// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Soundfont generic routines.
 *      It is intended that these should be used by any driver that is willing
 *      to accept soundfont patches.
 *
 *  Copyright (C) 1999 Steve Ratcliffe
 *  Copyright (c) 1999-2000 Takashi Iwai <tiwai@suse.de>
 */
/*
 * Deal with reading in of a soundfont.  Code follows the OSS way
 * of doing things so that the old sfxload utility can be used.
 * Everything may change when there is an alsa way of doing things.
 */
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/soundfont.h>
#include <sound/seq_oss_legacy.h>

/* Prototypes for static functions */

static int open_patch(struct snd_sf_list *sflist, const char __user *data,
                      int count, int client);
static struct snd_soundfont *newsf(struct snd_sf_list *sflist, int type, char *name);
static int is_identical_font(struct snd_soundfont *sf, int type, unsigned char *name);
static int close_patch(struct snd_sf_list *sflist);
static int probe_data(struct snd_sf_list *sflist, int sample_id);
static void set_zone_counter(struct snd_sf_list *sflist,
                             struct snd_soundfont *sf, struct snd_sf_zone *zp);
static struct snd_sf_zone *sf_zone_new(struct snd_sf_list *sflist,
                                       struct snd_soundfont *sf);
static void set_sample_counter(struct snd_sf_list *sflist,
                               struct snd_soundfont *sf, struct snd_sf_sample *sp);
static struct snd_sf_sample *sf_sample_new(struct snd_sf_list *sflist,
                                           struct snd_soundfont *sf);
static void sf_sample_delete(struct snd_sf_list *sflist,
                             struct snd_soundfont *sf, struct snd_sf_sample *sp);
static int load_map(struct snd_sf_list *sflist, const void __user *data, int count);
static int load_info(struct snd_sf_list *sflist, const void __user *data, long count);
static int remove_info(struct snd_sf_list *sflist, struct snd_soundfont *sf,
                       int bank, int instr);
static void init_voice_info(struct soundfont_voice_info *avp);
static void init_voice_parm(struct soundfont_voice_parm *pp);
static struct snd_sf_sample *set_sample(struct snd_soundfont *sf,
                                        struct soundfont_voice_info *avp);
static struct snd_sf_sample *find_sample(struct snd_soundfont *sf, int sample_id);
static int load_data(struct snd_sf_list *sflist, const void __user *data, long count);
static void rebuild_presets(struct snd_sf_list *sflist);
static void add_preset(struct snd_sf_list *sflist, struct snd_sf_zone *cur);
static void delete_preset(struct snd_sf_list *sflist, struct snd_sf_zone *zp);
static struct snd_sf_zone *search_first_zone(struct snd_sf_list *sflist,
                                             int bank, int preset, int key);
static int search_zones(struct snd_sf_list *sflist, int *notep, int vel,
                        int preset, int bank, struct snd_sf_zone **table,
                        int max_layers, int level);
static int get_index(int bank, int instr, int key);
static void snd_sf_init(struct snd_sf_list *sflist);
static void snd_sf_clear(struct snd_sf_list *sflist);

/*
 * lock access to sflist
 */
static void
lock_preset(struct snd_sf_list *sflist)
{
        unsigned long flags;
        mutex_lock(&sflist->presets_mutex);
        spin_lock_irqsave(&sflist->lock, flags);
        sflist->presets_locked = 1;
        spin_unlock_irqrestore(&sflist->lock, flags);
}


/*
 * remove lock
 */
static void
unlock_preset(struct snd_sf_list *sflist)
{
        unsigned long flags;
        spin_lock_irqsave(&sflist->lock, flags);
        sflist->presets_locked = 0;
        spin_unlock_irqrestore(&sflist->lock, flags);
        mutex_unlock(&sflist->presets_mutex);
}


/*
 * close the patch if the patch was opened by this client.
 */
int
snd_soundfont_close_check(struct snd_sf_list *sflist, int client)
{
        unsigned long flags;
        spin_lock_irqsave(&sflist->lock, flags);
        if (sflist->open_client == client)  {
                spin_unlock_irqrestore(&sflist->lock, flags);
                return close_patch(sflist);
        }
        spin_unlock_irqrestore(&sflist->lock, flags);
        return 0;
}


/*
 * Deal with a soundfont patch.  Any driver could use these routines
 * although it was designed for the AWE64.
 *
 * The sample_write and callargs pararameters allow a callback into
 * the actual driver to write sample data to the board or whatever
 * it wants to do with it.
 */
int
snd_soundfont_load(struct snd_sf_list *sflist, const void __user *data,
                   long count, int client)
{
        struct soundfont_patch_info patch;
        unsigned long flags;
        int  rc;

        if (count < (long)sizeof(patch)) {
                snd_printk(KERN_ERR "patch record too small %ld\n", count);
                return -EINVAL;
        }
        if (copy_from_user(&patch, data, sizeof(patch)))
                return -EFAULT;

        count -= sizeof(patch);
        data += sizeof(patch);

        if (patch.key != SNDRV_OSS_SOUNDFONT_PATCH) {
                snd_printk(KERN_ERR "The wrong kind of patch %x\n", patch.key);
                return -EINVAL;
        }
        if (count < patch.len) {
                snd_printk(KERN_ERR "Patch too short %ld, need %d\n",
                           count, patch.len);
                return -EINVAL;
        }
        if (patch.len < 0) {
                snd_printk(KERN_ERR "poor length %d\n", patch.len);
                return -EINVAL;
        }

        if (patch.type == SNDRV_SFNT_OPEN_PATCH) {
                /* grab sflist to open */
                lock_preset(sflist);
                rc = open_patch(sflist, data, count, client);
                unlock_preset(sflist);
                return rc;
        }

        /* check if other client already opened patch */
        spin_lock_irqsave(&sflist->lock, flags);
        if (sflist->open_client != client) {
                spin_unlock_irqrestore(&sflist->lock, flags);
                return -EBUSY;
        }
        spin_unlock_irqrestore(&sflist->lock, flags);

        lock_preset(sflist);
        rc = -EINVAL;
        switch (patch.type) {
        case SNDRV_SFNT_LOAD_INFO:
                rc = load_info(sflist, data, count);
                break;
        case SNDRV_SFNT_LOAD_DATA:
                rc = load_data(sflist, data, count);
                break;
        case SNDRV_SFNT_CLOSE_PATCH:
                rc = close_patch(sflist);
                break;
        case SNDRV_SFNT_REPLACE_DATA:
                /*rc = replace_data(&patch, data, count);*/
                break;
        case SNDRV_SFNT_MAP_PRESET:
                rc = load_map(sflist, data, count);
                break;
        case SNDRV_SFNT_PROBE_DATA:
                rc = probe_data(sflist, patch.optarg);
                break;
        case SNDRV_SFNT_REMOVE_INFO:
                /* patch must be opened */
                if (!sflist->currsf) {
                        snd_printk(KERN_ERR "soundfont: remove_info: "
                                   "patch not opened\n");
                        rc = -EINVAL;
                } else {
                        int bank, instr;
                        bank = ((unsigned short)patch.optarg >> 8) & 0xff;
                        instr = (unsigned short)patch.optarg & 0xff;
                        if (! remove_info(sflist, sflist->currsf, bank, instr))
                                rc = -EINVAL;
                        else
                                rc = 0;
                }
                break;
        }
        unlock_preset(sflist);

        return rc;
}


/* check if specified type is special font (GUS or preset-alias) */
static inline int
is_special_type(int type)
{
        type &= 0x0f;
        return (type == SNDRV_SFNT_PAT_TYPE_GUS ||
                type == SNDRV_SFNT_PAT_TYPE_MAP);
}


/* open patch; create sf list */
static int
open_patch(struct snd_sf_list *sflist, const char __user *data,
           int count, int client)
{
        struct soundfont_open_parm parm;
        struct snd_soundfont *sf;
        unsigned long flags;

        spin_lock_irqsave(&sflist->lock, flags);
        if (sflist->open_client >= 0 || sflist->currsf) {
                spin_unlock_irqrestore(&sflist->lock, flags);
                return -EBUSY;
        }
        spin_unlock_irqrestore(&sflist->lock, flags);

        if (copy_from_user(&parm, data, sizeof(parm)))
                return -EFAULT;

        if (is_special_type(parm.type)) {
                parm.type |= SNDRV_SFNT_PAT_SHARED;
                sf = newsf(sflist, parm.type, NULL);
        } else 
                sf = newsf(sflist, parm.type, parm.name);
        if (sf == NULL) {
                return -ENOMEM;
        }

        spin_lock_irqsave(&sflist->lock, flags);
        sflist->open_client = client;
        sflist->currsf = sf;
        spin_unlock_irqrestore(&sflist->lock, flags);

        return 0;
}

/*
 * Allocate a new soundfont structure.
 */
static struct snd_soundfont *
newsf(struct snd_sf_list *sflist, int type, char *name)
{
        struct snd_soundfont *sf;

        /* check the shared fonts */
        if (type & SNDRV_SFNT_PAT_SHARED) {
                for (sf = sflist->fonts; sf; sf = sf->next) {
                        if (is_identical_font(sf, type, name)) {
                                return sf;
                        }
                }
        }

        /* not found -- create a new one */
        sf = kzalloc(sizeof(*sf), GFP_KERNEL);
        if (sf == NULL)
                return NULL;
        sf->id = sflist->fonts_size;
        sflist->fonts_size++;

        /* prepend this record */
        sf->next = sflist->fonts;
        sflist->fonts = sf;

        sf->type = type;
        sf->zones = NULL;
        sf->samples = NULL;
        if (name)
                memcpy(sf->name, name, SNDRV_SFNT_PATCH_NAME_LEN);

        return sf;
}

/* check if the given name matches to the existing list */
static int
is_identical_font(struct snd_soundfont *sf, int type, unsigned char *name)
{
        return ((sf->type & SNDRV_SFNT_PAT_SHARED) &&
                (sf->type & 0x0f) == (type & 0x0f) &&
                (name == NULL ||
                 memcmp(sf->name, name, SNDRV_SFNT_PATCH_NAME_LEN) == 0));
}

/*
 * Close the current patch.
 */
static int
close_patch(struct snd_sf_list *sflist)
{
        unsigned long flags;

        spin_lock_irqsave(&sflist->lock, flags);
        sflist->currsf = NULL;
        sflist->open_client = -1;
        spin_unlock_irqrestore(&sflist->lock, flags);

        rebuild_presets(sflist);

        return 0;

}

/* probe sample in the current list -- nothing to be loaded */
static int
probe_data(struct snd_sf_list *sflist, int sample_id)
{
        /* patch must be opened */
        if (sflist->currsf) {
                /* search the specified sample by optarg */
                if (find_sample(sflist->currsf, sample_id))
                        return 0;
        }
        return -EINVAL;
}

/*
 * increment zone counter
 */
static void
set_zone_counter(struct snd_sf_list *sflist, struct snd_soundfont *sf,
                 struct snd_sf_zone *zp)
{
        zp->counter = sflist->zone_counter++;
        if (sf->type & SNDRV_SFNT_PAT_LOCKED)
                sflist->zone_locked = sflist->zone_counter;
}

/*
 * allocate a new zone record
 */
static struct snd_sf_zone *
sf_zone_new(struct snd_sf_list *sflist, struct snd_soundfont *sf)
{
        struct snd_sf_zone *zp;

        if ((zp = kzalloc(sizeof(*zp), GFP_KERNEL)) == NULL)
                return NULL;
        zp->next = sf->zones;
        sf->zones = zp;

        init_voice_info(&zp->v);

        set_zone_counter(sflist, sf, zp);
        return zp;
}


/*
 * increment sample counter
 */
static void
set_sample_counter(struct snd_sf_list *sflist, struct snd_soundfont *sf,
                   struct snd_sf_sample *sp)
{
        sp->counter = sflist->sample_counter++;
        if (sf->type & SNDRV_SFNT_PAT_LOCKED)
                sflist->sample_locked = sflist->sample_counter;
}

/*
 * allocate a new sample list record
 */
static struct snd_sf_sample *
sf_sample_new(struct snd_sf_list *sflist, struct snd_soundfont *sf)
{
        struct snd_sf_sample *sp;

        if ((sp = kzalloc(sizeof(*sp), GFP_KERNEL)) == NULL)
                return NULL;

        sp->next = sf->samples;
        sf->samples = sp;

        set_sample_counter(sflist, sf, sp);
        return sp;
}

/*
 * delete sample list -- this is an exceptional job.
 * only the last allocated sample can be deleted.
 */
static void
sf_sample_delete(struct snd_sf_list *sflist, struct snd_soundfont *sf,
                 struct snd_sf_sample *sp)
{
        /* only last sample is accepted */
        if (sp == sf->samples) {
                sf->samples = sp->next;
                kfree(sp);
        }
}


/* load voice map */
static int
load_map(struct snd_sf_list *sflist, const void __user *data, int count)
{
        struct snd_sf_zone *zp, *prevp;
        struct snd_soundfont *sf;
        struct soundfont_voice_map map;

        /* get the link info */
        if (count < (int)sizeof(map))
                return -EINVAL;
        if (copy_from_user(&map, data, sizeof(map)))
                return -EFAULT;

        if (map.map_instr < 0 || map.map_instr >= SF_MAX_INSTRUMENTS)
                return -EINVAL;
        
        sf = newsf(sflist, SNDRV_SFNT_PAT_TYPE_MAP|SNDRV_SFNT_PAT_SHARED, NULL);
        if (sf == NULL)
                return -ENOMEM;

        prevp = NULL;
        for (zp = sf->zones; zp; prevp = zp, zp = zp->next) {
                if (zp->mapped &&
                    zp->instr == map.map_instr &&
                    zp->bank == map.map_bank &&
                    zp->v.low == map.map_key &&
                    zp->v.start == map.src_instr &&
                    zp->v.end == map.src_bank &&
                    zp->v.fixkey == map.src_key) {
                        /* the same mapping is already present */
                        /* relink this record to the link head */
                        if (prevp) {
                                prevp->next = zp->next;
                                zp->next = sf->zones;
                                sf->zones = zp;
                        }
                        /* update the counter */
                        set_zone_counter(sflist, sf, zp);
                        return 0;
                }
        }

        /* create a new zone */
        if ((zp = sf_zone_new(sflist, sf)) == NULL)
                return -ENOMEM;

        zp->bank = map.map_bank;
        zp->instr = map.map_instr;
        zp->mapped = 1;
        if (map.map_key >= 0) {
                zp->v.low = map.map_key;
                zp->v.high = map.map_key;
        }
        zp->v.start = map.src_instr;
        zp->v.end = map.src_bank;
        zp->v.fixkey = map.src_key;
        zp->v.sf_id = sf->id;

        add_preset(sflist, zp);

        return 0;
}


/* remove the present instrument layers */
static int
remove_info(struct snd_sf_list *sflist, struct snd_soundfont *sf,
            int bank, int instr)
{
        struct snd_sf_zone *prev, *next, *p;
        int removed = 0;

        prev = NULL;
        for (p = sf->zones; p; p = next) {
                next = p->next;
                if (! p->mapped &&
                    p->bank == bank && p->instr == instr) {
                        /* remove this layer */
                        if (prev)
                                prev->next = next;
                        else
                                sf->zones = next;
                        removed++;
                        kfree(p);
                } else
                        prev = p;
        }
        if (removed)
                rebuild_presets(sflist);
        return removed;
}


/*
 * Read an info record from the user buffer and save it on the current
 * open soundfont.
 */
static int
load_info(struct snd_sf_list *sflist, const void __user *data, long count)
{
        struct snd_soundfont *sf;
        struct snd_sf_zone *zone;
        struct soundfont_voice_rec_hdr hdr;
        int i;

        /* patch must be opened */
        if ((sf = sflist->currsf) == NULL)
                return -EINVAL;

        if (is_special_type(sf->type))
                return -EINVAL;

        if (count < (long)sizeof(hdr)) {
                printk(KERN_ERR "Soundfont error: invalid patch zone length\n");
                return -EINVAL;
        }
        if (copy_from_user((char*)&hdr, data, sizeof(hdr)))
                return -EFAULT;
        
        data += sizeof(hdr);
        count -= sizeof(hdr);

        if (hdr.nvoices <= 0 || hdr.nvoices >= 100) {
                printk(KERN_ERR "Soundfont error: Illegal voice number %d\n",
                       hdr.nvoices);
                return -EINVAL;
        }

        if (count < (long)sizeof(struct soundfont_voice_info) * hdr.nvoices) {
                printk(KERN_ERR "Soundfont Error: "
                       "patch length(%ld) is smaller than nvoices(%d)\n",
                       count, hdr.nvoices);
                return -EINVAL;
        }

        switch (hdr.write_mode) {
        case SNDRV_SFNT_WR_EXCLUSIVE:
                /* exclusive mode - if the instrument already exists,
                   return error */
                for (zone = sf->zones; zone; zone = zone->next) {
                        if (!zone->mapped &&
                            zone->bank == hdr.bank &&
                            zone->instr == hdr.instr)
                                return -EINVAL;
                }
                break;
        case SNDRV_SFNT_WR_REPLACE:
                /* replace mode - remove the instrument if it already exists */
                remove_info(sflist, sf, hdr.bank, hdr.instr);
                break;
        }

        for (i = 0; i < hdr.nvoices; i++) {
                struct snd_sf_zone tmpzone;

                /* copy awe_voice_info parameters */
                if (copy_from_user(&tmpzone.v, data, sizeof(tmpzone.v))) {
                        return -EFAULT;
                }

                data += sizeof(tmpzone.v);
                count -= sizeof(tmpzone.v);

                tmpzone.bank = hdr.bank;
                tmpzone.instr = hdr.instr;
                tmpzone.mapped = 0;
                tmpzone.v.sf_id = sf->id;
                if (tmpzone.v.mode & SNDRV_SFNT_MODE_INIT_PARM)
                        init_voice_parm(&tmpzone.v.parm);

                /* create a new zone */
                if ((zone = sf_zone_new(sflist, sf)) == NULL) {
                        return -ENOMEM;
                }

                /* copy the temporary data */
                zone->bank = tmpzone.bank;
                zone->instr = tmpzone.instr;
                zone->v = tmpzone.v;

                /* look up the sample */
                zone->sample = set_sample(sf, &zone->v);
        }

        return 0;
}


/* initialize voice_info record */
static void
init_voice_info(struct soundfont_voice_info *avp)
{
        memset(avp, 0, sizeof(*avp));

        avp->root = 60;
        avp->high = 127;
        avp->velhigh = 127;
        avp->fixkey = -1;
        avp->fixvel = -1;
        avp->fixpan = -1;
        avp->pan = -1;
        avp->amplitude = 127;
        avp->scaleTuning = 100;

        init_voice_parm(&avp->parm);
}

/* initialize voice_parm record:
 * Env1/2: delay=0, attack=0, hold=0, sustain=0, decay=0, release=0.
 * Vibrato and Tremolo effects are zero.
 * Cutoff is maximum.
 * Chorus and Reverb effects are zero.
 */
static void
init_voice_parm(struct soundfont_voice_parm *pp)
{
        memset(pp, 0, sizeof(*pp));

        pp->moddelay = 0x8000;
        pp->modatkhld = 0x7f7f;
        pp->moddcysus = 0x7f7f;
        pp->modrelease = 0x807f;

        pp->voldelay = 0x8000;
        pp->volatkhld = 0x7f7f;
        pp->voldcysus = 0x7f7f;
        pp->volrelease = 0x807f;

        pp->lfo1delay = 0x8000;
        pp->lfo2delay = 0x8000;

        pp->cutoff = 0xff;
}       

/* search the specified sample */
static struct snd_sf_sample *
set_sample(struct snd_soundfont *sf, struct soundfont_voice_info *avp)
{
        struct snd_sf_sample *sample;

        sample = find_sample(sf, avp->sample);
        if (sample == NULL)
                return NULL;

        /* add in the actual sample offsets:
         * The voice_info addresses define only the relative offset
         * from sample pointers.  Here we calculate the actual DRAM
         * offset from sample pointers.
         */
        avp->start += sample->v.start;
        avp->end += sample->v.end;
        avp->loopstart += sample->v.loopstart;
        avp->loopend += sample->v.loopend;

        /* copy mode flags */
        avp->sample_mode = sample->v.mode_flags;

        return sample;
}

/* find the sample pointer with the given id in the soundfont */
static struct snd_sf_sample *
find_sample(struct snd_soundfont *sf, int sample_id)
{
        struct snd_sf_sample *p;

        if (sf == NULL)
                return NULL;

        for (p = sf->samples; p; p = p->next) {
                if (p->v.sample == sample_id)
                        return p;
        }
        return NULL;
}


/*
 * Load sample information, this can include data to be loaded onto
 * the soundcard.  It can also just be a pointer into soundcard ROM.
 * If there is data it will be written to the soundcard via the callback
 * routine.
 */
static int
load_data(struct snd_sf_list *sflist, const void __user *data, long count)
{
        struct snd_soundfont *sf;
        struct soundfont_sample_info sample_info;
        struct snd_sf_sample *sp;
        long off;

        /* patch must be opened */
        if ((sf = sflist->currsf) == NULL)
                return -EINVAL;

        if (is_special_type(sf->type))
                return -EINVAL;

        if (copy_from_user(&sample_info, data, sizeof(sample_info)))
                return -EFAULT;

        off = sizeof(sample_info);

        if (sample_info.size != (count-off)/2)
                return -EINVAL;

        /* Check for dup */
        if (find_sample(sf, sample_info.sample)) {
                /* if shared sample, skip this data */
                if (sf->type & SNDRV_SFNT_PAT_SHARED)
                        return 0;
                return -EINVAL;
        }

        /* Allocate a new sample structure */
        if ((sp = sf_sample_new(sflist, sf)) == NULL)
                return -ENOMEM;

        sp->v = sample_info;
        sp->v.sf_id = sf->id;
        sp->v.dummy = 0;
        sp->v.truesize = sp->v.size;

        /*
         * If there is wave data then load it.
         */
        if (sp->v.size > 0) {
                int  rc;
                rc = sflist->callback.sample_new
                        (sflist->callback.private_data, sp, sflist->memhdr,
                         data + off, count - off);
                if (rc < 0) {
                        sf_sample_delete(sflist, sf, sp);
                        return rc;
                }
                sflist->mem_used += sp->v.truesize;
        }

        return count;
}


/* log2_tbl[i] = log2(i+128) * 0x10000 */
static int log_tbl[129] = {
        0x70000, 0x702df, 0x705b9, 0x7088e, 0x70b5d, 0x70e26, 0x710eb, 0x713aa,
        0x71663, 0x71918, 0x71bc8, 0x71e72, 0x72118, 0x723b9, 0x72655, 0x728ed,
        0x72b80, 0x72e0e, 0x73098, 0x7331d, 0x7359e, 0x7381b, 0x73a93, 0x73d08,
        0x73f78, 0x741e4, 0x7444c, 0x746b0, 0x74910, 0x74b6c, 0x74dc4, 0x75019,
        0x75269, 0x754b6, 0x75700, 0x75946, 0x75b88, 0x75dc7, 0x76002, 0x7623a,
        0x7646e, 0x766a0, 0x768cd, 0x76af8, 0x76d1f, 0x76f43, 0x77164, 0x77382,
        0x7759d, 0x777b4, 0x779c9, 0x77bdb, 0x77dea, 0x77ff5, 0x781fe, 0x78404,
        0x78608, 0x78808, 0x78a06, 0x78c01, 0x78df9, 0x78fef, 0x791e2, 0x793d2,
        0x795c0, 0x797ab, 0x79993, 0x79b79, 0x79d5d, 0x79f3e, 0x7a11d, 0x7a2f9,
        0x7a4d3, 0x7a6ab, 0x7a880, 0x7aa53, 0x7ac24, 0x7adf2, 0x7afbe, 0x7b188,
        0x7b350, 0x7b515, 0x7b6d8, 0x7b899, 0x7ba58, 0x7bc15, 0x7bdd0, 0x7bf89,
        0x7c140, 0x7c2f5, 0x7c4a7, 0x7c658, 0x7c807, 0x7c9b3, 0x7cb5e, 0x7cd07,
        0x7ceae, 0x7d053, 0x7d1f7, 0x7d398, 0x7d538, 0x7d6d6, 0x7d872, 0x7da0c,
        0x7dba4, 0x7dd3b, 0x7ded0, 0x7e063, 0x7e1f4, 0x7e384, 0x7e512, 0x7e69f,
        0x7e829, 0x7e9b3, 0x7eb3a, 0x7ecc0, 0x7ee44, 0x7efc7, 0x7f148, 0x7f2c8,
        0x7f446, 0x7f5c2, 0x7f73d, 0x7f8b7, 0x7fa2f, 0x7fba5, 0x7fd1a, 0x7fe8d,
        0x80000,
};

/* convert from linear to log value
 *
 * conversion: value = log2(amount / base) * ratio
 *
 * argument:
 *   amount = linear value (unsigned, 32bit max)
 *   offset = base offset (:= log2(base) * 0x10000)
 *   ratio = division ratio
 *
 */
int
snd_sf_linear_to_log(unsigned int amount, int offset, int ratio)
{
        int v;
        int s, low, bit;
        
        if (amount < 2)
                return 0;
        for (bit = 0; ! (amount & 0x80000000L); bit++)
                amount <<= 1;
        s = (amount >> 24) & 0x7f;
        low = (amount >> 16) & 0xff;
        /* linear approxmimation by lower 8 bit */
        v = (log_tbl[s + 1] * low + log_tbl[s] * (0x100 - low)) >> 8;
        v -= offset;
        v = (v * ratio) >> 16;
        v += (24 - bit) * ratio;
        return v;
}

EXPORT_SYMBOL(snd_sf_linear_to_log);


#define OFFSET_MSEC             653117          /* base = 1000 */
#define OFFSET_ABSCENT          851781          /* base = 8176 */
#define OFFSET_SAMPLERATE       1011119         /* base = 44100 */

#define ABSCENT_RATIO           1200
#define TIMECENT_RATIO          1200
#define SAMPLERATE_RATIO        4096

/*
 * mHz to abscent
 * conversion: abscent = log2(MHz / 8176) * 1200
 */
static int
freq_to_note(int mhz)
{
        return snd_sf_linear_to_log(mhz, OFFSET_ABSCENT, ABSCENT_RATIO);
}

/* convert Hz to AWE32 rate offset:
 * sample pitch offset for the specified sample rate
 * rate=44100 is no offset, each 4096 is 1 octave (twice).
 * eg, when rate is 22050, this offset becomes -4096.
 *
 * conversion: offset = log2(Hz / 44100) * 4096
 */
static int
calc_rate_offset(int hz)
{
        return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
}


/* calculate GUS envelope time */
static int
calc_gus_envelope_time(int rate, int start, int end)
{
        int r, p, t;
        r = (3 - ((rate >> 6) & 3)) * 3;
        p = rate & 0x3f;
        if (!p)
                p = 1;
        t = end - start;
        if (t < 0) t = -t;
        if (13 > r)
                t = t << (13 - r);
        else
                t = t >> (r - 13);
        return (t * 10) / (p * 441);
}

/* convert envelope time parameter to soundfont parameters */

/* attack & decay/release time table (msec) */
static short attack_time_tbl[128] = {
32767, 32767, 5989, 4235, 2994, 2518, 2117, 1780, 1497, 1373, 1259, 1154, 1058, 970, 890, 816,
707, 691, 662, 634, 607, 581, 557, 533, 510, 489, 468, 448, 429, 411, 393, 377,
361, 345, 331, 317, 303, 290, 278, 266, 255, 244, 234, 224, 214, 205, 196, 188,
180, 172, 165, 158, 151, 145, 139, 133, 127, 122, 117, 112, 107, 102, 98, 94,
90, 86, 82, 79, 75, 72, 69, 66, 63, 61, 58, 56, 53, 51, 49, 47,
45, 43, 41, 39, 37, 36, 34, 33, 31, 30, 29, 28, 26, 25, 24, 23,
22, 21, 20, 19, 19, 18, 17, 16, 16, 15, 15, 14, 13, 13, 12, 12,
11, 11, 10, 10, 10, 9, 9, 8, 8, 8, 8, 7, 7, 7, 6, 0,
};

static short decay_time_tbl[128] = {
32767, 32767, 22614, 15990, 11307, 9508, 7995, 6723, 5653, 5184, 4754, 4359, 3997, 3665, 3361, 3082,
2828, 2765, 2648, 2535, 2428, 2325, 2226, 2132, 2042, 1955, 1872, 1793, 1717, 1644, 1574, 1507,
1443, 1382, 1324, 1267, 1214, 1162, 1113, 1066, 978, 936, 897, 859, 822, 787, 754, 722,
691, 662, 634, 607, 581, 557, 533, 510, 489, 468, 448, 429, 411, 393, 377, 361,
345, 331, 317, 303, 290, 278, 266, 255, 244, 234, 224, 214, 205, 196, 188, 180,
172, 165, 158, 151, 145, 139, 133, 127, 122, 117, 112, 107, 102, 98, 94, 90,
86, 82, 79, 75, 72, 69, 66, 63, 61, 58, 56, 53, 51, 49, 47, 45,
43, 41, 39, 37, 36, 34, 33, 31, 30, 29, 28, 26, 25, 24, 23, 22,
};

/* delay time = 0x8000 - msec/92 */
int
snd_sf_calc_parm_hold(int msec)
{
        int val = (0x7f * 92 - msec) / 92;
        if (val < 1) val = 1;
        if (val >= 126) val = 126;
        return val;
}

/* search an index for specified time from given time table */
static int
calc_parm_search(int msec, short *table)
{
        int left = 1, right = 127, mid;
        while (left < right) {
                mid = (left + right) / 2;
                if (msec < (int)table[mid])
                        left = mid + 1;
                else
                        right = mid;
        }
        return left;
}

/* attack time: search from time table */
int
snd_sf_calc_parm_attack(int msec)
{
        return calc_parm_search(msec, attack_time_tbl);
}

/* decay/release time: search from time table */
int
snd_sf_calc_parm_decay(int msec)
{
        return calc_parm_search(msec, decay_time_tbl);
}

int snd_sf_vol_table[128] = {
        255,111,95,86,79,74,70,66,63,61,58,56,54,52,50,49,
        47,46,45,43,42,41,40,39,38,37,36,35,34,34,33,32,
        31,31,30,29,29,28,27,27,26,26,25,24,24,23,23,22,
        22,21,21,21,20,20,19,19,18,18,18,17,17,16,16,16,
        15,15,15,14,14,14,13,13,13,12,12,12,11,11,11,10,
        10,10,10,9,9,9,8,8,8,8,7,7,7,7,6,6,
        6,6,5,5,5,5,5,4,4,4,4,3,3,3,3,3,
        2,2,2,2,2,1,1,1,1,1,0,0,0,0,0,0,
};


#define calc_gus_sustain(val)  (0x7f - snd_sf_vol_table[(val)/2])
#define calc_gus_attenuation(val)       snd_sf_vol_table[(val)/2]

/* load GUS patch */
static int
load_guspatch(struct snd_sf_list *sflist, const char __user *data,
              long count, int client)
{
        struct patch_info patch;
        struct snd_soundfont *sf;
        struct snd_sf_zone *zone;
        struct snd_sf_sample *smp;
        int note, sample_id;
        int rc;

        if (count < (long)sizeof(patch)) {
                snd_printk(KERN_ERR "patch record too small %ld\n", count);
                return -EINVAL;
        }
        if (copy_from_user(&patch, data, sizeof(patch)))
                return -EFAULT;
        
        count -= sizeof(patch);
        data += sizeof(patch);

        sf = newsf(sflist, SNDRV_SFNT_PAT_TYPE_GUS|SNDRV_SFNT_PAT_SHARED, NULL);
        if (sf == NULL)
                return -ENOMEM;
        if ((smp = sf_sample_new(sflist, sf)) == NULL)
                return -ENOMEM;
        sample_id = sflist->sample_counter;
        smp->v.sample = sample_id;
        smp->v.start = 0;
        smp->v.end = patch.len;
        smp->v.loopstart = patch.loop_start;
        smp->v.loopend = patch.loop_end;
        smp->v.size = patch.len;

        /* set up mode flags */
        smp->v.mode_flags = 0;
        if (!(patch.mode & WAVE_16_BITS))
                smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_8BITS;
        if (patch.mode & WAVE_UNSIGNED)
                smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_UNSIGNED;
        smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_NO_BLANK;
        if (!(patch.mode & (WAVE_LOOPING|WAVE_BIDIR_LOOP|WAVE_LOOP_BACK)))
                smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_SINGLESHOT;
        if (patch.mode & WAVE_BIDIR_LOOP)
                smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_BIDIR_LOOP;
        if (patch.mode & WAVE_LOOP_BACK)
                smp->v.mode_flags |= SNDRV_SFNT_SAMPLE_REVERSE_LOOP;

        if (patch.mode & WAVE_16_BITS) {
                /* convert to word offsets */
                smp->v.size /= 2;
                smp->v.end /= 2;
                smp->v.loopstart /= 2;
                smp->v.loopend /= 2;
        }
        /*smp->v.loopend++;*/

        smp->v.dummy = 0;
        smp->v.truesize = 0;
        smp->v.sf_id = sf->id;

        /* set up voice info */
        if ((zone = sf_zone_new(sflist, sf)) == NULL) {
                sf_sample_delete(sflist, sf, smp);

                return -ENOMEM;
        }

        /*
         * load wave data
         */
        if (sflist->callback.sample_new) {
                rc = sflist->callback.sample_new
                        (sflist->callback.private_data, smp, sflist->memhdr,
                         data, count);
                if (rc < 0) {
                        sf_sample_delete(sflist, sf, smp);
                        kfree(zone);
                        return rc;
                }
                /* memory offset is updated after */
        }

        /* update the memory offset here */
        sflist->mem_used += smp->v.truesize;

        zone->v.sample = sample_id; /* the last sample */
        zone->v.rate_offset = calc_rate_offset(patch.base_freq);
        note = freq_to_note(patch.base_note);
        zone->v.root = note / 100;
        zone->v.tune = -(note % 100);
        zone->v.low = (freq_to_note(patch.low_note) + 99) / 100;
        zone->v.high = freq_to_note(patch.high_note) / 100;
        /* panning position; -128 - 127 => 0-127 */
        zone->v.pan = (patch.panning + 128) / 2;
#if 0
        snd_printk(KERN_DEBUG
                   "gus: basefrq=%d (ofs=%d) root=%d,tune=%d, range:%d-%d\n",
                   (int)patch.base_freq, zone->v.rate_offset,
                   zone->v.root, zone->v.tune, zone->v.low, zone->v.high);
#endif

        /* detuning is ignored */
        /* 6points volume envelope */
        if (patch.mode & WAVE_ENVELOPES) {
                int attack, hold, decay, release;
                attack = calc_gus_envelope_time
                        (patch.env_rate[0], 0, patch.env_offset[0]);
                hold = calc_gus_envelope_time
                        (patch.env_rate[1], patch.env_offset[0],
                         patch.env_offset[1]);
                decay = calc_gus_envelope_time
                        (patch.env_rate[2], patch.env_offset[1],
                         patch.env_offset[2]);
                release = calc_gus_envelope_time
                        (patch.env_rate[3], patch.env_offset[1],
                         patch.env_offset[4]);
                release += calc_gus_envelope_time
                        (patch.env_rate[4], patch.env_offset[3],
                         patch.env_offset[4]);
                release += calc_gus_envelope_time
                        (patch.env_rate[5], patch.env_offset[4],
                         patch.env_offset[5]);
                zone->v.parm.volatkhld = 
                        (snd_sf_calc_parm_hold(hold) << 8) |
                        snd_sf_calc_parm_attack(attack);
                zone->v.parm.voldcysus = (calc_gus_sustain(patch.env_offset[2]) << 8) |
                        snd_sf_calc_parm_decay(decay);
                zone->v.parm.volrelease = 0x8000 | snd_sf_calc_parm_decay(release);
                zone->v.attenuation = calc_gus_attenuation(patch.env_offset[0]);
#if 0
                snd_printk(KERN_DEBUG
                           "gus: atkhld=%x, dcysus=%x, volrel=%x, att=%d\n",
                           zone->v.parm.volatkhld,
                           zone->v.parm.voldcysus,
                           zone->v.parm.volrelease,
                           zone->v.attenuation);
#endif
        }

        /* fast release */
        if (patch.mode & WAVE_FAST_RELEASE) {
                zone->v.parm.volrelease = 0x807f;
        }

        /* tremolo effect */
        if (patch.mode & WAVE_TREMOLO) {
                int rate = (patch.tremolo_rate * 1000 / 38) / 42;
                zone->v.parm.tremfrq = ((patch.tremolo_depth / 2) << 8) | rate;
        }
        /* vibrato effect */
        if (patch.mode & WAVE_VIBRATO) {
                int rate = (patch.vibrato_rate * 1000 / 38) / 42;
                zone->v.parm.fm2frq2 = ((patch.vibrato_depth / 6) << 8) | rate;
        }
        
        /* scale_freq, scale_factor, volume, and fractions not implemented */

        if (!(smp->v.mode_flags & SNDRV_SFNT_SAMPLE_SINGLESHOT))
                zone->v.mode = SNDRV_SFNT_MODE_LOOPING;
        else
                zone->v.mode = 0;

        /* append to the tail of the list */
        /*zone->bank = ctrls[AWE_MD_GUS_BANK];*/
        zone->bank = 0;
        zone->instr = patch.instr_no;
        zone->mapped = 0;
        zone->v.sf_id = sf->id;

        zone->sample = set_sample(sf, &zone->v);

        /* rebuild preset now */
        add_preset(sflist, zone);

        return 0;
}

/* load GUS patch */
int
snd_soundfont_load_guspatch(struct snd_sf_list *sflist, const char __user *data,
                            long count, int client)
{
        int rc;
        lock_preset(sflist);
        rc = load_guspatch(sflist, data, count, client);
        unlock_preset(sflist);
        return rc;
}


/*
 * Rebuild the preset table.  This is like a hash table in that it allows
 * quick access to the zone information.  For each preset there are zone
 * structures linked by next_instr and by next_zone.  Former is the whole
 * link for this preset, and latter is the link for zone (i.e. instrument/
 * bank/key combination).
 */
static void
rebuild_presets(struct snd_sf_list *sflist)
{
        struct snd_soundfont *sf;
        struct snd_sf_zone *cur;

        /* clear preset table */
        memset(sflist->presets, 0, sizeof(sflist->presets));

        /* search all fonts and insert each font */
        for (sf = sflist->fonts; sf; sf = sf->next) {
                for (cur = sf->zones; cur; cur = cur->next) {
                        if (! cur->mapped && cur->sample == NULL) {
                                /* try again to search the corresponding sample */
                                cur->sample = set_sample(sf, &cur->v);
                                if (cur->sample == NULL)
                                        continue;
                        }

                        add_preset(sflist, cur);
                }
        }
}


/*
 * add the given zone to preset table
 */
static void
add_preset(struct snd_sf_list *sflist, struct snd_sf_zone *cur)
{
        struct snd_sf_zone *zone;
        int index;

        zone = search_first_zone(sflist, cur->bank, cur->instr, cur->v.low);
        if (zone && zone->v.sf_id != cur->v.sf_id) {
                /* different instrument was already defined */
                struct snd_sf_zone *p;
                /* compare the allocated time */
                for (p = zone; p; p = p->next_zone) {
                        if (p->counter > cur->counter)
                                /* the current is older.. skipped */
                                return;
                }
                /* remove old zones */
                delete_preset(sflist, zone);
                zone = NULL; /* do not forget to clear this! */
        }

        /* prepend this zone */
        if ((index = get_index(cur->bank, cur->instr, cur->v.low)) < 0)
                return;
        cur->next_zone = zone; /* zone link */
        cur->next_instr = sflist->presets[index]; /* preset table link */
        sflist->presets[index] = cur;
}

/*
 * delete the given zones from preset_table
 */
static void
delete_preset(struct snd_sf_list *sflist, struct snd_sf_zone *zp)
{
        int index;
        struct snd_sf_zone *p;

        if ((index = get_index(zp->bank, zp->instr, zp->v.low)) < 0)
                return;
        for (p = sflist->presets[index]; p; p = p->next_instr) {
                while (p->next_instr == zp) {
                        p->next_instr = zp->next_instr;
                        zp = zp->next_zone;
                        if (zp == NULL)
                                return;
                }
        }
}


/*
 * Search matching zones from preset table.
 * The note can be rewritten by preset mapping (alias).
 * The found zones are stored on 'table' array.  max_layers defines
 * the maximum number of elements in this array.
 * This function returns the number of found zones.  0 if not found.
 */
int
snd_soundfont_search_zone(struct snd_sf_list *sflist, int *notep, int vel,
                          int preset, int bank,
                          int def_preset, int def_bank,
                          struct snd_sf_zone **table, int max_layers)
{
        int nvoices;
        unsigned long flags;

        /* this function is supposed to be called atomically,
         * so we check the lock.  if it's busy, just returns 0 to
         * tell the caller the busy state
         */
        spin_lock_irqsave(&sflist->lock, flags);
        if (sflist->presets_locked) {
                spin_unlock_irqrestore(&sflist->lock, flags);
                return 0;
        }
        nvoices = search_zones(sflist, notep, vel, preset, bank,
                               table, max_layers, 0);
        if (! nvoices) {
                if (preset != def_preset || bank != def_bank)
                        nvoices = search_zones(sflist, notep, vel,
                                               def_preset, def_bank,
                                               table, max_layers, 0);
        }
        spin_unlock_irqrestore(&sflist->lock, flags);
        return nvoices;
}


/*
 * search the first matching zone
 */
static struct snd_sf_zone *
search_first_zone(struct snd_sf_list *sflist, int bank, int preset, int key)
{
        int index;
        struct snd_sf_zone *zp;

        if ((index = get_index(bank, preset, key)) < 0)
                return NULL;
        for (zp = sflist->presets[index]; zp; zp = zp->next_instr) {
                if (zp->instr == preset && zp->bank == bank)
                        return zp;
        }
        return NULL;
}


/*
 * search matching zones from sflist.  can be called recursively.
 */
static int
search_zones(struct snd_sf_list *sflist, int *notep, int vel,
             int preset, int bank, struct snd_sf_zone **table,
             int max_layers, int level)
{
        struct snd_sf_zone *zp;
        int nvoices;

        zp = search_first_zone(sflist, bank, preset, *notep);
        nvoices = 0;
        for (; zp; zp = zp->next_zone) {
                if (*notep >= zp->v.low && *notep <= zp->v.high &&
                    vel >= zp->v.vellow && vel <= zp->v.velhigh) {
                        if (zp->mapped) {
                                /* search preset mapping (aliasing) */
                                int key = zp->v.fixkey;
                                preset = zp->v.start;
                                bank = zp->v.end;

                                if (level > 5) /* too deep alias level */
                                        return 0;
                                if (key < 0)
                                        key = *notep;
                                nvoices = search_zones(sflist, &key, vel,
                                                       preset, bank, table,
                                                       max_layers, level + 1);
                                if (nvoices > 0)
                                        *notep = key;
                                break;
                        }
                        table[nvoices++] = zp;
                        if (nvoices >= max_layers)
                                break;
                }
        }

        return nvoices;
}


/* calculate the index of preset table:
 * drums are mapped from 128 to 255 according to its note key.
 * other instruments are mapped from 0 to 127.
 * if the index is out of range, return -1.
 */
static int
get_index(int bank, int instr, int key)
{
        int index;
        if (SF_IS_DRUM_BANK(bank))
                index = key + SF_MAX_INSTRUMENTS;
        else
                index = instr;
        index = index % SF_MAX_PRESETS;
        if (index < 0)
                return -1;
        return index;
}

/*
 * Initialise the sflist structure.
 */
static void
snd_sf_init(struct snd_sf_list *sflist)
{
        memset(sflist->presets, 0, sizeof(sflist->presets));

        sflist->mem_used = 0;
        sflist->currsf = NULL;
        sflist->open_client = -1;
        sflist->fonts = NULL;
        sflist->fonts_size = 0;
        sflist->zone_counter = 0;
        sflist->sample_counter = 0;
        sflist->zone_locked = 0;
        sflist->sample_locked = 0;
}

/*
 * Release all list records
 */
static void
snd_sf_clear(struct snd_sf_list *sflist)
{
        struct snd_soundfont *sf, *nextsf;
        struct snd_sf_zone *zp, *nextzp;
        struct snd_sf_sample *sp, *nextsp;

        for (sf = sflist->fonts; sf; sf = nextsf) {
                nextsf = sf->next;
                for (zp = sf->zones; zp; zp = nextzp) {
                        nextzp = zp->next;
                        kfree(zp);
                }
                for (sp = sf->samples; sp; sp = nextsp) {
                        nextsp = sp->next;
                        if (sflist->callback.sample_free)
                                sflist->callback.sample_free(sflist->callback.private_data,
                                                             sp, sflist->memhdr);
                        kfree(sp);
                }
                kfree(sf);
        }

        snd_sf_init(sflist);
}


/*
 * Create a new sflist structure
 */
struct snd_sf_list *
snd_sf_new(struct snd_sf_callback *callback, struct snd_util_memhdr *hdr)
{
        struct snd_sf_list *sflist;

        if ((sflist = kzalloc(sizeof(*sflist), GFP_KERNEL)) == NULL)
                return NULL;

        mutex_init(&sflist->presets_mutex);
        spin_lock_init(&sflist->lock);
        sflist->memhdr = hdr;

        if (callback)
                sflist->callback = *callback;

        snd_sf_init(sflist);
        return sflist;
}


/*
 * Free everything allocated off the sflist structure.
 */
void
snd_sf_free(struct snd_sf_list *sflist)
{
        if (sflist == NULL)
                return;
        
        lock_preset(sflist);
        if (sflist->callback.sample_reset)
                sflist->callback.sample_reset(sflist->callback.private_data);
        snd_sf_clear(sflist);
        unlock_preset(sflist);

        kfree(sflist);
}

/*
 * Remove all samples
 * The soundcard should be silet before calling this function.
 */
int
snd_soundfont_remove_samples(struct snd_sf_list *sflist)
{
        lock_preset(sflist);
        if (sflist->callback.sample_reset)
                sflist->callback.sample_reset(sflist->callback.private_data);
        snd_sf_clear(sflist);
        unlock_preset(sflist);

        return 0;
}

/*
 * Remove unlocked samples.
 * The soundcard should be silent before calling this function.
 */
int
snd_soundfont_remove_unlocked(struct snd_sf_list *sflist)
{
        struct snd_soundfont *sf;
        struct snd_sf_zone *zp, *nextzp;
        struct snd_sf_sample *sp, *nextsp;

        lock_preset(sflist);

        if (sflist->callback.sample_reset)
                sflist->callback.sample_reset(sflist->callback.private_data);

        /* to be sure */
        memset(sflist->presets, 0, sizeof(sflist->presets));

        for (sf = sflist->fonts; sf; sf = sf->next) {
                for (zp = sf->zones; zp; zp = nextzp) {
                        if (zp->counter < sflist->zone_locked)
                                break;
                        nextzp = zp->next;
                        sf->zones = nextzp;
                        kfree(zp);
                }

                for (sp = sf->samples; sp; sp = nextsp) {
                        if (sp->counter < sflist->sample_locked)
                                break;
                        nextsp = sp->next;
                        sf->samples = nextsp;
                        sflist->mem_used -= sp->v.truesize;
                        if (sflist->callback.sample_free)
                                sflist->callback.sample_free(sflist->callback.private_data,
                                                             sp, sflist->memhdr);
                        kfree(sp);
                }
        }

        sflist->zone_counter = sflist->zone_locked;
        sflist->sample_counter = sflist->sample_locked;

        rebuild_presets(sflist);

        unlock_preset(sflist);
        return 0;
}