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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 1/3] xen-sndfront: add sound frontend driver
This is Para-virtual sound driver.
This driver creates sound files in /dev/snd/:
controlC0, pcmC0D0p, etc. Then it intercepts some
IOCTLs and redirects them to the backend driver.
Backend driver is build-in the kernel. It issues
those IOCTLs on the real sound files and returns
the result to the frontend driver.
Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>
---
include/xen/interface/io/sndif.h | 98 ++++
sound/drivers/Kconfig | 9 +
sound/drivers/Makefile | 2 +
sound/drivers/xen-sndfront.c | 1117 ++++++++++++++++++++++++++++++++++++++
4 files changed, 1226 insertions(+)
create mode 100644 include/xen/interface/io/sndif.h
create mode 100644 sound/drivers/xen-sndfront.c
diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h
new file mode 100644
index 0000000..9ef0c41
--- /dev/null
+++ b/include/xen/interface/io/sndif.h
@@ -0,0 +1,98 @@
+/******************************************************************************
+ * sndif.h
+ *
+ * Unified sound-device I/O interface for Xen guest OSes.
+ *
+ */
+#ifndef __XEN_PUBLIC_IO_SNDIF_H__
+#define __XEN_PUBLIC_IO_SNDIF_H__
+
+#include <xen/interface/io/ring.h>
+#include <xen/interface/grant_table.h>
+
+/*
+ * REQUEST CODES.
+ */
+#define SNDIF_OP_OPEN 0
+#define SNDIF_OP_CLOSE 1
+#define SNDIF_OP_READ 2
+#define SNDIF_OP_WRITE 3
+#define SNDIF_OP_IOCTL 4
+
+#define SNDIF_DEV_TYPE_CONTROL 0
+#define SNDIF_DEV_TYPE_STREAM_PLAY 1
+#define SNDIF_DEV_TYPE_STREAM_CAPTURE 2
+
+#define SNDIF_MAX_PAGES_PER_REQUEST 10
+
+#define SNDIF_DEV_ID_CNT 5
+
+/*
+ * STATUS RETURN CODES.
+ */
+ /* Operation failed for some unspecified reason (-EIO). */
+#define SNDIF_RSP_ERROR -1
+ /* Operation completed successfully. */
+#define SNDIF_RSP_OKAY 0
+
+struct sndif_request_open {
+ unsigned int dev_num;
+ unsigned int card_num;
+ unsigned int dev_type;
+ unsigned int _pad1;
+ uint64_t id; /* private guest value, echoed in resp */
+ unsigned int _pad2;
+ unsigned int _pad3;
+} __attribute__((__packed__));
+
+struct sndif_request_ioctl {
+ unsigned int dev_num;
+ unsigned int card_num;
+ unsigned int dev_type;
+ unsigned int cmd;
+ uint64_t id; /* private guest value, echoed in resp */
+ unsigned int add_len_to;
+ unsigned int add_len_from;
+ grant_ref_t gref[SNDIF_MAX_PAGES_PER_REQUEST];
+} __attribute__((__packed__));
+
+struct sndif_request_rw {
+ unsigned int dev_num;
+ unsigned int card_num;
+ unsigned int dev_type;
+ unsigned int _pad1;
+ uint64_t id; /* private guest value, echoed in resp */
+ unsigned int len;
+ unsigned int is_write;
+ grant_ref_t gref[SNDIF_MAX_PAGES_PER_REQUEST];
+} __attribute__((__packed__));
+
+struct sndif_request_common {
+ unsigned int dev_num;
+ unsigned int _pad2;
+ unsigned int dev_type;
+ unsigned int _pad3;
+ uint64_t id; /* private guest value, echoed in resp */
+ unsigned int _pad4;
+ unsigned int _pad5;
+} __attribute__((__packed__));
+
+struct sndif_request {
+ uint8_t operation; /* SNDIF_OP_??? */
+ union {
+ struct sndif_request_open open;
+ struct sndif_request_ioctl ioctl;
+ struct sndif_request_rw rw;
+ struct sndif_request_common common;
+ } u;
+} __attribute__((__packed__));
+
+struct sndif_response {
+ uint64_t id; /* copied from request */
+ uint8_t operation; /* copied from request */
+ int16_t status; /* SNDIF_RSP_??? */
+};
+
+DEFINE_RING_TYPES(sndif, struct sndif_request, struct sndif_response);
+
+#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */
diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig
index 8545da9..7364679 100644
--- a/sound/drivers/Kconfig
+++ b/sound/drivers/Kconfig
@@ -24,6 +24,15 @@ config SND_AC97_CODEC
select AC97_BUS
select SND_VMASTER
+config XEN_SND_FRONTEND
+ tristate "Xen virtual audio front-end driver support"
+ depends on SND && XEN_DOMU
+ default n
+ help
+ This driver implements the back-end of the Xen virtual
+ audio driver. It communicates with a back-end
+ in another domain.
+
menuconfig SND_DRIVERS
bool "Generic sound devices"
default y
diff --git a/sound/drivers/Makefile b/sound/drivers/Makefile
index 1a8440c..f9f7e19 100644
--- a/sound/drivers/Makefile
+++ b/sound/drivers/Makefile
@@ -11,6 +11,7 @@ snd-portman2x4-objs := portman2x4.o
snd-serial-u16550-objs := serial-u16550.o
snd-virmidi-objs := virmidi.o
snd-ml403-ac97cr-objs := ml403-ac97cr.o pcm-indirect2.o
+xen-sndfrontend-objs := xen-sndfront.o
# Toplevel Module Dependency
obj-$(CONFIG_SND_DUMMY) += snd-dummy.o
@@ -21,5 +22,6 @@ obj-$(CONFIG_SND_MTPAV) += snd-mtpav.o
obj-$(CONFIG_SND_MTS64) += snd-mts64.o
obj-$(CONFIG_SND_PORTMAN2X4) += snd-portman2x4.o
obj-$(CONFIG_SND_ML403_AC97CR) += snd-ml403-ac97cr.o
+obj-$(CONFIG_XEN_SND_FRONTEND) += xen-sndfrontend.o
obj-$(CONFIG_SND) += opl3/ opl4/ mpu401/ vx/ pcsp/
diff --git a/sound/drivers/xen-sndfront.c b/sound/drivers/xen-sndfront.c
new file mode 100644
index 0000000..c7f8827
--- /dev/null
+++ b/sound/drivers/xen-sndfront.c
@@ -0,0 +1,1117 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+
+#include <sound/asound.h>
+
+#include <xen/xen.h>
+#include <xen/events.h>
+#include <xen/page.h>
+#include <xen/grant_table.h>
+#include <xen/xenbus.h>
+#include <xen/interface/grant_table.h>
+
+#include <xen/interface/io/protocols.h>
+#include <xen/interface/io/sndif.h>
+
+#define VSND_MAJOR 160
+#define VSND_MINOR_CTRL 0
+#define VSND_MINOR_STREAM 32
+
+#define VSND_WAIT_ANSWER_TOUT 5000
+
+enum sndif_state {
+ SNDIF_STATE_DISCONNECTED,
+ SNDIF_STATE_CONNECTED,
+ SNDIF_STATE_SUSPENDED,
+};
+
+struct vsnd_stream {
+ dev_t dev;
+ struct vsnd_card *card;
+ unsigned int sample_bits;
+ unsigned int channels;
+ unsigned int stream_p;
+};
+
+struct vsnd_ctrl {
+ dev_t dev;
+ struct vsnd_card *card;
+};
+
+struct vsnd_card {
+ struct sndfront_info *fr_info;
+ unsigned int card_num;
+ unsigned int dev_num;
+ unsigned int dev_type;
+ unsigned int dev_id;
+ struct cdev cdev;
+ struct vsnd_stream *vstream;
+ struct vsnd_ctrl *vctrl;
+ grant_ref_t grefs[SNDIF_MAX_PAGES_PER_REQUEST];
+ unsigned char *buf;
+};
+
+#define SND_RING_SIZE __CONST_RING_SIZE(sndif, PAGE_SIZE)
+
+struct sndfront_info {
+ struct mutex mutex; /* protect sndfront closing state */
+ struct mutex tmp_fops_mutex; /* protect file operations */
+ struct completion completion;
+ spinlock_t io_lock; /* protect 'connected' member */
+ struct xenbus_device *xbdev;
+ enum sndif_state connected;
+ int ring_ref;
+ struct sndif_front_ring ring;
+ unsigned int evtchn, irq;
+ struct vsnd_card *vcard;
+ struct class *vsndcl;
+ int bret_code;
+ atomic_t file_refcnt;
+};
+
+static struct class *vsndclass;
+
+static const struct file_operations vsndcore_fops = {
+ .owner = THIS_MODULE,
+};
+
+#define GRANT_INVALID_REF 0
+
+static unsigned long vmalloc_to_mfn(void *address)
+{
+ return pfn_to_mfn(vmalloc_to_pfn(address));
+}
+
+static char *vsound_devnode(struct device *dev, umode_t *mode)
+{
+ return kasprintf(GFP_KERNEL, "vsnd/%s", dev_name(dev));
+}
+
+static inline
+struct snd_interval *pcm_param_to_interval(struct snd_pcm_hw_params *p, int n)
+{
+ return &p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
+}
+
+static inline int pcm_param_is_interval(int p)
+{
+ return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) &&
+ (p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL);
+}
+
+static unsigned int pcm_param_get_int(struct snd_pcm_hw_params *p, int n)
+{
+ if (pcm_param_is_interval(n)) {
+ struct snd_interval *i = pcm_param_to_interval(p, n);
+
+ if (i->integer)
+ return i->max;
+ }
+ return 0;
+}
+
+static inline void flush_requests(struct sndfront_info *info)
+{
+ int notify;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify);
+
+ if (notify)
+ notify_remote_via_irq(info->irq);
+}
+
+static int sndif_queue_request_open(struct sndfront_info *info)
+{
+ struct sndif_request *req;
+
+ if (unlikely(info->connected != SNDIF_STATE_CONNECTED))
+ return 1;
+
+ req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
+
+ req->operation = SNDIF_OP_OPEN;
+ req->u.open.dev_type = info->vcard->dev_type;
+ req->u.open.dev_num = info->vcard->dev_num;
+ req->u.open.card_num = info->vcard->card_num;
+ req->u.open.id = info->vcard->dev_id;
+
+ info->ring.req_prod_pvt++;
+
+ flush_requests(info);
+ return 0;
+}
+
+static int sndif_queue_request_close(struct sndfront_info *info)
+{
+ struct sndif_request *req;
+
+ if (unlikely(info->connected != SNDIF_STATE_CONNECTED))
+ return 1;
+
+ req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
+
+ req->operation = SNDIF_OP_CLOSE;
+ req->u.open.dev_type = info->vcard->dev_type;
+ req->u.open.dev_num = info->vcard->dev_num;
+ req->u.open.card_num = info->vcard->card_num;
+ req->u.open.id = info->vcard->dev_id;
+
+ info->ring.req_prod_pvt++;
+
+ flush_requests(info);
+ return 0;
+}
+
+static int sndif_queue_request_ioctl(struct sndfront_info *info,
+ unsigned int cmd,
+ unsigned int add_len_to,
+ unsigned int add_len_from)
+{
+ struct sndif_request *req;
+ grant_ref_t *gref;
+ int i;
+
+ if (unlikely(info->connected != SNDIF_STATE_CONNECTED))
+ return 1;
+
+ req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
+
+ req->operation = SNDIF_OP_IOCTL;
+ req->u.ioctl.dev_type = info->vcard->dev_type;
+ req->u.ioctl.dev_num = info->vcard->dev_num;
+ req->u.ioctl.card_num = info->vcard->card_num;
+ req->u.ioctl.id = info->vcard->dev_id;
+
+ req->u.ioctl.cmd = cmd;
+ req->u.ioctl.add_len_to = add_len_to;
+ req->u.ioctl.add_len_from = add_len_from;
+
+ gref = info->vcard->grefs;
+
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++)
+ req->u.ioctl.gref[i] = gref[i];
+
+ info->ring.req_prod_pvt++;
+
+ flush_requests(info);
+ return 0;
+}
+
+static int vsnd_file_open(struct inode *inode, struct file *file)
+{
+ struct sndfront_info *info;
+ struct vsnd_card *vcard;
+ unsigned long answer_tout;
+ int ret = 0;
+
+ vcard = container_of(inode->i_cdev, struct vsnd_card, cdev);
+ info = vcard->fr_info;
+
+ mutex_lock(&info->tmp_fops_mutex);
+ file->private_data = info;
+
+ if (atomic_inc_return(&info->file_refcnt) > 1)
+ goto end_fops_handler;
+
+ reinit_completion(&info->completion);
+
+ if (sndif_queue_request_open(info)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+
+ answer_tout = msecs_to_jiffies(VSND_WAIT_ANSWER_TOUT);
+ if (wait_for_completion_interruptible_timeout(&info->completion,
+ answer_tout) <= 0) {
+ ret = -ETIMEDOUT;
+ goto end_fops_handler;
+ }
+
+ ret = info->bret_code;
+
+end_fops_handler:
+ mutex_unlock(&info->tmp_fops_mutex);
+ return ret;
+}
+
+static int vsnd_file_release(struct inode *inode, struct file *file)
+{
+ struct sndfront_info *info;
+ unsigned long answer_tout;
+ int ret = 0;
+
+ info = file->private_data;
+
+ if (!info)
+ return -EINVAL;
+
+ mutex_lock(&info->tmp_fops_mutex);
+ if (atomic_dec_return(&info->file_refcnt) > 0)
+ goto end_fops_handler;
+
+ reinit_completion(&info->completion);
+
+ if (sndif_queue_request_close(info)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+
+ answer_tout = msecs_to_jiffies(VSND_WAIT_ANSWER_TOUT);
+ if (wait_for_completion_interruptible_timeout(&info->completion,
+ answer_tout) <= 0) {
+ ret = -ETIMEDOUT;
+ goto end_fops_handler;
+ }
+
+ ret = info->bret_code;
+
+end_fops_handler:
+ mutex_unlock(&info->tmp_fops_mutex);
+ return ret;
+}
+
+static
+long vsnd_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ unsigned char *shared_data;
+ struct sndfront_info *info;
+ int datalen = 0;
+ int ret = 0;
+ int ioctl_dir;
+ unsigned int add_len_to = 0;
+ unsigned int frames;
+ struct snd_pcm_hw_params *hw_params;
+ struct snd_xferi *esnd_xferi;
+ struct vsnd_stream *vstream;
+ struct snd_ctl_elem_list *elist = NULL;
+ unsigned int elist_cnt = 0;
+ unsigned int add_len_from = 0;
+ unsigned long answer_tout;
+
+ info = file->private_data;
+
+ if (!info)
+ return -EINVAL;
+
+ mutex_lock(&info->tmp_fops_mutex);
+
+ shared_data = info->vcard->buf;
+
+ ioctl_dir = (cmd >> _IOC_DIRSHIFT) & _IOC_DIRMASK;
+ datalen = (cmd >> _IOC_SIZESHIFT) & _IOC_SIZEMASK;
+
+ if (datalen > PAGE_SIZE * SNDIF_MAX_PAGES_PER_REQUEST) {
+ ret = -EFAULT;
+ goto end_fops_handler;
+ }
+
+ if (datalen && (ioctl_dir & _IOC_WRITE)) {
+ if (copy_from_user(shared_data, (void __user *)arg, datalen)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+ /* Wait data to be visible to the other end */
+ wmb();
+ }
+
+ switch (cmd) {
+ case SNDRV_PCM_IOCTL_WRITEI_FRAMES:
+ esnd_xferi = (struct snd_xferi *)shared_data;
+ vstream = info->vcard->vstream;
+ frames = esnd_xferi->frames;
+ add_len_to = vstream->channels * vstream->sample_bits / 8;
+ add_len_to *= frames;
+ if (add_len_to >
+ PAGE_SIZE * SNDIF_MAX_PAGES_PER_REQUEST - datalen) {
+ ret = -EFAULT;
+ goto end_fops_handler;
+ }
+
+ if (copy_from_user(shared_data + datalen,
+ esnd_xferi->buf, add_len_to)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+ /* Wait data to be visible to the other end */
+ wmb();
+ break;
+
+ case SNDRV_CTL_IOCTL_ELEM_LIST:
+ elist = (struct snd_ctl_elem_list *)shared_data;
+ elist_cnt = elist->count;
+
+ if (!elist_cnt)
+ break;
+
+ add_len_from = elist_cnt * sizeof(struct snd_ctl_elem_id);
+
+ break;
+ }
+
+ if (add_len_from > PAGE_SIZE * SNDIF_MAX_PAGES_PER_REQUEST - datalen) {
+ ret = -EFAULT;
+ goto end_fops_handler;
+ }
+
+ reinit_completion(&info->completion);
+
+ if (sndif_queue_request_ioctl(info, cmd, add_len_to, 0)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+
+ answer_tout = msecs_to_jiffies(VSND_WAIT_ANSWER_TOUT);
+ if (wait_for_completion_interruptible_timeout(&info->completion,
+ answer_tout) <= 0) {
+ ret = -ETIMEDOUT;
+ goto end_fops_handler;
+ }
+
+ ret = info->bret_code;
+
+ if (ret)
+ goto end_fops_handler;
+
+ if (datalen && (ioctl_dir & _IOC_READ)) {
+ /* Wait data to be available from the other end */
+ rmb();
+ if (copy_to_user((void __user *)arg, shared_data, datalen)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+ }
+
+ switch (cmd) {
+ case SNDRV_PCM_IOCTL_HW_PARAMS:
+ /* Get PCM hw parameters */
+ hw_params = (struct snd_pcm_hw_params *)shared_data;
+ vstream = info->vcard->vstream;
+ vstream->channels =
+ pcm_param_get_int(hw_params,
+ SNDRV_PCM_HW_PARAM_CHANNELS);
+ vstream->sample_bits =
+ pcm_param_get_int(hw_params,
+ SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+ break;
+
+ case SNDRV_CTL_IOCTL_ELEM_LIST:
+ /* copy extra data from additional pages */
+ if (!add_len_from)
+ break;
+
+ /* Wait data to be available from the other end */
+ rmb();
+ if (copy_to_user((void __user *)elist->pids,
+ shared_data + datalen, add_len_from)) {
+ ret = -EIO;
+ goto end_fops_handler;
+ }
+ break;
+ }
+
+end_fops_handler:
+ mutex_unlock(&info->tmp_fops_mutex);
+ return ret;
+}
+
+static const struct file_operations vsnd_file_ops = {
+ .open = vsnd_file_open,
+ .release = vsnd_file_release,
+ .unlocked_ioctl = vsnd_file_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static struct vsnd_ctrl *sndif_allocate_vctrl(struct sndfront_info *info)
+{
+ struct vsnd_ctrl *vctrl;
+ unsigned int card_num;
+ grant_ref_t gref_head;
+ unsigned long mfn;
+ int ref;
+ int i;
+
+ vctrl = kmalloc(sizeof(*vctrl), GFP_KERNEL);
+
+ if (!vctrl)
+ goto err_ret;
+
+ card_num = info->vcard->card_num;
+
+ vctrl->card = info->vcard;
+
+ vctrl->dev = MKDEV(VSND_MAJOR, VSND_MINOR_CTRL);
+ if (device_create(info->vsndcl, NULL, vctrl->dev, NULL,
+ "controlC%u", card_num) == NULL)
+ goto err_free_vctrl;
+
+ cdev_init(&info->vcard->cdev, &vsnd_file_ops);
+
+ if (cdev_add(&info->vcard->cdev, vctrl->dev, 1) < 0)
+ goto err_vctrl_dev_destroy;
+
+ info->vcard->buf = vmalloc(SNDIF_MAX_PAGES_PER_REQUEST * PAGE_SIZE);
+ if (!info->vcard->buf)
+ goto err_vctrl_cdev_del;
+
+ if (gnttab_alloc_grant_references(SNDIF_MAX_PAGES_PER_REQUEST,
+ &gref_head))
+ goto err_vctrl_free_buf;
+
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++) {
+ ref = gnttab_claim_grant_reference(&gref_head);
+ BUG_ON(ref == -ENOSPC);
+
+ mfn = vmalloc_to_mfn(info->vcard->buf + PAGE_SIZE * i);
+
+ gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+ mfn, 0);
+
+ info->vcard->grefs[i] = ref;
+ }
+
+ gnttab_free_grant_references(gref_head);
+ return vctrl;
+
+err_vctrl_free_buf:
+ vfree(info->vcard->buf);
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++)
+ gnttab_end_foreign_access(info->vcard->grefs[i], 0, 0UL);
+
+ gnttab_free_grant_references(gref_head);
+err_vctrl_cdev_del:
+ cdev_del(&info->vcard->cdev);
+err_vctrl_dev_destroy:
+ device_destroy(info->vsndcl, vctrl->dev);
+err_free_vctrl:
+ kfree(vctrl);
+err_ret:
+ return vctrl;
+}
+
+static void sndif_free_vctrl(struct sndfront_info *info)
+{
+ int i;
+ struct vsnd_card *vcard = info->vcard;
+ struct vsnd_ctrl *vctrl = vcard->vctrl;
+
+ if (vctrl) {
+ vfree(info->vcard->buf);
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++)
+ gnttab_end_foreign_access(vcard->grefs[i], 0, 0UL);
+
+ cdev_del(&info->vcard->cdev);
+ device_destroy(info->vsndcl, vctrl->dev);
+ kfree(vctrl);
+ }
+}
+
+static struct vsnd_stream *sndif_allocate_vstream(struct sndfront_info *info)
+{
+ struct vsnd_stream *vstream;
+ unsigned int card_num;
+ unsigned int dev_num;
+ unsigned int dev_minor;
+ grant_ref_t gref_head;
+ unsigned long mfn;
+ int ref;
+ int i;
+
+ vstream = kmalloc(sizeof(*vstream), GFP_KERNEL);
+
+ if (!vstream)
+ goto err_ret;
+
+ card_num = info->vcard->card_num;
+ dev_num = info->vcard->dev_num;
+ vstream->card = info->vcard;
+
+ if (info->vcard->dev_type == SNDIF_DEV_TYPE_STREAM_PLAY)
+ vstream->stream_p = 1;
+ else
+ vstream->stream_p = 0;
+
+ /* set default parameters */
+ vstream->channels = 2;
+ vstream->sample_bits = 16;
+
+ dev_minor = VSND_MINOR_STREAM + dev_num + 20 * (!!vstream->stream_p);
+ vstream->dev = MKDEV(VSND_MAJOR, dev_minor);
+ if (device_create(info->vsndcl, NULL, vstream->dev, NULL,
+ "pcmC%uD%u%c", card_num, dev_num,
+ vstream->stream_p ? 'p' : 'c') == NULL)
+ goto err_free_vstream;
+
+ cdev_init(&info->vcard->cdev, &vsnd_file_ops);
+
+ if (cdev_add(&info->vcard->cdev, vstream->dev, 1) < 0)
+ goto err_vstream_dev_destroy;
+
+ info->vcard->buf = vmalloc(SNDIF_MAX_PAGES_PER_REQUEST * PAGE_SIZE);
+ if (!info->vcard->buf)
+ goto err_vstream_cdev_del;
+
+ if (gnttab_alloc_grant_references(SNDIF_MAX_PAGES_PER_REQUEST,
+ &gref_head))
+ goto err_vstream_free_buf;
+
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++) {
+ ref = gnttab_claim_grant_reference(&gref_head);
+ BUG_ON(ref == -ENOSPC);
+
+ mfn = vmalloc_to_mfn(info->vcard->buf + PAGE_SIZE * i);
+
+ gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+ mfn, 0);
+
+ info->vcard->grefs[i] = ref;
+ }
+
+ gnttab_free_grant_references(gref_head);
+ return vstream;
+
+err_vstream_free_buf:
+ vfree(info->vcard->buf);
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++)
+ gnttab_end_foreign_access(info->vcard->grefs[i], 0, 0UL);
+
+ gnttab_free_grant_references(gref_head);
+err_vstream_cdev_del:
+ cdev_del(&info->vcard->cdev);
+err_vstream_dev_destroy:
+ device_destroy(info->vsndcl, vstream->dev);
+err_free_vstream:
+ kfree(vstream);
+err_ret:
+ return vstream;
+}
+
+static void sndif_free_vstream(struct sndfront_info *info)
+{
+ int i;
+ struct vsnd_card *vcard = info->vcard;
+ struct vsnd_stream *vstream = vcard->vstream;
+
+ if (vstream) {
+ vfree(info->vcard->buf);
+ for (i = 0; i < SNDIF_MAX_PAGES_PER_REQUEST; i++)
+ gnttab_end_foreign_access(vcard->grefs[i], 0, 0UL);
+
+ cdev_del(&info->vcard->cdev);
+ device_destroy(info->vsndcl, vstream->dev);
+ kfree(vstream);
+ }
+}
+
+static int sndif_add_virt_devices(struct sndfront_info *info,
+ unsigned int dev_type,
+ unsigned int dev_num,
+ unsigned int card_num,
+ unsigned int dev_id)
+{
+ int ret;
+
+ struct vsnd_card *vcard;
+ struct vsnd_ctrl *vctrl = NULL;
+ struct vsnd_stream *vstream = NULL;
+
+ vcard = kmalloc(sizeof(*vcard), GFP_KERNEL);
+
+ if (!vcard)
+ return -ENOMEM;
+
+ info->vsndcl = vsndclass;
+
+ vcard->card_num = card_num;
+ vcard->dev_num = dev_num;
+ vcard->dev_type = dev_type;
+ vcard->dev_id = dev_id;
+ vcard->fr_info = info;
+
+ info->vcard = vcard;
+
+ switch (dev_type) {
+ case SNDIF_DEV_TYPE_CONTROL:
+ vctrl = sndif_allocate_vctrl(info);
+
+ if (!vctrl) {
+ ret = -ENOMEM;
+ goto err_free_vcard;
+ }
+ break;
+
+ case SNDIF_DEV_TYPE_STREAM_PLAY:
+ case SNDIF_DEV_TYPE_STREAM_CAPTURE:
+ vstream = sndif_allocate_vstream(info);
+
+ if (!vstream) {
+ ret = -ENOMEM;
+ goto err_free_vcard;
+ }
+ break;
+
+ default:
+ ret = -EFAULT;
+ goto err_free_vcard;
+ }
+
+ info->vcard->vctrl = vctrl;
+ info->vcard->vstream = vstream;
+
+ return ret;
+
+err_free_vcard:
+ kfree(info->vcard);
+ return ret;
+}
+
+static void sndif_cleanup_virt_devices(struct sndfront_info *info)
+{
+ if (info->vcard) {
+ sndif_free_vstream(info);
+ sndif_free_vctrl(info);
+ kfree(info->vcard);
+ }
+}
+
+static void sndif_free(struct sndfront_info *info, int suspend)
+{
+ /* Free resources associated with old device channel. */
+ if (info->ring_ref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(info->ring_ref, 0,
+ (unsigned long)info->ring.sring);
+ info->ring_ref = GRANT_INVALID_REF;
+ info->ring.sring = NULL;
+ }
+ if (info->irq)
+ unbind_from_irqhandler(info->irq, info);
+ info->evtchn = 0;
+ info->irq = 0;
+}
+
+static irqreturn_t sndif_interrupt(int irq, void *data)
+{
+ struct sndif_response *bret;
+ RING_IDX i, rp;
+ unsigned long flags;
+ struct sndfront_info *info = (struct sndfront_info *)data;
+ int error;
+
+ spin_lock_irqsave(&info->io_lock, flags);
+
+ if (unlikely(info->connected != SNDIF_STATE_CONNECTED)) {
+ spin_unlock_irqrestore(&info->io_lock, flags);
+ return IRQ_HANDLED;
+ }
+
+ again:
+ rp = info->ring.sring->rsp_prod;
+ rmb(); /* Ensure we see queued responses up to 'rp'. */
+
+ for (i = info->ring.rsp_cons; i != rp; i++) {
+ unsigned long id;
+
+ bret = RING_GET_RESPONSE(&info->ring, i);
+ id = bret->id;
+
+ error = (bret->status == SNDIF_RSP_OKAY) ? 0 : -EIO;
+ switch (bret->operation) {
+ case SNDIF_OP_OPEN:
+ case SNDIF_OP_CLOSE:
+ case SNDIF_OP_IOCTL:
+ if (unlikely(bret->status != SNDIF_RSP_OKAY))
+ dev_dbg(&info->xbdev->dev,
+ "snddev data request error: %x\n",
+ bret->status);
+
+ info->bret_code = bret->status;
+ complete(&info->completion);
+ break;
+
+ default:
+ BUG();
+ }
+ }
+
+ info->ring.rsp_cons = i;
+
+ if (i != info->ring.req_prod_pvt) {
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do);
+ if (more_to_do)
+ goto again;
+ } else {
+ info->ring.sring->rsp_event = i + 1;
+ }
+
+ spin_unlock_irqrestore(&info->io_lock, flags);
+ return IRQ_HANDLED;
+}
+
+static int setup_sndring(struct xenbus_device *dev,
+ struct sndfront_info *info)
+{
+ struct sndif_sring *sring;
+ int err;
+
+ info->ring_ref = GRANT_INVALID_REF;
+
+ sring = (struct sndif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
+ if (!sring) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
+ return -ENOMEM;
+ }
+ SHARED_RING_INIT(sring);
+ FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
+ if (err < 0) {
+ free_page((unsigned long)sring);
+ info->ring.sring = NULL;
+ goto fail;
+ }
+ info->ring_ref = err;
+
+ err = xenbus_alloc_evtchn(dev, &info->evtchn);
+ if (err)
+ goto fail;
+
+ err = bind_evtchn_to_irqhandler(info->evtchn, sndif_interrupt, 0,
+ "sndif", info);
+ if (err <= 0) {
+ xenbus_dev_fatal(dev, err,
+ "bind_evtchn_to_irqhandler failed");
+ goto fail;
+ }
+ info->irq = err;
+
+ return 0;
+fail:
+ sndif_free(info, 0);
+ return err;
+}
+
+/* Common code used when first setting up, and when resuming. */
+static int talk_to_sndback(struct xenbus_device *dev,
+ struct sndfront_info *info)
+{
+ const char *message = NULL;
+ struct xenbus_transaction xbt;
+ int err;
+
+ /* Create shared ring, alloc event channel. */
+ err = setup_sndring(dev, info);
+ if (err)
+ goto out;
+
+again:
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto destroy_sndring;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename,
+ "ring-ref", "%u", info->ring_ref);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ err = xenbus_printf(xbt, dev->nodename,
+ "event-channel", "%u", info->evtchn);
+ if (err) {
+ message = "writing event-channel";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ if (err) {
+ if (err == -EAGAIN)
+ goto again;
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto destroy_sndring;
+ }
+
+ xenbus_switch_state(dev, XenbusStateInitialised);
+
+ return 0;
+
+ abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ if (message)
+ xenbus_dev_fatal(dev, err, "%s", message);
+ destroy_sndring:
+ sndif_free(info, 0);
+ out:
+ return err;
+}
+
+/**
+ * Entry point to this code when a new device is created. Allocate the basic
+ * structures and the ring buffer for communication with the backend, and
+ * inform the backend of the appropriate details for those. Switch to
+ * Initialised state.
+ */
+static int sndfront_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int err;
+ struct sndfront_info *info;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
+ return -ENOMEM;
+ }
+
+ mutex_init(&info->mutex);
+ mutex_init(&info->tmp_fops_mutex);
+ spin_lock_init(&info->io_lock);
+ init_completion(&info->completion);
+ info->xbdev = dev;
+ atomic_set(&info->file_refcnt, 0);
+
+ dev_set_drvdata(&dev->dev, info);
+
+ err = talk_to_sndback(dev, info);
+ if (err) {
+ kfree(info);
+ dev_set_drvdata(&dev->dev, NULL);
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * We are reconnecting to the backend, due to a suspend/resume, or a backend
+ * driver restart. We tear down our blkif structure and recreate it, but
+ * leave the device-layer structures intact so that this is transparent to the
+ * rest of the kernel.
+ */
+static int sndfront_resume(struct xenbus_device *dev)
+{
+ struct sndfront_info *info = dev_get_drvdata(&dev->dev);
+ int err;
+
+ dev_dbg(&dev->dev, "sndfront_resume: %s\n", dev->nodename);
+
+ sndif_free(info, info->connected == SNDIF_STATE_CONNECTED);
+
+ err = talk_to_sndback(dev, info);
+ if (info->connected == SNDIF_STATE_SUSPENDED && !err)
+ info->connected = SNDIF_STATE_CONNECTED;
+
+ return err;
+}
+
+static void
+sndfront_closing(struct sndfront_info *info)
+{
+ struct xenbus_device *xbdev = info->xbdev;
+
+ mutex_lock(&info->mutex);
+
+ if (xbdev->state == XenbusStateClosing) {
+ mutex_unlock(&info->mutex);
+ return;
+ }
+
+ mutex_unlock(&info->mutex);
+
+ xenbus_frontend_closed(xbdev);
+ sndif_cleanup_virt_devices(info);
+}
+
+/*
+ * Invoked when the backend is finally 'ready' (and has told produced
+ * the details about the physical device - #sectors, size, etc).
+ */
+static void sndfront_connect(struct sndfront_info *info)
+{
+ unsigned int dev_type;
+ unsigned int dev_num;
+ unsigned int card_num;
+ unsigned int dev_id;
+ int err;
+
+ switch (info->connected) {
+ case SNDIF_STATE_CONNECTED:
+
+ /* fall through */
+ case SNDIF_STATE_SUSPENDED:
+ return;
+
+ default:
+ break;
+ }
+
+ dev_dbg(&info->xbdev->dev, "%s:%s.\n",
+ __func__, info->xbdev->otherend);
+
+ xenbus_switch_state(info->xbdev, XenbusStateConnected);
+
+ spin_lock_irq(&info->io_lock);
+ info->connected = SNDIF_STATE_CONNECTED;
+ spin_unlock_irq(&info->io_lock);
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "dev_type", "%u",
+ &dev_type, NULL);
+ if (err)
+ return;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "dev_num", "%u",
+ &dev_num, NULL);
+ if (err)
+ return;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "card_num", "%u",
+ &card_num, NULL);
+ if (err)
+ return;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "dev_id", "%u",
+ &dev_id, NULL);
+ if (err)
+ return;
+
+ sndif_add_virt_devices(info, dev_type, dev_num, card_num, dev_id);
+}
+
+/**
+ * Callback received when the backend's state changes.
+ */
+static void sndback_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ struct sndfront_info *info = dev_get_drvdata(&dev->dev);
+
+ dev_dbg(&dev->dev, "sndfront:sndback_changed to state %d.\n",
+ backend_state);
+
+ switch (backend_state) {
+ case XenbusStateInitialising:
+ case XenbusStateInitWait:
+ case XenbusStateInitialised:
+ case XenbusStateReconfiguring:
+ case XenbusStateReconfigured:
+ case XenbusStateUnknown:
+ case XenbusStateClosed:
+ break;
+
+ case XenbusStateConnected:
+ sndfront_connect(info);
+ break;
+
+ case XenbusStateClosing:
+ sndfront_closing(info);
+ break;
+ }
+}
+
+static int sndfront_remove(struct xenbus_device *xbdev)
+{
+ struct sndfront_info *info = dev_get_drvdata(&xbdev->dev);
+
+ dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename);
+
+ sndif_free(info, 0);
+
+ return 0;
+}
+
+static const struct xenbus_device_id xen_snd_ids[] = {
+ { "vsnd" },
+ { "" }
+};
+
+static struct xenbus_driver xen_snd_driver = {
+ .name = "xensnd",
+ .ids = xen_snd_ids,
+ .probe = sndfront_probe,
+ .remove = sndfront_remove,
+ .resume = sndfront_resume,
+ .otherend_changed = sndback_changed,
+};
+
+static int __init xen_snd_front_init(void)
+{
+ int ret = 0;
+
+ /*FIXME: xen_pv_domain() should be here, but ARM hardcoded to hvm*/
+ if (!xen_domain())
+ return -ENODEV;
+
+ /* Nothing to do if running in dom0. */
+ if (xen_initial_domain())
+ return -ENODEV;
+
+ ret = register_chrdev(VSND_MAJOR, "vsnd", &vsndcore_fops);
+ if (ret < 0)
+ return ret;
+
+ vsndclass = class_create(THIS_MODULE, "vsnd");
+ if (!vsndclass) {
+ ret = -ENOMEM;
+ goto err_reg_chrdev;
+ }
+
+ vsndclass->devnode = vsound_devnode;
+
+ ret = xenbus_register_frontend(&xen_snd_driver);
+ if (ret < 0)
+ goto err_class_destroy;
+
+ return ret;
+
+err_class_destroy:
+ class_destroy(vsndclass);
+err_reg_chrdev:
+ unregister_chrdev(VSND_MAJOR, "vsnd");
+ return ret;
+}
+
+static void __exit xen_snd_front_cleanup(void)
+{
+ class_destroy(vsndclass);
+ unregister_chrdev(VSND_MAJOR, "vsnd");
+ xenbus_unregister_driver(&xen_snd_driver);
+}
+
+module_init(xen_snd_front_init);
+module_exit(xen_snd_front_cleanup);
+
+MODULE_DESCRIPTION("Xen virtual audio device frontend");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("xen:vsnd");
--
1.9.1
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