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authorSuthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com>2015-06-10 19:08:52 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-06-15 15:40:48 +0300
commitd0562674838c08ff142c0e9a8e12634e133c4361 (patch)
tree969dc352b9de229af3248a5ea11830c1db9eedaf /drivers/acpi
parentfaacd5ad83857300df4b7b1814ef2eb963063c14 (diff)
downloadlinux-d0562674838c08ff142c0e9a8e12634e133c4361.tar.xz
ACPI / scan: Parse _CCA and setup device coherency
This patch implements support for ACPI _CCA object, which is introduced in ACPIv5.1, can be used for specifying device DMA coherency attribute. The parsing logic traverses device namespace to parse coherency information, and stores it in acpi_device_flags. Then uses it to call arch_setup_dma_ops() when creating each device enumerated in DSDT during ACPI scan. This patch also introduces acpi_dma_is_coherent(), which provides an interface for device drivers to check the coherency information similarly to the of_dma_is_coherent(). Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/Kconfig3
-rw-r--r--drivers/acpi/acpi_platform.c2
-rw-r--r--drivers/acpi/glue.c5
-rw-r--r--drivers/acpi/scan.c35
4 files changed, 44 insertions, 1 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ab2cbb51c6aa..212735f3f074 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -54,6 +54,9 @@ config ACPI_GENERIC_GSI
config ACPI_SYSTEM_POWER_STATES_SUPPORT
bool
+config ACPI_CCA_REQUIRED
+ bool
+
config ACPI_SLEEP
bool
depends on SUSPEND || HIBERNATION
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 4bf75597f732..06a67d5f2846 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -103,7 +103,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
pdevinfo.res = resources;
pdevinfo.num_res = count;
pdevinfo.fwnode = acpi_fwnode_handle(adev);
- pdevinfo.dma_mask = DMA_BIT_MASK(32);
+ pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
pdev = platform_device_register_full(&pdevinfo);
if (IS_ERR(pdev))
dev_err(&adev->dev, "platform device creation failed: %ld\n",
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 39c485b0c25c..b9657af751d1 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -13,6 +13,7 @@
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>
+#include <linux/dma-mapping.h>
#include "internal.h"
@@ -167,6 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
struct list_head *physnode_list;
unsigned int node_id;
int retval = -EINVAL;
+ bool coherent;
if (has_acpi_companion(dev)) {
if (acpi_dev) {
@@ -223,6 +225,9 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
if (!has_acpi_companion(dev))
ACPI_COMPANION_SET(dev, acpi_dev);
+ if (acpi_check_dma(acpi_dev, &coherent))
+ arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
+
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/acpi/scan.c b/drivers/acpi/scan.c
index 0a099917a006..67509b23172c 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -11,6 +11,7 @@
#include <linux/kthread.h>
#include <linux/dmi.h>
#include <linux/nls.h>
+#include <linux/dma-mapping.h>
#include <asm/pgtable.h>
@@ -2111,6 +2112,39 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
kfree(pnp->unique_id);
}
+static void acpi_init_coherency(struct acpi_device *adev)
+{
+ unsigned long long cca = 0;
+ acpi_status status;
+ struct acpi_device *parent = adev->parent;
+
+ if (parent && parent->flags.cca_seen) {
+ /*
+ * From ACPI spec, OSPM will ignore _CCA if an ancestor
+ * already saw one.
+ */
+ adev->flags.cca_seen = 1;
+ cca = parent->flags.coherent_dma;
+ } else {
+ status = acpi_evaluate_integer(adev->handle, "_CCA",
+ NULL, &cca);
+ if (ACPI_SUCCESS(status))
+ adev->flags.cca_seen = 1;
+ else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
+ /*
+ * If architecture does not specify that _CCA is
+ * required for DMA-able devices (e.g. x86),
+ * we default to _CCA=1.
+ */
+ cca = 1;
+ else
+ acpi_handle_debug(adev->handle,
+ "ACPI device is missing _CCA.\n");
+ }
+
+ adev->flags.coherent_dma = cca;
+}
+
void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
int type, unsigned long long sta)
{
@@ -2129,6 +2163,7 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
device->flags.visited = false;
device_initialize(&device->dev);
dev_set_uevent_suppress(&device->dev, true);
+ acpi_init_coherency(device);
}
void acpi_device_add_finalize(struct acpi_device *device)