The RISC-V advanced platform-level interrupt controller (APLIC) has two modes of operation: 1) Direct mode and 2) MSI mode. (For more details, refer https://github.com/riscv/riscv-aia) In APLIC MSI-mode, wired interrupts are forwared as message signaled interrupts (MSIs) to CPUs via IMSIC. We extend the existing APLIC irqchip driver to support MSI-mode for RISC-V platforms having both wired interrupts and MSIs. Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> --- drivers/irqchip/Kconfig | 6 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-aplic-main.c | 2 +- drivers/irqchip/irq-riscv-aplic-main.h | 8 + drivers/irqchip/irq-riscv-aplic-msi.c | 285 +++++++++++++++++++++++++ 5 files changed, 301 insertions(+), 1 deletion(-) create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 8875065d8af9..1a337ab9dd41 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -549,6 +549,12 @@ config RISCV_APLIC depends on RISCV select IRQ_DOMAIN_HIERARCHY +config RISCV_APLIC_MSI + bool + depends on RISCV_APLIC + select GENERIC_MSI_IRQ + default RISCV_APLIC + config RISCV_IMSIC bool depends on RISCV diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index 7f8289790ed8..47995fdb2c60 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -96,6 +96,7 @@ 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_RISCV_APLIC) += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o +obj-$(CONFIG_RISCV_APLIC_MSI) += irq-riscv-aplic-msi.o obj-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c index d62a096774c4..f225ac77ea3c 100644 --- a/drivers/irqchip/irq-riscv-aplic-main.c +++ b/drivers/irqchip/irq-riscv-aplic-main.c @@ -203,7 +203,7 @@ static int aplic_probe(struct platform_device *pdev) * otherwise setup APLIC direct mode. */ if (fwnode_property_present(dev->fwnode, "msi-parent")) - rc = -ENODEV; + rc = aplic_msi_setup(dev, regs); else rc = aplic_direct_setup(dev, regs); if (rc) { diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h index 474a04229334..78267ec58098 100644 --- a/drivers/irqchip/irq-riscv-aplic-main.h +++ b/drivers/irqchip/irq-riscv-aplic-main.h @@ -41,5 +41,13 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode); int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs); int aplic_direct_setup(struct device *dev, void __iomem *regs); +#ifdef CONFIG_RISCV_APLIC_MSI +int aplic_msi_setup(struct device *dev, void __iomem *regs); +#else +static inline int aplic_msi_setup(struct device *dev, void __iomem *regs) +{ + return -ENODEV; +} +#endif #endif diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c new file mode 100644 index 000000000000..086d00e0429e --- /dev/null +++ b/drivers/irqchip/irq-riscv-aplic-msi.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + */ + +#include <linux/bitops.h> +#include <linux/cpu.h> +#include <linux/interrupt.h> +#include <linux/irqchip.h> +#include <linux/irqchip/riscv-aplic.h> +#include <linux/irqchip/riscv-imsic.h> +#include <linux/module.h> +#include <linux/msi.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/printk.h> +#include <linux/smp.h> + +#include "irq-riscv-aplic-main.h" + +static void aplic_msi_irq_unmask(struct irq_data *d) +{ + aplic_irq_unmask(d); + irq_chip_unmask_parent(d); +} + +static void aplic_msi_irq_mask(struct irq_data *d) +{ + aplic_irq_mask(d); + irq_chip_mask_parent(d); +} + +static void aplic_msi_irq_eoi(struct irq_data *d) +{ + struct aplic_priv *priv = irq_data_get_irq_chip_data(d); + u32 reg_off, reg_mask; + + /* + * EOI handling only required only for level-triggered + * interrupts in APLIC MSI mode. + */ + + reg_off = APLIC_CLRIP_BASE + ((d->hwirq / APLIC_IRQBITS_PER_REG) * 4); + reg_mask = BIT(d->hwirq % APLIC_IRQBITS_PER_REG); + switch (irqd_get_trigger_type(d)) { + case IRQ_TYPE_LEVEL_LOW: + if (!(readl(priv->regs + reg_off) & reg_mask)) + writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE); + break; + case IRQ_TYPE_LEVEL_HIGH: + if (readl(priv->regs + reg_off) & reg_mask) + writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE); + break; + } +} + +static struct irq_chip aplic_msi_chip = { + .name = "APLIC-MSI", + .irq_mask = aplic_msi_irq_mask, + .irq_unmask = aplic_msi_irq_unmask, + .irq_set_type = aplic_irq_set_type, + .irq_eoi = aplic_msi_irq_eoi, +#ifdef CONFIG_SMP + .irq_set_affinity = irq_chip_set_affinity_parent, +#endif + .flags = IRQCHIP_SET_TYPE_MASKED | + IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_MASK_ON_SUSPEND, +}; + +static int aplic_msi_irqdomain_translate(struct irq_domain *d, + struct irq_fwspec *fwspec, + unsigned long *hwirq, + unsigned int *type) +{ + struct aplic_priv *priv = platform_msi_get_host_data(d); + + return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type); +} + +static int aplic_msi_irqdomain_alloc(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs, + void *arg) +{ + int i, ret; + unsigned int type; + irq_hw_number_t hwirq; + struct irq_fwspec *fwspec = arg; + struct aplic_priv *priv = platform_msi_get_host_data(domain); + + ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type); + if (ret) + return ret; + + ret = platform_msi_device_domain_alloc(domain, virq, nr_irqs); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) { + irq_domain_set_info(domain, virq + i, hwirq + i, + &aplic_msi_chip, priv, handle_fasteoi_irq, + NULL, NULL); + /* + * APLIC does not implement irq_disable() so Linux interrupt + * subsystem will take a lazy approach for disabling an APLIC + * interrupt. This means APLIC interrupts are left unmasked + * upon system suspend and interrupts are not processed + * immediately upon system wake up. To tackle this, we disable + * the lazy approach for all APLIC interrupts. + */ + irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY); + } + + return 0; +} + +static const struct irq_domain_ops aplic_msi_irqdomain_ops = { + .translate = aplic_msi_irqdomain_translate, + .alloc = aplic_msi_irqdomain_alloc, + .free = platform_msi_device_domain_free, +}; + +static void aplic_msi_write_msg(struct msi_desc *desc, struct msi_msg *msg) +{ + unsigned int group_index, hart_index, guest_index, val; + struct irq_data *d = irq_get_irq_data(desc->irq); + struct aplic_priv *priv = irq_data_get_irq_chip_data(d); + struct aplic_msicfg *mc = &priv->msicfg; + phys_addr_t tppn, tbppn, msg_addr; + void __iomem *target; + + /* For zeroed MSI, simply write zero into the target register */ + if (!msg->address_hi && !msg->address_lo && !msg->data) { + target = priv->regs + APLIC_TARGET_BASE; + target += (d->hwirq - 1) * sizeof(u32); + writel(0, target); + return; + } + + /* Sanity check on message data */ + WARN_ON(msg->data > APLIC_TARGET_EIID_MASK); + + /* Compute target MSI address */ + msg_addr = (((u64)msg->address_hi) << 32) | msg->address_lo; + tppn = msg_addr >> APLIC_xMSICFGADDR_PPN_SHIFT; + + /* Compute target HART Base PPN */ + tbppn = tppn; + tbppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs); + tbppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs); + tbppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs); + WARN_ON(tbppn != mc->base_ppn); + + /* Compute target group and hart indexes */ + group_index = (tppn >> APLIC_xMSICFGADDR_PPN_HHX_SHIFT(mc->hhxs)) & + APLIC_xMSICFGADDR_PPN_HHX_MASK(mc->hhxw); + hart_index = (tppn >> APLIC_xMSICFGADDR_PPN_LHX_SHIFT(mc->lhxs)) & + APLIC_xMSICFGADDR_PPN_LHX_MASK(mc->lhxw); + hart_index |= (group_index << mc->lhxw); + WARN_ON(hart_index > APLIC_TARGET_HART_IDX_MASK); + + /* Compute target guest index */ + guest_index = tppn & APLIC_xMSICFGADDR_PPN_HART(mc->lhxs); + WARN_ON(guest_index > APLIC_TARGET_GUEST_IDX_MASK); + + /* Update IRQ TARGET register */ + target = priv->regs + APLIC_TARGET_BASE; + target += (d->hwirq - 1) * sizeof(u32); + val = (hart_index & APLIC_TARGET_HART_IDX_MASK) + << APLIC_TARGET_HART_IDX_SHIFT; + val |= (guest_index & APLIC_TARGET_GUEST_IDX_MASK) + << APLIC_TARGET_GUEST_IDX_SHIFT; + val |= (msg->data & APLIC_TARGET_EIID_MASK); + writel(val, target); +} + +int aplic_msi_setup(struct device *dev, void __iomem *regs) +{ + const struct imsic_global_config *imsic_global; + struct irq_domain *irqdomain; + struct aplic_priv *priv; + struct aplic_msicfg *mc; + phys_addr_t pa; + int rc; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + rc = aplic_setup_priv(priv, dev, regs); + if (!priv) { + dev_err(dev, "failed to create APLIC context\n"); + return rc; + } + mc = &priv->msicfg; + + /* + * The APLIC outgoing MSI config registers assume target MSI + * controller to be RISC-V AIA IMSIC controller. + */ + imsic_global = imsic_get_global_config(); + if (!imsic_global) { + dev_err(dev, "IMSIC global config not found\n"); + return -ENODEV; + } + + /* Find number of guest index bits (LHXS) */ + mc->lhxs = imsic_global->guest_index_bits; + if (APLIC_xMSICFGADDRH_LHXS_MASK < mc->lhxs) { + dev_err(dev, "IMSIC guest index bits big for APLIC LHXS\n"); + return -EINVAL; + } + + /* Find number of HART index bits (LHXW) */ + mc->lhxw = imsic_global->hart_index_bits; + if (APLIC_xMSICFGADDRH_LHXW_MASK < mc->lhxw) { + dev_err(dev, "IMSIC hart index bits big for APLIC LHXW\n"); + return -EINVAL; + } + + /* Find number of group index bits (HHXW) */ + mc->hhxw = imsic_global->group_index_bits; + if (APLIC_xMSICFGADDRH_HHXW_MASK < mc->hhxw) { + dev_err(dev, "IMSIC group index bits big for APLIC HHXW\n"); + return -EINVAL; + } + + /* Find first bit position of group index (HHXS) */ + mc->hhxs = imsic_global->group_index_shift; + if (mc->hhxs < (2 * APLIC_xMSICFGADDR_PPN_SHIFT)) { + dev_err(dev, "IMSIC group index shift should be >= %d\n", + (2 * APLIC_xMSICFGADDR_PPN_SHIFT)); + return -EINVAL; + } + mc->hhxs -= (2 * APLIC_xMSICFGADDR_PPN_SHIFT); + if (APLIC_xMSICFGADDRH_HHXS_MASK < mc->hhxs) { + dev_err(dev, "IMSIC group index shift big for APLIC HHXS\n"); + return -EINVAL; + } + + /* Compute PPN base */ + mc->base_ppn = imsic_global->base_addr >> APLIC_xMSICFGADDR_PPN_SHIFT; + mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs); + mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs); + mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs); + + /* Setup global config and interrupt delivery */ + aplic_init_hw_global(priv, true); + + /* Set the APLIC device MSI domain if not available */ + if (!dev_get_msi_domain(dev)) { + /* + * The device MSI domain for OF devices is only set at the + * time of populating/creating OF device. If the device MSI + * domain is discovered later after the OF device is created + * then we need to set it explicitly before using any platform + * MSI functions. + * + * In case of APLIC device, the parent MSI domain is always + * IMSIC and the IMSIC MSI domains are created later through + * the platform driver probing so we set it explicitly here. + */ + if (is_of_node(dev->fwnode)) + of_msi_configure(dev, to_of_node(dev->fwnode)); + } + + /* Create irq domain instance for the APLIC MSI-mode */ + irqdomain = platform_msi_create_device_domain( + dev, priv->nr_irqs + 1, + aplic_msi_write_msg, + &aplic_msi_irqdomain_ops, + priv); + if (!irqdomain) { + dev_err(dev, "failed to create MSI irq domain\n"); + return -ENOMEM; + } + + /* Advertise the interrupt controller */ + pa = priv->msicfg.base_ppn << APLIC_xMSICFGADDR_PPN_SHIFT; + dev_info(dev, "%d interrupts forwared to MSI base %pa\n", + priv->nr_irqs, &pa); + + return 0; +} -- 2.34.1
