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.pieralisi@xxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
---
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);
