Hi Lorenzo, On 14.04.2016 19:25, Lorenzo Pieralisi wrote:
On DT based systems, the of_dma_configure() API implements DMA configuration for a given device. On ACPI systems an API equivalent to of_dma_configure() is missing which implies that it is currently not possible to set-up DMA operations for devices through the ACPI generic kernel layer.This patch fills the gap by introducing acpi_dma_configure/deconfigure() calls, that carry out IOMMU configuration through IORT (on systems where it is present) and call arch_setup_dma_ops(...) with the retrieved parameters. The DMA range size passed to arch_setup_dma_ops() is sized according to the device coherent_dma_mask (starting at address 0x0), mirroring the DT probing path behaviour when a dma-ranges property is not provided for the device being probed; this changes the current arch_setup_dma_ops() call parameters in the ACPI probing case, but since arch_setup_dma_ops() is a NOP on all architectures but ARM/ARM64 this patch does not change the current kernel behaviour on them. This patch updates ACPI and PCI core code to use the newly introduced acpi_dma_configure function, providing the same functionality as of_dma_configure on ARM systems and leaving behaviour unchanged for all other arches. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com> Cc: Bjorn Helgaas <bhelg...@google.com> Cc: Robin Murphy <robin.mur...@arm.com> Cc: Tomasz Nowicki <t...@semihalf.com> Cc: Joerg Roedel <j...@8bytes.org> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net> --- drivers/acpi/glue.c | 4 +-- drivers/acpi/iort.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++ drivers/acpi/scan.c | 29 +++++++++++++++++ drivers/pci/probe.c | 3 +- include/acpi/acpi_bus.h | 2 ++ include/linux/acpi.h | 5 +++ include/linux/iort.h | 9 ++++++ 7 files changed, 133 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 5ea5dc2..f8d6564 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -227,8 +227,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) attr = acpi_get_dma_attr(acpi_dev); if (attr != DEV_DMA_NOT_SUPPORTED) - arch_setup_dma_ops(dev, 0, 0, NULL, - attr == DEV_DMA_COHERENT); + acpi_dma_configure(dev, attr); acpi_physnode_link_name(physical_node_name, node_id); retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, @@ -251,6 +250,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) return 0; err: + acpi_dma_deconfigure(dev); ACPI_COMPANION_SET(dev, NULL); put_device(dev); put_device(&acpi_dev->dev); diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c index 2b5ce65..b1bb8fb 100644 --- a/drivers/acpi/iort.c +++ b/drivers/acpi/iort.c @@ -72,6 +72,31 @@ int iort_iommu_set_node(struct iommu_ops *ops, struct acpi_iort_node *node, return 0; } +/** + * iort_iommu_get_node - Retrieve iort_iommu_node associated with an IORT node. + * + * @node: IORT table node to be looked-up + * + * Returns: iort_iommu_node pointer on success + * NULL on failure + */ +static struct iort_iommu_node *iort_iommu_get_node(struct acpi_iort_node *node) +{ + struct iort_iommu_node *iommu_node; + + spin_lock(&iort_iommu_lock); + list_for_each_entry(iommu_node, &iort_iommu_list, list) { + if (iommu_node->node == node) + goto found; + } + + iommu_node = NULL; +found: + spin_unlock(&iort_iommu_lock); + + return iommu_node; +} + typedef acpi_status (*iort_find_node_callback) (struct acpi_iort_node *node, void *context); @@ -405,6 +430,66 @@ iort_pci_get_domain(struct pci_dev *pdev, u32 req_id) return domain_handle; } +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) +{ + u32 *rid = data; + + *rid = alias; + return 0; +} + +/** + * iort_iommu_configure - Set-up IOMMU configuration for a device. + * + * @dev: device that requires IOMMU set-up + * + * Returns: iommu_ops pointer on configuration success + * NULL on configuration failure + */ +struct iommu_ops *iort_iommu_configure(struct device *dev) +{ + struct acpi_iort_node *node, *parent; + struct iommu_ops *ops = NULL; + struct iommu_fwspec fwspec; + struct iort_iommu_node *iommu_node; + u32 rid = 0, devid = 0; + + if (dev_is_pci(dev)) { + struct pci_bus *bus = to_pci_dev(dev)->bus; + + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, + &rid); + + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_find_dev_callback, &bus->dev); + } else + node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, + iort_find_dev_callback, dev);
I think this will not work for finding host bridge stream ID. We still need to use ACPI_IORT_NODE_PCI_ROOT_COMPLEX but 'dev' is not PCI device, right?
Thanks, Tomasz
