Map vmalloc buffer offset to page struct
struct page * snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream * substream, unsigned long offset);
substream
the substream with a buffer allocated by snd_pcm_lib_alloc_vmalloc_buffer
offset
offset in the buffer
This function is to be used as the page callback in the PCM ops.
The page struct, or NULL on failure.