From 22de0c4edf2fe1cdbca5e22c52c86a2289d04816 Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Tue, 8 Jul 2025 12:38:05 +0100
Subject: [dma] Use virtual addresses for dma_map()

Cache management operations must generally be performed on virtual
addresses rather than physical addresses.

Change the address parameter in dma_map() to be a virtual address, and
make dma() the API-level primitive instead of dma_phys().

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/include/ipxe/dma.h   | 42 +++++++++++++-----------------------------
 src/include/ipxe/iobuf.h |  3 +--
 2 files changed, 14 insertions(+), 31 deletions(-)

(limited to 'src/include')

diff --git a/src/include/ipxe/dma.h b/src/include/ipxe/dma.h
index 6e5c43289..d450ef523 100644
--- a/src/include/ipxe/dma.h
+++ b/src/include/ipxe/dma.h
@@ -68,7 +68,7 @@ struct dma_operations {
 	 * @ret rc		Return status code
 	 */
 	int ( * map ) ( struct dma_device *dma, struct dma_mapping *map,
-			physaddr_t addr, size_t len, int flags );
+			void *addr, size_t len, int flags );
 	/**
 	 * Unmap buffer
 	 *
@@ -178,8 +178,7 @@ struct dma_operations {
  */
 static inline __always_inline int
 DMAAPI_INLINE ( flat, dma_map ) ( struct dma_device *dma,
-				  struct dma_mapping *map,
-				  physaddr_t addr __unused,
+				  struct dma_mapping *map, void *addr __unused,
 				  size_t len __unused, int flags __unused ) {
 
 	/* Increment mapping count (for debugging) */
@@ -319,32 +318,31 @@ DMAAPI_INLINE ( flat, dma_set_mask ) ( struct dma_device *dma __unused,
 }
 
 /**
- * Get DMA address from physical address
+ * Get DMA address from virtual address
  *
  * @v map		DMA mapping
- * @v addr		Physical address within the mapped region
+ * @v addr		Address within the mapped region
  * @ret addr		Device-side DMA address
  */
 static inline __always_inline physaddr_t
-DMAAPI_INLINE ( flat, dma_phys ) ( struct dma_mapping *map __unused,
-				   physaddr_t addr ) {
+DMAAPI_INLINE ( flat, dma ) ( struct dma_mapping *map __unused, void *addr ) {
 
 	/* Use physical address as device address */
-	return addr;
+	return virt_to_phys ( addr );
 }
 
 /**
- * Get DMA address from physical address
+ * Get DMA address from virtual address
  *
  * @v map		DMA mapping
- * @v addr		Physical address within the mapped region
+ * @v addr		Address within the mapped region
  * @ret addr		Device-side DMA address
  */
 static inline __always_inline physaddr_t
-DMAAPI_INLINE ( op, dma_phys ) ( struct dma_mapping *map, physaddr_t addr ) {
+DMAAPI_INLINE ( op, dma ) ( struct dma_mapping *map, void *addr ) {
 
 	/* Adjust physical address using mapping offset */
-	return ( addr + map->offset );
+	return ( virt_to_phys ( addr ) + map->offset );
 }
 
 /**
@@ -358,7 +356,7 @@ DMAAPI_INLINE ( op, dma_phys ) ( struct dma_mapping *map, physaddr_t addr ) {
  * @ret rc		Return status code
  */
 int dma_map ( struct dma_device *dma, struct dma_mapping *map,
-	      physaddr_t addr, size_t len, int flags );
+	      void *addr, size_t len, int flags );
 
 /**
  * Unmap buffer
@@ -417,28 +415,14 @@ void dma_ufree ( struct dma_mapping *map, void *addr, size_t len );
  */
 void dma_set_mask ( struct dma_device *dma, physaddr_t mask );
 
-/**
- * Get DMA address from physical address
- *
- * @v map		DMA mapping
- * @v addr		Physical address within the mapped region
- * @ret addr		Device-side DMA address
- */
-physaddr_t dma_phys ( struct dma_mapping *map, physaddr_t addr );
-
 /**
  * Get DMA address from virtual address
  *
  * @v map		DMA mapping
- * @v addr		Virtual address within the mapped region
+ * @v addr		Address within the mapped region
  * @ret addr		Device-side DMA address
  */
-static inline __always_inline physaddr_t dma ( struct dma_mapping *map,
-					       void *addr ) {
-
-	/* Get DMA address from corresponding physical address */
-	return dma_phys ( map, virt_to_phys ( addr ) );
-}
+physaddr_t dma ( struct dma_mapping *map, void *addr );
 
 /**
  * Check if DMA unmapping is required
diff --git a/src/include/ipxe/iobuf.h b/src/include/ipxe/iobuf.h
index 2bdca6b5d..df8d0b854 100644
--- a/src/include/ipxe/iobuf.h
+++ b/src/include/ipxe/iobuf.h
@@ -230,8 +230,7 @@ static inline void iob_populate ( struct io_buffer *iobuf,
 static inline __always_inline int iob_map ( struct io_buffer *iobuf,
 					    struct dma_device *dma,
 					    size_t len, int flags ) {
-	return dma_map ( dma, &iobuf->map, virt_to_phys ( iobuf->data ),
-			 len, flags );
+	return dma_map ( dma, &iobuf->map, iobuf->data, len, flags );
 }
 
 /**
-- 
cgit v1.2.3-55-g7522