[RFC PATCH v2 31/31] kvx: Add IPI driver

From: Jules Maselbas <jmaselbas(a)kalray.eu&gt; The Inter-Processor Interrupt Controller (IPI) provides a fast synchronization mechanism to the software. It exposes eight independent set of registers that can be use to notify each processor in the cluster. test Co-developed-by: Clement Leger <clement(a)clement-leger.fr&gt; Signed-off-by: Clement Leger <clement(a)clement-leger.fr&gt; Co-developed-by: Guillaume Thouvenin <gthouvenin(a)kalray.eu&gt; Signed-off-by: Guillaume Thouvenin <gthouvenin(a)kalray.eu&gt; Co-developed-by: Julian Vetter <jvetter(a)kalray.eu&gt; Signed-off-by: Julian Vetter <jvetter(a)kalray.eu&gt; Co-developed-by: Luc Michel <lmichel(a)kalray.eu&gt; Signed-off-by: Luc Michel <lmichel(a)kalray.eu&gt; Signed-off-by: Jules Maselbas <jmaselbas(a)kalray.eu&gt; Signed-off-by: Yann Sionneau <ysionneau(a)kalray.eu&gt; --- Notes: V1 -> V2: new patch arch/kvx/include/asm/ipi.h | 16 ++++++ arch/kvx/platform/Makefile | 1 + arch/kvx/platform/ipi.c | 108 +++++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+) create mode 100644 arch/kvx/include/asm/ipi.h create mode 100644 arch/kvx/platform/ipi.c diff --git a/arch/kvx/include/asm/ipi.h b/arch/kvx/include/asm/ipi.h new file mode 100644 index 000000000000..137407a075e6 --- /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_probe(irqreturn_t (*ipi_irq_handler)(int, void *)); + +void kvx_ipi_send(const struct cpumask *mask); + +#endif /* _ASM_KVX_IPI_H */ diff --git a/arch/kvx/platform/Makefile b/arch/kvx/platform/Makefile index c7d0abb15c27..27f0914e0de5 100644 --- a/arch/kvx/platform/Makefile +++ b/arch/kvx/platform/Makefile @@ -4,3 +4,4 @@ # obj-$(CONFIG_SMP) += pwr_ctrl.o +obj-$(CONFIG_SMP) += ipi.o diff --git a/arch/kvx/platform/ipi.c b/arch/kvx/platform/ipi.c new file mode 100644 index 000000000000..a471039b1643 --- /dev/null +++ b/arch/kvx/platform/ipi.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2023 Kalray Inc. + * Author(s): Clement Leger + * Luc Michel + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/module.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> + +#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) + +struct kvx_ipi_ctrl { + void __iomem *regs; + unsigned int ipi_irq; +}; + +static struct kvx_ipi_ctrl kvx_ipi_controller; + +/** + * @kvx_pwr_ctrl_cpu_poweron Wakeup a cpu + * + * cpu: cpu to wakeup + */ +void kvx_ipi_send(const struct cpumask *mask) +{ + const unsigned long *maskb = cpumask_bits(mask); + + WARN_ON(*maskb & KVX_IPI_CPU_MASK); + writel(*maskb, kvx_ipi_controller.regs + IPI_INTERRUPT_OFFSET); +} + +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; +} + +int __init kvx_ipi_ctrl_probe(irqreturn_t (*ipi_irq_handler)(int, void *)) +{ + struct device_node *np; + int ret; + unsigned int ipi_irq; + void __iomem *ipi_base; + + np = of_find_compatible_node(NULL, NULL, "kalray,kvx-ipi-ctrl"); + BUG_ON(!np); + + ipi_base = of_iomap(np, 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(np, 0); + of_node_put(np); + 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; + } + + return 0; +} -- 2.37.2