[IOMMU] Debug info for AMD IOMMU event log

Print out the event log entry content for debug purposes.
Additionally, when IOMMU reset event log (due to event log overflow),
we should print out the event log content for debugging.

Signed-off-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Wei Wang <wei.wang2@amd.com>

1 files changed, 44 insertions, 36 deletions

diff --git a/xen/drivers/passthrough/amd/iommu_init.c b/xen/drivers/passthrough/amd/iommu_init.c
index 634930f488..8afd81babd 100644
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -270,42 +270,6 @@ static void set_iommu_event_log_control(struct amd_iommu *iommu,
     writel(entry, iommu->mmio_base + IOMMU_CONTROL_MMIO_OFFSET);
 }
 
-static void amd_iommu_reset_event_log(struct amd_iommu *iommu)
-{
-    u32 entry;
-    int log_run;
-    int loop_count = 1000;
-
-    /* wait until EventLogRun bit = 0 */
-    do {
-        entry = readl(iommu->mmio_base + IOMMU_STATUS_MMIO_OFFSET);
-        log_run = get_field_from_reg_u32(entry,
-                                        IOMMU_STATUS_EVENT_LOG_RUN_MASK,
-                                        IOMMU_STATUS_EVENT_LOG_RUN_SHIFT);
-        loop_count--;
-    } while ( log_run && loop_count );
-
-    if ( log_run )
-    {
-        AMD_IOMMU_DEBUG("Warning: EventLogRun bit is not cleared"
-                       "before reset!\n");
-        return;
-    }
-
-    set_iommu_event_log_control(iommu, IOMMU_CONTROL_DISABLED);
-
-    /*clear overflow bit */
-    set_field_in_reg_u32(IOMMU_CONTROL_DISABLED, entry,
-                         IOMMU_STATUS_EVENT_OVERFLOW_MASK,
-                         IOMMU_STATUS_EVENT_OVERFLOW_SHIFT, &entry);
-    writel(entry, iommu->mmio_base+IOMMU_STATUS_MMIO_OFFSET);
-
-    /*reset event log base address */
-    iommu->event_log_head = 0;
-
-    set_iommu_event_log_control(iommu, IOMMU_CONTROL_ENABLED);
-}
-
 static void parse_event_log_entry(u32 entry[]);
 
 static int amd_iommu_read_event_log(struct amd_iommu *iommu)
@@ -342,6 +306,45 @@ static int amd_iommu_read_event_log(struct amd_iommu *iommu)
     return 0;
 }
 
+static void amd_iommu_reset_event_log(struct amd_iommu *iommu)
+{
+    u32 entry;
+    int log_run;
+    int loop_count = 1000;
+
+    /* wait until EventLogRun bit = 0 */
+    do {
+        entry = readl(iommu->mmio_base + IOMMU_STATUS_MMIO_OFFSET);
+        log_run = get_field_from_reg_u32(entry,
+                                        IOMMU_STATUS_EVENT_LOG_RUN_MASK,
+                                        IOMMU_STATUS_EVENT_LOG_RUN_SHIFT);
+        loop_count--;
+    } while ( log_run && loop_count );
+
+    if ( log_run )
+    {
+        AMD_IOMMU_DEBUG("Warning: EventLogRun bit is not cleared"
+                       "before reset!\n");
+        return;
+    }
+
+    set_iommu_event_log_control(iommu, IOMMU_CONTROL_DISABLED);
+
+    /* read event log for debugging */
+    amd_iommu_read_event_log(iommu);
+
+    /*clear overflow bit */
+    set_field_in_reg_u32(IOMMU_CONTROL_DISABLED, entry,
+                         IOMMU_STATUS_EVENT_OVERFLOW_MASK,
+                         IOMMU_STATUS_EVENT_OVERFLOW_SHIFT, &entry);
+    writel(entry, iommu->mmio_base+IOMMU_STATUS_MMIO_OFFSET);
+
+    /*reset event log base address */
+    iommu->event_log_head = 0;
+
+    set_iommu_event_log_control(iommu, IOMMU_CONTROL_ENABLED);
+}
+
 static void iommu_msi_set_affinity(unsigned int irq, cpumask_t mask)
 {
     struct msi_msg msg;
@@ -492,6 +495,11 @@ static void parse_event_log_entry(u32 entry[])
             "%s: domain:%d, device id:0x%x, fault address:0x%"PRIx64"\n",
             event_str[code-1], domain_id, device_id, *addr);
     }
+    else
+    {
+        AMD_IOMMU_DEBUG("event 0x%08x 0x%08x 0x%08x 0x%08x\n", entry[0],
+                        entry[1], entry[2], entry[3]);
+    }
 }
 
 static void amd_iommu_page_fault(int irq, void *dev_id,