[PATCH 5.15 108/121] iommu/amd: use full 64-bit value in build_completion_wait()

Greg Kroah-Hartman
2022-09-13T14:45:25Z

From: John Sperbeck <jsperbeck@google.com>

[ Upstream commit 94a568ce32038d8ff9257004bb4632e60eb43a49 ]

We started using a 64 bit completion value. Unfortunately, we only
stored the low 32-bits, so a very large completion value would never
be matched in iommu_completion_wait().

Fixes: c69d89aff393 ("iommu/amd: Use 4K page for completion wait write-back semaphore")
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Link: https://lore.kernel.org/r/20220801192229.3358786-1-jsperbeck@google.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/amd/iommu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index e23e70af718f1..7154fb551ddc9 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -852,7 +852,8 @@ static void build_completion_wait(struct iommu_cmd *cmd,
memset(cmd, 0, sizeof(*cmd));
cmd->data[0] = lower_32_bits(paddr) | CMD_COMPL_WAIT_STORE_MASK;
cmd->data[1] = upper_32_bits(paddr);
- cmd->data[2] = data;
+ cmd->data[2] = lower_32_bits(data);
+ cmd->data[3] = upper_32_bits(data);
CMD_SET_TYPE(cmd, CMD_COMPL_WAIT);
}

--
2.35.1