From 6b7ce8927b5a4d739670d4dc0de301f2abfd9a5c Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Mon, 1 Jun 2020 14:45:40 +0530 Subject: irqchip: RISC-V per-HART local interrupt controller driver 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. We add a driver for the RISC-V local interrupt controller, which eventually replaces the RISC-V architecture code, allowing for a better split between arch code and drivers. The driver is compliant with RISC-V Hart-Level Interrupt Controller DT bindings located at: Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt Co-developed-by: Palmer Dabbelt Signed-off-by: Anup Patel [Palmer: Cleaned up warnings] Signed-off-by: Palmer Dabbelt --- drivers/irqchip/Kconfig | 13 ++++ drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-intc.c | 146 ++++++++++++++++++++++++++++++++++++++ drivers/irqchip/irq-sifive-plic.c | 32 ++++++--- 4 files changed, 183 insertions(+), 9 deletions(-) create mode 100644 drivers/irqchip/irq-riscv-intc.c (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 66b9a68f5e9f..29fead208cad 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 3a4ce283189a..133f9c45744a 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..a80fb1731c50 --- /dev/null +++ b/drivers/irqchip/irq-riscv-intc.c @@ -0,0 +1,146 @@ +// 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 + +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, BIT(d->hwirq)); +} + +static void riscv_intc_irq_unmask(struct irq_data *d) +{ + csr_set(CSR_IE, BIT(d->hwirq)); +} + +static int riscv_intc_cpu_starting(unsigned int cpu) +{ + csr_set(CSR_IE, BIT(RV_IRQ_SOFT)); + return 0; +} + +static int riscv_intc_cpu_dying(unsigned int cpu) +{ + csr_clear(CSR_IE, BIT(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); + + return 0; +} + +static const struct irq_domain_ops riscv_intc_domain_ops = { + .map = riscv_intc_domain_map, + .xlate = irq_domain_xlate_onecell, +}; + +static int __init riscv_intc_init(struct device_node *node, + struct device_node *parent) +{ + int rc, hartid; + + hartid = riscv_of_parent_hartid(node); + if (hartid < 0) { + pr_warn("unable to fine hart id for %pOF\n", node); + return 0; + } + + /* + * 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 to do INTC initialization + * for the INTC DT node belonging to boot CPU (or boot HART). + */ + if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) + return 0; + + intc_domain = irq_domain_add_linear(node, BITS_PER_LONG, + &riscv_intc_domain_ops, NULL); + if (!intc_domain) { + pr_err("unable to add IRQ domain\n"); + return -ENXIO; + } + + rc = set_handle_irq(&riscv_intc_irq); + if (rc) { + pr_err("failed to set irq handler\n"); + return rc; + } + + cpuhp_setup_state(CPUHP_AP_IRQ_RISCV_STARTING, + "irqchip/riscv/intc:starting", + riscv_intc_cpu_starting, + riscv_intc_cpu_dying); + + pr_info("%d local interrupts mapped\n", BITS_PER_LONG); + + return 0; +} + +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..eaa3e9fe54e9 100644 --- a/drivers/irqchip/irq-sifive-plic.c +++ b/drivers/irqchip/irq-sifive-plic.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -76,6 +77,7 @@ struct plic_handler { void __iomem *enable_base; struct plic_priv *priv; }; +static int plic_parent_irq; static bool plic_cpuhp_setup_done; static DEFINE_PER_CPU(struct plic_handler, plic_handlers); @@ -219,15 +221,17 @@ 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); + while ((hwirq = readl(claim))) { int irq = irq_find_mapping(handler->priv->irqdomain, hwirq); @@ -237,7 +241,8 @@ 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) @@ -248,10 +253,8 @@ static void plic_set_threshold(struct plic_handler *handler, u32 threshold) static int plic_dying_cpu(unsigned int cpu) { - struct plic_handler *handler = this_cpu_ptr(&plic_handlers); - - csr_clear(CSR_IE, IE_EIE); - plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD); + if (plic_parent_irq) + disable_percpu_irq(plic_parent_irq); return 0; } @@ -260,7 +263,11 @@ static int plic_starting_cpu(unsigned int cpu) { struct plic_handler *handler = this_cpu_ptr(&plic_handlers); - csr_set(CSR_IE, IE_EIE); + if (plic_parent_irq) + enable_percpu_irq(plic_parent_irq, + irq_get_trigger_type(plic_parent_irq)); + else + pr_warn("cpu%d: parent irq not available\n", cpu); plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD); return 0; @@ -328,6 +335,14 @@ static int __init plic_init(struct device_node *node, continue; } + /* Find parent domain and register chained handler */ + if (!plic_parent_irq && irq_find_host(parent.np)) { + plic_parent_irq = irq_of_parse_and_map(node, i); + if (plic_parent_irq) + irq_set_chained_handler(plic_parent_irq, + plic_handle_irq); + } + /* * When running in M-mode we need to ignore the S-mode handler. * Here we assume it always comes later, but that might be a @@ -368,7 +383,6 @@ done: 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: -- cgit v1.2.3