linux-kernel - [PATCH] powerpc/irq: Remove arch_local_irq_restore() for !CONFIG_CC_HAS_ASM

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Message-Id: <58df50c9e77e2ed945bacdead30412770578886b.1652715336.git.christophe.leroy@csgroup.eu>
Date:   Mon, 16 May 2022 17:36:04 +0200
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     Christophe Leroy <christophe.leroy@...roup.eu>,
        linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH] powerpc/irq: Remove arch_local_irq_restore() for !CONFIG_CC_HAS_ASM_GOTO

All supported versions of GCC support asm goto.

Remove the !CONFIG_CC_HAS_ASM_GOTO version of arch_local_irq_restore()

Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
 arch/powerpc/kernel/irq.c | 77 ---------------------------------------
 1 file changed, 77 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c768cde03e36..dd09919c3c66 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -216,7 +216,6 @@ static inline void replay_soft_interrupts_irqrestore(void)
 #define replay_soft_interrupts_irqrestore() replay_soft_interrupts()
 #endif
 
-#ifdef CONFIG_CC_HAS_ASM_GOTO
 notrace void arch_local_irq_restore(unsigned long mask)
 {
 	unsigned char irq_happened;
@@ -312,82 +311,6 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	__hard_irq_enable();
 	preempt_enable();
 }
-#else
-notrace void arch_local_irq_restore(unsigned long mask)
-{
-	unsigned char irq_happened;
-
-	/* Write the new soft-enabled value */
-	irq_soft_mask_set(mask);
-	if (mask)
-		return;
-
-	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-		WARN_ON_ONCE(in_nmi() || in_hardirq());
-
-	/*
-	 * From this point onward, we can take interrupts, preempt,
-	 * etc... unless we got hard-disabled. We check if an event
-	 * happened. If none happened, we know we can just return.
-	 *
-	 * We may have preempted before the check below, in which case
-	 * we are checking the "new" CPU instead of the old one. This
-	 * is only a problem if an event happened on the "old" CPU.
-	 *
-	 * External interrupt events will have caused interrupts to
-	 * be hard-disabled, so there is no problem, we
-	 * cannot have preempted.
-	 */
-	irq_happened = get_irq_happened();
-	if (!irq_happened) {
-		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-			WARN_ON_ONCE(!(mfmsr() & MSR_EE));
-		return;
-	}
-
-	/* We need to hard disable to replay. */
-	if (!(irq_happened & PACA_IRQ_HARD_DIS)) {
-		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-			WARN_ON_ONCE(!(mfmsr() & MSR_EE));
-		__hard_irq_disable();
-		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
-	} else {
-		/*
-		 * We should already be hard disabled here. We had bugs
-		 * where that wasn't the case so let's dbl check it and
-		 * warn if we are wrong. Only do that when IRQ tracing
-		 * is enabled as mfmsr() can be costly.
-		 */
-		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
-			if (WARN_ON_ONCE(mfmsr() & MSR_EE))
-				__hard_irq_disable();
-		}
-
-		if (irq_happened == PACA_IRQ_HARD_DIS) {
-			local_paca->irq_happened = 0;
-			__hard_irq_enable();
-			return;
-		}
-	}
-
-	/*
-	 * Disable preempt here, so that the below preempt_enable will
-	 * perform resched if required (a replayed interrupt may set
-	 * need_resched).
-	 */
-	preempt_disable();
-	irq_soft_mask_set(IRQS_ALL_DISABLED);
-	trace_hardirqs_off();
-
-	replay_soft_interrupts_irqrestore();
-	local_paca->irq_happened = 0;
-
-	trace_hardirqs_on();
-	irq_soft_mask_set(IRQS_ENABLED);
-	__hard_irq_enable();
-	preempt_enable();
-}
-#endif
 EXPORT_SYMBOL(arch_local_irq_restore);
 
 /*
-- 
2.35.1