MIPS: Probe for presence of KScratch registers.

Probe c0_config4 for KScratch registers and report them in /proc/cpuinfo.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1877/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/proc.c

@@ -74,6 +74,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		);
 	seq_printf(m, "shadow register sets\t: %d\n",
 		       cpu_data[n].srsets);
+	seq_printf(m, "kscratch registers\t: %d\n",
+		   hweight8(cpu_data[n].kscratch_mask));
 	seq_printf(m, "core\t\t\t: %d\n", cpu_data[n].core);
 
 	sprintf(fmt, "VCE%%c exceptions\t\t: %s\n",