// SPDX-License-Identifier: GPL-2.0-only /* * Multiplex several IPIs over a single HW IPI. * * Copyright (c) 2022 Ventana Micro Systems Inc. */ #define pr_fmt(fmt) "riscv: " fmt #include <linux/cpu.h> #include <linux/init.h> #include <linux/irq.h> #include <linux/irqchip/chained_irq.h> #include <linux/irqdomain.h> #include <asm/sbi.h> static int sbi_ipi_virq; static void sbi_ipi_handle(struct irq_desc *desc) { struct irq_chip *chip = irq_desc_get_chip(desc); chained_irq_enter(chip, desc); csr_clear(CSR_IP, IE_SIE); ipi_mux_process(); chained_irq_exit(chip, desc); } static int sbi_ipi_starting_cpu(unsigned int cpu) { enable_percpu_irq(sbi_ipi_virq, irq_get_trigger_type(sbi_ipi_virq)); return 0; } void __init sbi_ipi_init(void) { int virq; struct irq_domain *domain; if (riscv_ipi_have_virq_range()) return; domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY); if (!domain) { pr_err("unable to find INTC IRQ domain\n"); return; } sbi_ipi_virq = irq_create_mapping(domain, RV_IRQ_SOFT); if (!sbi_ipi_virq) { pr_err("unable to create INTC IRQ mapping\n"); return; } virq = ipi_mux_create(BITS_PER_BYTE, sbi_send_ipi); if (virq <= 0) { pr_err("unable to create muxed IPIs\n"); irq_dispose_mapping(sbi_ipi_virq); return; } irq_set_chained_handler(sbi_ipi_virq, sbi_ipi_handle); /* * Don't disable IPI when CPU goes offline because * the masking/unmasking of virtual IPIs is done * via generic IPI-Mux */ cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "irqchip/sbi-ipi:starting", sbi_ipi_starting_cpu, NULL); riscv_ipi_set_virq_range(virq, BITS_PER_BYTE, false); pr_info("providing IPIs using SBI IPI extension\n"); }