linux-4.4.1/dma_contiguous_reserve_area() の履歴(No.2)

• 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/dma_contiguous_reserve_area() へ行く。
  • 1 (2017-09-19 (火) 00:04:42)
  • 2 (2017-09-19 (火) 00:19:02)

参照元†

• linux-4.4.1/dma_contiguous_reserve()
• linux-4.4.1/dma_declare_contiguous()

説明†

• パス: 複数あり
  • CONFIG_DMA_CMA 有効: linux-4.4.1/drivers/base/dma-contiguous.c
  • CONFIG_DMA_CMA 無効: linux-4.4.1/include/linux/dma-contiguous.h

• FIXME: これは何？
  • 説明

引数†

• phys_addr_t size
  • linux-4.4.1/phys_addr_t
• phys_addr_t base
• phys_addr_t limit
• struct cma **res_cma
  • linux-4.4.1/cma
• bool fixed

返り値†

• int

参考†

実装†

CONFIG_DMA_CMA 有効: linux-4.4.1/drivers/base/dma-contiguous.c†

/**
 * dma_contiguous_reserve_area() - reserve custom contiguous area
 * @size: Size of the reserved area (in bytes),
 * @base: Base address of the reserved area optional, use 0 for any
 * @limit: End address of the reserved memory (optional, 0 for any).
 * @res_cma: Pointer to store the created cma region.
 * @fixed: hint about where to place the reserved area
 *
 * This function reserves memory from early allocator. It should be
 * called by arch specific code once the early allocator (memblock or bootmem)
 * has been activated and all other subsystems have already allocated/reserved
 * memory. This function allows to create custom reserved areas for specific
 * devices.
 *
 * If @fixed is true, reserve contiguous area at exactly @base.  If false,
 * reserve in range from @base to @limit.
 */
int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
				       phys_addr_t limit, struct cma **res_cma,
				       bool fixed)
{
	int ret;

	ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed, res_cma);
	if (ret)
		return ret;

• • linux-4.4.1/cma_declare_contiguous()

	/* Architecture specific contiguous memory fixup. */
	dma_contiguous_early_fixup(cma_get_base(*res_cma),
				cma_get_size(*res_cma));

• • linux-4.4.1/dma_contiguous_early_fixup()
  • linux-4.4.1/cma_get_base()
  • linux-4.4.1/cma_get_size()

	return 0;
}

CONFIG_DMA_CMA 無効: linux-4.4.1/include/linux/dma-contiguous.h†

static inline int dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
				       phys_addr_t limit, struct cma **res_cma,
				       bool fixed)
{
	return -ENOSYS;
}

コメント†