// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Abstract layer for MIDI v1.0 stream
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <sound/core.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/nospec.h>
#include <sound/rawmidi.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/minors.h>
#include <sound/initval.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Midlevel RawMidi code for ALSA.");
MODULE_LICENSE("GPL");

#ifdef CONFIG_SND_OSSEMUL
static int midi_map[SNDRV_CARDS];
static int amidi_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
module_param_array(midi_map, int, NULL, 0444);
MODULE_PARM_DESC(midi_map, "Raw MIDI device number assigned to 1st OSS device.");
module_param_array(amidi_map, int, NULL, 0444);
MODULE_PARM_DESC(amidi_map, "Raw MIDI device number assigned to 2nd OSS device.");
#endif /* CONFIG_SND_OSSEMUL */

static int snd_rawmidi_free(struct snd_rawmidi *rmidi);
static int snd_rawmidi_dev_free(struct snd_device *device);
static int snd_rawmidi_dev_register(struct snd_device *device);
static int snd_rawmidi_dev_disconnect(struct snd_device *device);

static LIST_HEAD(snd_rawmidi_devices);
static DEFINE_MUTEX(register_mutex);

#define rmidi_err(rmidi, fmt, args...) \
        dev_err(&(rmidi)->dev, fmt, ##args)
#define rmidi_warn(rmidi, fmt, args...) \
        dev_warn(&(rmidi)->dev, fmt, ##args)
#define rmidi_dbg(rmidi, fmt, args...) \
        dev_dbg(&(rmidi)->dev, fmt, ##args)

struct snd_rawmidi_status32 {
        s32 stream;
        s32 tstamp_sec;                 /* Timestamp */
        s32 tstamp_nsec;
        u32 avail;                      /* available bytes */
        u32 xruns;                      /* count of overruns since last status (in bytes) */
        unsigned char reserved[16];     /* reserved for future use */
};

#define SNDRV_RAWMIDI_IOCTL_STATUS32    _IOWR('W', 0x20, struct snd_rawmidi_status32)

struct snd_rawmidi_status64 {
        int stream;
        u8 rsvd[4];                     /* alignment */
        s64 tstamp_sec;                 /* Timestamp */
        s64 tstamp_nsec;
        size_t avail;                   /* available bytes */
        size_t xruns;                   /* count of overruns since last status (in bytes) */
        unsigned char reserved[16];     /* reserved for future use */
};

#define SNDRV_RAWMIDI_IOCTL_STATUS64    _IOWR('W', 0x20, struct snd_rawmidi_status64)

static struct snd_rawmidi *snd_rawmidi_search(struct snd_card *card, int device)
{
        struct snd_rawmidi *rawmidi;

        list_for_each_entry(rawmidi, &snd_rawmidi_devices, list)
                if (rawmidi->card == card && rawmidi->device == device)
                        return rawmidi;
        return NULL;
}

static inline unsigned short snd_rawmidi_file_flags(struct file *file)
{
        switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
        case FMODE_WRITE:
                return SNDRV_RAWMIDI_LFLG_OUTPUT;
        case FMODE_READ:
                return SNDRV_RAWMIDI_LFLG_INPUT;
        default:
                return SNDRV_RAWMIDI_LFLG_OPEN;
        }
}

static inline bool __snd_rawmidi_ready(struct snd_rawmidi_runtime *runtime)
{
        return runtime->avail >= runtime->avail_min;
}

static bool snd_rawmidi_ready(struct snd_rawmidi_substream *substream)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        unsigned long flags;
        bool ready;

        spin_lock_irqsave(&runtime->lock, flags);
        ready = __snd_rawmidi_ready(runtime);
        spin_unlock_irqrestore(&runtime->lock, flags);
        return ready;
}

static inline int snd_rawmidi_ready_append(struct snd_rawmidi_substream *substream,
                                           size_t count)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        return runtime->avail >= runtime->avail_min &&
               (!substream->append || runtime->avail >= count);
}

static void snd_rawmidi_input_event_work(struct work_struct *work)
{
        struct snd_rawmidi_runtime *runtime =
                container_of(work, struct snd_rawmidi_runtime, event_work);

        if (runtime->event)
                runtime->event(runtime->substream);
}

/* buffer refcount management: call with runtime->lock held */
static inline void snd_rawmidi_buffer_ref(struct snd_rawmidi_runtime *runtime)
{
        runtime->buffer_ref++;
}

static inline void snd_rawmidi_buffer_unref(struct snd_rawmidi_runtime *runtime)
{
        runtime->buffer_ref--;
}

static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
{
        struct snd_rawmidi_runtime *runtime;

        runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
        if (!runtime)
                return -ENOMEM;
        runtime->substream = substream;
        spin_lock_init(&runtime->lock);
        init_waitqueue_head(&runtime->sleep);
        INIT_WORK(&runtime->event_work, snd_rawmidi_input_event_work);
        runtime->event = NULL;
        runtime->buffer_size = PAGE_SIZE;
        runtime->avail_min = 1;
        if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
                runtime->avail = 0;
        else
                runtime->avail = runtime->buffer_size;
        runtime->buffer = kvzalloc(runtime->buffer_size, GFP_KERNEL);
        if (!runtime->buffer) {
                kfree(runtime);
                return -ENOMEM;
        }
        runtime->appl_ptr = runtime->hw_ptr = 0;
        substream->runtime = runtime;
        return 0;
}

static int snd_rawmidi_runtime_free(struct snd_rawmidi_substream *substream)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        kvfree(runtime->buffer);
        kfree(runtime);
        substream->runtime = NULL;
        return 0;
}

static inline void snd_rawmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
        if (!substream->opened)
                return;
        substream->ops->trigger(substream, up);
}

static void snd_rawmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
        if (!substream->opened)
                return;
        substream->ops->trigger(substream, up);
        if (!up)
                cancel_work_sync(&substream->runtime->event_work);
}

static void __reset_runtime_ptrs(struct snd_rawmidi_runtime *runtime,
                                 bool is_input)
{
        runtime->drain = 0;
        runtime->appl_ptr = runtime->hw_ptr = 0;
        runtime->avail = is_input ? 0 : runtime->buffer_size;
}

static void reset_runtime_ptrs(struct snd_rawmidi_runtime *runtime,
                               bool is_input)
{
        unsigned long flags;

        spin_lock_irqsave(&runtime->lock, flags);
        __reset_runtime_ptrs(runtime, is_input);
        spin_unlock_irqrestore(&runtime->lock, flags);
}

int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream)
{
        snd_rawmidi_output_trigger(substream, 0);
        reset_runtime_ptrs(substream->runtime, false);
        return 0;
}
EXPORT_SYMBOL(snd_rawmidi_drop_output);

int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream)
{
        int err;
        long timeout;
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        err = 0;
        runtime->drain = 1;
        timeout = wait_event_interruptible_timeout(runtime->sleep,
                                (runtime->avail >= runtime->buffer_size),
                                10*HZ);
        if (signal_pending(current))
                err = -ERESTARTSYS;
        if (runtime->avail < runtime->buffer_size && !timeout) {
                rmidi_warn(substream->rmidi,
                           "rawmidi drain error (avail = %li, buffer_size = %li)\n",
                           (long)runtime->avail, (long)runtime->buffer_size);
                err = -EIO;
        }
        runtime->drain = 0;
        if (err != -ERESTARTSYS) {
                /* we need wait a while to make sure that Tx FIFOs are empty */
                if (substream->ops->drain)
                        substream->ops->drain(substream);
                else
                        msleep(50);
                snd_rawmidi_drop_output(substream);
        }
        return err;
}
EXPORT_SYMBOL(snd_rawmidi_drain_output);

int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream)
{
        snd_rawmidi_input_trigger(substream, 0);
        reset_runtime_ptrs(substream->runtime, true);
        return 0;
}
EXPORT_SYMBOL(snd_rawmidi_drain_input);

/* look for an available substream for the given stream direction;
 * if a specific subdevice is given, try to assign it
 */
static int assign_substream(struct snd_rawmidi *rmidi, int subdevice,
                            int stream, int mode,
                            struct snd_rawmidi_substream **sub_ret)
{
        struct snd_rawmidi_substream *substream;
        struct snd_rawmidi_str *s = &rmidi->streams[stream];
        static const unsigned int info_flags[2] = {
                [SNDRV_RAWMIDI_STREAM_OUTPUT] = SNDRV_RAWMIDI_INFO_OUTPUT,
                [SNDRV_RAWMIDI_STREAM_INPUT] = SNDRV_RAWMIDI_INFO_INPUT,
        };

        if (!(rmidi->info_flags & info_flags[stream]))
                return -ENXIO;
        if (subdevice >= 0 && subdevice >= s->substream_count)
                return -ENODEV;

        list_for_each_entry(substream, &s->substreams, list) {
                if (substream->opened) {
                        if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
                            !(mode & SNDRV_RAWMIDI_LFLG_APPEND) ||
                            !substream->append)
                                continue;
                }
                if (subdevice < 0 || subdevice == substream->number) {
                        *sub_ret = substream;
                        return 0;
                }
        }
        return -EAGAIN;
}

/* open and do ref-counting for the given substream */
static int open_substream(struct snd_rawmidi *rmidi,
                          struct snd_rawmidi_substream *substream,
                          int mode)
{
        int err;

        if (substream->use_count == 0) {
                err = snd_rawmidi_runtime_create(substream);
                if (err < 0)
                        return err;
                err = substream->ops->open(substream);
                if (err < 0) {
                        snd_rawmidi_runtime_free(substream);
                        return err;
                }
                substream->opened = 1;
                substream->active_sensing = 0;
                if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
                        substream->append = 1;
                substream->pid = get_pid(task_pid(current));
                rmidi->streams[substream->stream].substream_opened++;
        }
        substream->use_count++;
        return 0;
}

static void close_substream(struct snd_rawmidi *rmidi,
                            struct snd_rawmidi_substream *substream,
                            int cleanup);

static int rawmidi_open_priv(struct snd_rawmidi *rmidi, int subdevice, int mode,
                             struct snd_rawmidi_file *rfile)
{
        struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
        int err;

        rfile->input = rfile->output = NULL;
        if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
                err = assign_substream(rmidi, subdevice,
                                       SNDRV_RAWMIDI_STREAM_INPUT,
                                       mode, &sinput);
                if (err < 0)
                        return err;
        }
        if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
                err = assign_substream(rmidi, subdevice,
                                       SNDRV_RAWMIDI_STREAM_OUTPUT,
                                       mode, &soutput);
                if (err < 0)
                        return err;
        }

        if (sinput) {
                err = open_substream(rmidi, sinput, mode);
                if (err < 0)
                        return err;
        }
        if (soutput) {
                err = open_substream(rmidi, soutput, mode);
                if (err < 0) {
                        if (sinput)
                                close_substream(rmidi, sinput, 0);
                        return err;
                }
        }

        rfile->rmidi = rmidi;
        rfile->input = sinput;
        rfile->output = soutput;
        return 0;
}

/* called from sound/core/seq/seq_midi.c */
int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
                            int mode, struct snd_rawmidi_file *rfile)
{
        struct snd_rawmidi *rmidi;
        int err = 0;

        if (snd_BUG_ON(!rfile))
                return -EINVAL;

        mutex_lock(&register_mutex);
        rmidi = snd_rawmidi_search(card, device);
        if (!rmidi)
                err = -ENODEV;
        else if (!try_module_get(rmidi->card->module))
                err = -ENXIO;
        mutex_unlock(&register_mutex);
        if (err < 0)
                return err;

        mutex_lock(&rmidi->open_mutex);
        err = rawmidi_open_priv(rmidi, subdevice, mode, rfile);
        mutex_unlock(&rmidi->open_mutex);
        if (err < 0)
                module_put(rmidi->card->module);
        return err;
}
EXPORT_SYMBOL(snd_rawmidi_kernel_open);

static int snd_rawmidi_open(struct inode *inode, struct file *file)
{
        int maj = imajor(inode);
        struct snd_card *card;
        int subdevice;
        unsigned short fflags;
        int err;
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_file *rawmidi_file = NULL;
        wait_queue_entry_t wait;

        if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK))
                return -EINVAL;         /* invalid combination */

        err = stream_open(inode, file);
        if (err < 0)
                return err;

        if (maj == snd_major) {
                rmidi = snd_lookup_minor_data(iminor(inode),
                                              SNDRV_DEVICE_TYPE_RAWMIDI);
#ifdef CONFIG_SND_OSSEMUL
        } else if (maj == SOUND_MAJOR) {
                rmidi = snd_lookup_oss_minor_data(iminor(inode),
                                                  SNDRV_OSS_DEVICE_TYPE_MIDI);
#endif
        } else
                return -ENXIO;

        if (rmidi == NULL)
                return -ENODEV;

        if (!try_module_get(rmidi->card->module)) {
                snd_card_unref(rmidi->card);
                return -ENXIO;
        }

        mutex_lock(&rmidi->open_mutex);
        card = rmidi->card;
        err = snd_card_file_add(card, file);
        if (err < 0)
                goto __error_card;
        fflags = snd_rawmidi_file_flags(file);
        if ((file->f_flags & O_APPEND) || maj == SOUND_MAJOR) /* OSS emul? */
                fflags |= SNDRV_RAWMIDI_LFLG_APPEND;
        rawmidi_file = kmalloc(sizeof(*rawmidi_file), GFP_KERNEL);
        if (rawmidi_file == NULL) {
                err = -ENOMEM;
                goto __error;
        }
        rawmidi_file->user_pversion = 0;
        init_waitqueue_entry(&wait, current);
        add_wait_queue(&rmidi->open_wait, &wait);
        while (1) {
                subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_RAWMIDI);
                err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);
                if (err >= 0)
                        break;
                if (err == -EAGAIN) {
                        if (file->f_flags & O_NONBLOCK) {
                                err = -EBUSY;
                                break;
                        }
                } else
                        break;
                set_current_state(TASK_INTERRUPTIBLE);
                mutex_unlock(&rmidi->open_mutex);
                schedule();
                mutex_lock(&rmidi->open_mutex);
                if (rmidi->card->shutdown) {
                        err = -ENODEV;
                        break;
                }
                if (signal_pending(current)) {
                        err = -ERESTARTSYS;
                        break;
                }
        }
        remove_wait_queue(&rmidi->open_wait, &wait);
        if (err < 0) {
                kfree(rawmidi_file);
                goto __error;
        }
#ifdef CONFIG_SND_OSSEMUL
        if (rawmidi_file->input && rawmidi_file->input->runtime)
                rawmidi_file->input->runtime->oss = (maj == SOUND_MAJOR);
        if (rawmidi_file->output && rawmidi_file->output->runtime)
                rawmidi_file->output->runtime->oss = (maj == SOUND_MAJOR);
#endif
        file->private_data = rawmidi_file;
        mutex_unlock(&rmidi->open_mutex);
        snd_card_unref(rmidi->card);
        return 0;

 __error:
        snd_card_file_remove(card, file);
 __error_card:
        mutex_unlock(&rmidi->open_mutex);
        module_put(rmidi->card->module);
        snd_card_unref(rmidi->card);
        return err;
}

static void close_substream(struct snd_rawmidi *rmidi,
                            struct snd_rawmidi_substream *substream,
                            int cleanup)
{
        if (--substream->use_count)
                return;

        if (cleanup) {
                if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
                        snd_rawmidi_input_trigger(substream, 0);
                else {
                        if (substream->active_sensing) {
                                unsigned char buf = 0xfe;
                                /* sending single active sensing message
                                 * to shut the device up
                                 */
                                snd_rawmidi_kernel_write(substream, &buf, 1);
                        }
                        if (snd_rawmidi_drain_output(substream) == -ERESTARTSYS)
                                snd_rawmidi_output_trigger(substream, 0);
                }
        }
        substream->ops->close(substream);
        if (substream->runtime->private_free)
                substream->runtime->private_free(substream);
        snd_rawmidi_runtime_free(substream);
        substream->opened = 0;
        substream->append = 0;
        put_pid(substream->pid);
        substream->pid = NULL;
        rmidi->streams[substream->stream].substream_opened--;
}

static void rawmidi_release_priv(struct snd_rawmidi_file *rfile)
{
        struct snd_rawmidi *rmidi;

        rmidi = rfile->rmidi;
        mutex_lock(&rmidi->open_mutex);
        if (rfile->input) {
                close_substream(rmidi, rfile->input, 1);
                rfile->input = NULL;
        }
        if (rfile->output) {
                close_substream(rmidi, rfile->output, 1);
                rfile->output = NULL;
        }
        rfile->rmidi = NULL;
        mutex_unlock(&rmidi->open_mutex);
        wake_up(&rmidi->open_wait);
}

/* called from sound/core/seq/seq_midi.c */
int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile)
{
        struct snd_rawmidi *rmidi;

        if (snd_BUG_ON(!rfile))
                return -ENXIO;

        rmidi = rfile->rmidi;
        rawmidi_release_priv(rfile);
        module_put(rmidi->card->module);
        return 0;
}
EXPORT_SYMBOL(snd_rawmidi_kernel_release);

static int snd_rawmidi_release(struct inode *inode, struct file *file)
{
        struct snd_rawmidi_file *rfile;
        struct snd_rawmidi *rmidi;
        struct module *module;

        rfile = file->private_data;
        rmidi = rfile->rmidi;
        rawmidi_release_priv(rfile);
        kfree(rfile);
        module = rmidi->card->module;
        snd_card_file_remove(rmidi->card, file);
        module_put(module);
        return 0;
}

static int snd_rawmidi_info(struct snd_rawmidi_substream *substream,
                            struct snd_rawmidi_info *info)
{
        struct snd_rawmidi *rmidi;

        if (substream == NULL)
                return -ENODEV;
        rmidi = substream->rmidi;
        memset(info, 0, sizeof(*info));
        info->card = rmidi->card->number;
        info->device = rmidi->device;
        info->subdevice = substream->number;
        info->stream = substream->stream;
        info->flags = rmidi->info_flags;
        strcpy(info->id, rmidi->id);
        strcpy(info->name, rmidi->name);
        strcpy(info->subname, substream->name);
        info->subdevices_count = substream->pstr->substream_count;
        info->subdevices_avail = (substream->pstr->substream_count -
                                  substream->pstr->substream_opened);
        return 0;
}

static int snd_rawmidi_info_user(struct snd_rawmidi_substream *substream,
                                 struct snd_rawmidi_info __user *_info)
{
        struct snd_rawmidi_info info;
        int err;

        err = snd_rawmidi_info(substream, &info);
        if (err < 0)
                return err;
        if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
                return -EFAULT;
        return 0;
}

static int __snd_rawmidi_info_select(struct snd_card *card,
                                     struct snd_rawmidi_info *info)
{
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_str *pstr;
        struct snd_rawmidi_substream *substream;

        rmidi = snd_rawmidi_search(card, info->device);
        if (!rmidi)
                return -ENXIO;
        if (info->stream < 0 || info->stream > 1)
                return -EINVAL;
        info->stream = array_index_nospec(info->stream, 2);
        pstr = &rmidi->streams[info->stream];
        if (pstr->substream_count == 0)
                return -ENOENT;
        if (info->subdevice >= pstr->substream_count)
                return -ENXIO;
        list_for_each_entry(substream, &pstr->substreams, list) {
                if ((unsigned int)substream->number == info->subdevice)
                        return snd_rawmidi_info(substream, info);
        }
        return -ENXIO;
}

int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info)
{
        int ret;

        mutex_lock(&register_mutex);
        ret = __snd_rawmidi_info_select(card, info);
        mutex_unlock(&register_mutex);
        return ret;
}
EXPORT_SYMBOL(snd_rawmidi_info_select);

static int snd_rawmidi_info_select_user(struct snd_card *card,
                                        struct snd_rawmidi_info __user *_info)
{
        int err;
        struct snd_rawmidi_info info;

        if (get_user(info.device, &_info->device))
                return -EFAULT;
        if (get_user(info.stream, &_info->stream))
                return -EFAULT;
        if (get_user(info.subdevice, &_info->subdevice))
                return -EFAULT;
        err = snd_rawmidi_info_select(card, &info);
        if (err < 0)
                return err;
        if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
                return -EFAULT;
        return 0;
}

static int resize_runtime_buffer(struct snd_rawmidi_runtime *runtime,
                                 struct snd_rawmidi_params *params,
                                 bool is_input)
{
        char *newbuf, *oldbuf;
        unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;

        if (params->buffer_size < 32 || params->buffer_size > 1024L * 1024L)
                return -EINVAL;
        if (framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP && (params->buffer_size & 0x1f) != 0)
                return -EINVAL;
        if (params->avail_min < 1 || params->avail_min > params->buffer_size)
                return -EINVAL;
        if (params->buffer_size != runtime->buffer_size) {
                newbuf = kvzalloc(params->buffer_size, GFP_KERNEL);
                if (!newbuf)
                        return -ENOMEM;
                spin_lock_irq(&runtime->lock);
                if (runtime->buffer_ref) {
                        spin_unlock_irq(&runtime->lock);
                        kvfree(newbuf);
                        return -EBUSY;
                }
                oldbuf = runtime->buffer;
                runtime->buffer = newbuf;
                runtime->buffer_size = params->buffer_size;
                __reset_runtime_ptrs(runtime, is_input);
                spin_unlock_irq(&runtime->lock);
                kvfree(oldbuf);
        }
        runtime->avail_min = params->avail_min;
        return 0;
}

int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
                              struct snd_rawmidi_params *params)
{
        if (substream->append && substream->use_count > 1)
                return -EBUSY;
        snd_rawmidi_drain_output(substream);
        substream->active_sensing = !params->no_active_sensing;
        return resize_runtime_buffer(substream->runtime, params, false);
}
EXPORT_SYMBOL(snd_rawmidi_output_params);

int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
                             struct snd_rawmidi_params *params)
{
        unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;
        unsigned int clock_type = params->mode & SNDRV_RAWMIDI_MODE_CLOCK_MASK;
        int err;

        if (framing == SNDRV_RAWMIDI_MODE_FRAMING_NONE && clock_type != SNDRV_RAWMIDI_MODE_CLOCK_NONE)
                return -EINVAL;
        else if (clock_type > SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW)
                return -EINVAL;
        if (framing > SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP)
                return -EINVAL;
        snd_rawmidi_drain_input(substream);
        err = resize_runtime_buffer(substream->runtime, params, true);
        if (err < 0)
                return err;

        substream->framing = framing;
        substream->clock_type = clock_type;
        return 0;
}
EXPORT_SYMBOL(snd_rawmidi_input_params);

static int snd_rawmidi_output_status(struct snd_rawmidi_substream *substream,
                                     struct snd_rawmidi_status64 *status)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        memset(status, 0, sizeof(*status));
        status->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
        spin_lock_irq(&runtime->lock);
        status->avail = runtime->avail;
        spin_unlock_irq(&runtime->lock);
        return 0;
}

static int snd_rawmidi_input_status(struct snd_rawmidi_substream *substream,
                                    struct snd_rawmidi_status64 *status)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        memset(status, 0, sizeof(*status));
        status->stream = SNDRV_RAWMIDI_STREAM_INPUT;
        spin_lock_irq(&runtime->lock);
        status->avail = runtime->avail;
        status->xruns = runtime->xruns;
        runtime->xruns = 0;
        spin_unlock_irq(&runtime->lock);
        return 0;
}

static int snd_rawmidi_ioctl_status32(struct snd_rawmidi_file *rfile,
                                      struct snd_rawmidi_status32 __user *argp)
{
        int err = 0;
        struct snd_rawmidi_status32 __user *status = argp;
        struct snd_rawmidi_status32 status32;
        struct snd_rawmidi_status64 status64;

        if (copy_from_user(&status32, argp,
                           sizeof(struct snd_rawmidi_status32)))
                return -EFAULT;

        switch (status32.stream) {
        case SNDRV_RAWMIDI_STREAM_OUTPUT:
                if (rfile->output == NULL)
                        return -EINVAL;
                err = snd_rawmidi_output_status(rfile->output, &status64);
                break;
        case SNDRV_RAWMIDI_STREAM_INPUT:
                if (rfile->input == NULL)
                        return -EINVAL;
                err = snd_rawmidi_input_status(rfile->input, &status64);
                break;
        default:
                return -EINVAL;
        }
        if (err < 0)
                return err;

        status32 = (struct snd_rawmidi_status32) {
                .stream = status64.stream,
                .tstamp_sec = status64.tstamp_sec,
                .tstamp_nsec = status64.tstamp_nsec,
                .avail = status64.avail,
                .xruns = status64.xruns,
        };

        if (copy_to_user(status, &status32, sizeof(*status)))
                return -EFAULT;

        return 0;
}

static int snd_rawmidi_ioctl_status64(struct snd_rawmidi_file *rfile,
                                      struct snd_rawmidi_status64 __user *argp)
{
        int err = 0;
        struct snd_rawmidi_status64 status;

        if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status64)))
                return -EFAULT;

        switch (status.stream) {
        case SNDRV_RAWMIDI_STREAM_OUTPUT:
                if (rfile->output == NULL)
                        return -EINVAL;
                err = snd_rawmidi_output_status(rfile->output, &status);
                break;
        case SNDRV_RAWMIDI_STREAM_INPUT:
                if (rfile->input == NULL)
                        return -EINVAL;
                err = snd_rawmidi_input_status(rfile->input, &status);
                break;
        default:
                return -EINVAL;
        }
        if (err < 0)
                return err;
        if (copy_to_user(argp, &status,
                         sizeof(struct snd_rawmidi_status64)))
                return -EFAULT;
        return 0;
}

static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        struct snd_rawmidi_file *rfile;
        void __user *argp = (void __user *)arg;

        rfile = file->private_data;
        if (((cmd >> 8) & 0xff) != 'W')
                return -ENOTTY;
        switch (cmd) {
        case SNDRV_RAWMIDI_IOCTL_PVERSION:
                return put_user(SNDRV_RAWMIDI_VERSION, (int __user *)argp) ? -EFAULT : 0;
        case SNDRV_RAWMIDI_IOCTL_INFO:
        {
                int stream;
                struct snd_rawmidi_info __user *info = argp;

                if (get_user(stream, &info->stream))
                        return -EFAULT;
                switch (stream) {
                case SNDRV_RAWMIDI_STREAM_INPUT:
                        return snd_rawmidi_info_user(rfile->input, info);
                case SNDRV_RAWMIDI_STREAM_OUTPUT:
                        return snd_rawmidi_info_user(rfile->output, info);
                default:
                        return -EINVAL;
                }
        }
        case SNDRV_RAWMIDI_IOCTL_USER_PVERSION:
                if (get_user(rfile->user_pversion, (unsigned int __user *)arg))
                        return -EFAULT;
                return 0;

        case SNDRV_RAWMIDI_IOCTL_PARAMS:
        {
                struct snd_rawmidi_params params;

                if (copy_from_user(&params, argp, sizeof(struct snd_rawmidi_params)))
                        return -EFAULT;
                if (rfile->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 2)) {
                        params.mode = 0;
                        memset(params.reserved, 0, sizeof(params.reserved));
                }
                switch (params.stream) {
                case SNDRV_RAWMIDI_STREAM_OUTPUT:
                        if (rfile->output == NULL)
                                return -EINVAL;
                        return snd_rawmidi_output_params(rfile->output, &params);
                case SNDRV_RAWMIDI_STREAM_INPUT:
                        if (rfile->input == NULL)
                                return -EINVAL;
                        return snd_rawmidi_input_params(rfile->input, &params);
                default:
                        return -EINVAL;
                }
        }
        case SNDRV_RAWMIDI_IOCTL_STATUS32:
                return snd_rawmidi_ioctl_status32(rfile, argp);
        case SNDRV_RAWMIDI_IOCTL_STATUS64:
                return snd_rawmidi_ioctl_status64(rfile, argp);
        case SNDRV_RAWMIDI_IOCTL_DROP:
        {
                int val;

                if (get_user(val, (int __user *) argp))
                        return -EFAULT;
                switch (val) {
                case SNDRV_RAWMIDI_STREAM_OUTPUT:
                        if (rfile->output == NULL)
                                return -EINVAL;
                        return snd_rawmidi_drop_output(rfile->output);
                default:
                        return -EINVAL;
                }
        }
        case SNDRV_RAWMIDI_IOCTL_DRAIN:
        {
                int val;

                if (get_user(val, (int __user *) argp))
                        return -EFAULT;
                switch (val) {
                case SNDRV_RAWMIDI_STREAM_OUTPUT:
                        if (rfile->output == NULL)
                                return -EINVAL;
                        return snd_rawmidi_drain_output(rfile->output);
                case SNDRV_RAWMIDI_STREAM_INPUT:
                        if (rfile->input == NULL)
                                return -EINVAL;
                        return snd_rawmidi_drain_input(rfile->input);
                default:
                        return -EINVAL;
                }
        }
        default:
                rmidi_dbg(rfile->rmidi,
                          "rawmidi: unknown command = 0x%x\n", cmd);
        }
        return -ENOTTY;
}

static int snd_rawmidi_control_ioctl(struct snd_card *card,
                                     struct snd_ctl_file *control,
                                     unsigned int cmd,
                                     unsigned long arg)
{
        void __user *argp = (void __user *)arg;

        switch (cmd) {
        case SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE:
        {
                int device;

                if (get_user(device, (int __user *)argp))
                        return -EFAULT;
                if (device >= SNDRV_RAWMIDI_DEVICES) /* next device is -1 */
                        device = SNDRV_RAWMIDI_DEVICES - 1;
                mutex_lock(&register_mutex);
                device = device < 0 ? 0 : device + 1;
                while (device < SNDRV_RAWMIDI_DEVICES) {
                        if (snd_rawmidi_search(card, device))
                                break;
                        device++;
                }
                if (device == SNDRV_RAWMIDI_DEVICES)
                        device = -1;
                mutex_unlock(&register_mutex);
                if (put_user(device, (int __user *)argp))
                        return -EFAULT;
                return 0;
        }
        case SNDRV_CTL_IOCTL_RAWMIDI_PREFER_SUBDEVICE:
        {
                int val;

                if (get_user(val, (int __user *)argp))
                        return -EFAULT;
                control->preferred_subdevice[SND_CTL_SUBDEV_RAWMIDI] = val;
                return 0;
        }
        case SNDRV_CTL_IOCTL_RAWMIDI_INFO:
                return snd_rawmidi_info_select_user(card, argp);
        }
        return -ENOIOCTLCMD;
}

static int receive_with_tstamp_framing(struct snd_rawmidi_substream *substream,
                        const unsigned char *buffer, int src_count, const struct timespec64 *tstamp)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        struct snd_rawmidi_framing_tstamp *dest_ptr;
        struct snd_rawmidi_framing_tstamp frame = { .tv_sec = tstamp->tv_sec, .tv_nsec = tstamp->tv_nsec };

        int dest_frames = 0;
        int orig_count = src_count;
        int frame_size = sizeof(struct snd_rawmidi_framing_tstamp);

        BUILD_BUG_ON(frame_size != 0x20);
        if (snd_BUG_ON((runtime->hw_ptr & 0x1f) != 0))
                return -EINVAL;

        while (src_count > 0) {
                if ((int)(runtime->buffer_size - runtime->avail) < frame_size) {
                        runtime->xruns += src_count;
                        break;
                }
                if (src_count >= SNDRV_RAWMIDI_FRAMING_DATA_LENGTH)
                        frame.length = SNDRV_RAWMIDI_FRAMING_DATA_LENGTH;
                else {
                        frame.length = src_count;
                        memset(frame.data, 0, SNDRV_RAWMIDI_FRAMING_DATA_LENGTH);
                }
                memcpy(frame.data, buffer, frame.length);
                buffer += frame.length;
                src_count -= frame.length;
                dest_ptr = (struct snd_rawmidi_framing_tstamp *) (runtime->buffer + runtime->hw_ptr);
                *dest_ptr = frame;
                runtime->avail += frame_size;
                runtime->hw_ptr += frame_size;
                runtime->hw_ptr %= runtime->buffer_size;
                dest_frames++;
        }
        return orig_count - src_count;
}

static struct timespec64 get_framing_tstamp(struct snd_rawmidi_substream *substream)
{
        struct timespec64 ts64 = {0, 0};

        switch (substream->clock_type) {
        case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW:
                ktime_get_raw_ts64(&ts64);
                break;
        case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC:
                ktime_get_ts64(&ts64);
                break;
        case SNDRV_RAWMIDI_MODE_CLOCK_REALTIME:
                ktime_get_real_ts64(&ts64);
                break;
        }
        return ts64;
}

/**
 * snd_rawmidi_receive - receive the input data from the device
 * @substream: the rawmidi substream
 * @buffer: the buffer pointer
 * @count: the data size to read
 *
 * Reads the data from the internal buffer.
 *
 * Return: The size of read data, or a negative error code on failure.
 */
int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
                        const unsigned char *buffer, int count)
{
        unsigned long flags;
        struct timespec64 ts64 = get_framing_tstamp(substream);
        int result = 0, count1;
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        if (!substream->opened)
                return -EBADFD;
        if (runtime->buffer == NULL) {
                rmidi_dbg(substream->rmidi,
                          "snd_rawmidi_receive: input is not active!!!\n");
                return -EINVAL;
        }

        spin_lock_irqsave(&runtime->lock, flags);
        if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
                result = receive_with_tstamp_framing(substream, buffer, count, &ts64);
        } else if (count == 1) {        /* special case, faster code */
                substream->bytes++;
                if (runtime->avail < runtime->buffer_size) {
                        runtime->buffer[runtime->hw_ptr++] = buffer[0];
                        runtime->hw_ptr %= runtime->buffer_size;
                        runtime->avail++;
                        result++;
                } else {
                        runtime->xruns++;
                }
        } else {
                substream->bytes += count;
                count1 = runtime->buffer_size - runtime->hw_ptr;
                if (count1 > count)
                        count1 = count;
                if (count1 > (int)(runtime->buffer_size - runtime->avail))
                        count1 = runtime->buffer_size - runtime->avail;
                memcpy(runtime->buffer + runtime->hw_ptr, buffer, count1);
                runtime->hw_ptr += count1;
                runtime->hw_ptr %= runtime->buffer_size;
                runtime->avail += count1;
                count -= count1;
                result += count1;
                if (count > 0) {
                        buffer += count1;
                        count1 = count;
                        if (count1 > (int)(runtime->buffer_size - runtime->avail)) {
                                count1 = runtime->buffer_size - runtime->avail;
                                runtime->xruns += count - count1;
                        }
                        if (count1 > 0) {
                                memcpy(runtime->buffer, buffer, count1);
                                runtime->hw_ptr = count1;
                                runtime->avail += count1;
                                result += count1;
                        }
                }
        }
        if (result > 0) {
                if (runtime->event)
                        schedule_work(&runtime->event_work);
                else if (__snd_rawmidi_ready(runtime))
                        wake_up(&runtime->sleep);
        }
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result;
}
EXPORT_SYMBOL(snd_rawmidi_receive);

static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
                                     unsigned char __user *userbuf,
                                     unsigned char *kernelbuf, long count)
{
        unsigned long flags;
        long result = 0, count1;
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        unsigned long appl_ptr;
        int err = 0;

        spin_lock_irqsave(&runtime->lock, flags);
        snd_rawmidi_buffer_ref(runtime);
        while (count > 0 && runtime->avail) {
                count1 = runtime->buffer_size - runtime->appl_ptr;
                if (count1 > count)
                        count1 = count;
                if (count1 > (int)runtime->avail)
                        count1 = runtime->avail;

                /* update runtime->appl_ptr before unlocking for userbuf */
                appl_ptr = runtime->appl_ptr;
                runtime->appl_ptr += count1;
                runtime->appl_ptr %= runtime->buffer_size;
                runtime->avail -= count1;

                if (kernelbuf)
                        memcpy(kernelbuf + result, runtime->buffer + appl_ptr, count1);
                if (userbuf) {
                        spin_unlock_irqrestore(&runtime->lock, flags);
                        if (copy_to_user(userbuf + result,
                                         runtime->buffer + appl_ptr, count1))
                                err = -EFAULT;
                        spin_lock_irqsave(&runtime->lock, flags);
                        if (err)
                                goto out;
                }
                result += count1;
                count -= count1;
        }
 out:
        snd_rawmidi_buffer_unref(runtime);
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result > 0 ? result : err;
}

long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
                             unsigned char *buf, long count)
{
        snd_rawmidi_input_trigger(substream, 1);
        return snd_rawmidi_kernel_read1(substream, NULL/*userbuf*/, buf, count);
}
EXPORT_SYMBOL(snd_rawmidi_kernel_read);

static ssize_t snd_rawmidi_read(struct file *file, char __user *buf, size_t count,
                                loff_t *offset)
{
        long result;
        int count1;
        struct snd_rawmidi_file *rfile;
        struct snd_rawmidi_substream *substream;
        struct snd_rawmidi_runtime *runtime;

        rfile = file->private_data;
        substream = rfile->input;
        if (substream == NULL)
                return -EIO;
        runtime = substream->runtime;
        snd_rawmidi_input_trigger(substream, 1);
        result = 0;
        while (count > 0) {
                spin_lock_irq(&runtime->lock);
                while (!__snd_rawmidi_ready(runtime)) {
                        wait_queue_entry_t wait;

                        if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
                                spin_unlock_irq(&runtime->lock);
                                return result > 0 ? result : -EAGAIN;
                        }
                        init_waitqueue_entry(&wait, current);
                        add_wait_queue(&runtime->sleep, &wait);
                        set_current_state(TASK_INTERRUPTIBLE);
                        spin_unlock_irq(&runtime->lock);
                        schedule();
                        remove_wait_queue(&runtime->sleep, &wait);
                        if (rfile->rmidi->card->shutdown)
                                return -ENODEV;
                        if (signal_pending(current))
                                return result > 0 ? result : -ERESTARTSYS;
                        spin_lock_irq(&runtime->lock);
                        if (!runtime->avail) {
                                spin_unlock_irq(&runtime->lock);
                                return result > 0 ? result : -EIO;
                        }
                }
                spin_unlock_irq(&runtime->lock);
                count1 = snd_rawmidi_kernel_read1(substream,
                                                  (unsigned char __user *)buf,
                                                  NULL/*kernelbuf*/,
                                                  count);
                if (count1 < 0)
                        return result > 0 ? result : count1;
                result += count1;
                buf += count1;
                count -= count1;
        }
        return result;
}

/**
 * snd_rawmidi_transmit_empty - check whether the output buffer is empty
 * @substream: the rawmidi substream
 *
 * Return: 1 if the internal output buffer is empty, 0 if not.
 */
int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        int result;
        unsigned long flags;

        if (runtime->buffer == NULL) {
                rmidi_dbg(substream->rmidi,
                          "snd_rawmidi_transmit_empty: output is not active!!!\n");
                return 1;
        }
        spin_lock_irqsave(&runtime->lock, flags);
        result = runtime->avail >= runtime->buffer_size;
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_empty);

/**
 * __snd_rawmidi_transmit_peek - copy data from the internal buffer
 * @substream: the rawmidi substream
 * @buffer: the buffer pointer
 * @count: data size to transfer
 *
 * This is a variant of snd_rawmidi_transmit_peek() without spinlock.
 */
int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
                              unsigned char *buffer, int count)
{
        int result, count1;
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        if (runtime->buffer == NULL) {
                rmidi_dbg(substream->rmidi,
                          "snd_rawmidi_transmit_peek: output is not active!!!\n");
                return -EINVAL;
        }
        result = 0;
        if (runtime->avail >= runtime->buffer_size) {
                /* warning: lowlevel layer MUST trigger down the hardware */
                goto __skip;
        }
        if (count == 1) {       /* special case, faster code */
                *buffer = runtime->buffer[runtime->hw_ptr];
                result++;
        } else {
                count1 = runtime->buffer_size - runtime->hw_ptr;
                if (count1 > count)
                        count1 = count;
                if (count1 > (int)(runtime->buffer_size - runtime->avail))
                        count1 = runtime->buffer_size - runtime->avail;
                memcpy(buffer, runtime->buffer + runtime->hw_ptr, count1);
                count -= count1;
                result += count1;
                if (count > 0) {
                        if (count > (int)(runtime->buffer_size - runtime->avail - count1))
                                count = runtime->buffer_size - runtime->avail - count1;
                        memcpy(buffer + count1, runtime->buffer, count);
                        result += count;
                }
        }
      __skip:
        return result;
}
EXPORT_SYMBOL(__snd_rawmidi_transmit_peek);

/**
 * snd_rawmidi_transmit_peek - copy data from the internal buffer
 * @substream: the rawmidi substream
 * @buffer: the buffer pointer
 * @count: data size to transfer
 *
 * Copies data from the internal output buffer to the given buffer.
 *
 * Call this in the interrupt handler when the midi output is ready,
 * and call snd_rawmidi_transmit_ack() after the transmission is
 * finished.
 *
 * Return: The size of copied data, or a negative error code on failure.
 */
int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
                              unsigned char *buffer, int count)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        int result;
        unsigned long flags;

        spin_lock_irqsave(&runtime->lock, flags);
        result = __snd_rawmidi_transmit_peek(substream, buffer, count);
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_peek);

/**
 * __snd_rawmidi_transmit_ack - acknowledge the transmission
 * @substream: the rawmidi substream
 * @count: the transferred count
 *
 * This is a variant of __snd_rawmidi_transmit_ack() without spinlock.
 */
int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;

        if (runtime->buffer == NULL) {
                rmidi_dbg(substream->rmidi,
                          "snd_rawmidi_transmit_ack: output is not active!!!\n");
                return -EINVAL;
        }
        snd_BUG_ON(runtime->avail + count > runtime->buffer_size);
        runtime->hw_ptr += count;
        runtime->hw_ptr %= runtime->buffer_size;
        runtime->avail += count;
        substream->bytes += count;
        if (count > 0) {
                if (runtime->drain || __snd_rawmidi_ready(runtime))
                        wake_up(&runtime->sleep);
        }
        return count;
}
EXPORT_SYMBOL(__snd_rawmidi_transmit_ack);

/**
 * snd_rawmidi_transmit_ack - acknowledge the transmission
 * @substream: the rawmidi substream
 * @count: the transferred count
 *
 * Advances the hardware pointer for the internal output buffer with
 * the given size and updates the condition.
 * Call after the transmission is finished.
 *
 * Return: The advanced size if successful, or a negative error code on failure.
 */
int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        int result;
        unsigned long flags;

        spin_lock_irqsave(&runtime->lock, flags);
        result = __snd_rawmidi_transmit_ack(substream, count);
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_ack);

/**
 * snd_rawmidi_transmit - copy from the buffer to the device
 * @substream: the rawmidi substream
 * @buffer: the buffer pointer
 * @count: the data size to transfer
 *
 * Copies data from the buffer to the device and advances the pointer.
 *
 * Return: The copied size if successful, or a negative error code on failure.
 */
int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
                         unsigned char *buffer, int count)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        int result;
        unsigned long flags;

        spin_lock_irqsave(&runtime->lock, flags);
        if (!substream->opened)
                result = -EBADFD;
        else {
                count = __snd_rawmidi_transmit_peek(substream, buffer, count);
                if (count <= 0)
                        result = count;
                else
                        result = __snd_rawmidi_transmit_ack(substream, count);
        }
        spin_unlock_irqrestore(&runtime->lock, flags);
        return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit);

/**
 * snd_rawmidi_proceed - Discard the all pending bytes and proceed
 * @substream: rawmidi substream
 *
 * Return: the number of discarded bytes
 */
int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream)
{
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        unsigned long flags;
        int count = 0;

        spin_lock_irqsave(&runtime->lock, flags);
        if (runtime->avail < runtime->buffer_size) {
                count = runtime->buffer_size - runtime->avail;
                __snd_rawmidi_transmit_ack(substream, count);
        }
        spin_unlock_irqrestore(&runtime->lock, flags);
        return count;
}
EXPORT_SYMBOL(snd_rawmidi_proceed);

static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
                                      const unsigned char __user *userbuf,
                                      const unsigned char *kernelbuf,
                                      long count)
{
        unsigned long flags;
        long count1, result;
        struct snd_rawmidi_runtime *runtime = substream->runtime;
        unsigned long appl_ptr;

        if (!kernelbuf && !userbuf)
                return -EINVAL;
        if (snd_BUG_ON(!runtime->buffer))
                return -EINVAL;

        result = 0;
        spin_lock_irqsave(&runtime->lock, flags);
        if (substream->append) {
                if ((long)runtime->avail < count) {
                        spin_unlock_irqrestore(&runtime->lock, flags);
                        return -EAGAIN;
                }
        }
        snd_rawmidi_buffer_ref(runtime);
        while (count > 0 && runtime->avail > 0) {
                count1 = runtime->buffer_size - runtime->appl_ptr;
                if (count1 > count)
                        count1 = count;
                if (count1 > (long)runtime->avail)
                        count1 = runtime->avail;

                /* update runtime->appl_ptr before unlocking for userbuf */
                appl_ptr = runtime->appl_ptr;
                runtime->appl_ptr += count1;
                runtime->appl_ptr %= runtime->buffer_size;
                runtime->avail -= count1;

                if (kernelbuf)
                        memcpy(runtime->buffer + appl_ptr,
                               kernelbuf + result, count1);
                else if (userbuf) {
                        spin_unlock_irqrestore(&runtime->lock, flags);
                        if (copy_from_user(runtime->buffer + appl_ptr,
                                           userbuf + result, count1)) {
                                spin_lock_irqsave(&runtime->lock, flags);
                                result = result > 0 ? result : -EFAULT;
                                goto __end;
                        }
                        spin_lock_irqsave(&runtime->lock, flags);
                }
                result += count1;
                count -= count1;
        }
      __end:
        count1 = runtime->avail < runtime->buffer_size;
        snd_rawmidi_buffer_unref(runtime);
        spin_unlock_irqrestore(&runtime->lock, flags);
        if (count1)
                snd_rawmidi_output_trigger(substream, 1);
        return result;
}

long snd_rawmidi_kernel_write(struct snd_rawmidi_substream *substream,
                              const unsigned char *buf, long count)
{
        return snd_rawmidi_kernel_write1(substream, NULL, buf, count);
}
EXPORT_SYMBOL(snd_rawmidi_kernel_write);

static ssize_t snd_rawmidi_write(struct file *file, const char __user *buf,
                                 size_t count, loff_t *offset)
{
        long result, timeout;
        int count1;
        struct snd_rawmidi_file *rfile;
        struct snd_rawmidi_runtime *runtime;
        struct snd_rawmidi_substream *substream;

        rfile = file->private_data;
        substream = rfile->output;
        runtime = substream->runtime;
        /* we cannot put an atomic message to our buffer */
        if (substream->append && count > runtime->buffer_size)
                return -EIO;
        result = 0;
        while (count > 0) {
                spin_lock_irq(&runtime->lock);
                while (!snd_rawmidi_ready_append(substream, count)) {
                        wait_queue_entry_t wait;

                        if (file->f_flags & O_NONBLOCK) {
                                spin_unlock_irq(&runtime->lock);
                                return result > 0 ? result : -EAGAIN;
                        }
                        init_waitqueue_entry(&wait, current);
                        add_wait_queue(&runtime->sleep, &wait);
                        set_current_state(TASK_INTERRUPTIBLE);
                        spin_unlock_irq(&runtime->lock);
                        timeout = schedule_timeout(30 * HZ);
                        remove_wait_queue(&runtime->sleep, &wait);
                        if (rfile->rmidi->card->shutdown)
                                return -ENODEV;
                        if (signal_pending(current))
                                return result > 0 ? result : -ERESTARTSYS;
                        spin_lock_irq(&runtime->lock);
                        if (!runtime->avail && !timeout) {
                                spin_unlock_irq(&runtime->lock);
                                return result > 0 ? result : -EIO;
                        }
                }
                spin_unlock_irq(&runtime->lock);
                count1 = snd_rawmidi_kernel_write1(substream, buf, NULL, count);
                if (count1 < 0)
                        return result > 0 ? result : count1;
                result += count1;
                buf += count1;
                if ((size_t)count1 < count && (file->f_flags & O_NONBLOCK))
                        break;
                count -= count1;
        }
        if (file->f_flags & O_DSYNC) {
                spin_lock_irq(&runtime->lock);
                while (runtime->avail != runtime->buffer_size) {
                        wait_queue_entry_t wait;
                        unsigned int last_avail = runtime->avail;

                        init_waitqueue_entry(&wait, current);
                        add_wait_queue(&runtime->sleep, &wait);
                        set_current_state(TASK_INTERRUPTIBLE);
                        spin_unlock_irq(&runtime->lock);
                        timeout = schedule_timeout(30 * HZ);
                        remove_wait_queue(&runtime->sleep, &wait);
                        if (signal_pending(current))
                                return result > 0 ? result : -ERESTARTSYS;
                        if (runtime->avail == last_avail && !timeout)
                                return result > 0 ? result : -EIO;
                        spin_lock_irq(&runtime->lock);
                }
                spin_unlock_irq(&runtime->lock);
        }
        return result;
}

static __poll_t snd_rawmidi_poll(struct file *file, poll_table *wait)
{
        struct snd_rawmidi_file *rfile;
        struct snd_rawmidi_runtime *runtime;
        __poll_t mask;

        rfile = file->private_data;
        if (rfile->input != NULL) {
                runtime = rfile->input->runtime;
                snd_rawmidi_input_trigger(rfile->input, 1);
                poll_wait(file, &runtime->sleep, wait);
        }
        if (rfile->output != NULL) {
                runtime = rfile->output->runtime;
                poll_wait(file, &runtime->sleep, wait);
        }
        mask = 0;
        if (rfile->input != NULL) {
                if (snd_rawmidi_ready(rfile->input))
                        mask |= EPOLLIN | EPOLLRDNORM;
        }
        if (rfile->output != NULL) {
                if (snd_rawmidi_ready(rfile->output))
                        mask |= EPOLLOUT | EPOLLWRNORM;
        }
        return mask;
}

/*
 */
#ifdef CONFIG_COMPAT
#include "rawmidi_compat.c"
#else
#define snd_rawmidi_ioctl_compat        NULL
#endif

/*
 */

static void snd_rawmidi_proc_info_read(struct snd_info_entry *entry,
                                       struct snd_info_buffer *buffer)
{
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_substream *substream;
        struct snd_rawmidi_runtime *runtime;
        unsigned long buffer_size, avail, xruns;
        unsigned int clock_type;
        static const char *clock_names[4] = { "none", "realtime", "monotonic", "monotonic raw" };

        rmidi = entry->private_data;
        snd_iprintf(buffer, "%s\n\n", rmidi->name);
        mutex_lock(&rmidi->open_mutex);
        if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT) {
                list_for_each_entry(substream,
                                    &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
                                    list) {
                        snd_iprintf(buffer,
                                    "Output %d\n"
                                    "  Tx bytes     : %lu\n",
                                    substream->number,
                                    (unsigned long) substream->bytes);
                        if (substream->opened) {
                                snd_iprintf(buffer,
                                    "  Owner PID    : %d\n",
                                    pid_vnr(substream->pid));
                                runtime = substream->runtime;
                                spin_lock_irq(&runtime->lock);
                                buffer_size = runtime->buffer_size;
                                avail = runtime->avail;
                                spin_unlock_irq(&runtime->lock);
                                snd_iprintf(buffer,
                                    "  Mode         : %s\n"
                                    "  Buffer size  : %lu\n"
                                    "  Avail        : %lu\n",
                                    runtime->oss ? "OSS compatible" : "native",
                                    buffer_size, avail);
                        }
                }
        }
        if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_INPUT) {
                list_for_each_entry(substream,
                                    &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
                                    list) {
                        snd_iprintf(buffer,
                                    "Input %d\n"
                                    "  Rx bytes     : %lu\n",
                                    substream->number,
                                    (unsigned long) substream->bytes);
                        if (substream->opened) {
                                snd_iprintf(buffer,
                                            "  Owner PID    : %d\n",
                                            pid_vnr(substream->pid));
                                runtime = substream->runtime;
                                spin_lock_irq(&runtime->lock);
                                buffer_size = runtime->buffer_size;
                                avail = runtime->avail;
                                xruns = runtime->xruns;
                                spin_unlock_irq(&runtime->lock);
                                snd_iprintf(buffer,
                                            "  Buffer size  : %lu\n"
                                            "  Avail        : %lu\n"
                                            "  Overruns     : %lu\n",
                                            buffer_size, avail, xruns);
                                if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
                                        clock_type = substream->clock_type >> SNDRV_RAWMIDI_MODE_CLOCK_SHIFT;
                                        if (!snd_BUG_ON(clock_type >= ARRAY_SIZE(clock_names)))
                                                snd_iprintf(buffer,
                                                            "  Framing      : tstamp\n"
                                                            "  Clock type   : %s\n",
                                                            clock_names[clock_type]);
                                }
                        }
                }
        }
        mutex_unlock(&rmidi->open_mutex);
}

/*
 *  Register functions
 */

static const struct file_operations snd_rawmidi_f_ops = {
        .owner =        THIS_MODULE,
        .read =         snd_rawmidi_read,
        .write =        snd_rawmidi_write,
        .open =         snd_rawmidi_open,
        .release =      snd_rawmidi_release,
        .llseek =       no_llseek,
        .poll =         snd_rawmidi_poll,
        .unlocked_ioctl =       snd_rawmidi_ioctl,
        .compat_ioctl = snd_rawmidi_ioctl_compat,
};

static int snd_rawmidi_alloc_substreams(struct snd_rawmidi *rmidi,
                                        struct snd_rawmidi_str *stream,
                                        int direction,
                                        int count)
{
        struct snd_rawmidi_substream *substream;
        int idx;

        for (idx = 0; idx < count; idx++) {
                substream = kzalloc(sizeof(*substream), GFP_KERNEL);
                if (!substream)
                        return -ENOMEM;
                substream->stream = direction;
                substream->number = idx;
                substream->rmidi = rmidi;
                substream->pstr = stream;
                list_add_tail(&substream->list, &stream->substreams);
                stream->substream_count++;
        }
        return 0;
}

static void release_rawmidi_device(struct device *dev)
{
        kfree(container_of(dev, struct snd_rawmidi, dev));
}

/**
 * snd_rawmidi_new - create a rawmidi instance
 * @card: the card instance
 * @id: the id string
 * @device: the device index
 * @output_count: the number of output streams
 * @input_count: the number of input streams
 * @rrawmidi: the pointer to store the new rawmidi instance
 *
 * Creates a new rawmidi instance.
 * Use snd_rawmidi_set_ops() to set the operators to the new instance.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_rawmidi_new(struct snd_card *card, char *id, int device,
                    int output_count, int input_count,
                    struct snd_rawmidi **rrawmidi)
{
        struct snd_rawmidi *rmidi;
        int err;
        static const struct snd_device_ops ops = {
                .dev_free = snd_rawmidi_dev_free,
                .dev_register = snd_rawmidi_dev_register,
                .dev_disconnect = snd_rawmidi_dev_disconnect,
        };

        if (snd_BUG_ON(!card))
                return -ENXIO;
        if (rrawmidi)
                *rrawmidi = NULL;
        rmidi = kzalloc(sizeof(*rmidi), GFP_KERNEL);
        if (!rmidi)
                return -ENOMEM;
        rmidi->card = card;
        rmidi->device = device;
        mutex_init(&rmidi->open_mutex);
        init_waitqueue_head(&rmidi->open_wait);
        INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams);
        INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams);

        if (id != NULL)
                strscpy(rmidi->id, id, sizeof(rmidi->id));

        snd_device_initialize(&rmidi->dev, card);
        rmidi->dev.release = release_rawmidi_device;
        dev_set_name(&rmidi->dev, "midiC%iD%i", card->number, device);

        err = snd_rawmidi_alloc_substreams(rmidi,
                                           &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT],
                                           SNDRV_RAWMIDI_STREAM_INPUT,
                                           input_count);
        if (err < 0)
                goto error;
        err = snd_rawmidi_alloc_substreams(rmidi,
                                           &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT],
                                           SNDRV_RAWMIDI_STREAM_OUTPUT,
                                           output_count);
        if (err < 0)
                goto error;
        err = snd_device_new(card, SNDRV_DEV_RAWMIDI, rmidi, &ops);
        if (err < 0)
                goto error;

        if (rrawmidi)
                *rrawmidi = rmidi;
        return 0;

 error:
        snd_rawmidi_free(rmidi);
        return err;
}
EXPORT_SYMBOL(snd_rawmidi_new);

static void snd_rawmidi_free_substreams(struct snd_rawmidi_str *stream)
{
        struct snd_rawmidi_substream *substream;

        while (!list_empty(&stream->substreams)) {
                substream = list_entry(stream->substreams.next, struct snd_rawmidi_substream, list);
                list_del(&substream->list);
                kfree(substream);
        }
}

static int snd_rawmidi_free(struct snd_rawmidi *rmidi)
{
        if (!rmidi)
                return 0;

        snd_info_free_entry(rmidi->proc_entry);
        rmidi->proc_entry = NULL;
        mutex_lock(&register_mutex);
        if (rmidi->ops && rmidi->ops->dev_unregister)
                rmidi->ops->dev_unregister(rmidi);
        mutex_unlock(&register_mutex);

        snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
        snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
        if (rmidi->private_free)
                rmidi->private_free(rmidi);
        put_device(&rmidi->dev);
        return 0;
}

static int snd_rawmidi_dev_free(struct snd_device *device)
{
        struct snd_rawmidi *rmidi = device->device_data;

        return snd_rawmidi_free(rmidi);
}

#if IS_ENABLED(CONFIG_SND_SEQUENCER)
static void snd_rawmidi_dev_seq_free(struct snd_seq_device *device)
{
        struct snd_rawmidi *rmidi = device->private_data;

        rmidi->seq_dev = NULL;
}
#endif

static int snd_rawmidi_dev_register(struct snd_device *device)
{
        int err;
        struct snd_info_entry *entry;
        char name[16];
        struct snd_rawmidi *rmidi = device->device_data;

        if (rmidi->device >= SNDRV_RAWMIDI_DEVICES)
                return -ENOMEM;
        err = 0;
        mutex_lock(&register_mutex);
        if (snd_rawmidi_search(rmidi->card, rmidi->device))
                err = -EBUSY;
        else
                list_add_tail(&rmidi->list, &snd_rawmidi_devices);
        mutex_unlock(&register_mutex);
        if (err < 0)
                return err;

        err = snd_register_device(SNDRV_DEVICE_TYPE_RAWMIDI,
                                  rmidi->card, rmidi->device,
                                  &snd_rawmidi_f_ops, rmidi, &rmidi->dev);
        if (err < 0) {
                rmidi_err(rmidi, "unable to register\n");
                goto error;
        }
        if (rmidi->ops && rmidi->ops->dev_register) {
                err = rmidi->ops->dev_register(rmidi);
                if (err < 0)
                        goto error_unregister;
        }
#ifdef CONFIG_SND_OSSEMUL
        rmidi->ossreg = 0;
        if ((int)rmidi->device == midi_map[rmidi->card->number]) {
                if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
                                            rmidi->card, 0, &snd_rawmidi_f_ops,
                                            rmidi) < 0) {
                        rmidi_err(rmidi,
                                  "unable to register OSS rawmidi device %i:%i\n",
                                  rmidi->card->number, 0);
                } else {
                        rmidi->ossreg++;
#ifdef SNDRV_OSS_INFO_DEV_MIDI
                        snd_oss_info_register(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number, rmidi->name);
#endif
                }
        }
        if ((int)rmidi->device == amidi_map[rmidi->card->number]) {
                if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
                                            rmidi->card, 1, &snd_rawmidi_f_ops,
                                            rmidi) < 0) {
                        rmidi_err(rmidi,
                                  "unable to register OSS rawmidi device %i:%i\n",
                                  rmidi->card->number, 1);
                } else {
                        rmidi->ossreg++;
                }
        }
#endif /* CONFIG_SND_OSSEMUL */
        sprintf(name, "midi%d", rmidi->device);
        entry = snd_info_create_card_entry(rmidi->card, name, rmidi->card->proc_root);
        if (entry) {
                entry->private_data = rmidi;
                entry->c.text.read = snd_rawmidi_proc_info_read;
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        rmidi->proc_entry = entry;
#if IS_ENABLED(CONFIG_SND_SEQUENCER)
        if (!rmidi->ops || !rmidi->ops->dev_register) { /* own registration mechanism */
                if (snd_seq_device_new(rmidi->card, rmidi->device, SNDRV_SEQ_DEV_ID_MIDISYNTH, 0, &rmidi->seq_dev) >= 0) {
                        rmidi->seq_dev->private_data = rmidi;
                        rmidi->seq_dev->private_free = snd_rawmidi_dev_seq_free;
                        sprintf(rmidi->seq_dev->name, "MIDI %d-%d", rmidi->card->number, rmidi->device);
                        snd_device_register(rmidi->card, rmidi->seq_dev);
                }
        }
#endif
        return 0;

 error_unregister:
        snd_unregister_device(&rmidi->dev);
 error:
        mutex_lock(&register_mutex);
        list_del(&rmidi->list);
        mutex_unlock(&register_mutex);
        return err;
}

static int snd_rawmidi_dev_disconnect(struct snd_device *device)
{
        struct snd_rawmidi *rmidi = device->device_data;
        int dir;

        mutex_lock(&register_mutex);
        mutex_lock(&rmidi->open_mutex);
        wake_up(&rmidi->open_wait);
        list_del_init(&rmidi->list);
        for (dir = 0; dir < 2; dir++) {
                struct snd_rawmidi_substream *s;

                list_for_each_entry(s, &rmidi->streams[dir].substreams, list) {
                        if (s->runtime)
                                wake_up(&s->runtime->sleep);
                }
        }

#ifdef CONFIG_SND_OSSEMUL
        if (rmidi->ossreg) {
                if ((int)rmidi->device == midi_map[rmidi->card->number]) {
                        snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 0);
#ifdef SNDRV_OSS_INFO_DEV_MIDI
                        snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number);
#endif
                }
                if ((int)rmidi->device == amidi_map[rmidi->card->number])
                        snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 1);
                rmidi->ossreg = 0;
        }
#endif /* CONFIG_SND_OSSEMUL */
        snd_unregister_device(&rmidi->dev);
        mutex_unlock(&rmidi->open_mutex);
        mutex_unlock(&register_mutex);
        return 0;
}

/**
 * snd_rawmidi_set_ops - set the rawmidi operators
 * @rmidi: the rawmidi instance
 * @stream: the stream direction, SNDRV_RAWMIDI_STREAM_XXX
 * @ops: the operator table
 *

 * Sets the rawmidi operators for the given stream direction.
 */
void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
                         const struct snd_rawmidi_ops *ops)
{
        struct snd_rawmidi_substream *substream;

        list_for_each_entry(substream, &rmidi->streams[stream].substreams, list)
                substream->ops = ops;
}
EXPORT_SYMBOL(snd_rawmidi_set_ops);

/*
 *  ENTRY functions
 */

static int __init alsa_rawmidi_init(void)
{

        snd_ctl_register_ioctl(snd_rawmidi_control_ioctl);
        snd_ctl_register_ioctl_compat(snd_rawmidi_control_ioctl);
#ifdef CONFIG_SND_OSSEMUL
        { int i;
        /* check device map table */
        for (i = 0; i < SNDRV_CARDS; i++) {
                if (midi_map[i] < 0 || midi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
                        pr_err("ALSA: rawmidi: invalid midi_map[%d] = %d\n",
                               i, midi_map[i]);
                        midi_map[i] = 0;
                }
                if (amidi_map[i] < 0 || amidi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
                        pr_err("ALSA: rawmidi: invalid amidi_map[%d] = %d\n",
                               i, amidi_map[i]);
                        amidi_map[i] = 1;
                }
        }
        }
#endif /* CONFIG_SND_OSSEMUL */
        return 0;
}

static void __exit alsa_rawmidi_exit(void)
{
        snd_ctl_unregister_ioctl(snd_rawmidi_control_ioctl);
        snd_ctl_unregister_ioctl_compat(snd_rawmidi_control_ioctl);
}

module_init(alsa_rawmidi_init)
module_exit(alsa_rawmidi_exit)