Add callout for when the DIMM to NEST freq ratio exceeds 1.5

Change-Id: I4d3e9db7d6bc6900b518397d41e87890dc1d5b0f
CQ: SW416091
RTC: 186535
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/53226
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Reviewed-by: ANDRE A. MARIN <aamarin@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/53239
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

3 files changed, 124 insertions, 1 deletions

diff --git a/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.C b/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.C
index 96bb34185..40b6ed54c 100644
--- a/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.C
+++ b/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.C
@@ -22,3 +22,82 @@
 /* permissions and limitations under the License.                         */
 /*                                                                        */
 /* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file workarounds/freq_workarounds.C
+/// @brief Frequency related workarounds
+///
+// *HWP HWP Owner: Louis Stermole <stermole@us.ibm.com>
+// *HWP HWP Backup: Stephen Glancy <sglancy@us.ibm.com>
+// *HWP Team: Memory
+// *HWP Level: 3
+// *HWP Consumed by: FSP:HB
+
+#include <fapi2.H>
+
+#include <mss.H>
+#include <lib/workarounds/freq_workarounds.H>
+#include <lib/utils/assert_noexit.H>
+
+namespace mss
+{
+
+namespace workarounds
+{
+
+///
+/// @brief Ensures the ratio between DIMM and NEST frequencies is within allowable limit
+/// @param[in] i_target - the MCBIST target to check
+/// @param[in] i_dimm_speed - dimm speed in MT/s
+/// @param[in] i_nest_freq - nest freq in MHz
+/// @return FAPI2_RC_SUCCESS iff ok
+///
+fapi2::ReturnCode check_dimm_nest_freq_ratio( const fapi2::Target<fapi2::TARGET_TYPE_MCBIST>& i_target,
+        const uint64_t i_dimm_speed,
+        const uint32_t i_nest_freq )
+{
+    constexpr double MAX_MEM_NEST_FREQ_RATIO = 1.5;
+    double l_ratio = 0;
+
+    FAPI_INF("%s Checking the MEM to NEST frequency ratio versus the allowed limit", mss::c_str(i_target));
+
+    // Protect against nest_freq == 0 (divide by zero)
+    // This should never happen, so do a code callout
+    FAPI_ASSERT((i_nest_freq != 0) && (i_dimm_speed != 0),
+                fapi2::MSS_FREQ_OR_NEST_FREQ_IS_ZERO()
+                .set_MSS_FREQ(i_dimm_speed)
+                .set_NEST_FREQ(i_nest_freq),
+                "%s saw a zero memory or nest frequency when checking mem to nest freq ratio: mss: %d, nest: %d",
+                mss::c_str(i_target),
+                i_dimm_speed,
+                i_nest_freq);
+
+    // Check limit
+    l_ratio = static_cast<double>(i_dimm_speed) / static_cast<double>(i_nest_freq);
+    FAPI_INF("l_ratio = %f, max_ratio = %f", l_ratio, MAX_MEM_NEST_FREQ_RATIO);
+
+    if (l_ratio > MAX_MEM_NEST_FREQ_RATIO)
+    {
+        // Deconfigure MCSes
+        for ( const auto& l_mcs : mss::find_targets<fapi2::TARGET_TYPE_MCS>(i_target) )
+        {
+            MSS_ASSERT_NOEXIT(false,
+                              fapi2::MSS_FREQ_TO_NEST_FREQ_RATIO_TOO_LARGE()
+                              .set_MSS_FREQ(i_dimm_speed)
+                              .set_NEST_FREQ(i_nest_freq)
+                              .set_MCS_TARGET(l_mcs),
+                              "Deconfiguring %s due to the memory to nest frequency ratio being too large: mss: %d, nest: %d, ratio: %f",
+                              mss::c_str(l_mcs),
+                              i_dimm_speed,
+                              i_nest_freq,
+                              l_ratio);
+        }
+    }
+
+fapi_try_exit:
+    return fapi2::current_err;
+}
+
+} // namespace workarounds
+
+} // namespace mss
diff --git a/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.H b/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.H
index 2c3d6b269..ac8afcb86 100644
--- a/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.H
+++ b/src/import/chips/p9/procedures/hwp/memory/lib/workarounds/freq_workarounds.H
@@ -22,3 +22,38 @@
 /* permissions and limitations under the License.                         */
 /*                                                                        */
 /* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file workarounds/freq_workarounds.H
+/// @brief Frequency related workarounds
+///
+// *HWP HWP Owner: Louis Stermole <stermole@us.ibm.com>
+// *HWP HWP Backup: Stephen Glancy <sglancy@us.ibm.com>
+// *HWP Team: Memory
+// *HWP Level: 3
+// *HWP Consumed by: FSP:HB
+
+#include <fapi2.H>
+
+#include <mss.H>
+
+namespace mss
+{
+
+namespace workarounds
+{
+
+///
+/// @brief Ensures the ratio between DIMM and NEST frequencies is within allowable limit
+/// @param[in] i_target - the MCBIST target to check
+/// @param[in] i_dimm_speed - dimm speed in MT/s
+/// @param[in] i_nest_freq - nest freq in MHz
+/// @return FAPI2_RC_SUCCESS iff ok
+///
+fapi2::ReturnCode check_dimm_nest_freq_ratio( const fapi2::Target<fapi2::TARGET_TYPE_MCBIST>& i_target,
+        const uint64_t i_dimm_speed,
+        const uint32_t i_nest_freq );
+
+} // namespace workarounds
+
+} // namespace mss
diff --git a/src/import/chips/p9/procedures/hwp/memory/p9_mss_freq.C b/src/import/chips/p9/procedures/hwp/memory/p9_mss_freq.C
index ce2bb06e1..a9bed597f 100644
--- a/src/import/chips/p9/procedures/hwp/memory/p9_mss_freq.C
+++ b/src/import/chips/p9/procedures/hwp/memory/p9_mss_freq.C
@@ -28,7 +28,7 @@
 /// @brief Calculate and save off DIMM frequencies
 ///
 // *HWP HWP Owner: Andre Marin <aamarin@us.ibm.com>
-// *HWP HWP Backup: Jacob Harvey <jlharvey@us.ibm.com>
+// *HWP HWP Backup: Louis Stermole <stermole@us.ibm.com>
 // *HWP Team: Memory
 // *HWP Level: 3
 // *HWP Consumed by: FSP:HB
@@ -49,6 +49,7 @@
 #include <lib/spd/spd_factory.H>
 #include <lib/freq/cas_latency.H>
 #include <lib/freq/sync.H>
+#include <lib/workarounds/freq_workarounds.H>
 #include <generic/memory/lib/utils/c_str.H>
 #include <generic/memory/lib/utils/find.H>
 #include <lib/utils/count_dimm.H>
@@ -82,6 +83,9 @@ extern "C"
         std::vector< std::vector<uint64_t> > l_min_dimm_freq(mss::MCS_PER_MC, std::vector<uint64_t> (mss::PORTS_PER_MCS,  0) );
         std::vector<uint32_t> l_supported_freqs;
 
+        uint64_t l_mss_freq = 0;
+        uint32_t l_nest_freq = 0;
+
         // If there are no DIMM, we can just get out.
         if (mss::count_dimm(l_mcbist) == 0)
         {
@@ -162,6 +166,11 @@ extern "C"
         FAPI_TRY(mss::set_freq_attrs(l_mcbist, l_min_dimm_freq),
                  "%s. Failed set_freq_attrs()", mss::c_str(i_target) );
 
+        // Check MEM/NEST frequency ratio
+        FAPI_TRY( mss::freq_pb_mhz(l_nest_freq) );
+        FAPI_TRY( mss::freq(l_mcbist, l_mss_freq) );
+        FAPI_TRY( mss::workarounds::check_dimm_nest_freq_ratio(l_mcbist, l_mss_freq, l_nest_freq) );
+
     fapi_try_exit:
         return fapi2::current_err;