Received: by 2002:a25:ef43:0:0:0:0:0 with SMTP id w3csp221840ybm; Thu, 28 May 2020 21:19:47 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzL4TbxZqrWxZXbQboa9AHvKT05GWS/CzAh4Sg14JUTG9pFIqCjDAtYJ/t52HnD1PbaHWUx X-Received: by 2002:a17:906:d8d7:: with SMTP id re23mr5674896ejb.22.1590725987180; Thu, 28 May 2020 21:19:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1590725987; cv=none; d=google.com; s=arc-20160816; b=bnvgKnxPVQ0tyAq/5cj/151gZzbo4ADRsaBkrfN+egtRrkd5NaKPNpO7R6AR8mgQ0L 28GoANe++SF+b+edpoDtHp8PRBnqtxnLglo96Ix8R5ESvmcR3fx97KrD35K4poJpcJRo a+OjMp8gWAGZ4XA+OpNpFyB4Accvep5HHHgTwxFbXWqm9dhSMYa5OmXWPhVpasXrVQVg 6YmzdDqaCTAXO22hf+Sajasn3D4dktPvmDaTuyE6pvk5BnLTdBWiJsvs6u24VP/uyo0G /fXwHexM8kjiHuOmJiAVOXMvnSpWhcZrC/i0jbzjVHqDMEdZJl3G7SIIk+jYCezDd28K 3Bbw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=jyR6+TRuGXwjdlWw89msQrE59vFUaYSiqo/1mMaFUzM=; b=BOx4v/PSowJin8xPsbSx4GhsideZIKP+x8UsZUxjOc0ReF4oJPNs5wbiSkE0YpFAoP PtRcY1UhsHKtfEMd641zSRpPjxFWMVT2Mt3PXBuKVEeJJ+5qjGEj/ez04YiWrXla+Gap Vu4j8wR/IEkgmcPPzcDx0Iy7dA5clvNP0bklk0wv21D6Sgzy071sT5Y0RDmxmFKLHCNg 1iSLhKo3e74yEZqz0zCnRgiuTg9pc8DckBkAr2Jg5hCqGzREfBfZgpi5TJF1Wg2Y9eT5 ezIZ9anvDrl4PxxStZyrLYQZ15UWNXYw/1t9QfC69MuXizubxEpgWHzQO/e80Pk30kqL uh0g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@brainfault-org.20150623.gappssmtp.com header.s=20150623 header.b=JO2X4kLp; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id dg13si5114210edb.330.2020.05.28.21.19.24; Thu, 28 May 2020 21:19:47 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@brainfault-org.20150623.gappssmtp.com header.s=20150623 header.b=JO2X4kLp; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388794AbgE2EPi (ORCPT + 99 others); Fri, 29 May 2020 00:15:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbgE2EPh (ORCPT ); Fri, 29 May 2020 00:15:37 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C3D4C08C5C6 for ; Thu, 28 May 2020 21:15:36 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id q11so1858844wrp.3 for ; Thu, 28 May 2020 21:15:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brainfault-org.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=jyR6+TRuGXwjdlWw89msQrE59vFUaYSiqo/1mMaFUzM=; b=JO2X4kLpDwJbZQS3OmZsOggv+kReWAZZSBmE+G/AuCXJbIfNwuUHS2v8gXR0D/waVo XwBfZ4MBEGQwO9c06Zw9frizz0GchHrsUJsOk3oYm9S3utY8upYD49PYsGpW9vrNVRtv D9EbYxp1HfM6bX/VF2HDz5ucjL+OPhM1k+lbxa4+Wnn6qaWKxJCWu1UWToz9ngqUP8/5 h6IDdvqJS5ETsoMF+nWZisIjTm640E4itO1yhicHbs0o1Y2WyppG9P8i8p7o+CIYp2BR 0FDfzSN1ES6fgz+Ss0863LYWWR4R9ild2+NohZCtkenbPDSH2tg7ID78OyS0EHJ8jSGS WZ3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=jyR6+TRuGXwjdlWw89msQrE59vFUaYSiqo/1mMaFUzM=; b=QovSaqu8qFJvcnKI0eeM3/bN0uD4VjS4rCS+qGvyGvDWmohkwQIXphvsM9LvOwcBFq nn7yhaULUHTu/C0EPcAdY0Pa2OgMmhMjUE7fw3O3Mnr+148R3ysqW06xYzCijfp7UVWp l99+mboNZ5zf5xQ+KSXj0zJc4ABxCfrj8YK7e6LKwlXgj8cpGj0aN0Q+kJQ0m3VhRtU+ Fjnyhtcax912GKEoAGfZEJclam/2OZkniYyC2pzsxc87W6I/KRb3VQkISE78sLEyAXcO v1Jef43MWGWoV5wSbPopDwRv8YihKXqtPicE1FaEbOBlV5WaPQhpP389HVOmefSBbdM4 73Dw== X-Gm-Message-State: AOAM5319EiumH0pQuEQ95n2+1S4ekDwsMrsWDY54UohsvIgky7DQouSc D3AHEp3kA6NS/XVLtci5ahwgFSjLJpkBGNt+0iZi/A== X-Received: by 2002:a5d:4484:: with SMTP id j4mr6457362wrq.325.1590725734630; Thu, 28 May 2020 21:15:34 -0700 (PDT) MIME-Version: 1.0 References: <20200521133301.816665-4-anup.patel@wdc.com> In-Reply-To: From: Anup Patel Date: Fri, 29 May 2020 09:45:23 +0530 Message-ID: Subject: Re: [PATCH v5 3/6] irqchip: RISC-V per-HART local interrupt controller driver To: Palmer Dabbelt Cc: Anup Patel , Paul Walmsley , Albert Ou , Daniel Lezcano , Thomas Gleixner , Jason Cooper , Marc Zyngier , Atish Patra , Alistair Francis , linux-riscv , "linux-kernel@vger.kernel.org List" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 29, 2020 at 8:10 AM Palmer Dabbelt wrote: > > On Thu, 21 May 2020 06:32:58 PDT (-0700), Anup Patel wrote: > > The RISC-V per-HART local interrupt controller manages software > > interrupts, timer interrupts, external interrupts (which are routed > > via the platform level interrupt controller) and other per-HART > > local interrupts. > > > > This patch adds a driver for the RISC-V local interrupt controller. > > It is a major re-write over perviously submitted version. > > (Refer, https://www.spinics.net/lists/devicetree/msg241230.html) > > > > Few advantages of this new driver over previous one are: > > 1. All local interrupts are registered as per-CPU interrupts > > 2. The RISC-V timer driver can register timer interrupt handler > > using kernel irq subsystem without relying on arch/riscv to > > explicitly call it's interrupt handler > > 3. The KVM RISC-V can use this driver to implement interrupt > > handler for per-HART guest external interrupt defined by > > the RISC-V H-Extension > > 4. In future, we can develop drivers for devices with per-HART > > interrupts without changing arch code or this driver (example, > > CLINT timer driver for RISC-V M-mode kernel) > > > > The RISC-V INTC driver is compliant with RISC-V Hart-Level Interrupt > > Controller DT bindings located at: > > Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt > > > > Signed-off-by: Palmer Dabbelt > > Signed-off-by: Anup Patel > > --- > > arch/riscv/Kconfig | 1 + > > arch/riscv/include/asm/irq.h | 2 - > > arch/riscv/kernel/irq.c | 33 +----- > > arch/riscv/kernel/traps.c | 2 - > > drivers/irqchip/Kconfig | 13 ++ > > drivers/irqchip/Makefile | 1 + > > drivers/irqchip/irq-riscv-intc.c | 158 +++++++++++++++++++++++++ > > drivers/irqchip/irq-sifive-plic.c | 38 +++++- > > include/linux/cpuhotplug.h | 1 + > > include/linux/irqchip/irq-riscv-intc.h | 20 ++++ > > 10 files changed, 229 insertions(+), 40 deletions(-) > > create mode 100644 drivers/irqchip/irq-riscv-intc.c > > create mode 100644 include/linux/irqchip/irq-riscv-intc.h > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 90a008e28f7e..822cb0e1a380 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -40,6 +40,7 @@ config RISCV > > select HAVE_PERF_REGS > > select HAVE_PERF_USER_STACK_DUMP > > select HAVE_SYSCALL_TRACEPOINTS > > + select HANDLE_DOMAIN_IRQ > > select IRQ_DOMAIN > > select SPARSE_IRQ > > select SYSCTL_EXCEPTION_TRACE > > diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h > > index 0183e15ace66..a9e5f07a7e9c 100644 > > --- a/arch/riscv/include/asm/irq.h > > +++ b/arch/riscv/include/asm/irq.h > > @@ -10,8 +10,6 @@ > > #include > > #include > > > > -#define NR_IRQS 0 > > - > > void riscv_timer_interrupt(void); > > > > #include > > diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c > > index bb0bfcd537e7..eb8777642ce6 100644 > > --- a/arch/riscv/kernel/irq.c > > +++ b/arch/riscv/kernel/irq.c > > @@ -7,7 +7,6 @@ > > > > #include > > #include > > -#include > > #include > > #include > > > > @@ -19,39 +18,13 @@ int arch_show_interrupts(struct seq_file *p, int prec) > > > > asmlinkage __visible void __irq_entry do_IRQ(struct pt_regs *regs) > > { > > - struct pt_regs *old_regs; > > - > > - switch (regs->cause & ~CAUSE_IRQ_FLAG) { > > - case RV_IRQ_TIMER: > > - old_regs = set_irq_regs(regs); > > - irq_enter(); > > - riscv_timer_interrupt(); > > - irq_exit(); > > - set_irq_regs(old_regs); > > - break; > > -#ifdef CONFIG_SMP > > - case RV_IRQ_SOFT: > > - /* > > - * We only use software interrupts to pass IPIs, so if a non-SMP > > - * system gets one, then we don't know what to do. > > - */ > > - handle_IPI(regs); > > - break; > > -#endif > > - case RV_IRQ_EXT: > > - old_regs = set_irq_regs(regs); > > - irq_enter(); > > + if (handle_arch_irq) > > handle_arch_irq(regs); > > - irq_exit(); > > - set_irq_regs(old_regs); > > - break; > > - default: > > - pr_alert("unexpected interrupt cause 0x%lx", regs->cause); > > - BUG(); > > - } > > } > > > > void __init init_IRQ(void) > > { > > irqchip_init(); > > + if (!handle_arch_irq) > > + panic("No interrupt controller found."); > > } > > diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c > > index 7f58fa53033f..f48c76aadbf3 100644 > > --- a/arch/riscv/kernel/traps.c > > +++ b/arch/riscv/kernel/traps.c > > @@ -178,6 +178,4 @@ void trap_init(void) > > csr_write(CSR_SCRATCH, 0); > > /* Set the exception vector address */ > > csr_write(CSR_TVEC, &handle_exception); > > - /* Enable interrupts */ > > - csr_write(CSR_IE, IE_SIE); > > } > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig > > index a85aada04a64..95d6137a8117 100644 > > --- a/drivers/irqchip/Kconfig > > +++ b/drivers/irqchip/Kconfig > > @@ -493,6 +493,19 @@ config TI_SCI_INTA_IRQCHIP > > If you wish to use interrupt aggregator irq resources managed by the > > TI System Controller, say Y here. Otherwise, say N. > > > > +config RISCV_INTC > > + bool "RISC-V Local Interrupt Controller" > > + depends on RISCV > > + default y > > + help > > + This enables support for the per-HART local interrupt controller > > + found in standard RISC-V systems. The per-HART local interrupt > > + controller handles timer interrupts, software interrupts, and > > + hardware interrupts. Without a per-HART local interrupt controller, > > + a RISC-V system will be unable to handle any interrupts. > > + > > + If you don't know what to do here, say Y. > > + > > config SIFIVE_PLIC > > bool "SiFive Platform-Level Interrupt Controller" > > depends on RISCV > > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile > > index 37bbe39bf909..b8319f045472 100644 > > --- a/drivers/irqchip/Makefile > > +++ b/drivers/irqchip/Makefile > > @@ -98,6 +98,7 @@ obj-$(CONFIG_NDS32) += irq-ativic32.o > > obj-$(CONFIG_QCOM_PDC) += qcom-pdc.o > > obj-$(CONFIG_CSKY_MPINTC) += irq-csky-mpintc.o > > obj-$(CONFIG_CSKY_APB_INTC) += irq-csky-apb-intc.o > > +obj-$(CONFIG_RISCV_INTC) += irq-riscv-intc.o > > obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o > > obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o > > obj-$(CONFIG_IMX_INTMUX) += irq-imx-intmux.o > > diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c > > new file mode 100644 > > index 000000000000..2f364e6a87f9 > > --- /dev/null > > +++ b/drivers/irqchip/irq-riscv-intc.c > > @@ -0,0 +1,158 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (C) 2012 Regents of the University of California > > + * Copyright (C) 2017-2018 SiFive > > + * Copyright (C) 2020 Western Digital Corporation or its affiliates. > > + */ > > + > > +#define pr_fmt(fmt) "riscv-intc: " fmt > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +static struct device_node *intc_domain_node; > > +static struct irq_domain *intc_domain; > > + > > +static asmlinkage void riscv_intc_irq(struct pt_regs *regs) > > +{ > > + struct pt_regs *old_regs; > > + unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG; > > + > > + if (unlikely(cause >= BITS_PER_LONG)) > > + panic("unexpected interrupt cause"); > > + > > + switch (cause) { > > + case RV_IRQ_TIMER: > > + old_regs = set_irq_regs(regs); > > + irq_enter(); > > + riscv_timer_interrupt(); > > + irq_exit(); > > + set_irq_regs(old_regs); > > + break; > > +#ifdef CONFIG_SMP > > + case RV_IRQ_SOFT: > > + /* > > + * We only use software interrupts to pass IPIs, so if a > > + * non-SMP system gets one, then we don't know what to do. > > + */ > > + handle_IPI(regs); > > + break; > > +#endif > > + default: > > + handle_domain_irq(intc_domain, cause, regs); > > + break; > > + } > > +} > > + > > +/* > > + * On RISC-V systems local interrupts are masked or unmasked by writing > > + * the SIE (Supervisor Interrupt Enable) CSR. As CSRs can only be written > > + * on the local hart, these functions can only be called on the hart that > > + * corresponds to the IRQ chip. > > + */ > > + > > +static void riscv_intc_irq_mask(struct irq_data *d) > > +{ > > + csr_clear(CSR_IE, 1 << (long)d->hwirq); > > +} > > + > > +static void riscv_intc_irq_unmask(struct irq_data *d) > > +{ > > + csr_set(CSR_IE, 1 << (long)d->hwirq); > > +} > > + > > +static int riscv_intc_cpu_starting(unsigned int cpu) > > +{ > > + csr_write(CSR_IE, 1UL << RV_IRQ_SOFT); > > + csr_write(CSR_IP, 0); > > + return 0; > > +} > > + > > +static int riscv_intc_cpu_dying(unsigned int cpu) > > +{ > > + csr_clear(CSR_IE, 1UL << RV_IRQ_SOFT); > > + return 0; > > +} > > + > > +static struct irq_chip riscv_intc_chip = { > > + .name = "RISC-V INTC", > > + .irq_mask = riscv_intc_irq_mask, > > + .irq_unmask = riscv_intc_irq_unmask, > > +}; > > + > > +static int riscv_intc_domain_map(struct irq_domain *d, unsigned int irq, > > + irq_hw_number_t hwirq) > > +{ > > + irq_set_percpu_devid(irq); > > + irq_domain_set_info(d, irq, hwirq, &riscv_intc_chip, d->host_data, > > + handle_percpu_devid_irq, NULL, NULL); > > + irq_set_status_flags(irq, IRQ_NOAUTOEN); > > + > > + return 0; > > +} > > + > > +static const struct irq_domain_ops riscv_intc_domain_ops = { > > + .map = riscv_intc_domain_map, > > + .xlate = irq_domain_xlate_onecell, > > +}; > > + > > +/* Get the OF device node used by INTC irq domain */ > > +struct device_node *riscv_of_intc_domain_node(void) > > +{ > > + return intc_domain_node; > > +} > > +EXPORT_SYMBOL_GPL(riscv_of_intc_domain_node); > > + > > +static int __init riscv_intc_init(struct device_node *node, > > + struct device_node *parent) > > +{ > > + int hartid; > > + > > + /* > > + * The DT will have one INTC DT node under each CPU (or HART) > > + * DT node so riscv_intc_init() function will be called once > > + * for each INTC DT node. We only need INTC initialization for > > + * the INTC DT node belonging to boot CPU (or boot HART). > > + */ > > + hartid = riscv_of_parent_hartid(node); > > + if (hartid < 0) > > + return 0; > > This should at least be a warning, as it's an invalid device tree. Okay, I will add a pr_warn() here. > > > + if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) > > + return 0; > > There should be a comment about this one, as it only works becuase there's one > CPU up and running while interrupts are being enabled. The first comment block in riscv_intc_init() tries to explain it. If you want I can move the comment block just above this "if-statement" > > > + > > + intc_domain = irq_domain_add_linear(node, BITS_PER_LONG, > > + &riscv_intc_domain_ops, NULL); > > + if (!intc_domain) > > + goto error_add_linear; > > + > > + /* > > + * We save the DT node used for creating irq domain and provide > > + * it to other drivers using iscv_of_intc_domain_node() function. > > Missing the "r" in iscv_of_intc_domain_node Okay, will update. > > > + */ > > + intc_domain_node = of_node_get(node); > > + > > + set_handle_irq(&riscv_intc_irq); > > So there's now this implicit assumption that every CPU node has a > riscv,cpu-intc. That's probably fine, as we don't have any other first-level > interrupt controllers, but at least whacking a warning if set_handle_irq() > fails seems prudent. It'd be best to actually check that assumption (maybe > before quitting above?) and actually installing the percpu OF nodes, but that > would take a performance hit so I'm not sure it's worth it. Yes, we should have a warning if set_handle_irq() fails. I will update. > > > + > > + cpuhp_setup_state(CPUHP_AP_IRQ_RISCV_STARTING, > > + "irqchip/riscv/intc:starting", > > + riscv_intc_cpu_starting, > > + riscv_intc_cpu_dying); > > + > > + pr_info("%lu local interrupts mapped\n", (long)BITS_PER_LONG); > > + > > + return 0; > > + > > +error_add_linear: > > + pr_warn("unable to add IRQ domain\n"); > > + return -ENXIO; > > +} > > + > > +IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init); > > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c > > index 16d31d114c30..4f9b2877aa9d 100644 > > --- a/drivers/irqchip/irq-sifive-plic.c > > +++ b/drivers/irqchip/irq-sifive-plic.c > > @@ -9,6 +9,8 @@ > > #include > > #include > > #include > > +#include > > +#include > > #include > > #include > > #include > > @@ -60,6 +62,7 @@ > > #define PLIC_ENABLE_THRESHOLD 0 > > > > struct plic_priv { > > + int parent_irq; > > struct cpumask lmask; > > struct irq_domain *irqdomain; > > void __iomem *regs; > > @@ -219,15 +222,17 @@ static const struct irq_domain_ops plic_irqdomain_ops = { > > * that source ID back to the same claim register. This automatically enables > > * and disables the interrupt, so there's nothing else to do. > > */ > > -static void plic_handle_irq(struct pt_regs *regs) > > +static void plic_handle_irq(struct irq_desc *desc) > > { > > struct plic_handler *handler = this_cpu_ptr(&plic_handlers); > > + struct irq_chip *chip = irq_desc_get_chip(desc); > > void __iomem *claim = handler->hart_base + CONTEXT_CLAIM; > > irq_hw_number_t hwirq; > > > > WARN_ON_ONCE(!handler->present); > > > > - csr_clear(CSR_IE, IE_EIE); > > + chained_irq_enter(chip, desc); > > + > > Ya, it's pretty clear putting the local interrupt controller in irqchip is the > right way to go :) > > > while ((hwirq = readl(claim))) { > > int irq = irq_find_mapping(handler->priv->irqdomain, hwirq); > > > > @@ -237,7 +242,8 @@ static void plic_handle_irq(struct pt_regs *regs) > > else > > generic_handle_irq(irq); > > } > > - csr_set(CSR_IE, IE_EIE); > > + > > + chained_irq_exit(chip, desc); > > } > > > > static void plic_set_threshold(struct plic_handler *handler, u32 threshold) > > @@ -250,7 +256,8 @@ static int plic_dying_cpu(unsigned int cpu) > > { > > struct plic_handler *handler = this_cpu_ptr(&plic_handlers); > > > > - csr_clear(CSR_IE, IE_EIE); > > + if (handler->priv->parent_irq) > > + disable_percpu_irq(handler->priv->parent_irq); > > plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD); > > > > return 0; > > @@ -259,8 +266,10 @@ static int plic_dying_cpu(unsigned int cpu) > > static int plic_starting_cpu(unsigned int cpu) > > { > > struct plic_handler *handler = this_cpu_ptr(&plic_handlers); > > + int pirq = handler->priv->parent_irq; > > > > - csr_set(CSR_IE, IE_EIE); > > + if (pirq) > > + enable_percpu_irq(pirq, irq_get_trigger_type(pirq)); > > plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD); > > > > return 0; > > @@ -273,6 +282,7 @@ static int __init plic_init(struct device_node *node, > > u32 nr_irqs; > > struct plic_priv *priv; > > struct plic_handler *handler; > > + struct of_phandle_args intc_args; > > > > priv = kzalloc(sizeof(*priv), GFP_KERNEL); > > if (!priv) > > @@ -354,6 +364,23 @@ static int __init plic_init(struct device_node *node, > > nr_handlers++; > > } > > > > + /* > > + * We can have multiple PLIC instances so setup chained handler > > + * for all PLIC instances. > > + */ > > + intc_args.np = riscv_of_intc_domain_node(); > > + intc_args.args_count = 1; > > + intc_args.args[0] = RV_IRQ_EXT; > > You could just use the value from the device tree rather than deciding on the > value a-priori. It's a bit pedantic to worry about that now, as the PLIC > assumes that there's a RISC-V system and its parent is an cpu-intc, but it > always seems ugly that the PLIC driver is so RISC-V specific. We are creating only one RISC-V INTC irq_domain for the DT node belonging to the boot CPU. This becomes a problem for multiple PLIC instances because the interrupts-extended property of the PLIC DT node only points to a subset of HARTs. Let me know if you have any other suggestion. > > > + priv->parent_irq = irq_create_of_mapping(&intc_args); > > + if (priv->parent_irq) > > + irq_set_chained_handler(priv->parent_irq, > > + plic_handle_irq); > > + else { > > + pr_err("%pOFP: intc mapping failed\n", node); > > + error = -ENODEV; > > + goto out_iounmap; > > + } > > + > > /* > > * We can have multiple PLIC instances so setup cpuhp state only > > * when context handler for current/boot CPU is present. > > @@ -368,7 +395,6 @@ static int __init plic_init(struct device_node *node, > > > > pr_info("%pOFP: mapped %d interrupts with %d handlers for" > > " %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts); > > - set_handle_irq(plic_handle_irq); > > return 0; > > > > out_iounmap: > > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > > index 77d70b633531..57b1f8f777d9 100644 > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -102,6 +102,7 @@ enum cpuhp_state { > > CPUHP_AP_IRQ_ARMADA_XP_STARTING, > > CPUHP_AP_IRQ_BCM2836_STARTING, > > CPUHP_AP_IRQ_MIPS_GIC_STARTING, > > + CPUHP_AP_IRQ_RISCV_STARTING, > > CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING, > > CPUHP_AP_ARM_MVEBU_COHERENCY, > > CPUHP_AP_MICROCODE_LOADER, > > diff --git a/include/linux/irqchip/irq-riscv-intc.h b/include/linux/irqchip/irq-riscv-intc.h > > new file mode 100644 > > index 000000000000..b11d38353099 > > --- /dev/null > > +++ b/include/linux/irqchip/irq-riscv-intc.h > > @@ -0,0 +1,20 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only */ > > +/* > > + * Copyright (C) 2020 Western Digital Corporation or its affiliates. > > + */ > > + > > +#ifndef __INCLUDE_LINUX_IRQCHIP_IRQ_RISCV_INTC_H > > +#define __INCLUDE_LINUX_IRQCHIP_IRQ_RISCV_INTC_H > > + > > +struct device_node; > > + > > +#ifdef CONFIG_RISCV_INTC > > +struct device_node *riscv_of_intc_domain_node(void); > > +#else > > +static inline struct device_node *riscv_of_intc_domain_node(void) > > +{ > > + return NULL; > > +} > > +#endif > > + > > +#endif > > These issues are all pretty minor, so I'm OK with this getting merged as-is. I > fixed up some minor stuff and have it on my intc branch as 2bd957e2b0b6 > ("irqchip: RISC-V per-HART local interrupt controller driver"), but if the > irqchip folks want to take the patches then I'm not opposed to either version > getting merged. > > Acked-by: Palmer Dabbelt Thanks, I can quickly send v6 with your comments addressed in a few hours. Do you want me to send v6 ? Regards, Anup