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authorChristoph Hellwig <hch@lst.de>2020-03-23 20:19:30 +0300
committerChristoph Hellwig <hch@lst.de>2020-07-19 10:29:29 +0300
commitd35834c64820c7ef397f8a244061d4450720540e (patch)
tree5a2df279a26c6175bfc9dbf9859c52468967aa70 /include/linux/device.h
parent2f9237d4f6df49b74c51cdac555b0a9979d0c237 (diff)
downloadlinux-d35834c64820c7ef397f8a244061d4450720540e.tar.xz
dma-mapping: add a dma_ops_bypass flag to struct device
Several IOMMU drivers have a bypass mode where they can use a direct mapping if the devices DMA mask is large enough. Add generic support to the core dma-mapping code to do that to switch those drivers to a common solution. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Diffstat (limited to 'include/linux/device.h')
-rw-r--r--include/linux/device.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/device.h b/include/linux/device.h
index 4c4af98321eb..1f71acf37f78 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -523,6 +523,11 @@ struct dev_links_info {
* sync_state() callback.
* @dma_coherent: this particular device is dma coherent, even if the
* architecture supports non-coherent devices.
+ * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
+ * streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
+ * and optionall (if the coherent mask is large enough) also
+ * for dma allocations. This flag is managed by the dma ops
+ * instance from ->dma_supported.
*
* At the lowest level, every device in a Linux system is represented by an
* instance of struct device. The device structure contains the information
@@ -623,6 +628,9 @@ struct device {
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
bool dma_coherent:1;
#endif
+#ifdef CONFIG_DMA_OPS_BYPASS
+ bool dma_ops_bypass : 1;
+#endif
};
static inline struct device *kobj_to_dev(struct kobject *kobj)