snd_pcm_lib_mmap_iomem 1317 include/sound/pcm.h #define snd_pcm_lib_mmap_iomem	NULL
snd_pcm_lib_mmap_iomem 3454 sound/core/pcm_native.c int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream,