1 files changed, 521 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
new file mode 100644
index 000000000..317659fde
--- /dev/null
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -0,0 +1,521 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
+ */
+#ifndef _ASM_POWERPC_HW_IRQ_H
+#define _ASM_POWERPC_HW_IRQ_H
+
+#ifdef __KERNEL__
+
+#include <linux/errno.h>
+#include <linux/compiler.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+
+#ifdef CONFIG_PPC64
+
+/*
+ * PACA flags in paca->irq_happened.
+ *
+ * This bits are set when interrupts occur while soft-disabled
+ * and allow a proper replay.
+ *
+ * The PACA_IRQ_HARD_DIS is set whenever we hard disable. It is almost
+ * always in synch with the MSR[EE] state, except:
+ * - A window in interrupt entry, where hardware disables MSR[EE] and that
+ *   must be "reconciled" with the soft mask state.
+ * - NMI interrupts that hit in awkward places, until they fix the state.
+ * - When local irqs are being enabled and state is being fixed up.
+ * - When returning from an interrupt there are some windows where this
+ *   can become out of synch, but gets fixed before the RFI or before
+ *   executing the next user instruction (see arch/powerpc/kernel/interrupt.c).
+ */
+#define PACA_IRQ_HARD_DIS	0x01
+#define PACA_IRQ_DBELL		0x02
+#define PACA_IRQ_EE		0x04
+#define PACA_IRQ_DEC		0x08 /* Or FIT */
+#define PACA_IRQ_HMI		0x10
+#define PACA_IRQ_PMI		0x20
+#define PACA_IRQ_REPLAYING	0x40
+
+/*
+ * Some soft-masked interrupts must be hard masked until they are replayed
+ * (e.g., because the soft-masked handler does not clear the exception).
+ * Interrupt replay itself must remain hard masked too.
+ */
+#ifdef CONFIG_PPC_BOOK3S
+#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE|PACA_IRQ_PMI|PACA_IRQ_REPLAYING)
+#else
+#define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE|PACA_IRQ_REPLAYING)
+#endif
+
+#endif /* CONFIG_PPC64 */
+
+/*
+ * flags for paca->irq_soft_mask
+ */
+#define IRQS_ENABLED		0
+#define IRQS_DISABLED		1 /* local_irq_disable() interrupts */
+#define IRQS_PMI_DISABLED	2
+#define IRQS_ALL_DISABLED	(IRQS_DISABLED | IRQS_PMI_DISABLED)
+
+#ifndef __ASSEMBLY__
+
+static inline void __hard_irq_enable(void)
+{
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
+		wrtee(MSR_EE);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_EIE);
+	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		__mtmsrd(MSR_EE | MSR_RI, 1);
+	else
+		mtmsr(mfmsr() | MSR_EE);
+}
+
+static inline void __hard_irq_disable(void)
+{
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
+		wrtee(0);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_EID);
+	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		__mtmsrd(MSR_RI, 1);
+	else
+		mtmsr(mfmsr() & ~MSR_EE);
+}
+
+static inline void __hard_EE_RI_disable(void)
+{
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
+		wrtee(0);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_NRI);
+	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		__mtmsrd(0, 1);
+	else
+		mtmsr(mfmsr() & ~(MSR_EE | MSR_RI));
+}
+
+static inline void __hard_RI_enable(void)
+{
+	if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
+		return;
+
+	if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_EID);
+	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		__mtmsrd(MSR_RI, 1);
+	else
+		mtmsr(mfmsr() | MSR_RI);
+}
+
+#ifdef CONFIG_PPC64
+#include <asm/paca.h>
+
+static inline notrace unsigned long irq_soft_mask_return(void)
+{
+	unsigned long flags;
+
+	asm volatile(
+		"lbz %0,%1(13)"
+		: "=r" (flags)
+		: "i" (offsetof(struct paca_struct, irq_soft_mask)));
+
+	return flags;
+}
+
+/*
+ * The "memory" clobber acts as both a compiler barrier
+ * for the critical section and as a clobber because
+ * we changed paca->irq_soft_mask
+ */
+static inline notrace void irq_soft_mask_set(unsigned long mask)
+{
+	/*
+	 * The irq mask must always include the STD bit if any are set.
+	 *
+	 * and interrupts don't get replayed until the standard
+	 * interrupt (local_irq_disable()) is unmasked.
+	 *
+	 * Other masks must only provide additional masking beyond
+	 * the standard, and they are also not replayed until the
+	 * standard interrupt becomes unmasked.
+	 *
+	 * This could be changed, but it will require partial
+	 * unmasks to be replayed, among other things. For now, take
+	 * the simple approach.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON(mask && !(mask & IRQS_DISABLED));
+
+	asm volatile(
+		"stb %0,%1(13)"
+		:
+		: "r" (mask),
+		  "i" (offsetof(struct paca_struct, irq_soft_mask))
+		: "memory");
+}
+
+static inline notrace unsigned long irq_soft_mask_set_return(unsigned long mask)
+{
+	unsigned long flags = irq_soft_mask_return();
+
+	irq_soft_mask_set(mask);
+
+	return flags;
+}
+
+static inline notrace unsigned long irq_soft_mask_or_return(unsigned long mask)
+{
+	unsigned long flags = irq_soft_mask_return();
+
+	irq_soft_mask_set(flags | mask);
+
+	return flags;
+}
+
+static inline notrace unsigned long irq_soft_mask_andc_return(unsigned long mask)
+{
+	unsigned long flags = irq_soft_mask_return();
+
+	irq_soft_mask_set(flags & ~mask);
+
+	return flags;
+}
+
+static inline unsigned long arch_local_save_flags(void)
+{
+	return irq_soft_mask_return();
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	irq_soft_mask_set(IRQS_DISABLED);
+}
+
+extern void arch_local_irq_restore(unsigned long);
+
+static inline void arch_local_irq_enable(void)
+{
+	arch_local_irq_restore(IRQS_ENABLED);
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+	return irq_soft_mask_or_return(IRQS_DISABLED);
+}
+
+static inline bool arch_irqs_disabled_flags(unsigned long flags)
+{
+	return flags & IRQS_DISABLED;
+}
+
+static inline bool arch_irqs_disabled(void)
+{
+	return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+static inline void set_pmi_irq_pending(void)
+{
+	/*
+	 * Invoked from PMU callback functions to set PMI bit in the paca.
+	 * This has to be called with irq's disabled (via hard_irq_disable()).
+	 */
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(mfmsr() & MSR_EE);
+
+	get_paca()->irq_happened |= PACA_IRQ_PMI;
+}
+
+static inline void clear_pmi_irq_pending(void)
+{
+	/*
+	 * Invoked from PMU callback functions to clear the pending PMI bit
+	 * in the paca.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(mfmsr() & MSR_EE);
+
+	get_paca()->irq_happened &= ~PACA_IRQ_PMI;
+}
+
+static inline bool pmi_irq_pending(void)
+{
+	/*
+	 * Invoked from PMU callback functions to check if there is a pending
+	 * PMI bit in the paca.
+	 */
+	if (get_paca()->irq_happened & PACA_IRQ_PMI)
+		return true;
+
+	return false;
+}
+
+#ifdef CONFIG_PPC_BOOK3S
+/*
+ * To support disabling and enabling of irq with PMI, set of
+ * new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore()
+ * functions are added. These macros are implemented using generic
+ * linux local_irq_* code from include/linux/irqflags.h.
+ */
+#define raw_local_irq_pmu_save(flags)					\
+	do {								\
+		typecheck(unsigned long, flags);			\
+		flags = irq_soft_mask_or_return(IRQS_DISABLED |	\
+				IRQS_PMI_DISABLED);			\
+	} while(0)
+
+#define raw_local_irq_pmu_restore(flags)				\
+	do {								\
+		typecheck(unsigned long, flags);			\
+		arch_local_irq_restore(flags);				\
+	} while(0)
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+#define powerpc_local_irq_pmu_save(flags)			\
+	 do {							\
+		raw_local_irq_pmu_save(flags);			\
+		if (!raw_irqs_disabled_flags(flags))		\
+			trace_hardirqs_off();			\
+	} while(0)
+#define powerpc_local_irq_pmu_restore(flags)			\
+	do {							\
+		if (!raw_irqs_disabled_flags(flags))		\
+			trace_hardirqs_on();			\
+		raw_local_irq_pmu_restore(flags);		\
+	} while(0)
+#else
+#define powerpc_local_irq_pmu_save(flags)			\
+	do {							\
+		raw_local_irq_pmu_save(flags);			\
+	} while(0)
+#define powerpc_local_irq_pmu_restore(flags)			\
+	do {							\
+		raw_local_irq_pmu_restore(flags);		\
+	} while (0)
+#endif  /* CONFIG_TRACE_IRQFLAGS */
+
+#endif /* CONFIG_PPC_BOOK3S */
+
+#define hard_irq_disable()	do {					\
+	unsigned long flags;						\
+	__hard_irq_disable();						\
+	flags = irq_soft_mask_set_return(IRQS_ALL_DISABLED);		\
+	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;			\
+	if (!arch_irqs_disabled_flags(flags)) {				\
+		asm volatile("std%X0 %1,%0" : "=m" (local_paca->saved_r1) \
+					    : "r" (current_stack_pointer)); \
+		trace_hardirqs_off();					\
+	}								\
+} while(0)
+
+static inline bool __lazy_irq_pending(u8 irq_happened)
+{
+	return !!(irq_happened & ~PACA_IRQ_HARD_DIS);
+}
+
+/*
+ * Check if a lazy IRQ is pending. Should be called with IRQs hard disabled.
+ */
+static inline bool lazy_irq_pending(void)
+{
+	return __lazy_irq_pending(get_paca()->irq_happened);
+}
+
+/*
+ * Check if a lazy IRQ is pending, with no debugging checks.
+ * Should be called with IRQs hard disabled.
+ * For use in RI disabled code or other constrained situations.
+ */
+static inline bool lazy_irq_pending_nocheck(void)
+{
+	return __lazy_irq_pending(local_paca->irq_happened);
+}
+
+bool power_pmu_wants_prompt_pmi(void);
+
+/*
+ * This is called by asynchronous interrupts to check whether to
+ * conditionally re-enable hard interrupts after having cleared
+ * the source of the interrupt. They are kept disabled if there
+ * is a different soft-masked interrupt pending that requires hard
+ * masking.
+ */
+static inline bool should_hard_irq_enable(struct pt_regs *regs)
+{
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+		WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
+		WARN_ON(!(get_paca()->irq_happened & PACA_IRQ_HARD_DIS));
+		WARN_ON(mfmsr() & MSR_EE);
+	}
+
+	if (!IS_ENABLED(CONFIG_PERF_EVENTS))
+		return false;
+	/*
+	 * If the PMU is not running, there is not much reason to enable
+	 * MSR[EE] in irq handlers because any interrupts would just be
+	 * soft-masked.
+	 *
+	 * TODO: Add test for 64e
+	 */
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64)) {
+		if (!power_pmu_wants_prompt_pmi())
+			return false;
+		/*
+		 * If PMIs are disabled then IRQs should be disabled as well,
+		 * so we shouldn't see this condition, check for it just in
+		 * case because we are about to enable PMIs.
+		 */
+		if (WARN_ON_ONCE(regs->softe & IRQS_PMI_DISABLED))
+			return false;
+	}
+
+	if (get_paca()->irq_happened & PACA_IRQ_MUST_HARD_MASK)
+		return false;
+
+	return true;
+}
+
+/*
+ * Do the hard enabling, only call this if should_hard_irq_enable is true.
+ * This allows PMI interrupts to profile irq handlers.
+ */
+static inline void do_hard_irq_enable(void)
+{
+	/*
+	 * Asynch interrupts come in with IRQS_ALL_DISABLED,
+	 * PACA_IRQ_HARD_DIS, and MSR[EE]=0.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		irq_soft_mask_andc_return(IRQS_PMI_DISABLED);
+	get_paca()->irq_happened &= ~PACA_IRQ_HARD_DIS;
+	__hard_irq_enable();
+}
+
+static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
+{
+	return (regs->softe & IRQS_DISABLED);
+}
+
+extern bool prep_irq_for_idle(void);
+extern bool prep_irq_for_idle_irqsoff(void);
+extern void irq_set_pending_from_srr1(unsigned long srr1);
+
+#define fini_irq_for_idle_irqsoff() trace_hardirqs_off();
+
+extern void force_external_irq_replay(void);
+
+static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
+{
+	regs->softe = val;
+}
+#else /* CONFIG_PPC64 */
+
+static inline notrace unsigned long irq_soft_mask_return(void)
+{
+	return 0;
+}
+
+static inline unsigned long arch_local_save_flags(void)
+{
+	return mfmsr();
+}
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	if (IS_ENABLED(CONFIG_BOOKE))
+		wrtee(flags);
+	else
+		mtmsr(flags);
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+	unsigned long flags = arch_local_save_flags();
+
+	if (IS_ENABLED(CONFIG_BOOKE))
+		wrtee(0);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_EID);
+	else
+		mtmsr(flags & ~MSR_EE);
+
+	return flags;
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	__hard_irq_disable();
+}
+
+static inline void arch_local_irq_enable(void)
+{
+	__hard_irq_enable();
+}
+
+static inline bool arch_irqs_disabled_flags(unsigned long flags)
+{
+	return (flags & MSR_EE) == 0;
+}
+
+static inline bool arch_irqs_disabled(void)
+{
+	return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+#define hard_irq_disable()		arch_local_irq_disable()
+
+static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
+{
+	return !(regs->msr & MSR_EE);
+}
+
+static __always_inline bool should_hard_irq_enable(struct pt_regs *regs)
+{
+	return false;
+}
+
+static inline void do_hard_irq_enable(void)
+{
+	BUILD_BUG();
+}
+
+static inline void clear_pmi_irq_pending(void) { }
+static inline void set_pmi_irq_pending(void) { }
+static inline bool pmi_irq_pending(void) { return false; }
+
+static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
+{
+}
+#endif /* CONFIG_PPC64 */
+
+static inline unsigned long mtmsr_isync_irqsafe(unsigned long msr)
+{
+#ifdef CONFIG_PPC64
+	if (arch_irqs_disabled()) {
+		/*
+		 * With soft-masking, MSR[EE] can change from 1 to 0
+		 * asynchronously when irqs are disabled, and we don't want to
+		 * set MSR[EE] back to 1 here if that has happened. A race-free
+		 * way to do this is ensure EE is already 0. Another way it
+		 * could be done is with a RESTART_TABLE handler, but that's
+		 * probably overkill here.
+		 */
+		msr &= ~MSR_EE;
+		mtmsr_isync(msr);
+		irq_soft_mask_set(IRQS_ALL_DISABLED);
+		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+	} else
+#endif
+		mtmsr_isync(msr);
+
+	return msr;
+}
+
+
+#define ARCH_IRQ_INIT_FLAGS	IRQ_NOREQUEST
+
+#endif  /* __ASSEMBLY__ */
+#endif	/* __KERNEL__ */
+#endif	/* _ASM_POWERPC_HW_IRQ_H */