This patch adds support for setting up PCI device DMA coherency from
ACPI _CCA object that should normally be specified in the DSDT node
of its PCI host bridge.
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
---
drivers/pci/probe.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 31e3eef..40eed54 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -12,6 +12,7 @@
#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"
@@ -1638,7 +1639,7 @@ static void pci_set_msi_domain(struct pci_dev *dev)
* @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)
{
@@ -1647,6 +1648,15 @@ 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);
--
2.1.0
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