2 files changed, 48 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 91cc31087e8a..66a0ba37a8a3 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -180,10 +180,20 @@ struct rftype {
  * struct mbm_state - status for each MBM counter in each domain
  * @chunks:     Total data moved (multiply by rdt_group.mon_scale to get bytes)
  * @prev_msr    Value of IA32_QM_CTR for this RMID last time we read it
+ * @chunks_bw   Total local data moved. Used for bandwidth calculation
+ * @prev_bw_msr:Value of previous IA32_QM_CTR for bandwidth counting
+ * @prev_bw     The most recent bandwidth in MBps
+ * @delta_bw    Difference between the current and previous bandwidth
+ * @delta_comp  Indicates whether to compute the delta_bw
  */
 struct mbm_state {
         u64     chunks;
         u64     prev_msr;
+        u64     chunks_bw;
+        u64     prev_bw_msr;
+        u32     prev_bw;
+        u32     delta_bw;
+        bool    delta_comp;
 };
 
 /**
diff --git a/arch/x86/kernel/cpu/intel_rdt_monitor.c b/arch/x86/kernel/cpu/intel_rdt_monitor.c
index 681450eee428..7690402c42b7 100644
--- a/arch/x86/kernel/cpu/intel_rdt_monitor.c
+++ b/arch/x86/kernel/cpu/intel_rdt_monitor.c
@@ -225,10 +225,18 @@ void free_rmid(u32 rmid)
                 list_add_tail(&entry->list, &rmid_free_lru);
 }
 
+static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr)
+{
+        u64 shift = 64 - MBM_CNTR_WIDTH, chunks;
+
+        chunks = (cur_msr << shift) - (prev_msr << shift);
+        return chunks >>= shift;
+}
+
 static int __mon_event_count(u32 rmid, struct rmid_read *rr)
 {
-        u64 chunks, shift, tval;
         struct mbm_state *m;
+        u64 chunks, tval;
 
         tval = __rmid_read(rmid, rr->evtid);
         if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
@@ -254,14 +262,12 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
         }
 
         if (rr->first) {
-                m->prev_msr = tval;
-                m->chunks = 0;
+                memset(m, 0, sizeof(struct mbm_state));
+                m->prev_bw_msr = m->prev_msr = tval;
                 return 0;
         }
 
-        shift = 64 - MBM_CNTR_WIDTH;
-        chunks = (tval << shift) - (m->prev_msr << shift);
-        chunks >>= shift;
+        chunks = mbm_overflow_count(m->prev_msr, tval);
         m->chunks += chunks;
         m->prev_msr = tval;
 
@@ -270,6 +276,32 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
 }
 
 /*
+ * Supporting function to calculate the memory bandwidth
+ * and delta bandwidth in MBps.
+ */
+static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
+{
+        struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
+        struct mbm_state *m = &rr->d->mbm_local[rmid];
+        u64 tval, cur_bw, chunks;
+
+        tval = __rmid_read(rmid, rr->evtid);
+        if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
+                return;
+
+        chunks = mbm_overflow_count(m->prev_bw_msr, tval);
+        m->chunks_bw += chunks;
+        m->chunks = m->chunks_bw;
+        cur_bw = (chunks * r->mon_scale) >> 20;
+
+        if (m->delta_comp)
+                m->delta_bw = abs(cur_bw - m->prev_bw);
+        m->delta_comp = false;
+        m->prev_bw = cur_bw;
+        m->prev_bw_msr = tval;
+}
+
+/*
  * This is called via IPI to read the CQM/MBM counters
  * on a domain.
  */