powerpc/64: mark irqs hard disabled in boot paca

This prevents interrupts in early boot (e.g., program check) from
enabling MSR[EE], potentially causing endian mismatch or other
crashes when reporting early boot traps.

Fixes: 4423eb5a ("powerpc/64/interrupt: make normal synchronous interrupts enable MSR[EE] if possible")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926054305.2671436-3-npiggin@gmail.com

arch/powerpc/kernel/setup_64.c

@@ -182,8 +182,10 @@ static void __init fixup_boot_paca(void)
 	get_paca()->cpu_start = 1;
 	/* Allow percpu accesses to work until we setup percpu data */
 	get_paca()->data_offset = 0;
-	/* Mark interrupts disabled in PACA */
+	/* Mark interrupts soft and hard disabled in PACA */
 	irq_soft_mask_set(IRQS_DISABLED);
+	get_paca()->irq_happened = PACA_IRQ_HARD_DIS;
+	WARN_ON(mfmsr() & MSR_EE);
 }
 
 static void __init configure_exceptions(void)