From patchwork Thu Mar 4 21:38:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 12116863 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D1E6C433E0 for ; Thu, 4 Mar 2021 21:46:04 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0255C64FF0 for ; Thu, 4 Mar 2021 21:46:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0255C64FF0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=marcan.st Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gYOKyf0Y387+otjv23pV2iVMNkbnr7cC14DvGs1ovSg=; b=Rew13Ek8IqQYX4mr184iQJgID ZzEd6KoguZkG4CRRNl3rhytuozDf3K/pzNHZI5HP+KHlxHnoZ5zpj1I+AgNF/bEQRER8usxFtPIOX p1AFozUqkUqngwmp0A+SHSsBzFZ5HqBUGx8tBgON9YKeMfQB0vF70u/h5AXKInKbHdSQQEaKg6Xy1 nDP+7AIEdEBaevOcCCL7IUl7/abkZGfxECrKGxn4OZp8FAbkTIGADgpUTEwHuPoPQ5BjpI+xdYQyI W5hKiD8uYPFTkGkioi8R3pC+i3me6nikXBGn6PUSda/qCGkrKjXbzdbFoW5RVRF8Tc+5vTFYWWhGj 9VJkNU66g==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lHvlK-00AFaq-8N; Thu, 04 Mar 2021 21:44:02 +0000 Received: from marcansoft.com ([212.63.210.85] helo=mail.marcansoft.com) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lHvij-00AE0x-J7 for linux-arm-kernel@lists.infradead.org; Thu, 04 Mar 2021 21:41:30 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 66664426F7; Thu, 4 Mar 2021 21:41:14 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Cc: Hector Martin , Marc Zyngier , Rob Herring , Arnd Bergmann , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , devicetree@vger.kernel.org, linux-serial@vger.kernel.org, linux-doc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFT PATCH v3 16/27] irqchip/apple-aic: Add support for the Apple Interrupt Controller Date: Fri, 5 Mar 2021 06:38:51 +0900 Message-Id: <20210304213902.83903-17-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210304213902.83903-1-marcan@marcan.st> References: <20210304213902.83903-1-marcan@marcan.st> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This is the root interrupt controller used on Apple ARM SoCs such as the M1. This irqchip driver performs multiple functions: * Handles both IRQs and FIQs * Drives the AIC peripheral itself (which handles IRQs) * Dispatches FIQs to downstream hard-wired clients (currently the ARM timer). * Implements a virtual IPI multiplexer to funnel multiple Linux IPIs into a single hardware IPI Signed-off-by: Hector Martin --- MAINTAINERS | 2 + drivers/irqchip/Kconfig | 8 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-apple-aic.c | 710 ++++++++++++++++++++++++++++++++ include/linux/cpuhotplug.h | 1 + 5 files changed, 722 insertions(+) create mode 100644 drivers/irqchip/irq-apple-aic.c diff --git a/MAINTAINERS b/MAINTAINERS index 744e086d28cd..28bd46f4f7a7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1648,6 +1648,8 @@ T: git https://github.com/AsahiLinux/linux.git F: Documentation/devicetree/bindings/arm/apple.yaml F: Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml F: arch/arm64/include/asm/sysreg_apple.h +F: drivers/irqchip/irq-apple-aic.c +F: include/dt-bindings/interrupt-controller/apple-aic.h ARM/ARTPEC MACHINE SUPPORT M: Jesper Nilsson diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 15536e321df5..d3a14f304ec8 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -577,4 +577,12 @@ config MST_IRQ help Support MStar Interrupt Controller. +config APPLE_AIC + bool "Apple Interrupt Controller (AIC)" + depends on ARM64 + default ARCH_APPLE + help + Support for the Apple Interrupt Controller found on Apple Silicon SoCs, + such as the M1. + endmenu diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index c59b95a0532c..eb6a515f0f64 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -113,3 +113,4 @@ obj-$(CONFIG_LOONGSON_PCH_MSI) += irq-loongson-pch-msi.o obj-$(CONFIG_MST_IRQ) += irq-mst-intc.o obj-$(CONFIG_SL28CPLD_INTC) += irq-sl28cpld.o obj-$(CONFIG_MACH_REALTEK_RTL) += irq-realtek-rtl.o +obj-$(CONFIG_APPLE_AIC) += irq-apple-aic.o diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c new file mode 100644 index 000000000000..ddc0856f36a5 --- /dev/null +++ b/drivers/irqchip/irq-apple-aic.c @@ -0,0 +1,710 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright The Asahi Linux Contributors + * + * Based on irq-lpc32xx: + * Copyright 2015-2016 Vladimir Zapolskiy + * Based on irq-bcm2836: + * Copyright 2015 Broadcom + */ + +/* + * AIC is a fairly simple interrupt controller with the following features: + * + * - 896 level-triggered hardware IRQs + * - Single mask bit per IRQ + * - Per-IRQ affinity setting + * - Automatic masking on event delivery (auto-ack) + * - Software triggering (ORed with hw line) + * - 2 per-CPU IPIs (meant as "self" and "other", but they are + * interchangeable if not symmetric) + * - Automatic prioritization (single event/ack register per CPU, lower IRQs = + * higher priority) + * - Automatic masking on ack + * - Default "this CPU" register view and explicit per-CPU views + * + * In addition, this driver also handles FIQs, as these are routed to the same + * IRQ vector. These are used for Fast IPIs (TODO), the ARMv8 timer IRQs, and + * performance counters (TODO). + * + * Implementation notes: + * + * - This driver creates two IRQ domains, one for HW IRQs and internal FIQs, + * and one for IPIs. + * - Since Linux needs more than 2 IPIs, we implement a software IRQ controller + * and funnel all IPIs into one per-CPU IPI (the second "self" IPI is unused). + * - FIQ hwirq numbers are assigned after true hwirqs, and are per-cpu. + * - DT bindings use 3-cell form (like GIC): + * - <0 nr flags> - hwirq #nr + * - <1 nr flags> - FIQ #nr + * - nr=0 Physical HV timer + * - nr=1 Virtual HV timer + * - nr=2 Physical guest timer + * - nr=3 Virtual guest timer + * + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define AIC_INFO 0x0004 +#define AIC_INFO_NR_HW GENMASK(15, 0) + +#define AIC_CONFIG 0x0010 + +#define AIC_WHOAMI 0x2000 +#define AIC_EVENT 0x2004 +#define AIC_EVENT_TYPE GENMASK(31, 16) +#define AIC_EVENT_NUM GENMASK(15, 0) + +#define AIC_EVENT_TYPE_HW 1 +#define AIC_EVENT_TYPE_IPI 4 +#define AIC_EVENT_IPI_OTHER 1 +#define AIC_EVENT_IPI_SELF 2 + +#define AIC_IPI_SEND 0x2008 +#define AIC_IPI_ACK 0x200c +#define AIC_IPI_MASK_SET 0x2024 +#define AIC_IPI_MASK_CLR 0x2028 + +#define AIC_IPI_SEND_CPU(cpu) BIT(cpu) + +#define AIC_IPI_OTHER BIT(0) +#define AIC_IPI_SELF BIT(31) + +#define AIC_TARGET_CPU 0x3000 +#define AIC_SW_SET 0x4000 +#define AIC_SW_CLR 0x4080 +#define AIC_MASK_SET 0x4100 +#define AIC_MASK_CLR 0x4180 + +#define AIC_CPU_IPI_SET(cpu) (0x5008 + ((cpu) << 7)) +#define AIC_CPU_IPI_CLR(cpu) (0x500c + ((cpu) << 7)) +#define AIC_CPU_IPI_MASK_SET(cpu) (0x5024 + ((cpu) << 7)) +#define AIC_CPU_IPI_MASK_CLR(cpu) (0x5028 + ((cpu) << 7)) + +#define MASK_REG(x) (4 * ((x) >> 5)) +#define MASK_BIT(x) BIT((x) & 0x1f) + +#define AIC_NR_FIQ 4 +#define AIC_NR_SWIPI 32 + +/* + * Max 31 bits in IPI SEND register (top bit is self). + * >=32-core chips will need code changes anyway. + */ +#define AIC_MAX_CPUS 31 + +struct aic_irq_chip { + void __iomem *base; + struct irq_domain *hw_domain; + struct irq_domain *ipi_domain; + int nr_hw; + int ipi_hwirq; +}; + +static atomic_t aic_vipi_flag[AIC_MAX_CPUS]; +static atomic_t aic_vipi_enable[AIC_MAX_CPUS]; + +static struct aic_irq_chip *aic_irqc; + +static void aic_handle_ipi(struct pt_regs *regs); + +static u32 aic_ic_read(struct aic_irq_chip *ic, u32 reg) +{ + return readl_relaxed(ic->base + reg); +} + +static void aic_ic_write(struct aic_irq_chip *ic, u32 reg, u32 val) +{ + writel_relaxed(val, ic->base + reg); +} + +/* + * IRQ irqchip + */ + +static void aic_irq_mask(struct irq_data *d) +{ + struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); + + aic_ic_write(ic, AIC_MASK_SET + MASK_REG(d->hwirq), + MASK_BIT(d->hwirq)); +} + +static void aic_irq_unmask(struct irq_data *d) +{ + struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); + + aic_ic_write(ic, AIC_MASK_CLR + MASK_REG(d->hwirq), + MASK_BIT(d->hwirq)); +} + +static void aic_irq_eoi(struct irq_data *d) +{ + /* + * Reading the interrupt reason automatically acknowledges and masks + * the IRQ, so we just unmask it here if needed. + */ + if (!irqd_irq_disabled(d) && !irqd_irq_masked(d)) + aic_irq_unmask(d); +} + +static void __exception_irq_entry aic_handle_irq(struct pt_regs *regs) +{ + struct aic_irq_chip *ic = aic_irqc; + u32 event, type, irq; + + do { + /* + * We cannot use a relaxed read here, as DMA needs to be + * ordered with respect to the IRQ firing. + */ + event = readl(ic->base + AIC_EVENT); + type = FIELD_GET(AIC_EVENT_TYPE, event); + irq = FIELD_GET(AIC_EVENT_NUM, event); + + if (type == AIC_EVENT_TYPE_HW) + handle_domain_irq(aic_irqc->hw_domain, irq, regs); + else if (type == AIC_EVENT_TYPE_IPI && irq == 1) + aic_handle_ipi(regs); + else if (event != 0) + pr_err("Unknown IRQ event %d, %d\n", type, irq); + } while (event); + + /* + * vGIC maintenance interrupts end up here too, so we need to check + * for them separately. Just report and disable vGIC for now, until + * we implement this properly. + */ + if ((read_sysreg_s(SYS_ICH_HCR_EL2) & ICH_HCR_EN) && + read_sysreg_s(SYS_ICH_MISR_EL2) != 0) { + pr_err("vGIC IRQ fired, disabling.\n"); + sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EN, 0); + } +} + +static int aic_irq_set_affinity(struct irq_data *d, + const struct cpumask *mask_val, bool force) +{ + irq_hw_number_t hwirq = irqd_to_hwirq(d); + struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); + int cpu; + + if (hwirq > ic->nr_hw) + return -EINVAL; + + if (force) + cpu = cpumask_first(mask_val); + else + cpu = cpumask_any_and(mask_val, cpu_online_mask); + + aic_ic_write(ic, AIC_TARGET_CPU + hwirq * 4, BIT(cpu)); + irq_data_update_effective_affinity(d, cpumask_of(cpu)); + + return IRQ_SET_MASK_OK; +} + +static int aic_irq_set_type(struct irq_data *d, unsigned int type) +{ + return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL; +} + +static struct irq_chip aic_chip = { + .name = "AIC", + .irq_mask = aic_irq_mask, + .irq_unmask = aic_irq_unmask, + .irq_eoi = aic_irq_eoi, + .irq_set_affinity = aic_irq_set_affinity, + .irq_set_type = aic_irq_set_type, +}; + +/* + * FIQ irqchip + */ + +static void aic_fiq_mask(struct irq_data *d) +{ + /* Only the guest timers have real mask bits, unfortunately. */ + switch (d->hwirq) { + case AIC_TMR_GUEST_PHYS: + sysreg_clear_set_s(SYS_APL_VM_TMR_FIQ_ENA_EL1, VM_TMR_FIQ_ENABLE_P, 0); + break; + case AIC_TMR_GUEST_VIRT: + sysreg_clear_set_s(SYS_APL_VM_TMR_FIQ_ENA_EL1, VM_TMR_FIQ_ENABLE_V, 0); + break; + } +} + +static void aic_fiq_unmask(struct irq_data *d) +{ + switch (d->hwirq) { + case AIC_TMR_GUEST_PHYS: + sysreg_clear_set_s(SYS_APL_VM_TMR_FIQ_ENA_EL1, 0, VM_TMR_FIQ_ENABLE_P); + break; + case AIC_TMR_GUEST_VIRT: + sysreg_clear_set_s(SYS_APL_VM_TMR_FIQ_ENA_EL1, 0, VM_TMR_FIQ_ENABLE_V); + break; + } +} + +static void aic_fiq_eoi(struct irq_data *d) +{ + /* We mask to ack (where we can), so we need to unmask at EOI. */ + if (!irqd_irq_disabled(d) && !irqd_irq_masked(d)) + aic_fiq_unmask(d); +} + +#define TIMER_FIRING(x) \ + (((x) & (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_MASK | \ + ARCH_TIMER_CTRL_IT_STAT)) == \ + (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_STAT)) + +static void __exception_irq_entry aic_handle_fiq(struct pt_regs *regs) +{ + /* + * It would be really nice if we had a system register that lets us get + * the FIQ source state without having to peek down into sources... + * but such a register does not seem to exist. + * + * So, we have these potential sources to test for: + * - Fast IPIs (not yet used) + * - The 4 timers (CNTP, CNTV for each of HV and guest) + * - Per-core PMCs (not yet supported) + * - Per-cluster uncore PMCs (not yet supported) + * + * Since not dealing with any of these results in a FIQ storm, + * we check for everything here, even things we don't support yet. + */ + + if (read_sysreg_s(SYS_APL_IPI_SR_EL1) & IPI_SR_PENDING) { + pr_warn("Fast IPI fired. Acking.\n"); + write_sysreg_s(IPI_SR_PENDING, SYS_APL_IPI_SR_EL1); + } + + if (TIMER_FIRING(read_sysreg(cntp_ctl_el0))) + handle_domain_irq(aic_irqc->hw_domain, + aic_irqc->nr_hw + AIC_TMR_HV_PHYS, regs); + + if (TIMER_FIRING(read_sysreg(cntv_ctl_el0))) + handle_domain_irq(aic_irqc->hw_domain, + aic_irqc->nr_hw + AIC_TMR_HV_VIRT, regs); + + if (TIMER_FIRING(read_sysreg_s(SYS_CNTP_CTL_EL02))) + handle_domain_irq(aic_irqc->hw_domain, + aic_irqc->nr_hw + AIC_TMR_GUEST_PHYS, regs); + + if (TIMER_FIRING(read_sysreg_s(SYS_CNTV_CTL_EL02))) + handle_domain_irq(aic_irqc->hw_domain, + aic_irqc->nr_hw + AIC_TMR_GUEST_VIRT, regs); + + if ((read_sysreg_s(SYS_APL_PMCR0_EL1) & (PMCR0_IMODE | PMCR0_IACT)) + == (FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_FIQ) | PMCR0_IACT)) { + /* + * Not supported yet, let's figure out how to handle this when + * we implement these proprietary performance counters. For now, + * just mask it and move on. + */ + pr_warn("PMC FIQ fired. Masking.\n"); + sysreg_clear_set_s(SYS_APL_PMCR0_EL1, PMCR0_IMODE | PMCR0_IACT, + FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF)); + } + + if (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ && + (read_sysreg_s(SYS_APL_UPMSR_EL1) & UPMSR_IACT)) { + /* Same story with uncore PMCs */ + pr_warn("Uncore PMC FIQ fired. Masking.\n"); + sysreg_clear_set_s(SYS_APL_UPMCR0_EL1, UPMCR0_IMODE, + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); + } +} + +static struct irq_chip fiq_chip = { + .name = "AIC-FIQ", + .irq_mask = aic_fiq_mask, + .irq_unmask = aic_fiq_unmask, + .irq_ack = aic_fiq_mask, + .irq_eoi = aic_fiq_eoi, + .irq_set_type = aic_irq_set_type, +}; + +/* + * Main IRQ domain + */ + +static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq, + irq_hw_number_t hw) +{ + struct aic_irq_chip *ic = id->host_data; + + if (hw < ic->nr_hw) { + irq_domain_set_info(id, irq, hw, &aic_chip, id->host_data, + handle_fasteoi_irq, NULL, NULL); + irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq))); + } else { + irq_set_percpu_devid(irq); + irq_domain_set_info(id, irq, hw, &fiq_chip, id->host_data, + handle_percpu_devid_irq, NULL, NULL); + } + + return 0; +} + +static int aic_irq_domain_translate(struct irq_domain *id, + struct irq_fwspec *fwspec, + unsigned long *hwirq, + unsigned int *type) +{ + struct aic_irq_chip *ic = id->host_data; + + if (fwspec->param_count != 3 || !is_of_node(fwspec->fwnode)) + return -EINVAL; + + switch (fwspec->param[0]) { + case AIC_IRQ: + if (fwspec->param[1] >= ic->nr_hw) + return -EINVAL; + *hwirq = 0; + break; + case AIC_FIQ: + if (fwspec->param[1] >= AIC_NR_FIQ) + return -EINVAL; + *hwirq = ic->nr_hw; + break; + default: + return -EINVAL; + } + + *hwirq += fwspec->param[1]; + *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK; + + return 0; +} + +static int aic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + unsigned int type = IRQ_TYPE_NONE; + struct irq_fwspec *fwspec = arg; + irq_hw_number_t hwirq; + int i, ret; + + ret = aic_irq_domain_translate(domain, fwspec, &hwirq, &type); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) { + ret = aic_irq_domain_map(domain, virq + i, hwirq + i); + if (ret) + return ret; + } + + return 0; +} + +static void aic_irq_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + int i; + + for (i = 0; i < nr_irqs; i++) { + struct irq_data *d = irq_domain_get_irq_data(domain, virq + i); + + irq_set_handler(virq + i, NULL); + irq_domain_reset_irq_data(d); + } +} + +static const struct irq_domain_ops aic_irq_domain_ops = { + .translate = aic_irq_domain_translate, + .alloc = aic_irq_domain_alloc, + .free = aic_irq_domain_free, +}; + +/* + * IPI irqchip + */ + +static void aic_ipi_mask(struct irq_data *d) +{ + u32 irq_bit = BIT(irqd_to_hwirq(d)); + int this_cpu = smp_processor_id(); + + /* No specific ordering requirements needed here. */ + atomic_andnot(irq_bit, &aic_vipi_enable[this_cpu]); +} + +static void aic_ipi_unmask(struct irq_data *d) +{ + struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); + u32 irq_bit = BIT(irqd_to_hwirq(d)); + int this_cpu = smp_processor_id(); + + /* + * This must complete before the atomic_read_acquire() below to avoid + * racing aic_ipi_send_mask(). Use a dummy fetch op with release + * semantics for this. This is arch-specific: ARMv8 B2.3.3 specifies + * that writes with Release semantics are Barrier-ordered-before reads + * with Acquire semantics, even though the Linux arch-independent + * definition of these atomic ops does not. + */ + (void)atomic_fetch_or_release(irq_bit, &aic_vipi_enable[this_cpu]); + + /* + * If a pending vIPI was unmasked, raise a HW IPI to ourselves. + * No barriers needed here since this is a self-IPI. + */ + if (atomic_read_acquire(&aic_vipi_flag[this_cpu]) & irq_bit) + aic_ic_write(ic, AIC_IPI_SEND, AIC_IPI_SEND_CPU(this_cpu)); +} + +static void aic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask) +{ + struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); + u32 irq_bit = BIT(irqd_to_hwirq(d)); + u32 send = 0; + int cpu; + unsigned long pending; + + for_each_cpu(cpu, mask) { + /* + * This sequence is the mirror of the one in aic_ipi_unmask(); + * see the comment there. Additionally, release semantics + * ensure that the vIPI flag set is ordered after any shared + * memory accesses that precede it. This therefore also pairs + * with the atomic_fetch_andnot in aic_handle_ipi(). + */ + pending = atomic_fetch_or_release(irq_bit, &aic_vipi_flag[cpu]); + + if (!(pending & irq_bit) && (atomic_read_acquire(&aic_vipi_enable[cpu]) & irq_bit)) + send |= AIC_IPI_SEND_CPU(cpu); + } + + /* + * The flag writes must complete before the physical IPI is issued + * to another CPU. This is implied by the control dependency on + * the result of atomic_read_acquire() above, which is itself + * already ordered after the vIPI flag write. + */ + if (send) + aic_ic_write(ic, AIC_IPI_SEND, send); +} + +static struct irq_chip ipi_chip = { + .name = "AIC-IPI", + .irq_mask = aic_ipi_mask, + .irq_unmask = aic_ipi_unmask, + .ipi_send_mask = aic_ipi_send_mask, +}; + +/* + * IPI IRQ domain + */ + +static void aic_handle_ipi(struct pt_regs *regs) +{ + int this_cpu = smp_processor_id(); + int i; + unsigned long enabled, firing; + + /* + * Ack the IPI. We need to order this after the AIC event read, but + * that is enforced by normal MMIO ordering guarantees. + */ + aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_OTHER); + + /* + * The mask read does not need to be ordered. Only we can change + * our own mask anyway, so no races are possible here, as long as + * we are properly in the interrupt handler (which is covered by + * the barrier that is part of the top-level AIC handler's readl()). + */ + enabled = atomic_read(&aic_vipi_enable[this_cpu]); + + /* + * Clear the IPIs we are about to handle. This pairs with the + * atomic_fetch_or_release() in aic_ipi_send_mask(), and needs to be + * ordered after the aic_ic_write() above (to avoid dropping vIPIs) and + * before IPI handling code (to avoid races handling vIPIs before they + * are signaled). The former is taken care of by the release semantics + * of the write portion, while the latter is taken care of by the + * acquire semantics of the read portion. + */ + firing = atomic_fetch_andnot(enabled, &aic_vipi_flag[this_cpu]) & enabled; + + for_each_set_bit(i, &firing, AIC_NR_SWIPI) { + handle_domain_irq(aic_irqc->ipi_domain, i, regs); + } + + /* + * No ordering needed here; at worst this just changes the timing of + * when the next IPI will be delivered. + */ + aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER); +} + +static int aic_ipi_alloc(struct irq_domain *d, unsigned int virq, + unsigned int nr_irqs, void *args) +{ + int i; + + for (i = 0; i < nr_irqs; i++) { + irq_set_percpu_devid(virq + i); + irq_domain_set_info(d, virq + i, i, &ipi_chip, d->host_data, + handle_percpu_devid_irq, NULL, NULL); + } + + return 0; +} + +static void aic_ipi_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs) +{ + /* Not freeing IPIs */ +} + +static const struct irq_domain_ops aic_ipi_domain_ops = { + .alloc = aic_ipi_alloc, + .free = aic_ipi_free, +}; + +static int aic_init_smp(struct aic_irq_chip *irqc, struct device_node *node) +{ + int base_ipi; + + irqc->ipi_domain = irq_domain_create_linear(irqc->hw_domain->fwnode, AIC_NR_SWIPI, + &aic_ipi_domain_ops, irqc); + if (WARN_ON(!irqc->ipi_domain)) + return -ENODEV; + + irqc->ipi_domain->flags |= IRQ_DOMAIN_FLAG_IPI_SINGLE; + irq_domain_update_bus_token(irqc->ipi_domain, DOMAIN_BUS_IPI); + + base_ipi = __irq_domain_alloc_irqs(irqc->ipi_domain, -1, AIC_NR_SWIPI, + NUMA_NO_NODE, NULL, false, NULL); + + if (WARN_ON(!base_ipi)) { + irq_domain_remove(irqc->ipi_domain); + return -ENODEV; + } + + set_smp_ipi_range(base_ipi, AIC_NR_SWIPI); + + return 0; +} + +static int aic_init_cpu(unsigned int cpu) +{ + /* Mask all hard-wired per-CPU IRQ/FIQ sources */ + + /* vGIC maintenance IRQ */ + sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EN, 0); + + /* Pending Fast IPI FIQs */ + write_sysreg_s(IPI_SR_PENDING, SYS_APL_IPI_SR_EL1); + + /* Timer FIQs */ + sysreg_clear_set(cntp_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK); + sysreg_clear_set(cntv_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK); + sysreg_clear_set_s(SYS_CNTP_CTL_EL02, 0, ARCH_TIMER_CTRL_IT_MASK); + sysreg_clear_set_s(SYS_CNTV_CTL_EL02, 0, ARCH_TIMER_CTRL_IT_MASK); + + /* PMC FIQ */ + sysreg_clear_set_s(SYS_APL_PMCR0_EL1, PMCR0_IMODE | PMCR0_IACT, + FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF)); + + /* Uncore PMC FIQ */ + sysreg_clear_set_s(SYS_APL_UPMCR0_EL1, UPMCR0_IMODE, + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); + + /* + * Make sure the kernel's idea of logical CPU order is the same as AIC's + * If we ever end up with a mismatch here, we will have to introduce + * a mapping table similar to what other irqchip drivers do. + */ + WARN_ON(aic_ic_read(aic_irqc, AIC_WHOAMI) != smp_processor_id()); + + /* + * Always keep IPIs unmasked at the hardware level (except auto-masking + * by AIC during processing). We manage masks at the vIPI level. + */ + aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_SELF | AIC_IPI_OTHER); + aic_ic_write(aic_irqc, AIC_IPI_MASK_SET, AIC_IPI_SELF); + aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER); + + return 0; + +} + +static int __init aic_of_ic_init(struct device_node *node, struct device_node *parent) +{ + int i; + void __iomem *regs; + u32 info; + struct aic_irq_chip *irqc; + + regs = of_iomap(node, 0); + if (WARN_ON(!regs)) + return -EIO; + + irqc = kzalloc(sizeof(*irqc), GFP_KERNEL); + if (!irqc) + return -ENOMEM; + + aic_irqc = irqc; + irqc->base = regs; + + info = aic_ic_read(irqc, AIC_INFO); + irqc->nr_hw = FIELD_GET(AIC_INFO_NR_HW, info); + + irqc->hw_domain = irq_domain_create_linear(of_node_to_fwnode(node), + irqc->nr_hw + AIC_NR_FIQ, + &aic_irq_domain_ops, irqc); + if (WARN_ON(!irqc->hw_domain)) { + iounmap(irqc->base); + kfree(irqc); + return -ENODEV; + } + + irq_domain_update_bus_token(irqc->hw_domain, DOMAIN_BUS_WIRED); + + if (aic_init_smp(irqc, node)) { + irq_domain_remove(irqc->hw_domain); + iounmap(irqc->base); + kfree(irqc); + return -ENODEV; + } + + set_handle_irq(aic_handle_irq); + set_handle_fiq(aic_handle_fiq); + + for (i = 0; i < BITS_TO_U32(irqc->nr_hw); i++) + aic_ic_write(irqc, AIC_MASK_SET + i * 4, ~0); + for (i = 0; i < BITS_TO_U32(irqc->nr_hw); i++) + aic_ic_write(irqc, AIC_SW_CLR + i * 4, ~0); + for (i = 0; i < irqc->nr_hw; i++) + aic_ic_write(irqc, AIC_TARGET_CPU + i * 4, 1); + + cpuhp_setup_state(CPUHP_AP_IRQ_APPLE_AIC_STARTING, + "irqchip/apple-aic/ipi:starting", + aic_init_cpu, NULL); + + pr_info("AIC: initialized with %d IRQs, %d FIQs, %d vIPIs\n", + irqc->nr_hw, AIC_NR_FIQ, AIC_NR_SWIPI); + + return 0; +} + +IRQCHIP_DECLARE(apple_m1_aic, "apple,aic", aic_of_ic_init); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f14adb882338..f56eee992c75 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -100,6 +100,7 @@ enum cpuhp_state { CPUHP_AP_CPU_PM_STARTING, CPUHP_AP_IRQ_GIC_STARTING, CPUHP_AP_IRQ_HIP04_STARTING, + CPUHP_AP_IRQ_APPLE_AIC_STARTING, CPUHP_AP_IRQ_ARMADA_XP_STARTING, CPUHP_AP_IRQ_BCM2836_STARTING, CPUHP_AP_IRQ_MIPS_GIC_STARTING,