Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The biggest changes are MPAM enablement in drivers/resctrl and new PMU
  support under drivers/perf.

  On the core side, FEAT_LSUI lets futex atomic operations with EL0
  permissions, avoiding PAN toggling.

  The rest is mostly TLB invalidation refactoring, further generic entry
  work, sysreg updates and a few fixes.

  Core features:

   - Add support for FEAT_LSUI, allowing futex atomic operations without
     toggling Privileged Access Never (PAN)

   - Further refactor the arm64 exception handling code towards the
     generic entry infrastructure

   - Optimise __READ_ONCE() with CONFIG_LTO=y and allow alias analysis
     through it

  Memory management:

   - Refactor the arm64 TLB invalidation API and implementation for
     better control over barrier placement and level-hinted invalidation

   - Enable batched TLB flushes during memory hot-unplug

   - Fix rodata=full block mapping support for realm guests (when
     BBML2_NOABORT is available)

  Perf and PMU:

   - Add support for a whole bunch of system PMUs featured in NVIDIA's
     Tegra410 SoC (cspmu extensions for the fabric and PCIe, new drivers
     for CPU/C2C memory latency PMUs)

   - Clean up iomem resource handling in the Arm CMN driver

   - Fix signedness handling of AA64DFR0.{PMUVer,PerfMon}

  MPAM (Memory Partitioning And Monitoring):

   - Add architecture context-switch and hiding of the feature from KVM

   - Add interface to allow MPAM to be exposed to user-space using
     resctrl

   - Add errata workaround for some existing platforms

   - Add documentation for using MPAM and what shape of platforms can
     use resctrl

  Miscellaneous:

   - Check DAIF (and PMR, where relevant) at task-switch time

   - Skip TFSR_EL1 checks and barriers in synchronous MTE tag check mode
     (only relevant to asynchronous or asymmetric tag check modes)

   - Remove a duplicate allocation in the kexec code

   - Remove redundant save/restore of SCS SP on entry to/from EL0

   - Generate the KERNEL_HWCAP_ definitions from the arm64 hwcap
     descriptions

   - Add kselftest coverage for cmpbr_sigill()

   - Update sysreg definitions"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (109 commits)
  arm64: rsi: use linear-map alias for realm config buffer
  arm64: Kconfig: fix duplicate word in CMDLINE help text
  arm64: mte: Skip TFSR_EL1 checks and barriers in synchronous tag check mode
  arm64/sysreg: Update ID_AA64SMFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ZFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64FPFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ISAR2_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ISAR0_EL1 description to DDI0601 2025-12
  arm64/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps
  arm64: kexec: Remove duplicate allocation for trans_pgd
  ACPI: AGDI: fix missing newline in error message
  arm64: Check DAIF (and PMR) at task-switch time
  arm64: entry: Use split preemption logic
  arm64: entry: Use irqentry_{enter_from,exit_to}_kernel_mode()
  arm64: entry: Consistently prefix arm64-specific wrappers
  arm64: entry: Don't preempt with SError or Debug masked
  entry: Split preemption from irqentry_exit_to_kernel_mode()
  entry: Split kernel mode logic from irqentry_{enter,exit}()
  entry: Move irqentry_enter() prototype later
  entry: Remove local_irq_{enable,disable}_exit_to_user()
  ...

1 files changed, 10 insertions, 99 deletions

diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 9e1a6afb07f2..19d2244a9fef 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -47,7 +47,7 @@ static __always_inline unsigned long __exit_to_user_mode_loop(struct pt_regs *re
 	 */
 	while (ti_work & EXIT_TO_USER_MODE_WORK_LOOP) {
 
-		local_irq_enable_exit_to_user(ti_work);
+		local_irq_enable();
 
 		if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)) {
 			if (!rseq_grant_slice_extension(ti_work, TIF_SLICE_EXT_DENY))
@@ -74,7 +74,7 @@ static __always_inline unsigned long __exit_to_user_mode_loop(struct pt_regs *re
 		 * might have changed while interrupts and preemption was
 		 * enabled above.
 		 */
-		local_irq_disable_exit_to_user();
+		local_irq_disable();
 
 		/* Check if any of the above work has queued a deferred wakeup */
 		tick_nohz_user_enter_prepare();
@@ -105,70 +105,16 @@ __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
 
 noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
 {
-	irqentry_state_t ret = {
-		.exit_rcu = false,
-	};
-
 	if (user_mode(regs)) {
-		irqentry_enter_from_user_mode(regs);
-		return ret;
-	}
+		irqentry_state_t ret = {
+			.exit_rcu = false,
+		};
 
-	/*
-	 * If this entry hit the idle task invoke ct_irq_enter() whether
-	 * RCU is watching or not.
-	 *
-	 * Interrupts can nest when the first interrupt invokes softirq
-	 * processing on return which enables interrupts.
-	 *
-	 * Scheduler ticks in the idle task can mark quiescent state and
-	 * terminate a grace period, if and only if the timer interrupt is
-	 * not nested into another interrupt.
-	 *
-	 * Checking for rcu_is_watching() here would prevent the nesting
-	 * interrupt to invoke ct_irq_enter(). If that nested interrupt is
-	 * the tick then rcu_flavor_sched_clock_irq() would wrongfully
-	 * assume that it is the first interrupt and eventually claim
-	 * quiescent state and end grace periods prematurely.
-	 *
-	 * Unconditionally invoke ct_irq_enter() so RCU state stays
-	 * consistent.
-	 *
-	 * TINY_RCU does not support EQS, so let the compiler eliminate
-	 * this part when enabled.
-	 */
-	if (!IS_ENABLED(CONFIG_TINY_RCU) &&
-	    (is_idle_task(current) || arch_in_rcu_eqs())) {
-		/*
-		 * If RCU is not watching then the same careful
-		 * sequence vs. lockdep and tracing is required
-		 * as in irqentry_enter_from_user_mode().
-		 */
-		lockdep_hardirqs_off(CALLER_ADDR0);
-		ct_irq_enter();
-		instrumentation_begin();
-		kmsan_unpoison_entry_regs(regs);
-		trace_hardirqs_off_finish();
-		instrumentation_end();
-
-		ret.exit_rcu = true;
+		irqentry_enter_from_user_mode(regs);
 		return ret;
 	}
 
-	/*
-	 * If RCU is watching then RCU only wants to check whether it needs
-	 * to restart the tick in NOHZ mode. rcu_irq_enter_check_tick()
-	 * already contains a warning when RCU is not watching, so no point
-	 * in having another one here.
-	 */
-	lockdep_hardirqs_off(CALLER_ADDR0);
-	instrumentation_begin();
-	kmsan_unpoison_entry_regs(regs);
-	rcu_irq_enter_check_tick();
-	trace_hardirqs_off_finish();
-	instrumentation_end();
-
-	return ret;
+	return irqentry_enter_from_kernel_mode(regs);
 }
 
 /**
@@ -212,45 +158,10 @@ void dynamic_irqentry_exit_cond_resched(void)
 
 noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state)
 {
-	lockdep_assert_irqs_disabled();
-
-	/* Check whether this returns to user mode */
-	if (user_mode(regs)) {
+	if (user_mode(regs))
 		irqentry_exit_to_user_mode(regs);
-	} else if (!regs_irqs_disabled(regs)) {
-		/*
-		 * If RCU was not watching on entry this needs to be done
-		 * carefully and needs the same ordering of lockdep/tracing
-		 * and RCU as the return to user mode path.
-		 */
-		if (state.exit_rcu) {
-			instrumentation_begin();
-			hrtimer_rearm_deferred();
-			/* Tell the tracer that IRET will enable interrupts */
-			trace_hardirqs_on_prepare();
-			lockdep_hardirqs_on_prepare();
-			instrumentation_end();
-			ct_irq_exit();
-			lockdep_hardirqs_on(CALLER_ADDR0);
-			return;
-		}
-
-		instrumentation_begin();
-		if (IS_ENABLED(CONFIG_PREEMPTION))
-			irqentry_exit_cond_resched();
-
-		hrtimer_rearm_deferred();
-		/* Covers both tracing and lockdep */
-		trace_hardirqs_on();
-		instrumentation_end();
-	} else {
-		/*
-		 * IRQ flags state is correct already. Just tell RCU if it
-		 * was not watching on entry.
-		 */
-		if (state.exit_rcu)
-			ct_irq_exit();
-	}
+	else
+		irqentry_exit_to_kernel_mode(regs, state);
 }
 
 irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs)