[PATCH v2 1/7] swiotlb: Use a helper to initialize swiotlb fields in struct device

[Petr Tesarik <petrtesarik@xxxxxxxxxxxxxxx>]

From: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>

Move swiotlb initialization code to swiotlb.h. This change also
allows to provide a stub implementation if swiotlb is not
configured, getting rid of an #ifdef in driver core.

Signed-off-by: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>
---
 drivers/base/core.c     |  4 +---
 include/linux/swiotlb.h | 12 ++++++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6878dfcbf0d6..a5dc7c673102 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3060,9 +3060,7 @@ void device_initialize(struct device *dev)
     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
 	dev->dma_coherent = dma_default_coherent;
 #endif
-#ifdef CONFIG_SWIOTLB
-	dev->dma_io_tlb_mem = &io_tlb_default_mem;
-#endif
+	swiotlb_dev_init(dev);
 }
 EXPORT_SYMBOL_GPL(device_initialize);
 
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index bcef10e20ea4..b65b7330f7e5 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -119,6 +119,15 @@ static inline bool is_swiotlb_force_bounce(struct device *dev)
 	return mem && mem->force_bounce;
 }
 
+/**
+ * swiotlb_dev_init() - initialize swiotlb fields in &struct device
+ * @dev: device to be initialized
+ */
+static inline void swiotlb_dev_init(struct device *dev)
+{
+	dev->dma_io_tlb_mem = &io_tlb_default_mem;
+}
+
 void swiotlb_init(bool addressing_limited, unsigned int flags);
 void __init swiotlb_exit(void);
 size_t swiotlb_max_mapping_size(struct device *dev);
@@ -128,6 +137,9 @@ void __init swiotlb_adjust_size(unsigned long size);
 static inline void swiotlb_init(bool addressing_limited, unsigned int flags)
 {
 }
+static inline void swiotlb_dev_init(struct device *dev)
+{
+}
 static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
 {
 	return false;
-- 
2.25.1