From 0d6d9bd4c1d587d62508ad6e8ae68fd4094bc427 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Mon, 22 Sep 2025 13:09:10 -0400
Subject: kern: dma: Add DMA address helpers

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/include/io/dma/alloc.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

(limited to 'src/sys/include/io')

diff --git a/src/sys/include/io/dma/alloc.h b/src/sys/include/io/dma/alloc.h
index b1034c4..f18fc1d 100644
--- a/src/sys/include/io/dma/alloc.h
+++ b/src/sys/include/io/dma/alloc.h
@@ -31,8 +31,31 @@
 #define _DMA_ALLOC_H_
 
 #include <sys/types.h>
+#include <sys/cdefs.h>
 #include <vm/vm.h>
 
+/*
+ * Represents a physical address that may be used
+ * with direct memory access
+ */
+typedef uintptr_t dma_addr_t;
+
+/*
+ * Convert virtual DMA pages to physical DMA
+ * addresses.
+ */
+__always_inline static dma_addr_t
+dma_get_pa(void *pgbuf)
+{
+    return VIRT_TO_PHYS(pgbuf);
+}
+
+__always_inline static void *
+dma_get_va(dma_addr_t pa)
+{
+    return PHYS_TO_VIRT(pa);
+}
+
 /*
  * Allocate a buffer suitable for Direct Memory
  * Access
-- 
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