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path: root/drivers/iommu/amd/init.c
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Diffstat (limited to 'drivers/iommu/amd/init.c')
-rw-r--r--drivers/iommu/amd/init.c28
1 files changed, 19 insertions, 9 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 7e66ddfa323f..186a567e6823 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -821,11 +821,16 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu)
BUG_ON(iommu->cmd_buf == NULL);
- entry = iommu_virt_to_phys(iommu->cmd_buf);
- entry |= MMIO_CMD_SIZE_512;
-
- memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
- &entry, sizeof(entry));
+ if (!is_kdump_kernel()) {
+ /*
+ * Command buffer is re-used for kdump kernel and setting
+ * of MMIO register is not required.
+ */
+ entry = iommu_virt_to_phys(iommu->cmd_buf);
+ entry |= MMIO_CMD_SIZE_512;
+ memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
+ &entry, sizeof(entry));
+ }
amd_iommu_reset_cmd_buffer(iommu);
}
@@ -876,10 +881,15 @@ static void iommu_enable_event_buffer(struct amd_iommu *iommu)
BUG_ON(iommu->evt_buf == NULL);
- entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
-
- memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
- &entry, sizeof(entry));
+ if (!is_kdump_kernel()) {
+ /*
+ * Event buffer is re-used for kdump kernel and setting
+ * of MMIO register is not required.
+ */
+ entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+ memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
+ &entry, sizeof(entry));
+ }
/* set head and tail to zero manually */
writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);