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Date:   Fri, 7 Aug 2020 13:11:26 +0200
From:   peterz@infradead.org
To:     Nicholas Piggin <npiggin@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, Ingo Molnar <mingo@redhat.com>,
        Will Deacon <will@kernel.org>,
        Alexey Kardashevskiy <aik@ozlabs.ru>
Subject: Re: [PATCH 1/2] lockdep: improve current->(hard|soft)irqs_enabled
 synchronisation with actual irq state
Message-ID: <20200807111126.GI2674@hirez.programming.kicks-ass.net>
References: <20200723105615.1268126-1-npiggin@gmail.com>
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What's wrong with something like this?

AFAICT there's no reason to actually try and add IRQ tracing here, it's
just a hand full of instructions at the most.

---

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 3a0db7b0b46e..6be22c1838e2 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -196,33 +196,6 @@ static inline bool arch_irqs_disabled(void)
 		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);			\
-		trace_hardirqs_off();				\
-	} while(0)
-#define powerpc_local_irq_pmu_restore(flags)			\
-	do {							\
-		if (raw_irqs_disabled_flags(flags)) {		\
-			raw_local_irq_pmu_restore(flags);	\
-			trace_hardirqs_off();			\
-		} else {					\
-			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 */
 
 #ifdef CONFIG_PPC_BOOK3E
diff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h
index bc4bd19b7fc2..b357a35672b1 100644
--- a/arch/powerpc/include/asm/local.h
+++ b/arch/powerpc/include/asm/local.h
@@ -32,9 +32,9 @@ static __inline__ void local_##op(long i, local_t *l)			\
 {									\
 	unsigned long flags;						\
 									\
-	powerpc_local_irq_pmu_save(flags);				\
+	raw_powerpc_local_irq_pmu_save(flags);				\
 	l->v c_op i;						\
-	powerpc_local_irq_pmu_restore(flags);				\
+	raw_powerpc_local_irq_pmu_restore(flags);				\
 }
 
 #define LOCAL_OP_RETURN(op, c_op)					\
@@ -43,9 +43,9 @@ static __inline__ long local_##op##_return(long a, local_t *l)		\
 	long t;								\
 	unsigned long flags;						\
 									\
-	powerpc_local_irq_pmu_save(flags);				\
+	raw_powerpc_local_irq_pmu_save(flags);				\
 	t = (l->v c_op a);						\
-	powerpc_local_irq_pmu_restore(flags);				\
+	raw_powerpc_local_irq_pmu_restore(flags);				\
 									\
 	return t;							\
 }
@@ -81,11 +81,11 @@ static __inline__ long local_cmpxchg(local_t *l, long o, long n)
 	long t;
 	unsigned long flags;
 
-	powerpc_local_irq_pmu_save(flags);
+	raw_powerpc_local_irq_pmu_save(flags);
 	t = l->v;
 	if (t == o)
 		l->v = n;
-	powerpc_local_irq_pmu_restore(flags);
+	raw_powerpc_local_irq_pmu_restore(flags);
 
 	return t;
 }
@@ -95,10 +95,10 @@ static __inline__ long local_xchg(local_t *l, long n)
 	long t;
 	unsigned long flags;
 
-	powerpc_local_irq_pmu_save(flags);
+	raw_powerpc_local_irq_pmu_save(flags);
 	t = l->v;
 	l->v = n;
-	powerpc_local_irq_pmu_restore(flags);
+	raw_powerpc_local_irq_pmu_restore(flags);
 
 	return t;
 }
@@ -117,12 +117,12 @@ static __inline__ int local_add_unless(local_t *l, long a, long u)
 	unsigned long flags;
 	int ret = 0;
 
-	powerpc_local_irq_pmu_save(flags);
+	raw_powerpc_local_irq_pmu_save(flags);
 	if (l->v != u) {
 		l->v += a;
 		ret = 1;
 	}
-	powerpc_local_irq_pmu_restore(flags);
+	raw_powerpc_local_irq_pmu_restore(flags);
 
 	return ret;
 }