[PATCH 1/4] swiotlb: Split common code from swiotlb.{c,h}

["GuoRui.Yu" <GuoRui.Yu@linux.alibaba.com>]

Split swiotlb_bounce, swiotlb_release_slots, and is_swiotlb_buffer from
swiotlb.{c,h} to common-swiotlb.c, and prepare for the new swiotlb
implementaion.

Signed-off-by: GuoRui.Yu <GuoRui.Yu@linux.alibaba.com>
---
 include/linux/swiotlb.h     | 10 ++---
 kernel/dma/Makefile         |  2 +-
 kernel/dma/common-swiotlb.c | 74 +++++++++++++++++++++++++++++++++
 kernel/dma/swiotlb.c        | 82 ++++---------------------------------
 4 files changed, 88 insertions(+), 80 deletions(-)
 create mode 100644 kernel/dma/common-swiotlb.c

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 35bc4e281c21..c5e74d3f9cbf 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -58,6 +58,9 @@ void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
 		size_t size, enum dma_data_direction dir);
 dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs);
+void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size,
+			   enum dma_data_direction dir);
+void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr);
 
 #ifdef CONFIG_SWIOTLB
 
@@ -105,12 +108,7 @@ struct io_tlb_mem {
 };
 extern struct io_tlb_mem io_tlb_default_mem;
 
-static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
-{
-	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
-
-	return mem && paddr >= mem->start && paddr < mem->end;
-}
+bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr);
 
 static inline bool is_swiotlb_force_bounce(struct device *dev)
 {
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile
index 21926e46ef4f..fc0ea13bc089 100644
--- a/kernel/dma/Makefile
+++ b/kernel/dma/Makefile
@@ -6,7 +6,7 @@ obj-$(CONFIG_DMA_OPS)			+= dummy.o
 obj-$(CONFIG_DMA_CMA)			+= contiguous.o
 obj-$(CONFIG_DMA_DECLARE_COHERENT)	+= coherent.o
 obj-$(CONFIG_DMA_API_DEBUG)		+= debug.o
-obj-$(CONFIG_SWIOTLB)			+= swiotlb.o
+obj-$(CONFIG_SWIOTLB)			+= swiotlb.o common-swiotlb.o
 obj-$(CONFIG_DMA_COHERENT_POOL)		+= pool.o
 obj-$(CONFIG_MMU)			+= remap.o
 obj-$(CONFIG_DMA_MAP_BENCHMARK)		+= map_benchmark.o
diff --git a/kernel/dma/common-swiotlb.c b/kernel/dma/common-swiotlb.c
new file mode 100644
index 000000000000..d477d5f2a71b
--- /dev/null
+++ b/kernel/dma/common-swiotlb.c
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/dma-direct.h>
+#include <linux/swiotlb.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/swiotlb.h>
+
+/*
+ * Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing
+ * to the device copy the data into it as well.
+ */
+dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	phys_addr_t swiotlb_addr;
+	dma_addr_t dma_addr;
+
+	trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size);
+
+	swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir,
+			attrs);
+	if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
+		return DMA_MAPPING_ERROR;
+
+	/* Ensure that the address returned is DMA'ble */
+	dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr);
+	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
+		swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir,
+			attrs | DMA_ATTR_SKIP_CPU_SYNC);
+		dev_WARN_ONCE(dev, 1,
+			"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
+			&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
+		return DMA_MAPPING_ERROR;
+	}
+
+	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		arch_sync_dma_for_device(swiotlb_addr, size, dir);
+	return dma_addr;
+}
+
+/*
+ * tlb_addr is the physical address of the bounce buffer to unmap.
+ */
+void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr,
+			      size_t mapping_size, enum dma_data_direction dir,
+			      unsigned long attrs)
+{
+	/*
+	 * First, sync the memory before unmapping the entry
+	 */
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
+	    (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
+		swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_FROM_DEVICE);
+
+	swiotlb_release_slots(dev, tlb_addr);
+}
+
+void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr,
+		size_t size, enum dma_data_direction dir)
+{
+	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
+		swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE);
+	else
+		BUG_ON(dir != DMA_FROM_DEVICE);
+}
+
+void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
+		size_t size, enum dma_data_direction dir)
+{
+	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
+		swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE);
+	else
+		BUG_ON(dir != DMA_TO_DEVICE);
+}
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index a34c38bbe28f..f3ff4de08653 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -48,9 +48,6 @@
 #include <linux/slab.h>
 #endif
 
-#define CREATE_TRACE_POINTS
-#include <trace/events/swiotlb.h>
-
 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
 
 /*
@@ -523,7 +520,7 @@ static unsigned int swiotlb_align_offset(struct device *dev, u64 addr)
 /*
  * Bounce: copy the swiotlb buffer from or back to the original dma location
  */
-static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size,
+void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size,
 			   enum dma_data_direction dir)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
@@ -793,7 +790,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
 	return tlb_addr;
 }
 
-static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
+void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
 	unsigned long flags;
@@ -840,74 +837,6 @@ static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
 	spin_unlock_irqrestore(&area->lock, flags);
 }
 
-/*
- * tlb_addr is the physical address of the bounce buffer to unmap.
- */
-void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr,
-			      size_t mapping_size, enum dma_data_direction dir,
-			      unsigned long attrs)
-{
-	/*
-	 * First, sync the memory before unmapping the entry
-	 */
-	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
-	    (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
-		swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_FROM_DEVICE);
-
-	swiotlb_release_slots(dev, tlb_addr);
-}
-
-void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr,
-		size_t size, enum dma_data_direction dir)
-{
-	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
-		swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE);
-	else
-		BUG_ON(dir != DMA_FROM_DEVICE);
-}
-
-void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
-		size_t size, enum dma_data_direction dir)
-{
-	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
-		swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE);
-	else
-		BUG_ON(dir != DMA_TO_DEVICE);
-}
-
-/*
- * Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing
- * to the device copy the data into it as well.
- */
-dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
-		enum dma_data_direction dir, unsigned long attrs)
-{
-	phys_addr_t swiotlb_addr;
-	dma_addr_t dma_addr;
-
-	trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size);
-
-	swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir,
-			attrs);
-	if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
-		return DMA_MAPPING_ERROR;
-
-	/* Ensure that the address returned is DMA'ble */
-	dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr);
-	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
-		swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir,
-			attrs | DMA_ATTR_SKIP_CPU_SYNC);
-		dev_WARN_ONCE(dev, 1,
-			"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
-			&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
-		return DMA_MAPPING_ERROR;
-	}
-
-	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		arch_sync_dma_for_device(swiotlb_addr, size, dir);
-	return dma_addr;
-}
-
 size_t swiotlb_max_mapping_size(struct device *dev)
 {
 	int min_align_mask = dma_get_min_align_mask(dev);
@@ -924,6 +853,13 @@ size_t swiotlb_max_mapping_size(struct device *dev)
 	return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE - min_align;
 }
 
+bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
+{
+	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
+
+	return mem && paddr >= mem->start && paddr < mem->end;
+}
+
 bool is_swiotlb_active(struct device *dev)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
-- 
2.31.1