[PATCH V4 8/8] PCI: ACPI: Add support for PCI device DMA coherency
From: helgaas@kernel.org (Bjorn Helgaas)
Date: 2015-10-27 14:48:12
Also in:
linux-acpi, linux-pci, lkml
On Wed, Oct 21, 2015 at 08:52:11AM -0700, Suravee Suthikulpanit wrote:
quoted hunk ↗ jump to hunk
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 | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 09264f8..6e9f7e6 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c@@ -1642,17 +1642,26 @@ 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) { 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);
This fixes the leak I mentioned earlier, since we now put the bridge device before returning. But I guess I'd still prefer to see the leak fix as a patch by itself instead of fixing it incidentally here.
+ } else if (has_acpi_companion(bridge)) {
+ struct acpi_device *adev = to_acpi_node(bridge->fwnode);
+ enum dev_dma_attr attr = acpi_get_dma_attr(adev);
+
+ if (attr != DEV_DMA_NOT_SUPPORTED)
+ arch_setup_dma_ops(&dev->dev, 0, 0, NULL,
+ attr == DEV_DMA_COHERENT);
+ else
+ WARN(1, FW_BUG "PCI device %s fail to setup DMA.\n",
+ pci_name(dev));
This should use dev_warn() so the format is the same as for other
messages related to "dev".
Personally, I would write this as:
if (attr == DEV_DMA_NOT_SUPPORTED)
dev_warn(&dev->dev, "DMA not supported\n");
else
arch_setup_dma_ops(...);
to avoid the double negative in the conditional.
} pci_put_host_bridge_device(bridge); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/