MIPS: dump_tlb: Only dump PageGrain if interesting

The PageGrain register may not exist if certain architectural features
aren't present, therefore only print out its value when dumping the TLB
registers if it is expected to contain fields relevant to the TLB.

Fixes: d1e9a4f5 ("MIPS: Add SysRq operation to dump TLBs on all CPUs")
Reported-by: NJoshua Kinard <kumba@gentoo.org>
Reported-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10723/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/lib/dump_tlb.c

@@ -23,7 +23,8 @@ void dump_tlb_regs(void)
 	pr_info("EntryLo0 : %0*lx\n", field, read_c0_entrylo0());
 	pr_info("EntryLo1 : %0*lx\n", field, read_c0_entrylo1());
 	pr_info("Wired    : %0x\n", read_c0_wired());
-	pr_info("PageGrain: %0x\n", read_c0_pagegrain());
+	if (cpu_has_small_pages || cpu_has_rixi || cpu_has_xpa)
+		pr_info("PageGrain: %0x\n", read_c0_pagegrain());
 	if (cpu_has_htw) {
 		pr_info("PWField  : %0*lx\n", field, read_c0_pwfield());
 		pr_info("PWSize   : %0*lx\n", field, read_c0_pwsize());