[PATCH V2 4/4] PCI: ACPI: Add support for PCI device DMA coherency
From: Suravee.Suthikulpanit@amd.com (Suravee Suthikulpanit)
Date: 2015-08-25 17:34:15
Also in:
linux-acpi, linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
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@amd.com> CC: Bjorn Helgaas <bhelgaas@google.com> CC: Catalin Marinas <catalin.marinas@arm.com> CC: Rob Herring <robh+dt@kernel.org> CC: Will Deacon <redacted> CC: Rafael J. Wysocki <redacted> CC: Murali Karicheri <redacted> --- drivers/pci/probe.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4de6594..2fd2a60 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c@@ -1551,17 +1551,22 @@ static void pci_init_capabilities(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) { struct device *bridge = pci_get_host_bridge_device(dev); if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) { - if (!bridge->parent) - return; - - of_dma_configure(&dev->dev, bridge->parent->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_node(bridge->fwnode); + int coherent = acpi_check_dma_coherency(adev); + + if (-1 != coherent) + arch_setup_dma_ops(&dev->dev, 0, 0, NULL, coherent); } pci_put_host_bridge_device(bridge);
--
2.1.0