Merge branch 'acpi-cca'

* acpi-cca:
  ufs: fix TRUE and FALSE re-define build error
  megaraid_sas: fix TRUE and FALSE re-define build error
  amd-xgbe: Unify coherency checking logic with device_dma_is_coherent()
  crypto: ccp - Unify coherency checking logic with device_dma_is_coherent()
  device property: Introduces device_dma_is_coherent()
  arm64 : Introduce support for ACPI _CCA object
  ACPI / scan: Parse _CCA and setup device coherency

1 files changed, 36 insertions, 1 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 5dec08d7aa64..b43276f339ef 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -209,7 +209,9 @@ struct acpi_device_flags {
 	u32 hotplug_notify:1;
 	u32 is_dock_station:1;
 	u32 of_compatible_ok:1;
-	u32 reserved:22;
+	u32 coherent_dma:1;
+	u32 cca_seen:1;
+	u32 reserved:20;
 };
 
 /* File System */
@@ -380,6 +382,39 @@ struct acpi_device {
 	void (*remove)(struct acpi_device *);
 };
 
+static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
+{
+	bool ret = false;
+
+	if (!adev)
+		return ret;
+
+	/**
+	 * Currently, we only support _CCA=1 (i.e. coherent_dma=1)
+	 * This should be equivalent to specifyig dma-coherent for
+	 * a device in OF.
+	 *
+	 * For the case when _CCA=0 (i.e. coherent_dma=0 && cca_seen=1),
+	 * There are two cases:
+	 * case 1. Do not support and disable DMA.
+	 * case 2. Support but rely on arch-specific cache maintenance for
+	 *         non-coherence DMA operations.
+	 * Currently, we implement case 1 above.
+	 *
+	 * For the case when _CCA is missing (i.e. cca_seen=0) and
+	 * platform specifies ACPI_CCA_REQUIRED, we do not support DMA,
+	 * and fallback to arch-specific default handling.
+	 *
+	 * See acpi_init_coherency() for more info.
+	 */
+	if (adev->flags.coherent_dma) {
+		ret = true;
+		if (coherent)
+			*coherent = adev->flags.coherent_dma;
+	}
+	return ret;
+}
+
 static inline bool is_acpi_node(struct fwnode_handle *fwnode)
 {
 	return fwnode && fwnode->type == FWNODE_ACPI;