[PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

Hi Lorenzo,

On Thu, Jan 19, 2017 at 08:35:54PM +0530, Sricharan R wrote:

quoted

With all the DT based devices getting their dma ops configured
during probe time to have the right iommu setup, let us do the
same for acpi based devices as well.

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

Signed-off-by: Sricharan R <redacted>
---
 * Removed the dma configuration for the pci devices in case of ACPI
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/acpi/glue.c        |  5 -----
 drivers/base/dma-mapping.c | 13 ++++++++++++-
 drivers/pci/probe.c        | 25 -------------------------
 3 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index fb19e1c..c05f241 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c

@@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	struct list_head *physnode_list;
 	unsigned int node_id;
 	int retval = -EINVAL;
-	enum dev_dma_attr attr;

 	if (has_acpi_companion(dev)) {
 		if (acpi_dev) {

@@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	if (!has_acpi_companion(dev))
 		ACPI_COMPANION_SET(dev, acpi_dev);

-	attr = acpi_get_dma_attr(acpi_dev);
-	if (attr != DEV_DMA_NOT_SUPPORTED)
-		acpi_dma_configure(dev, attr);
-
 	acpi_physnode_link_name(physical_node_name, node_id);
 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 				   physical_node_name);

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index f82212c..294942d 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c

@@ -7,6 +7,7 @@
  * This file is released under the GPLv2.
  */

+#include <linux/acpi.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>

@@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
 {
 	struct device *_dev = dev;
 	int is_pci = dev_is_pci(dev);
+	enum dev_dma_attr attr;
 	int ret = 0;

 	if (is_pci) {

@@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
 			_dev = _dev->parent;
 	}

-	if (_dev->of_node)
+	if (_dev->of_node) {
 		ret = of_dma_configure(dev, _dev->of_node);
+	} else if (has_acpi_companion(_dev)) {
+		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
+
+		if (attr == DEV_DMA_NOT_SUPPORTED)
+			dev_warn(dev, "DMA not supported.\n");

The changes you are making are correct but now this dev_warn spits hell
for non-pci devices that do not support DMA (ie they do not have a _CCA
on CONFIG_ACPI_CCA_REQUIRED systems), so you will have to remove it
given that this path is now shared.

ok, will remove this WARN now.

Regards,
 Sricharan