From: Yann Sionneau <ysionneau@xxxxxxxxxxxxx> The Inter-Processor Interrupt Controller (IPI) provides a fast synchronization mechanism to the software. It exposes eight independent sets of registers that can be used to notify each processor in the cluster. Co-developed-by: Clement Leger <clement@xxxxxxxxxxxxxxxx> Signed-off-by: Clement Leger <clement@xxxxxxxxxxxxxxxx> Co-developed-by: Guillaume Thouvenin <thouveng@xxxxxxxxx> Signed-off-by: Guillaume Thouvenin <thouveng@xxxxxxxxx> Co-developed-by: Julian Vetter <jvetter@xxxxxxxxxxxxx> Signed-off-by: Julian Vetter <jvetter@xxxxxxxxxxxxx> Co-developed-by: Luc Michel <luc@xxxxxxxxxx> Signed-off-by: Luc Michel <luc@xxxxxxxxxx> Signed-off-by: Jules Maselbas <jmaselbas@xxxxxxxx> Signed-off-by: Yann Sionneau <ysionneau@xxxxxxxxxxxxx> --- Notes: V1 -> V2: new patch V2 -> V3: - Restructured IPI code according to reviewer feedback - move from arch/kvx/platform to drivers/irqchip/ - remove bogus comment - call set_smp_cross_call() to set smpboot.c's ipi function pointer - feedbacks: https://lore.kernel.org/bpf/Y8qlOpYgDefMPqWH@xxxxxxxxx/T/#mb02884ea498e627c2621973157330f2ea9977190 --- arch/kvx/include/asm/ipi.h | 16 ++++ drivers/irqchip/Kconfig | 4 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-kvx-ipi-ctrl.c | 143 +++++++++++++++++++++++++++++ 4 files changed, 164 insertions(+) create mode 100644 arch/kvx/include/asm/ipi.h create mode 100644 drivers/irqchip/irq-kvx-ipi-ctrl.c diff --git a/arch/kvx/include/asm/ipi.h b/arch/kvx/include/asm/ipi.h new file mode 100644 index 0000000000000..a23275d19d225 --- /dev/null +++ b/arch/kvx/include/asm/ipi.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + */ + +#ifndef _ASM_KVX_IPI_H +#define _ASM_KVX_IPI_H + +#include <linux/irqreturn.h> + +int kvx_ipi_ctrl_init(struct device_node *node, struct device_node *parent); + +void kvx_ipi_send(const struct cpumask *mask, unsigned int operation); + +#endif /* _ASM_KVX_IPI_H */ diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index da1dbd79dab54..65db9990cf475 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -337,6 +337,10 @@ config KVX_CORE_INTC depends on KVX select IRQ_DOMAIN +config KVX_IPI_CTRL + bool + depends on KVX + config KVX_APIC_GIC bool depends on KVX diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index 30b69db8789f7..f8fa246df74d2 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_BRCMSTB_L2_IRQ) += irq-brcmstb-l2.o obj-$(CONFIG_KEYSTONE_IRQ) += irq-keystone.o obj-$(CONFIG_MIPS_GIC) += irq-mips-gic.o obj-$(CONFIG_KVX_CORE_INTC) += irq-kvx-core-intc.o +obj-$(CONFIG_KVX_IPI_CTRL) += irq-kvx-ipi-ctrl.o obj-$(CONFIG_KVX_APIC_GIC) += irq-kvx-apic-gic.o obj-$(CONFIG_KVX_ITGEN) += irq-kvx-itgen.o obj-$(CONFIG_KVX_APIC_MAILBOX) += irq-kvx-apic-mailbox.o diff --git a/drivers/irqchip/irq-kvx-ipi-ctrl.c b/drivers/irqchip/irq-kvx-ipi-ctrl.c new file mode 100644 index 0000000000000..09d955a5c109a --- /dev/null +++ b/drivers/irqchip/irq-kvx-ipi-ctrl.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2024 Kalray Inc. + * + * Author(s): Clement Leger + * Jonathan Borne + * Luc Michel + */ + +#define pr_fmt(fmt) "kvx_ipi_ctrl: " fmt + +#include <linux/smp.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/module.h> +#include <linux/irqchip.h> +#include <linux/of_irq.h> +#include <linux/cpumask.h> +#include <linux/interrupt.h> +#include <linux/cpuhotplug.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> + +#include <asm/ipi.h> + +#define IPI_INTERRUPT_OFFSET 0x0 +#define IPI_MASK_OFFSET 0x20 + +/* + * IPI controller can signal RM and PE0 -> 15 + * In order to restrict that to the PE, write the corresponding mask + */ +#define KVX_IPI_CPU_MASK (~0xFFFF) + +/* A collection of single bit ipi messages. */ +static DEFINE_PER_CPU_ALIGNED(unsigned long, ipi_data); + +struct kvx_ipi_ctrl { + void __iomem *regs; + unsigned int ipi_irq; +}; + +static struct kvx_ipi_ctrl kvx_ipi_controller; + +void kvx_ipi_send(const struct cpumask *mask, unsigned int operation) +{ + const unsigned long *maskb = cpumask_bits(mask); + unsigned long flags; + int cpu; + + /* Set operation that must be done by receiver */ + for_each_cpu(cpu, mask) + set_bit(operation, &per_cpu(ipi_data, cpu)); + + /* Commit the write before sending IPI */ + smp_wmb(); + + local_irq_save(flags); + + WARN_ON(*maskb & KVX_IPI_CPU_MASK); + writel(*maskb, kvx_ipi_controller.regs + IPI_INTERRUPT_OFFSET); + + local_irq_restore(flags); +} + +static int kvx_ipi_starting_cpu(unsigned int cpu) +{ + enable_percpu_irq(kvx_ipi_controller.ipi_irq, IRQ_TYPE_NONE); + + return 0; +} + +static int kvx_ipi_dying_cpu(unsigned int cpu) +{ + disable_percpu_irq(kvx_ipi_controller.ipi_irq); + + return 0; +} + +static irqreturn_t ipi_irq_handler(int irq, void *dev_id) +{ + unsigned long *pending_ipis = &per_cpu(ipi_data, smp_processor_id()); + + while (true) { + unsigned long ops = xchg(pending_ipis, 0); + + if (!ops) + return IRQ_HANDLED; + + handle_IPI(ops); + } + + return IRQ_HANDLED; +} + +int __init kvx_ipi_ctrl_init(struct device_node *node, + struct device_node *parent) +{ + int ret; + unsigned int ipi_irq; + void __iomem *ipi_base; + + BUG_ON(!node); + + ipi_base = of_iomap(node, 0); + BUG_ON(!ipi_base); + + kvx_ipi_controller.regs = ipi_base; + + /* Init mask for interrupts to PE0 -> PE15 */ + writel(KVX_IPI_CPU_MASK, kvx_ipi_controller.regs + IPI_MASK_OFFSET); + + ipi_irq = irq_of_parse_and_map(node, 0); + if (!ipi_irq) { + pr_err("Failed to parse irq: %d\n", ipi_irq); + return -EINVAL; + } + + ret = request_percpu_irq(ipi_irq, ipi_irq_handler, + "kvx_ipi", &kvx_ipi_controller); + if (ret) { + pr_err("can't register interrupt %d (%d)\n", + ipi_irq, ret); + return ret; + } + kvx_ipi_controller.ipi_irq = ipi_irq; + + ret = cpuhp_setup_state(CPUHP_AP_IRQ_KVX_STARTING, + "kvx/ipi:online", + kvx_ipi_starting_cpu, + kvx_ipi_dying_cpu); + if (ret < 0) { + pr_err("Failed to setup hotplug state"); + return ret; + } + + set_smp_cross_call(kvx_ipi_send); + pr_info("controller probed\n"); + + return 0; +} +IRQCHIP_DECLARE(kvx_ipi_ctrl, "kalray,coolidge-ipi-ctrl", kvx_ipi_ctrl_init); -- 2.45.2
