cxl/events: Add extra validity checks for CVME count in DRAM Event Record

According to the CXL Specification Revision 3.2, Section 8.2.10.2.1.2,
Table 8-58 (DRAM Event Record), the CVME (Corrected Volatile Memory Error)
Count field is valid under the following conditions:
1. The Threshold Event bit is set in the Memory Event Descriptor field,
and
2. The CVME Count must be greater than 0 for events where the Advanced
Programmable Threshold Counter has expired.

Additionally, if the Advanced Programmable Corrected Memory Error Counter
Expire bit in the Memory Event Type field is set, then the Threshold Event
bit in the Memory Event Descriptor field shall also be set.

Add validity checks for the above conditions while reporting the event to
the userspace.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250717101817.2104-4-shiju.jose@huawei.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index ba4a29afd3aa583b18a63a09c3336c409da1f212..445889b128cdd917906225041ed95a97da0a9e49 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -941,6 +941,15 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
                        if (cxl_store_rec_dram((struct cxl_memdev *)cxlmd, evt))
                                dev_dbg(&cxlmd->dev, "CXL store rec_dram failed\n");
 
+                       if (evt->dram.media_hdr.descriptor &
+                           CXL_GMER_EVT_DESC_THRESHOLD_EVENT)
+                               WARN_ON_ONCE((evt->dram.media_hdr.type &
+                                             CXL_DER_MEM_EVT_TYPE_AP_CME_COUNTER_EXPIRE) &&
+                                            !get_unaligned_le24(evt->dram.cvme_count));
+                       else
+                               WARN_ON_ONCE(evt->dram.media_hdr.type &
+                                            CXL_DER_MEM_EVT_TYPE_AP_CME_COUNTER_EXPIRE);
+
                        trace_cxl_dram(cxlmd, type, cxlr, hpa, hpa_alias,
                                       &evt->dram);
                }

diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
index c38f94ca0ca1118e6ab1a9a96b314be0ad6ee63d..462c2e892ba2ea601067e44e1dfad5237200d888 100644 (file)
--- a/drivers/cxl/core/trace.h
+++ b/drivers/cxl/core/trace.h
@@ -661,7 +661,10 @@ TRACE_EVENT(cxl_dram,
                       CXL_EVENT_GEN_MED_COMP_ID_SIZE);
                __entry->sub_channel = rec->sub_channel;
                __entry->cme_threshold_ev_flags = rec->cme_threshold_ev_flags;
-               __entry->cvme_count = get_unaligned_le24(rec->cvme_count);
+               if (rec->media_hdr.descriptor & CXL_GMER_EVT_DESC_THRESHOLD_EVENT)
+                       __entry->cvme_count = get_unaligned_le24(rec->cvme_count);
+               else
+                       __entry->cvme_count = 0;
        ),
 
        CXL_EVT_TP_printk("dpa=%llx dpa_flags='%s' descriptor='%s' type='%s' sub_type='%s' " \