powerpc: consider CPU count while calculating crashkernel value

The next patch in the series adds more CPUs to the capture kernel,
which increases the memory requirement for the capture kernel.
Experiments show that powerpc needs 1 MB of additional memory for every
CPU added.

Therefore, while calculating the crashkernel size, make sure to include
an additional 1 MB for every CPU configured in the capture kernel.

The changes are implemented in such a way that if the user changes the
nr_cpus value in the kdump configuration, the script will adapt
accordingly.

Signed-off-by: Sourabh Jain <[email protected]>

Author: sourabhjains

kdump-lib.sh

@@ -975,6 +975,24 @@ _crashkernel_add()
 	echo "${ret%,}"
 }
 
+
+find_nr_cpus()
+{
+	local _cmdline_append
+	local _nr_cpus
+
+	# shellcheck disable=SC2153
+	if [[  $DEFAULT_DUMP_MODE == "fadump" ]]; then
+		_cmdline_append="$FADUMP_COMMANDLINE_APPEND"
+	else
+		_cmdline_append="$KDUMP_COMMANDLINE_APPEND"
+	fi
+	_nr_cpus=$(echo "$_cmdline_append" | sed -n 's/.*nr_cpus=\([0-9]\+\).*/\1/p')
+	ddebug "Configured nr_cpus=$_nr_cpus"
+	echo "$_nr_cpus"
+}
+
+
 # get default crashkernel
 # $1 dump mode, if not specified, dump_mode will be judged by is_fadump_capable
 # $2 kernel-release, if not specified, got by _get_kdump_kernel_version
@@ -1025,6 +1043,14 @@ kdump_get_arch_recommend_crashkernel()
 			has_mlx5 && ((_delta += 150))
 		fi
 	elif [[ $_arch == "ppc64le" ]]; then
+		local _per_cpu_area
+		local _nr_cpus
+
+		# 1MB per CPU
+		_per_cpu_area=1
+		_nr_cpus=$(find_nr_cpus)
+
+		_delta=$(( _delta + _per_cpu_area * _nr_cpus ))
 		if [[ $_dump_mode == "fadump" ]]; then
 			_ck_cmdline="4G-16G:768M,16G-64G:1G,64G-128G:2G,128G-1T:4G,1T-2T:6G,2T-4T:12G,4T-8T:20G,8T-16T:36G,16T-32T:64G,32T-64T:128G,64T-:180G"
 		else