Merge tag 'powerpc-4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - a fix for hugetlb with 4K pages, broken by our recent changes for
   split PMD PTL.

 - set the correct assembler machine type on e500mc, needed since
   binutils 2.26 introduced two forms for the "wait" instruction.

 - a fix for potential missed TLB flushes with MADV_[FREE|DONTNEED] etc.
   and THP on Power9 Radix.

 - three fixes to try and make our panic handling more robust by hard
   disabling interrupts, and not marking stopped CPUs as offline because
   they haven't been properly offlined.

 - three other minor fixes.

Thanks to: Aneesh Kumar K.V, Michael Jeanson, Nicholas Piggin.

* tag 'powerpc-4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm/hash/4k: Free hugetlb page table caches correctly.
  powerpc/64s/radix: Fix radix_kvm_prefetch_workaround paca access of not possible CPU
  powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n
  powerpc/64: hard disable irqs on the panic()ing CPU
  powerpc: smp_send_stop do not offline stopped CPUs
  powerpc/64: hard disable irqs in panic_smp_self_stop
  powerpc/64s: Fix DT CPU features Power9 DD2.1 logic
  powerpc/64s/radix: Fix MADV_[FREE|DONTNEED] TLB flush miss problem with THP
  powerpc/e500mc: Set assembler machine type to e500mc

1 files changed, 10 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 62b1a40d8957..40b44bb53a4e 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -701,11 +701,18 @@ static int ppc_panic_event(struct notifier_block *this,
                              unsigned long event, void *ptr)
 {
 	/*
+	 * panic does a local_irq_disable, but we really
+	 * want interrupts to be hard disabled.
+	 */
+	hard_irq_disable();
+
+	/*
 	 * If firmware-assisted dump has been registered then trigger
 	 * firmware-assisted dump and let firmware handle everything else.
 	 */
 	crash_fadump(NULL, ptr);
-	ppc_md.panic(ptr);  /* May not return */
+	if (ppc_md.panic)
+		ppc_md.panic(ptr);  /* May not return */
 	return NOTIFY_DONE;
 }
 
@@ -716,7 +723,8 @@ static struct notifier_block ppc_panic_block = {
 
 void __init setup_panic(void)
 {
-	if (!ppc_md.panic)
+	/* PPC64 always does a hard irq disable in its panic handler */
+	if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
 		return;
 	atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
 }