linux-kernel - [PATCH 1/4] IRQ,x86: remove redundant memory copy operations in chip->irq_set

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Date:	Mon,  2 Apr 2012 00:33:49 +0800
From:	Jiang Liu <liuj97@...il.com>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	Jiang Liu <jiang.liu@...wei.com>, Jiang Liu <liuj97@...il.com>,
	Keping Chen <chenkeping@...wei.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/4] IRQ,x86: remove redundant memory copy operations in chip->irq_set_affinity()

Changeset 3b8249e7 has introduced standard return value IRQ_SET_MASK_OK(0) and
IRQ_SET_MASK_OK_NOCOPY(1) for interrupt controller chip's set_irq_affinity()
method. If chip->irq_set_affinity() doesn't change the affinity mask passed in,
it should return IRQ_SET_MASK_OK and the core logic will copy the affinity
mask to irq_data->affinity field.

Several xxx_irq_set_affinity() methods for x86 platforms still return
0(IRQ_SET_MASK_OK) after copying the affinity mask to irq_data->affinity field,
so remove the redundant memory copy operations.

Signed-off-by: Jiang Liu <jiang.liu@...wei.com>
---
 arch/x86/kernel/apic/io_apic.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 6d10a66..c68954e 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2326,9 +2326,8 @@ int __ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
 	if (assign_irq_vector(data->irq, data->chip_data, mask))
 		return -1;
 
-	cpumask_copy(data->affinity, mask);
-
 	*dest_id = apic->cpu_mask_to_apicid_and(mask, cfg->domain);
+
 	return 0;
 }
 
@@ -2403,7 +2402,6 @@ ir_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
 	if (cfg->move_in_progress)
 		send_cleanup_vector(cfg);
 
-	cpumask_copy(data->affinity, mask);
 	return 0;
 }
 
@@ -3832,6 +3830,8 @@ void __init setup_ioapic_dest(void)
 			ir_ioapic_set_affinity(idata, mask, false);
 		else
 			ioapic_set_affinity(idata, mask, false);
+
+		cpumask_copy(idata->affinity, mask);
 	}
 
 }
-- 
1.7.5.4

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