-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 2 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 ||
- (adev->flags.cca_seen && IS_ENABLED(CONFIG_ARM64))) {
- ret = true;
- if (coherent)
- *coherent = adev->flags.coherent_dma;
- }
- return ret;
-}
-