powerpc/64s/pseries: radix flush translations before MMU is enabled at boot

Radix guests are responsible for managing their own translation caches,
so make them match bare metal radix and hash, and make each CPU flush
all its translations right before enabling its MMU.

Radix guests may not flush partition scope translations, so in
tlbiel_all, make these flushes conditional on CPU_FTR_HVMODE. Process
scope translations are the only type visible to the guest.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-5-npiggin@gmail.com

arch/powerpc/mm/book3s64/radix_pgtable.c

@@ -616,7 +616,6 @@ void __init radix__early_init_mmu(void)
 
 	/* Switch to the guard PID before turning on MMU */
 	radix__switch_mmu_context(NULL, &init_mm);
-	if (cpu_has_feature(CPU_FTR_HVMODE))
 	tlbiel_all();
 }
 
@@ -637,7 +636,6 @@ void radix__early_init_mmu_secondary(void)
 	}
 
 	radix__switch_mmu_context(NULL, &init_mm);
-	if (cpu_has_feature(CPU_FTR_HVMODE))
 	tlbiel_all();
 }
 

arch/powerpc/mm/book3s64/radix_tlb.c

@@ -51,11 +51,15 @@ static void tlbiel_all_isa300(unsigned int num_sets, unsigned int is)
 	 * and partition table entries. Then flush the remaining sets of the
 	 * TLB.
 	 */
+
+	if (early_cpu_has_feature(CPU_FTR_HVMODE)) {
+		/* MSR[HV] should flush partition scope translations first. */
 		tlbiel_radix_set_isa300(0, is, 0, RIC_FLUSH_ALL, 0);
 		for (set = 1; set < num_sets; set++)
 			tlbiel_radix_set_isa300(set, is, 0, RIC_FLUSH_TLB, 0);
+	}
 
-	/* Do the same for process scoped entries. */
+	/* Flush process scoped entries. */
 	tlbiel_radix_set_isa300(0, is, 0, RIC_FLUSH_ALL, 1);
 	for (set = 1; set < num_sets; set++)
 		tlbiel_radix_set_isa300(set, is, 0, RIC_FLUSH_TLB, 1);