PCI: ACPI: Add support for PCI device DMA coherency

#include <linux/module.h>

#include <linux/cpumask.h>

#include <linux/pci-aspm.h>

#include <linux/acpi.h>

#include <asm-generic/pci-bridge.h>

#include "pci.h"

 * @dev: ptr to pci_dev struct of the PCI device

 *

 * Function to update PCI devices's DMA configuration using the same

 * info from the OF node of host bridge's parent (if any).

 * info from the OF node or ACPI node of host bridge's parent (if any).

 */

static void pci_dma_configure(struct pci_dev *dev)

{

	if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {

		if (bridge->parent)

			of_dma_configure(&dev->dev, bridge->parent->of_node);

	} else if (has_acpi_companion(bridge)) {

		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);

		enum dev_dma_attr attr = acpi_get_dma_attr(adev);

		if (attr == DEV_DMA_NOT_SUPPORTED)

			dev_warn(&dev->dev, "DMA not supported.\n");

		else

			arch_setup_dma_ops(&dev->dev, 0, 0, NULL,

					   attr == DEV_DMA_COHERENT);

	}

	pci_put_host_bridge_device(bridge);