iommu/amd: Update event log pointer as soon as processing is complete

Update event buffer head pointer once driver completes processing. So
that IOMMU can write new log without waiting for driver to complete
processing all event logs.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20240828111029.5429-2-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 87c5385ce3f28621163bd4ade8dfeebd3937f404..8ada0b227ca1a4c22d6aebe24bd5b56d012609b0 100644 (file)
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -825,10 +825,12 @@ static void iommu_poll_events(struct amd_iommu *iommu)
 
        while (head != tail) {
                iommu_print_event(iommu, iommu->evt_buf + head);
+
+               /* Update head pointer of hardware ring-buffer */
                head = (head + EVENT_ENTRY_SIZE) % EVT_BUFFER_SIZE;
+               writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
        }
 
-       writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
 }
 
 #ifdef CONFIG_IRQ_REMAP