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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-11-07 01:30:10 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-11-07 01:30:10 +0100
commitf2115faaf0df42623638dfbfc5bdaab6ef7375ab (patch)
treef8bbd5a1ad3fbcb0b60e455d0dcf29a9fc25602c /drivers/acpi/scan.c
parentMerge tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff)
parentPCI: ACPI: Add support for PCI device DMA coherency (diff)
downloadlinux-f2115faaf0df42623638dfbfc5bdaab6ef7375ab.tar.xz
linux-f2115faaf0df42623638dfbfc5bdaab6ef7375ab.zip
Merge branch 'acpi-pci'
* acpi-pci: PCI: ACPI: Add support for PCI device DMA coherency PCI: OF: Move of_pci_dma_configure() to pci_dma_configure() of/pci: Fix pci_get_host_bridge_device leak device property: ACPI: Remove unused DMA APIs device property: ACPI: Make use of the new DMA Attribute APIs device property: Adding DMA Attribute APIs for Generic Devices ACPI: Adding DMA Attribute APIs for ACPI Device device property: Introducing enum dev_dma_attr ACPI: Honor ACPI _CCA attribute setting Conflicts: drivers/crypto/ccp/ccp-platform.c
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index daf9fc8329e6..78d5f02a073b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1308,6 +1308,48 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
kfree(pnp->unique_id);
}
+/**
+ * acpi_dma_supported - Check DMA support for the specified device.
+ * @adev: The pointer to acpi device
+ *
+ * Return false if DMA is not supported. Otherwise, return true
+ */
+bool acpi_dma_supported(struct acpi_device *adev)
+{
+ if (!adev)
+ return false;
+
+ if (adev->flags.cca_seen)
+ return true;
+
+ /*
+ * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
+ * DMA on "Intel platforms". Presumably that includes all x86 and
+ * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
+ */
+ if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
+ return true;
+
+ return false;
+}
+
+/**
+ * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
+ * @adev: The pointer to acpi device
+ *
+ * Return enum dev_dma_attr.
+ */
+enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
+{
+ if (!acpi_dma_supported(adev))
+ return DEV_DMA_NOT_SUPPORTED;
+
+ if (adev->flags.coherent_dma)
+ return DEV_DMA_COHERENT;
+ else
+ return DEV_DMA_NON_COHERENT;
+}
+
static void acpi_init_coherency(struct acpi_device *adev)
{
unsigned long long cca = 0;