This is a note to let you know that I've just added the patch titled
iommu/dart: Initialize DART_STREAMS_ENABLE
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-dart-initialize-dart_streams_enable.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0b443412a45a9594a91649a6aa7cb93219e1673b
Author: Sven Peter <sven@xxxxxxxxxxxxx>
Date: Tue Oct 19 18:22:53 2021 +0200
iommu/dart: Initialize DART_STREAMS_ENABLE
[ Upstream commit 5a009fc1364170b240a4d351b345e69bb3728b3e ]
DART has an additional global register to control which streams are
isolated. This register is a bit redundant since DART_TCR can already
be used to control isolation and is usually initialized to DART_STREAM_ALL
by the time we get control. Some DARTs (namely the one used for the audio
controller) however have some streams disabled initially. Make sure those
work by initializing DART_STREAMS_ENABLE during reset.
Reported-by: Martin Povišer <povik@xxxxxxxxxxxxxx>
Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
Reviewed-by: Hector Martin <marcan@xxxxxxxxx>
Link: https://lore.kernel.org/r/20211019162253.45919-1-sven@xxxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index fdfa39ec2a4d4..ad69eeb5ac5ba 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -70,6 +70,8 @@
#define DART_ERROR_ADDR_HI 0x54
#define DART_ERROR_ADDR_LO 0x50
+#define DART_STREAMS_ENABLE 0xfc
+
#define DART_TCR(sid) (0x100 + 4 * (sid))
#define DART_TCR_TRANSLATE_ENABLE BIT(7)
#define DART_TCR_BYPASS0_ENABLE BIT(8)
@@ -301,6 +303,9 @@ static int apple_dart_hw_reset(struct apple_dart *dart)
apple_dart_hw_disable_dma(&stream_map);
apple_dart_hw_clear_all_ttbrs(&stream_map);
+ /* enable all streams globally since TCR is used to control isolation */
+ writel(DART_STREAM_ALL, dart->regs + DART_STREAMS_ENABLE);
+
/* clear any pending errors before the interrupt is unmasked */
writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR);
