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 for now are just wrappers around arch_setup_dma_ops() and
arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.
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.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> [pci]
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/scan.c | 24 ++++++++++++++++++++++++
drivers/pci/probe.c | 3 +--
include/acpi/acpi_bus.h | 2 ++
include/linux/acpi.h | 5 +++++
5 files changed, 34 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/scan.c b/drivers/acpi/scan.c
index e878fc7..9614232 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1370,6 +1370,30 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
return DEV_DMA_NON_COHERENT;
}
+/**
+ * acpi_dma_configure - Set-up DMA configuration for the device.
+ * @dev: The pointer to the device
+ * @attr: device dma attributes
+ */
+void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
+{
+ /*
+ * Assume dma valid range starts at 0 and covers the whole
+ * coherent_dma_mask.
+ */
+ arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, NULL,
+ attr == DEV_DMA_COHERENT);
+}
+
+/**
+ * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
+ * @dev: The pointer to the device
+ */
+void acpi_dma_deconfigure(struct device *dev)
+{
+ arch_teardown_dma_ops(dev);
+}
+
static void acpi_init_coherency(struct acpi_device *adev)
{
unsigned long long cca = 0;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 93f280d..e96d482 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1734,8 +1734,7 @@ static void pci_dma_configure(struct pci_dev *dev)
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);
+ acpi_dma_configure(&dev->dev, attr);
}
pci_put_host_bridge_device(bridge);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index c1a524d..4242c31 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -573,6 +573,8 @@ struct acpi_pci_root {
bool acpi_dma_supported(struct acpi_device *adev);
enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
+void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
+void acpi_dma_deconfigure(struct device *dev);
struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
u64 address, bool check_children);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c5eaf2f..05d4e48 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -729,6 +729,11 @@ static inline enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
return DEV_DMA_NOT_SUPPORTED;
}
+static inline void acpi_dma_configure(struct device *dev,
+ enum dev_dma_attr attr) { }
+
+static inline void acpi_dma_deconfigure(struct device *dev) { }
+
#define ACPI_PTR(_ptr) (NULL)
static inline void acpi_device_set_enumerated(struct acpi_device *adev)
--
2.10.0
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
