linux-4.4.1/snd_pcm_lib_default_mmap() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-4.4.1/snd_pcm_lib_default_mmap() へ行く。
  • 1 (2016-05-04 (水) 09:23:04)

参照元†

説明†

• パス: linux-4.4.1/sound/core/pcm_native.c

• FIXME: これは何？
  • 説明

引数†

• struct snd_pcm_substream *substream
  • linux-4.4.1/snd_pcm_substream
• struct vm_area_struct *area
  • linux-4.4.1/vm_area_struct

返り値†

• int

参考†

実装†

/**
 * snd_pcm_lib_default_mmap - Default PCM data mmap function
 * @substream: PCM substream
 * @area: VMA
 *
 * This is the default mmap handler for PCM data.  When mmap pcm_ops is NULL,
 * this function is invoked implicitly.
 */
int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
                             struct vm_area_struct *area)
{
        area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
#ifdef CONFIG_GENERIC_ALLOCATOR

• • linux-4.4.1/CONFIG_GENERIC_ALLOCATOR

        if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_IRAM) {
                area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
                return remap_pfn_range(area, area->vm_start,
                                substream->dma_buffer.addr >> PAGE_SHIFT,
                                area->vm_end - area->vm_start, area->vm_page_prot);

• • linux-4.4.1/pgprot_writecombine()
  • linux-4.4.1/remap_pfn_range()

        }
#endif /* CONFIG_GENERIC_ALLOCATOR */
#ifndef CONFIG_X86 /* for avoiding warnings arch/x86/mm/pat.c */

• • linux-4.4.1/CONFIG_X86

        if (!substream->ops->page &&
            substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)
                return dma_mmap_coherent(substream->dma_buffer.dev.dev,
                                         area,
                                         substream->runtime->dma_area,
                                         substream->runtime->dma_addr,
                                         area->vm_end - area->vm_start);

• • linux-4.4.1/dma_mmap_coherent()

#endif /* CONFIG_X86 */
        /* mmap with fault handler */
        area->vm_ops = &snd_pcm_vm_ops_data_fault;

• • linux-4.4.1/snd_pcm_vm_ops_data_fault(global)

        return 0;
}
EXPORT_SYMBOL_GPL(snd_pcm_lib_default_mmap);

• • linux-4.4.1/EXPORT_SYMBOL_GPL()

コメント†