Merge branch 'for-next/misc' into for-next/core

* for-next/misc:
  arm64: simplify arch_static_branch/_jump function
  arm64: Add the arm64.no32bit_el0 command line option
  arm64: defer clearing DAIF.D
  arm64: assembler: update stale comment for disable_step_tsk
  arm64/sysreg: Update PIE permission encodings
  arm64: Add Neoverse-V2 part
  arm64: Remove unnecessary irqflags alternative.h include

3 files changed, 18 insertions, 2 deletions

diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c
index aad399796e81..48c1aa456af9 100644
--- a/arch/arm64/kernel/pi/idreg-override.c
+++ b/arch/arm64/kernel/pi/idreg-override.c
@@ -108,6 +108,7 @@ static const struct ftr_set_desc pfr0 __prel64_initconst = {
 	.override	= &id_aa64pfr0_override,
 	.fields		= {
 	        FIELD("sve", ID_AA64PFR0_EL1_SVE_SHIFT, pfr0_sve_filter),
+		FIELD("el0", ID_AA64PFR0_EL1_EL0_SHIFT, NULL),
 		{}
 	},
 };
@@ -223,6 +224,7 @@ static const struct {
 	{ "nokaslr",			"arm64_sw.nokaslr=1" },
 	{ "rodata=off",			"arm64_sw.rodataoff=1" },
 	{ "arm64.nolva",		"id_aa64mmfr2.varange=0" },
+	{ "arm64.no32bit_el0",		"id_aa64pfr0.el0=1" },
 };
 
 static int __init parse_hexdigit(const char *p, u64 *v)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 65a052bf741f..a096e2451044 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -298,8 +298,15 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 	dynamic_scs_init();
 
 	/*
-	 * Unmask SError as soon as possible after initializing earlycon so
-	 * that we can report any SErrors immediately.
+	 * The primary CPU enters the kernel with all DAIF exceptions masked.
+	 *
+	 * We must unmask Debug and SError before preemption or scheduling is
+	 * possible to ensure that these are consistently unmasked across
+	 * threads, and we want to unmask SError as soon as possible after
+	 * initializing earlycon so that we can report any SErrors immediately.
+	 *
+	 * IRQ and FIQ will be unmasked after the root irqchip has been
+	 * detected and initialized.
 	 */
 	local_daif_restore(DAIF_PROCCTX_NOIRQ);
 
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 4ced34f62dab..31c8b3094dd7 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -264,6 +264,13 @@ asmlinkage notrace void secondary_start_kernel(void)
 	set_cpu_online(cpu, true);
 	complete(&cpu_running);
 
+	/*
+	 * Secondary CPUs enter the kernel with all DAIF exceptions masked.
+	 *
+	 * As with setup_arch() we must unmask Debug and SError exceptions, and
+	 * as the root irqchip has already been detected and initialized we can
+	 * unmask IRQ and FIQ at the same time.
+	 */
 	local_daif_restore(DAIF_PROCCTX);
 
 	/*