Fix tREFI calculation to use MRW REFRESH REQUEST RATE as opposed to T…

…EMP RANGE

Reverting to P8 attribute used to calculate tREFI. Lab request
expects to use MRW REFRESH REQUEST RATE since it has more enum
options to control refresh range and assure we are in SPEC.

Change-Id: Ibdb6023c60fdf000f642becb53513ecaaf88aa15
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/35003
Reviewed-by: Michael D. Pardeik <pardeik@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Matt K. Light <mklight@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/35435
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>

src/import/chips/p9/procedures/hwp/memory/lib/dimm/eff_dimm.C

@@ -636,7 +636,7 @@ fapi2::ReturnCode eff_dimm::dram_trefi()
         case fapi2::ENUM_ATTR_MSS_MRW_FINE_REFRESH_MODE_NORMAL:
 
             FAPI_TRY( calc_trefi( mss::refresh_rate::REF1X,
-                                  iv_temp_refresh_range,
+                                  iv_refresh_rate_request,
                                   l_trefi_in_ps),
                       "Failed to calculate tREF1 for target %s", mss::c_str(iv_dimm) );
             break;
@@ -645,7 +645,7 @@ fapi2::ReturnCode eff_dimm::dram_trefi()
         case fapi2::ENUM_ATTR_MSS_MRW_FINE_REFRESH_MODE_FLY_2X:
 
             FAPI_TRY( calc_trefi( mss::refresh_rate::REF2X,
-                                  iv_temp_refresh_range,
+                                  iv_refresh_rate_request,
                                   l_trefi_in_ps),
                       "Failed to calculate tREF2 for target %s", mss::c_str(iv_dimm) );
             break;
@@ -654,7 +654,7 @@ fapi2::ReturnCode eff_dimm::dram_trefi()
         case fapi2::ENUM_ATTR_MSS_MRW_FINE_REFRESH_MODE_FLY_4X:
 
             FAPI_TRY( calc_trefi( mss::refresh_rate::REF4X,
-                                  iv_temp_refresh_range,
+                                  iv_refresh_rate_request,
                                   l_trefi_in_ps),
                       "Failed to calculate tREF4  for target %s", mss::c_str(iv_dimm) );
             break;
@@ -674,7 +674,9 @@ fapi2::ReturnCode eff_dimm::dram_trefi()
 
     {
         // Calculate refresh cycle time in nCK & set attribute
+        constexpr double PERCENT_ADJUST = 0.999;
         std::vector<uint16_t> l_mcs_attrs_trefi(PORTS_PER_MCS, 0);
+
         uint64_t l_trefi_in_nck  = 0;
 
         // Retrieve MCS attribute data
@@ -687,6 +689,16 @@ fapi2::ReturnCode eff_dimm::dram_trefi()
                                   l_trefi_in_nck),
                    "Error in calculating tREFI for target %s, with value of l_trefi_in_ps: %d", mss::c_str(iv_dimm), l_trefi_in_ps);
 
+        // Per Mike P., requested 99.9% of tREFI calculation to avoid any latency impact and violation of any
+        // refresh specification (across all number of ranks and frequencies) observed during lab tests.
+
+        FAPI_INF("For %s, adjusting tREFI calculation by 99.9%, calculated tREFI (nck): %lu, adjusted tREFI (nck): %lu,",
+                 mss::c_str(iv_dimm), l_trefi_in_nck, l_trefi_in_nck * PERCENT_ADJUST);
+
+        // The compiler does this under the covers but just to be explicit on intent:
+        // Floating point arithmetic and truncation of result saved to an unsigned integer
+        l_trefi_in_nck = static_cast<double>(l_trefi_in_nck * PERCENT_ADJUST);
+
         FAPI_INF("tCK (ps): %d, tREFI (ps): %d, tREFI (nck): %d",
                  iv_tCK_in_ps, l_trefi_in_ps, l_trefi_in_nck);
 

src/import/chips/p9/procedures/hwp/memory/lib/dimm/eff_dimm.H

@@ -65,7 +65,7 @@ class eff_dimm
         // using attribute accessors
         // Could create getters & setters...
         uint8_t iv_refresh_mode;
-        uint8_t iv_temp_refresh_range;
+        uint8_t iv_refresh_rate_request;
 
         //Delete the default
         eff_dimm () = delete;
@@ -92,7 +92,7 @@ class eff_dimm
 
             FAPI_TRY( clock_period(iv_dimm, iv_tCK_in_ps), "Failed to calculate clock period (tCK)" );
 
-            FAPI_TRY( mss::mrw_temp_refresh_range(iv_temp_refresh_range), "Failed mrw_temp_refresh_range()" );
+            FAPI_TRY( mss::mrw_refresh_rate_request(iv_refresh_rate_request), "Failed mrw_temp_refresh_rate_request()" );
             FAPI_TRY( mss::mrw_fine_refresh_mode(iv_refresh_mode), "Failed mrw_fine_refresh_mode()" );
 
             FAPI_TRY( mss::freq(find_target<fapi2::TARGET_TYPE_MCBIST>(iv_dimm), iv_freq));

src/import/chips/p9/procedures/hwp/memory/lib/eff_config/timing.C

@@ -88,49 +88,56 @@ static const std::vector<std::pair<uint8_t, uint64_t> > TRFC_DLR4 =
 ///
 /// @brief Calculates refresh interval time
 /// @param[in] i_mode fine refresh rate mode
-/// @param[in] i_temp_refresh_range temperature refresh range
+/// @param[in] i_refresh_request_rate refresh rate
 /// @param[out] o_value timing val in ps
 /// @return fapi2::ReturnCode
 ///
 fapi2::ReturnCode calc_trefi( const refresh_rate i_mode,
-                              const uint8_t i_temp_refresh_range,
+                              const uint8_t i_refresh_request_rate,
                               uint64_t& o_timing )
 {
-    uint64_t l_multiplier = 0;
-    uint64_t l_quotient = 0;
-    uint64_t l_remainder = 0;
+    uint64_t l_refresh_request = 0;
+    constexpr double TEN_PERCENT_FASTER = 0.90;
 
-    switch(i_temp_refresh_range)
+    switch(i_refresh_request_rate)
     {
-        case fapi2::ENUM_ATTR_MSS_MRW_TEMP_REFRESH_RANGE_NORMAL:
-            l_multiplier = temp_mode::NORMAL;
+        case fapi2::ENUM_ATTR_MSS_MRW_REFRESH_RATE_REQUEST_SINGLE:
+            l_refresh_request = TREFI_BASE;
             break;
 
-        case fapi2::ENUM_ATTR_MSS_MRW_TEMP_REFRESH_RANGE_EXTEND:
-            l_multiplier = temp_mode::EXTENDED;
+        case fapi2::ENUM_ATTR_MSS_MRW_REFRESH_RATE_REQUEST_DOUBLE:
+            // We are truncating but there is no remainder with TREFI_BASE, so we are okay
+            l_refresh_request = TREFI_BASE / 2;
+            break;
+
+        case fapi2::ENUM_ATTR_MSS_MRW_REFRESH_RATE_REQUEST_SINGLE_10_PERCENT_FASTER:
+            // We are truncating but there is no remainder with TREFI_BASE, so we are okay
+            // 10% faster so 100% - 10% = 90%
+            l_refresh_request = TREFI_BASE * TEN_PERCENT_FASTER;
+            break;
+
+        case fapi2::ENUM_ATTR_MSS_MRW_REFRESH_RATE_REQUEST_DOUBLE_10_PERCENT_FASTER:
+            // We are truncating but there is no remainder with TREFI_BASE, so we are okay
+            // 10% faster so 100% - 10% = 90%
+            l_refresh_request = (TREFI_BASE / 2) * TEN_PERCENT_FASTER;
             break;
 
         default:
-            // Temperature Refresh Range will be a platform attribute set by the MRW,
-            // which they "shouldn't" mess up as long as use "attribute" enums.
-            // if someone messes this up we can at least catch it
-            FAPI_ASSERT( false,
-                         fapi2::MSS_INVALID_TEMP_REFRESH()
-                         .set_TEMP_REFRESH_RANGE(i_temp_refresh_range),
-                         "Incorrect Temperature Ref. Range received: %d ",
-                         i_temp_refresh_range);
+            // Will catch incorrect MRW value set
+            FAPI_ASSERT(false,
+                        fapi2::MSS_INVALID_REFRESH_RATE_REQUEST().set_REFRESH_RATE_REQUEST(i_refresh_request_rate),
+                        "Incorrect refresh request rate received: %d ", i_refresh_request_rate);
             break;
     }
 
-    l_quotient = TREFI_BASE / ( int64_t(i_mode) * l_multiplier );
-    l_remainder = TREFI_BASE % ( int64_t(i_mode) * l_multiplier );
-    o_timing = l_quotient + (l_remainder == 0 ? 0 : 1);
+    o_timing =  (l_refresh_request / i_mode);
 
-    FAPI_INF( "tREFI: %d, quotient: %d, remainder: %d, tREFI_base: %d",
-              o_timing, l_quotient, l_remainder, TREFI_BASE );
+    FAPI_INF( "tREFI (ps): %d, refresh request (ps): %d, tREFI_base (ps): %d, REF%dX",
+              o_timing, l_refresh_request, TREFI_BASE, i_mode );
 
-    // FAPI_ASSERT doesn't set current error to good
+    // FAPI_ASSERT doesn't set current_err as good
     return fapi2::FAPI2_RC_SUCCESS;
+
 fapi_try_exit:
     return fapi2::current_err;
 }

src/import/chips/p9/procedures/hwp/memory/lib/eff_config/timing.H

@@ -68,15 +68,15 @@ enum guard_band : uint16_t
     // when doing integer math, we add-in the inverse correction factor
     // Formula used for derivation:
     // Guardband = 1000 * (1000* correction_factor) - 1
-    INVERSE_DDR3_CORRECTION_FACTOR = 989,
-    INVERSE_DDR4_CORRECTION_FACTOR = 974,
+    INVERSE_DDR3_CORRECTION_FACTOR = 989, ///< DDR3 correction factor
+    INVERSE_DDR4_CORRECTION_FACTOR = 974, ///< DDR4 correction factor
 };
 
-enum class refresh_rate : uint8_t
+enum refresh_rate : uint8_t
 {
-    REF1X = 1,
-    REF2X = 2,
-    REF4X = 4,
+    REF1X = 1, ///< Refresh rate 1X
+    REF2X = 2, ///< Refresh rate 2X
+    REF4X = 4, ///< Refresh rate 4X
 };
 
 namespace spd

src/import/chips/p9/procedures/hwp/memory/lib/mss_attribute_accessors.H

@@ -19920,7 +19920,7 @@ fapi_try_exit:
 /// us (SINGLE_10_PERCENT_FASTER) 3.51 us
 /// (DOUBLE_10_PERCENT_FASTER)
 ///
-inline fapi2::ReturnCode mrw_refresh_rate_select(uint8_t& o_value)
+inline fapi2::ReturnCode mrw_refresh_rate_request(uint8_t& o_value)
 {
 
     FAPI_TRY( FAPI_ATTR_GET(fapi2::ATTR_MSS_MRW_REFRESH_RATE_REQUEST, fapi2::Target<fapi2::TARGET_TYPE_SYSTEM>(),

src/import/chips/p9/procedures/xml/attribute_info/memory_mrw_attributes.xml

@@ -158,7 +158,7 @@
     </enum>
     <default>0x0</default>
     <initToZero/>
-    <mssAccessorName>mrw_refresh_rate_select</mssAccessorName>
+    <mssAccessorName>mrw_refresh_rate_request</mssAccessorName>
   </attribute>
 
   <attribute>

src/import/chips/p9/procedures/xml/error_info/p9_memory_mss_eff_config.xml

@@ -385,6 +385,19 @@
     </callout>
   </hwpError>
 
+  <hwpError>
+    <rc>RC_MSS_INVALID_REFRESH_RATE_REQUEST</rc>
+    <description>
+      Invalid refresh request rate received.
+      Possibly due to bad MRW setting for ATTR_MSS_MRW_REFRESH_RATE_REQUEST.
+    </description>
+    <ffdc>REFRESH_RATE_REQUEST</ffdc>
+    <callout>
+      <procedure>CODE</procedure>
+      <priority>HIGH</priority>
+    </callout>
+  </hwpError>
+
   <hwpError>
     <rc>RC_MSS_INVALID_FINE_REFRESH</rc>
     <description>