diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/irqchip/irq-riscv-aplic-msi.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c new file mode 100644 index 0000000000..028444af48 --- /dev/null +++ b/drivers/irqchip/irq-riscv-aplic-msi.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + */ + +#include <linux/bitfield.h> +#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_mask(struct irq_data *d) +{ + aplic_irq_mask(d); + irq_chip_mask_parent(d); +} + +static void aplic_msi_irq_unmask(struct irq_data *d) +{ + irq_chip_unmask_parent(d); + aplic_irq_unmask(d); +} + +static void aplic_msi_irq_eoi(struct irq_data *d) +{ + struct aplic_priv *priv = irq_data_get_irq_chip_data(d); + + /* + * EOI handling is required only for level-triggered interrupts + * when APLIC is in MSI mode. + */ + + switch (irqd_get_trigger_type(d)) { + case IRQ_TYPE_LEVEL_LOW: + case IRQ_TYPE_LEVEL_HIGH: + /* + * The section "4.9.2 Special consideration for level-sensitive interrupt + * sources" of the RISC-V AIA specification says: + * + * A second option is for the interrupt service routine to write the + * APLIC’s source identity number for the interrupt to the domain’s + * setipnum register just before exiting. This will cause the interrupt’s + * pending bit to be set to one again if the source is still asserting + * an interrupt, but not if the source is not asserting an interrupt. + */ + writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE); + break; + } +} + +static void aplic_msi_write_msg(struct irq_data *d, struct msi_msg *msg) +{ + unsigned int group_index, hart_index, guest_index, val; + 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 = FIELD_PREP(APLIC_TARGET_HART_IDX, hart_index); + val |= FIELD_PREP(APLIC_TARGET_GUEST_IDX, guest_index); + val |= FIELD_PREP(APLIC_TARGET_EIID, msg->data); + writel(val, target); +} + +static void aplic_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) +{ + arg->desc = desc; + arg->hwirq = (u32)desc->data.icookie.value; +} + +static int aplic_msi_translate(struct irq_domain *d, struct irq_fwspec *fwspec, + unsigned long *hwirq, unsigned int *type) +{ + struct msi_domain_info *info = d->host_data; + struct aplic_priv *priv = info->data; + + return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type); +} + +static const struct msi_domain_template aplic_msi_template = { + .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 + .irq_write_msi_msg = aplic_msi_write_msg, + .flags = IRQCHIP_SET_TYPE_MASKED | + IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_MASK_ON_SUSPEND, + }, + + .ops = { + .set_desc = aplic_msi_set_desc, + .msi_translate = aplic_msi_translate, + }, + + .info = { + .bus_token = DOMAIN_BUS_WIRED_TO_MSI, + .flags = MSI_FLAG_USE_DEV_FWNODE, + .handler = handle_fasteoi_irq, + .handler_name = "fasteoi", + }, +}; + +int aplic_msi_setup(struct device *dev, void __iomem *regs) +{ + const struct imsic_global_config *imsic_global; + 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 (rc) { + 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)); + } + + if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN, &aplic_msi_template, + priv->nr_irqs + 1, priv, priv)) { + 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 forwarded to MSI base %pa\n", priv->nr_irqs, &pa); + + return 0; +} |