
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if (ret < 0)
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xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
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else
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xenbus_switch_state(xb_dev, XenbusStateInitialised);
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break;
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case XenbusStateConnected:
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if (xb_dev->state != XenbusStateInitialised)
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break;
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ret = sndback_connect(front_info);
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if (ret < 0)
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xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
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else
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xenbus_switch_state(xb_dev, XenbusStateConnected);
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break;
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case XenbusStateClosing:
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/*
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* In this state backend starts freeing resources,
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* so let it go into closed state first, so we can also
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* remove ours.
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*/
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break;
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case XenbusStateUnknown:
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case XenbusStateClosed:
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if (xb_dev->state == XenbusStateClosed)
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break;
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sndback_disconnect(front_info);
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break;
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}
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}
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static int xen_drv_probe(struct xenbus_device *xb_dev,
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const struct xenbus_device_id *id)
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{
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struct xen_snd_front_info *front_info;
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front_info = devm_kzalloc(&xb_dev->dev,
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sizeof(*front_info), GFP_KERNEL);
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if (!front_info)
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return -ENOMEM;
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front_info->xb_dev = xb_dev;
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dev_set_drvdata(&xb_dev->dev, front_info);
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return xenbus_switch_state(xb_dev, XenbusStateInitialising);
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}
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static int xen_drv_remove(struct xenbus_device *dev)
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{
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struct xen_snd_front_info *front_info = dev_get_drvdata(&dev->dev);
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int to = 100;
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xenbus_switch_state(dev, XenbusStateClosing);
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/*
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* On driver removal it is disconnected from XenBus,
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* so no backend state change events come via .otherend_changed
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* callback. This prevents us from exiting gracefully, e.g.
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* signaling the backend to free event channels, waiting for its
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* state to change to XenbusStateClosed and cleaning at our end.
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* Normally when front driver removed backend will finally go into
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* XenbusStateInitWait state.
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*
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* Workaround: read backend's state manually and wait with time-out.
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*/
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while ((xenbus_read_unsigned(front_info->xb_dev->otherend, "state",
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XenbusStateUnknown) != XenbusStateInitWait) &&
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--to)
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msleep(10);
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if (!to) {
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unsigned int state;
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state = xenbus_read_unsigned(front_info->xb_dev->otherend,
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"state", XenbusStateUnknown);
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pr_err("Backend state is %s while removing driver\n",
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xenbus_strstate(state));
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}
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xen_snd_drv_fini(front_info);
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xenbus_frontend_closed(dev);
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return 0;
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}
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static const struct xenbus_device_id xen_drv_ids[] = {
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{ XENSND_DRIVER_NAME },
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{ "" }
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};
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static struct xenbus_driver xen_driver = {
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.ids = xen_drv_ids,
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.probe = xen_drv_probe,
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.remove = xen_drv_remove,
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.otherend_changed = sndback_changed,
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};
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static int __init xen_drv_init(void)
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{
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if (!xen_domain())
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return -ENODEV;
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if (!xen_has_pv_devices())
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return -ENODEV;
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/* At the moment we only support case with XEN_PAGE_SIZE == PAGE_SIZE */
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if (XEN_PAGE_SIZE != PAGE_SIZE) {
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pr_err(XENSND_DRIVER_NAME ": different kernel and Xen page sizes are not supported: XEN_PAGE_SIZE (%lu) != PAGE_SIZE (%lu)\n",
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XEN_PAGE_SIZE, PAGE_SIZE);
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return -ENODEV;
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}
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pr_info("Initialising Xen " XENSND_DRIVER_NAME " frontend driver\n");
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return xenbus_register_frontend(&xen_driver);
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}
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static void __exit xen_drv_fini(void)
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{
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pr_info("Unregistering Xen " XENSND_DRIVER_NAME " frontend driver\n");
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xenbus_unregister_driver(&xen_driver);
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}
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module_init(xen_drv_init);
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module_exit(xen_drv_fini);
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MODULE_DESCRIPTION("Xen virtual sound device frontend");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("xen:" XENSND_DRIVER_NAME);
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