Re: [PATCH 3/3] powerpc: Set crashkernel offset to mid of RMA region

From: Sourabh Jain
Date: Mon Oct 04 2021 - 13:17:51 EST


Hello Aneesh,

@@ -1235,6 +1235,9 @@ int __init early_init_dt_scan_rtas(unsigned long node,
      entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
      sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
  +    if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
+        powerpc_firmware_features |= FW_FEATURE_LPAR;
+

The equivalent check that we currently do more than checking ibm,hypertas-functions.

    if (!strcmp(uname, "rtas") || !strcmp(uname, "rtas@0")) {
        prop = of_get_flat_dt_prop(node, "ibm,hypertas-functions",
                       &len);
        if (prop) {
            powerpc_firmware_features |= FW_FEATURE_LPAR;
            fw_hypertas_feature_init(prop, len);
}

If ibm,hypertas-functions prop has to be part of rtas or rtas@0 node to decide we are on LPAR then how about splitting the probe_fw_features functions into two functions, one to detect FW_FEATURE_LPAR and another function to do the rest?

also do we expect other firmware features to be set along with FW_FEATURE_LPAR?


No only FW_FEATURE_LPAR feature so that kernel can decide the crashkernel offset accordingly.


Thanks for the review.

- Sourabh Jain