linux-kernel - [PATCH v2 1/3] irqchip: dw-apb-ictl: always use use {readl|writel}

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Date:	Wed, 12 Nov 2014 14:22:52 +0800
From:	Jisheng Zhang <jszhang@...vell.com>
To:	<tglx@...utronix.de>, <jason@...edaemon.net>
CC:	<linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	Jisheng Zhang <jszhang@...vell.com>
Subject: [PATCH v2 1/3] irqchip: dw-apb-ictl: always use use {readl|writel}_relaxed

There's no DMA at all, the device type memory attribute can ensure the
operations order and relaxed version imply compiler barrier, so we are safe
to use relaxed version to improve the performance a bit.

Signed-off-by: Jisheng Zhang <jszhang@...vell.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>
---
 drivers/irqchip/irq-dw-apb-ictl.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-dw-apb-ictl.c b/drivers/irqchip/irq-dw-apb-ictl.c
index 31e231e..fcc3385 100644
--- a/drivers/irqchip/irq-dw-apb-ictl.c
+++ b/drivers/irqchip/irq-dw-apb-ictl.c
@@ -94,16 +94,16 @@ static int __init dw_apb_ictl_init(struct device_node *np,
 	 */
 
 	/* mask and enable all interrupts */
-	writel(~0, iobase + APB_INT_MASK_L);
-	writel(~0, iobase + APB_INT_MASK_H);
-	writel(~0, iobase + APB_INT_ENABLE_L);
-	writel(~0, iobase + APB_INT_ENABLE_H);
+	writel_relaxed(~0, iobase + APB_INT_MASK_L);
+	writel_relaxed(~0, iobase + APB_INT_MASK_H);
+	writel_relaxed(~0, iobase + APB_INT_ENABLE_L);
+	writel_relaxed(~0, iobase + APB_INT_ENABLE_H);
 
-	reg = readl(iobase + APB_INT_ENABLE_H);
+	reg = readl_relaxed(iobase + APB_INT_ENABLE_H);
 	if (reg)
 		nrirqs = 32 + fls(reg);
 	else
-		nrirqs = fls(readl(iobase + APB_INT_ENABLE_L));
+		nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L));
 
 	domain = irq_domain_add_linear(np, nrirqs,
 				       &irq_generic_chip_ops, NULL);
-- 
2.1.3

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