[reactos] 01/02: [HALX86] Partly implement HalCalculateScatterGatherListSize

[Hervé Poussineau]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=eb283043d5967c71445d0…

commit eb283043d5967c71445d03224391f6c022e2bdbc
Author:     Hervé Poussineau <hpoussin(a)reactos.org>
AuthorDate: Sun Nov 7 12:17:53 2021 +0100
Commit:     Hervé Poussineau <hpoussin(a)reactos.org>
CommitDate: Sun Nov 7 14:07:55 2021 +0100

    [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