Re: [PATCH v4 18/25] powernv/fadump: process architected register state data provided by firmware

On 14/08/19 10:45 PM, Mahesh J Salgaonkar wrote:

On 2019-07-16 17:04:08 Tue, Hari Bathini wrote:

quoted

From: Hari Bathini <redacted>

Firmware provides architected register state data at the time of crash.
Process this data and build CPU notes to append to ELF core.

Signed-off-by: Hari Bathini <redacted>
Signed-off-by: Vasant Hegde <redacted>
---
 arch/powerpc/kernel/fadump-common.h          |    4 +
 arch/powerpc/platforms/powernv/opal-fadump.c |  197 ++++++++++++++++++++++++--
 arch/powerpc/platforms/powernv/opal-fadump.h |   39 +++++
 3 files changed, 228 insertions(+), 12 deletions(-)

[...]

quoted

@@ -430,6 +577,32 @@ int __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, ulong node)
 			return 1;
 		}
 
+		ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &addr);
+		if ((ret != OPAL_SUCCESS) || !addr) {
+			pr_err("Failed to get CPU metadata (%lld)\n", ret);
+			return 1;
+		}
+
+		addr = be64_to_cpu(addr);
+		pr_debug("CPU metadata addr: %llx\n", addr);
+
+		opal_cpu_metadata = __va(addr);
+		r_opal_cpu_metadata = (void *)addr;
+		fadump_conf->cpu_state_data_version =
+			be32_to_cpu(r_opal_cpu_metadata->cpu_data_version);
+		if (fadump_conf->cpu_state_data_version !=
+		    HDAT_FADUMP_CPU_DATA_VERSION) {
+			pr_err("CPU data format version (%lu) mismatch!\n",
+			       fadump_conf->cpu_state_data_version);
+			return 1;
+		}

I think cpu data version mismatch check should still be done early on?

quoted

+		fadump_conf->cpu_state_entry_size =
+			be32_to_cpu(r_opal_cpu_metadata->cpu_data_size);
+		fadump_conf->cpu_state_destination_addr =
+			be64_to_cpu(r_opal_cpu_metadata->region[0].dest);
+		fadump_conf->cpu_state_data_size =
+			be64_to_cpu(r_opal_cpu_metadata->region[0].size);
+

opal_fadump_dt_scan isn't the right place to do this. Can you please move above
cpu related data processing to opal_fadump_build_cpu_notes() ?

I will move the above cpu related data processing to opal_fadump_build_cpu_notes().

Thanks
Hari