From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752791AbaB0Vhj (ORCPT ); Thu, 27 Feb 2014 16:37:39 -0500 Received: from denmail01-v4020.amcc.com ([192.195.68.30]:44194 "EHLO denmail01.apm.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751326AbaB0Vhi (ORCPT ); Thu, 27 Feb 2014 16:37:38 -0500 From: Feng Kan To: tglx@linutronix.de, patches@apm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, marc.zyngier@arm.com Cc: Feng Kan , Vinayak Kale Subject: [PATCH V3] irqchip:gic: change access of gicc_ctrl register to read modify write. Date: Thu, 27 Feb 2014 14:36:53 -0700 Message-Id: <1393537013-6264-1-git-send-email-fkan@apm.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This change is made to preserve the GIC v2 releated bits in the GIC_CPU_CTRL register (also known as the GICC_CTLR register in spec). The original code only set the enable/disable group bit in this register. This code will preserve the bypass bits configured by the bootload except the enable/disable bit. The main reason for this change is to allow the bypass bits specified in the v2 spec to remain untouched by the current GIC code. In the X-Gene platform, the bypass functionality is not used and bypass must be disabled at all time. Signed-off-by: Vinayak Kale Acked-by: Anup Patel Signed-off-by: Feng Kan --- V3 Changes: - Sorry, forgot to change the mask for cpu_init path assumed bootloader setup bits correctly. V2 Changes: - only mask off v2 bypass bits drivers/irqchip/irq-gic.c | 32 +++++++++++++++++++++++++++++--- 1 files changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 341c601..3ca7995 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -418,6 +418,7 @@ static void gic_cpu_init(struct gic_chip_data *gic) void __iomem *dist_base = gic_data_dist_base(gic); void __iomem *base = gic_data_cpu_base(gic); unsigned int cpu_mask, cpu = smp_processor_id(); + unsigned int ctrl_mask; int i; /* @@ -449,13 +450,29 @@ static void gic_cpu_init(struct gic_chip_data *gic) writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4); writel_relaxed(0xf0, base + GIC_CPU_PRIMASK); - writel_relaxed(1, base + GIC_CPU_CTRL); + + ctrl_mask = readl(base + GIC_CPU_CTRL); + + /* Mask out the gic v2 bypass bits */ + ctrl_mask &= 0x1e0; + + /* Enable group 0 */ + ctrl_mask |= 0x1; + writel_relaxed(ctrl_mask, base + GIC_CPU_CTRL); } void gic_cpu_if_down(void) { + unsigned int ctrl_mask; void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]); - writel_relaxed(0, cpu_base + GIC_CPU_CTRL); + + ctrl_mask = readl(cpu_base + GIC_CPU_CTRL); + /* + * Disable grp enable bit, leave the bypass bits alone as changing + * them could leave the system unstable + */ + ctrl_mask &= 0x1e0; + writel_relaxed(ctrl_mask, cpu_base + GIC_CPU_CTRL); } #ifdef CONFIG_CPU_PM @@ -566,6 +583,7 @@ static void gic_cpu_restore(unsigned int gic_nr) { int i; u32 *ptr; + unsigned int ctrl_mask; void __iomem *dist_base; void __iomem *cpu_base; @@ -590,7 +608,15 @@ static void gic_cpu_restore(unsigned int gic_nr) writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4); writel_relaxed(0xf0, cpu_base + GIC_CPU_PRIMASK); - writel_relaxed(1, cpu_base + GIC_CPU_CTRL); + + ctrl_mask = readl(cpu_base + GIC_CPU_CTRL); + + /* Mask out the gic v2 bypass bits */ + ctrl_mask &= 0x1e0; + + /* Enable group 0 */ + ctrl_mask |= 0x1; + writel_relaxed(ctrl_mask, cpu_base + GIC_CPU_CTRL); } static int gic_notifier(struct notifier_block *self, unsigned long cmd, void *v) -- 1.7.1