From c3b6bcc292da80ea08a979af177538ffdbbae36b Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 10 May 2012 16:11:15 +0200 Subject: [PATCH] ALSA: hda - Fix concurrent hash accesses The amp and caps hashes aren't protected properly for concurrent accesses. Protect them via a new mutex now. But it can't be so simple as originally thought: since the update of a hash table entry itself might trigger the power-up sequence which again accesses the hash table, we can't cover the whole function simply via mutex. Thus the update part has to be split from the mutex and revalidated. Signed-off-by: Takashi Iwai --- sound/pci/hda/hda_codec.c | 201 +++++++++++++++++++++++--------------- sound/pci/hda/hda_codec.h | 1 + 2 files changed, 121 insertions(+), 81 deletions(-) diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 5e7c4bf83abe..7a621f5986e0 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -1255,6 +1255,7 @@ int /*__devinit*/ snd_hda_codec_new(struct hda_bus *bus, codec->addr = codec_addr; mutex_init(&codec->spdif_mutex); mutex_init(&codec->control_mutex); + mutex_init(&codec->hash_mutex); init_hda_cache(&codec->amp_cache, sizeof(struct hda_amp_info)); init_hda_cache(&codec->cmd_cache, sizeof(struct hda_cache_head)); snd_array_init(&codec->mixers, sizeof(struct hda_nid_item), 32); @@ -1605,6 +1606,60 @@ get_alloc_amp_hash(struct hda_codec *codec, u32 key) return (struct hda_amp_info *)get_alloc_hash(&codec->amp_cache, key); } +/* overwrite the value with the key in the caps hash */ +static int write_caps_hash(struct hda_codec *codec, u32 key, unsigned int val) +{ + struct hda_amp_info *info; + + mutex_lock(&codec->hash_mutex); + info = get_alloc_amp_hash(codec, key); + if (!info) { + mutex_unlock(&codec->hash_mutex); + return -EINVAL; + } + info->amp_caps = val; + info->head.val |= INFO_AMP_CAPS; + mutex_unlock(&codec->hash_mutex); + return 0; +} + +/* query the value from the caps hash; if not found, fetch the current + * value from the given function and store in the hash + */ +static unsigned int +query_caps_hash(struct hda_codec *codec, hda_nid_t nid, int dir, u32 key, + unsigned int (*func)(struct hda_codec *, hda_nid_t, int)) +{ + struct hda_amp_info *info; + unsigned int val; + + mutex_lock(&codec->hash_mutex); + info = get_alloc_amp_hash(codec, key); + if (!info) { + mutex_unlock(&codec->hash_mutex); + return 0; + } + if (!(info->head.val & INFO_AMP_CAPS)) { + mutex_unlock(&codec->hash_mutex); /* for reentrance */ + val = func(codec, nid, dir); + write_caps_hash(codec, key, val); + } else { + val = info->amp_caps; + mutex_unlock(&codec->hash_mutex); + } + return val; +} + +static unsigned int read_amp_cap(struct hda_codec *codec, hda_nid_t nid, + int direction) +{ + if (!(get_wcaps(codec, nid) & AC_WCAP_AMP_OVRD)) + nid = codec->afg; + return snd_hda_param_read(codec, nid, + direction == HDA_OUTPUT ? + AC_PAR_AMP_OUT_CAP : AC_PAR_AMP_IN_CAP); +} + /** * query_amp_caps - query AMP capabilities * @codec: the HD-auio codec @@ -1619,22 +1674,9 @@ get_alloc_amp_hash(struct hda_codec *codec, u32 key) */ u32 query_amp_caps(struct hda_codec *codec, hda_nid_t nid, int direction) { - struct hda_amp_info *info; - - info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, direction, 0)); - if (!info) - return 0; - if (!(info->head.val & INFO_AMP_CAPS)) { - if (!(get_wcaps(codec, nid) & AC_WCAP_AMP_OVRD)) - nid = codec->afg; - info->amp_caps = snd_hda_param_read(codec, nid, - direction == HDA_OUTPUT ? - AC_PAR_AMP_OUT_CAP : - AC_PAR_AMP_IN_CAP); - if (info->amp_caps) - info->head.val |= INFO_AMP_CAPS; - } - return info->amp_caps; + return query_caps_hash(codec, nid, direction, + HDA_HASH_KEY(nid, direction, 0), + read_amp_cap); } EXPORT_SYMBOL_HDA(query_amp_caps); @@ -1654,34 +1696,12 @@ EXPORT_SYMBOL_HDA(query_amp_caps); int snd_hda_override_amp_caps(struct hda_codec *codec, hda_nid_t nid, int dir, unsigned int caps) { - struct hda_amp_info *info; - - info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, dir, 0)); - if (!info) - return -EINVAL; - info->amp_caps = caps; - info->head.val |= INFO_AMP_CAPS; - return 0; + return write_caps_hash(codec, HDA_HASH_KEY(nid, dir, 0), caps); } EXPORT_SYMBOL_HDA(snd_hda_override_amp_caps); -static unsigned int -query_caps_hash(struct hda_codec *codec, hda_nid_t nid, u32 key, - unsigned int (*func)(struct hda_codec *, hda_nid_t)) -{ - struct hda_amp_info *info; - - info = get_alloc_amp_hash(codec, key); - if (!info) - return 0; - if (!info->head.val) { - info->head.val |= INFO_AMP_CAPS; - info->amp_caps = func(codec, nid); - } - return info->amp_caps; -} - -static unsigned int read_pin_cap(struct hda_codec *codec, hda_nid_t nid) +static unsigned int read_pin_cap(struct hda_codec *codec, hda_nid_t nid, + int dir) { return snd_hda_param_read(codec, nid, AC_PAR_PIN_CAP); } @@ -1699,7 +1719,7 @@ static unsigned int read_pin_cap(struct hda_codec *codec, hda_nid_t nid) */ u32 snd_hda_query_pin_caps(struct hda_codec *codec, hda_nid_t nid) { - return query_caps_hash(codec, nid, HDA_HASH_PINCAP_KEY(nid), + return query_caps_hash(codec, nid, 0, HDA_HASH_PINCAP_KEY(nid), read_pin_cap); } EXPORT_SYMBOL_HDA(snd_hda_query_pin_caps); @@ -1717,41 +1737,47 @@ EXPORT_SYMBOL_HDA(snd_hda_query_pin_caps); int snd_hda_override_pin_caps(struct hda_codec *codec, hda_nid_t nid, unsigned int caps) { - struct hda_amp_info *info; - info = get_alloc_amp_hash(codec, HDA_HASH_PINCAP_KEY(nid)); - if (!info) - return -ENOMEM; - info->amp_caps = caps; - info->head.val |= INFO_AMP_CAPS; - return 0; + return write_caps_hash(codec, HDA_HASH_PINCAP_KEY(nid), caps); } EXPORT_SYMBOL_HDA(snd_hda_override_pin_caps); -/* - * read the current volume to info - * if the cache exists, read the cache value. +/* read or sync the hash value with the current value; + * call within hash_mutex */ -static unsigned int get_vol_mute(struct hda_codec *codec, - struct hda_amp_info *info, hda_nid_t nid, - int ch, int direction, int index) +static struct hda_amp_info * +update_amp_hash(struct hda_codec *codec, hda_nid_t nid, int ch, + int direction, int index) { - u32 val, parm; - - if (info->head.val & INFO_AMP_VOL(ch)) - return info->vol[ch]; + struct hda_amp_info *info; + unsigned int parm, val = 0; + bool val_read = false; - parm = ch ? AC_AMP_GET_RIGHT : AC_AMP_GET_LEFT; - parm |= direction == HDA_OUTPUT ? AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT; - parm |= index; - val = snd_hda_codec_read(codec, nid, 0, + retry: + info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, direction, index)); + if (!info) + return NULL; + if (!(info->head.val & INFO_AMP_VOL(ch))) { + if (!val_read) { + mutex_unlock(&codec->hash_mutex); + parm = ch ? AC_AMP_GET_RIGHT : AC_AMP_GET_LEFT; + parm |= direction == HDA_OUTPUT ? + AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT; + parm |= index; + val = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_AMP_GAIN_MUTE, parm); - info->vol[ch] = val & 0xff; - info->head.val |= INFO_AMP_VOL(ch); - return info->vol[ch]; + val &= 0xff; + val_read = true; + mutex_lock(&codec->hash_mutex); + goto retry; + } + info->vol[ch] = val; + info->head.val |= INFO_AMP_VOL(ch); + } + return info; } /* - * write the current volume in info to the h/w and update the cache + * write the current volume in info to the h/w */ static void put_vol_mute(struct hda_codec *codec, struct hda_amp_info *info, hda_nid_t nid, int ch, int direction, int index, @@ -1768,7 +1794,6 @@ static void put_vol_mute(struct hda_codec *codec, struct hda_amp_info *info, else parm |= val; snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_AMP_GAIN_MUTE, parm); - info->vol[ch] = val; } /** @@ -1785,10 +1810,14 @@ int snd_hda_codec_amp_read(struct hda_codec *codec, hda_nid_t nid, int ch, int direction, int index) { struct hda_amp_info *info; - info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, direction, index)); - if (!info) - return 0; - return get_vol_mute(codec, info, nid, ch, direction, index); + unsigned int val = 0; + + mutex_lock(&codec->hash_mutex); + info = update_amp_hash(codec, nid, ch, direction, index); + if (info) + val = info->vol[ch]; + mutex_unlock(&codec->hash_mutex); + return val; } EXPORT_SYMBOL_HDA(snd_hda_codec_amp_read); @@ -1810,15 +1839,23 @@ int snd_hda_codec_amp_update(struct hda_codec *codec, hda_nid_t nid, int ch, { struct hda_amp_info *info; - info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, direction, idx)); - if (!info) - return 0; if (snd_BUG_ON(mask & ~0xff)) mask &= 0xff; val &= mask; - val |= get_vol_mute(codec, info, nid, ch, direction, idx) & ~mask; - if (info->vol[ch] == val) + + mutex_lock(&codec->hash_mutex); + info = update_amp_hash(codec, nid, ch, direction, idx); + if (!info) { + mutex_unlock(&codec->hash_mutex); + return 0; + } + val |= info->vol[ch] & ~mask; + if (info->vol[ch] == val) { + mutex_unlock(&codec->hash_mutex); return 0; + } + info->vol[ch] = val; + mutex_unlock(&codec->hash_mutex); put_vol_mute(codec, info, nid, ch, direction, idx, val); return 1; } @@ -3693,7 +3730,8 @@ unsigned int snd_hda_calc_stream_format(unsigned int rate, } EXPORT_SYMBOL_HDA(snd_hda_calc_stream_format); -static unsigned int get_pcm_param(struct hda_codec *codec, hda_nid_t nid) +static unsigned int get_pcm_param(struct hda_codec *codec, hda_nid_t nid, + int dir) { unsigned int val = 0; if (nid != codec->afg && @@ -3708,11 +3746,12 @@ static unsigned int get_pcm_param(struct hda_codec *codec, hda_nid_t nid) static unsigned int query_pcm_param(struct hda_codec *codec, hda_nid_t nid) { - return query_caps_hash(codec, nid, HDA_HASH_PARPCM_KEY(nid), + return query_caps_hash(codec, nid, 0, HDA_HASH_PARPCM_KEY(nid), get_pcm_param); } -static unsigned int get_stream_param(struct hda_codec *codec, hda_nid_t nid) +static unsigned int get_stream_param(struct hda_codec *codec, hda_nid_t nid, + int dir) { unsigned int streams = snd_hda_param_read(codec, nid, AC_PAR_STREAM); if (!streams || streams == -1) @@ -3724,7 +3763,7 @@ static unsigned int get_stream_param(struct hda_codec *codec, hda_nid_t nid) static unsigned int query_stream_param(struct hda_codec *codec, hda_nid_t nid) { - return query_caps_hash(codec, nid, HDA_HASH_PARSTR_KEY(nid), + return query_caps_hash(codec, nid, 0, HDA_HASH_PARSTR_KEY(nid), get_stream_param); } diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h index fce30b42bc46..29a311b05f2d 100644 --- a/sound/pci/hda/hda_codec.h +++ b/sound/pci/hda/hda_codec.h @@ -827,6 +827,7 @@ struct hda_codec { struct mutex spdif_mutex; struct mutex control_mutex; + struct mutex hash_mutex; struct snd_array spdif_out; unsigned int spdif_in_enable; /* SPDIF input enable? */ const hda_nid_t *slave_dig_outs; /* optional digital out slave widgets */ -- 2.20.1