Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932683AbaGUOsO (ORCPT ); Mon, 21 Jul 2014 10:48:14 -0400 Received: from mail-wg0-f43.google.com ([74.125.82.43]:64912 "EHLO mail-wg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932519AbaGUOsL (ORCPT ); Mon, 21 Jul 2014 10:48:11 -0400 From: Daniel Thompson To: Russell King , Thomas Gleixner , Jason Cooper Cc: Daniel Thompson , Marex Vasut , Harro Haan , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org, linaro-kernel@lists.linaro.org, John Stultz , Nicolas Pitre , Christoffer Dall , Sricharan R Subject: [PATCH RFC 2/9] irqchip: gic: Add support for FIQ management Date: Mon, 21 Jul 2014 15:47:13 +0100 Message-Id: <1405954040-30399-3-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1405954040-30399-1-git-send-email-daniel.thompson@linaro.org> References: <1405954040-30399-1-git-send-email-daniel.thompson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces callbacks to route interrupts to or away from the FIQ signal and registers these callbacks with the FIQ infrastructure (if the device can supports it). Both these aspects combine and allow a driver to deploy a FIQ handler without any machine specific knowledge; it can be used effectively on multi-platform kernels. Signed-off-by: Daniel Thompson Cc: Thomas Gleixner Cc: Jason Cooper Cc: Nicolas Pitre Cc: Christoffer Dall Cc: Sricharan R --- drivers/irqchip/irq-gic.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index bbffca3..d3c7559 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -366,6 +366,69 @@ static struct irq_chip gic_chip = { }; #ifdef CONFIG_FIQ +/* + * Shift an interrupt between Group 0 and Group 1. + * + * In addition to changing the group we also modify the priority to + * match what "ARM strongly recommends" for a system where no Group 1 + * interrupt must ever preempt a Group 0 interrupt. + */ +static void gic_set_group_irq(struct irq_data *d, int group) +{ + unsigned int grp_reg = gic_irq(d) / 32 * 4; + u32 grp_mask = 1 << (gic_irq(d) % 32); + u32 grp_val; + + unsigned int pri_reg = (gic_irq(d) / 4) * 4; + u32 pri_mask = 1 << (7 + ((gic_irq(d) % 4) * 8)); + u32 pri_val; + + raw_spin_lock(&irq_controller_lock); + + grp_val = readl_relaxed(gic_dist_base(d) + GIC_DIST_IGROUP + grp_reg); + pri_val = readl_relaxed(gic_dist_base(d) + GIC_DIST_PRI + pri_reg); + + if (group) { + grp_val |= grp_mask; + pri_val |= pri_mask; + } else { + grp_val &= ~grp_mask; + pri_val &= ~pri_mask; + } + + writel_relaxed(grp_val, gic_dist_base(d) + GIC_DIST_IGROUP + grp_reg); + writel_relaxed(pri_val, gic_dist_base(d) + GIC_DIST_PRI + pri_reg); + + raw_spin_unlock(&irq_controller_lock); +} + +static void gic_enable_fiq(struct irq_data *d) +{ + gic_set_group_irq(d, 0); +} + +static void gic_disable_fiq(struct irq_data *d) +{ + gic_set_group_irq(d, 1); +} + +static int gic_ack_fiq(struct irq_data *d) +{ + struct gic_chip_data *gic = irq_data_get_irq_chip_data(d); + u32 irqstat, irqnr; + + irqstat = readl_relaxed(gic_data_cpu_base(gic) + GIC_CPU_INTACK); + irqnr = irqstat & GICC_IAR_INT_ID_MASK; + return irq_find_mapping(gic->domain, irqnr); +} + +static struct fiq_chip gic_fiq = { + .fiq_enable = gic_enable_fiq, + .fiq_disable = gic_disable_fiq, + .fiq_ack = gic_ack_fiq, + .fiq_eoi = gic_eoi_irq, +}; + static void __init gic_init_fiq(struct gic_chip_data *gic, irq_hw_number_t first_irq, unsigned int num_irqs) @@ -394,6 +457,12 @@ static void __init gic_init_fiq(struct gic_chip_data *gic, if (!gic->fiq_enable) return; + + /* + * FIQ is supported on this device! Register our chip data. + */ + for (i = 0; i < num_irqs; i++) + fiq_register_mapping(first_irq + i, &gic_fiq); } #else /* CONFIG_FIQ */ static inline void gic_init_fiq(struct gic_chip_data *gic, -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/