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

Author: willdeacon

Documentation/admin-guide/kernel-parameters.txt

@@ -431,6 +431,9 @@
 	arcrimi=	[HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
 			Format: <io>,<irq>,<nodeID>
 
+	arm64.no32bit_el0 [ARM64] Unconditionally disable the execution of
+			32 bit applications.
+
 	arm64.nobti	[ARM64] Unconditionally disable Branch Target
 			Identification support
 

arch/arm64/include/asm/assembler.h

@@ -50,16 +50,12 @@
 	msr	daif, \flags
 	.endm
 
-	.macro	enable_dbg
-	msr	daifclr, #8
-	.endm
-
 	.macro	disable_step_tsk, flgs, tmp
 	tbz	\flgs, #TIF_SINGLESTEP, 9990f
 	mrs	\tmp, mdscr_el1
 	bic	\tmp, \tmp, #DBG_MDSCR_SS
 	msr	mdscr_el1, \tmp
-	isb	// Synchronise with enable_dbg
+	isb	// Take effect before a subsequent clear of DAIF.D
 9990:
 	.endm
 

arch/arm64/include/asm/cputype.h

@@ -86,6 +86,7 @@
 #define ARM_CPU_PART_CORTEX_X2		0xD48
 #define ARM_CPU_PART_NEOVERSE_N2	0xD49
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
+#define ARM_CPU_PART_NEOVERSE_V2	0xD4F
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -159,6 +160,7 @@
 #define MIDR_CORTEX_X2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X2)
 #define MIDR_NEOVERSE_N2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N2)
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
+#define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)

arch/arm64/include/asm/irqflags.h

@@ -5,7 +5,6 @@
 #ifndef __ASM_IRQFLAGS_H
 #define __ASM_IRQFLAGS_H
 
-#include <asm/alternative.h>
 #include <asm/barrier.h>
 #include <asm/ptrace.h>
 #include <asm/sysreg.h>

arch/arm64/include/asm/jump_label.h

@@ -15,17 +15,23 @@
 
 #define JUMP_LABEL_NOP_SIZE		AARCH64_INSN_SIZE
 
+#define JUMP_TABLE_ENTRY(key, label)			\
+	".pushsection	__jump_table, \"aw\"\n\t"	\
+	".align		3\n\t"				\
+	".long		1b - ., %l["#label"] - .\n\t"	\
+	".quad		%c0 - .\n\t"			\
+	".popsection\n\t"				\
+	:  :  "i"(key) :  : label
+
 static __always_inline bool arch_static_branch(struct static_key * const key,
 					       const bool branch)
 {
+	char *k = &((char *)key)[branch];
+
 	asm goto(
 		"1:	nop					\n\t"
-		 "	.pushsection	__jump_table, \"aw\"	\n\t"
-		 "	.align		3			\n\t"
-		 "	.long		1b - ., %l[l_yes] - .	\n\t"
-		 "	.quad		%c0 - .			\n\t"
-		 "	.popsection				\n\t"
-		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
+		JUMP_TABLE_ENTRY(k, l_yes)
+		);
 
 	return false;
 l_yes:
@@ -35,15 +41,11 @@ static __always_inline bool arch_static_branch(struct static_key * const key,
 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
 						    const bool branch)
 {
+	char *k = &((char *)key)[branch];
 	asm goto(
 		"1:	b		%l[l_yes]		\n\t"
-		 "	.pushsection	__jump_table, \"aw\"	\n\t"
-		 "	.align		3			\n\t"
-		 "	.long		1b - ., %l[l_yes] - .	\n\t"
-		 "	.quad		%c0 - .			\n\t"
-		 "	.popsection				\n\t"
-		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
-
+		JUMP_TABLE_ENTRY(k, l_yes)
+		);
 	return false;
 l_yes:
 	return true;

arch/arm64/include/asm/sysreg.h

@@ -1036,18 +1036,18 @@
  * Permission Indirection Extension (PIE) permission encodings.
  * Encodings with the _O suffix, have overlays applied (Permission Overlay Extension).
  */
-#define PIE_NONE_O	0x0
-#define PIE_R_O		0x1
-#define PIE_X_O		0x2
-#define PIE_RX_O	0x3
-#define PIE_RW_O	0x5
-#define PIE_RWnX_O	0x6
-#define PIE_RWX_O	0x7
-#define PIE_R		0x8
-#define PIE_GCS		0x9
-#define PIE_RX		0xa
-#define PIE_RW		0xc
-#define PIE_RWX		0xe
+#define PIE_NONE_O	UL(0x0)
+#define PIE_R_O		UL(0x1)
+#define PIE_X_O		UL(0x2)
+#define PIE_RX_O	UL(0x3)
+#define PIE_RW_O	UL(0x5)
+#define PIE_RWnX_O	UL(0x6)
+#define PIE_RWX_O	UL(0x7)
+#define PIE_R		UL(0x8)
+#define PIE_GCS		UL(0x9)
+#define PIE_RX		UL(0xa)
+#define PIE_RW		UL(0xc)
+#define PIE_RWX		UL(0xe)
 
 #define PIRx_ELx_PERM(idx, perm)	((perm) << ((idx) * 4))
 

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)

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);
 

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);
 
 	/*

arch/arm64/mm/proc.S

@@ -135,14 +135,6 @@ SYM_FUNC_START(cpu_do_resume)
 
 	msr	tcr_el1, x8
 	msr	vbar_el1, x9
-
-	/*
-	 * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking
-	 * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug
-	 * exception. Mask them until local_daif_restore() in cpu_suspend()
-	 * resets them.
-	 */
-	disable_daif
 	msr	mdscr_el1, x10
 
 	msr	sctlr_el1, x12
@@ -466,8 +458,6 @@ SYM_FUNC_START(__cpu_setup)
 	msr	cpacr_el1, xzr			// Reset cpacr_el1
 	mov	x1, #1 << 12			// Reset mdscr_el1 and disable
 	msr	mdscr_el1, x1			// access to the DCC from EL0
-	isb					// Unmask debug exceptions now,
-	enable_dbg				// since this is per-cpu
 	reset_pmuserenr_el0 x1			// Disable PMU access from EL0
 	reset_amuserenr_el0 x1			// Disable AMU access from EL0