From eb283043d5967c71445d03224391f6c022e2bdbc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herv=C3=A9=20Poussineau?= <hpoussin@reactos.org>
Date: Sun, 7 Nov 2021 12:17:53 +0100
Subject: [PATCH] [HALX86] Partly implement HalCalculateScatterGatherListSize

---
 hal/halx86/generic/dma.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/hal/halx86/generic/dma.c b/hal/halx86/generic/dma.c
index 76a2e21f76c..f14bbf59fb6 100644
--- a/hal/halx86/generic/dma.c
+++ b/hal/halx86/generic/dma.c
@@ -1173,8 +1173,18 @@ HalCalculateScatterGatherListSize(
     OUT PULONG ScatterGatherListSize,
     OUT PULONG pNumberOfMapRegisters)
 {
-    UNIMPLEMENTED;
-    return STATUS_NOT_IMPLEMENTED;
+    ULONG NumberOfMapRegisters;
+    ULONG SgSize;
+
+    UNIMPLEMENTED_ONCE;
+
+    NumberOfMapRegisters = PAGE_ROUND_UP(Length) >> PAGE_SHIFT;
+    SgSize = sizeof(SCATTER_GATHER_CONTEXT);
+
+    *ScatterGatherListSize = SgSize;
+    if (pNumberOfMapRegisters) *pNumberOfMapRegisters = NumberOfMapRegisters;
+
+    return STATUS_SUCCESS;
 }
 
 NTSTATUS