The RISC-V advanced interrupt architecture (AIA) specification defines a new MSI controller for managing MSIs and IPIs on a RISC-V platform. This new MSI controller is referred to as incoming message signalled interrupt controller (IMSIC) which manages MSI on per-HART (or per-CPU) basis. (For more details refer https://github.com/riscv/riscv-aia) This patch adds an irqchip driver for RISC-V IMSIC which provides IPIs and platform MSIs to the Linux RISC-V kernel. Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> --- drivers/irqchip/Kconfig | 7 +- drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-imsic.c | 1028 +++++++++++++++++++++++++++ include/linux/irqchip/riscv-imsic.h | 86 +++ 4 files changed, 1121 insertions(+), 1 deletion(-) create mode 100644 drivers/irqchip/irq-riscv-imsic.c create mode 100644 include/linux/irqchip/riscv-imsic.h diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 09e422da482f..8ef18be5f37b 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -30,7 +30,6 @@ config ARM_GIC_V2M config GIC_NON_BANKED bool - config ARM_GIC_V3 bool select IRQ_DOMAIN_HIERARCHY @@ -545,6 +544,12 @@ config SIFIVE_PLIC select IRQ_DOMAIN_HIERARCHY select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP +config RISCV_IMSIC + bool + depends on RISCV + select IRQ_DOMAIN_HIERARCHY + select GENERIC_MSI_IRQ + config EXYNOS_IRQ_COMBINER bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index ffd945fe71aa..577bde3e986b 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM) += irq-qcom-mpm.o obj-$(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-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic.o obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o obj-$(CONFIG_IMX_INTMUX) += irq-imx-intmux.o diff --git a/drivers/irqchip/irq-riscv-imsic.c b/drivers/irqchip/irq-riscv-imsic.c new file mode 100644 index 000000000000..971fad638c9f --- /dev/null +++ b/drivers/irqchip/irq-riscv-imsic.c @@ -0,0 +1,1028 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + */ + +#define pr_fmt(fmt) "riscv-imsic: " fmt +#include <linux/bitmap.h> +#include <linux/cpu.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iommu.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqchip/riscv-imsic.h> +#include <linux/irqdomain.h> +#include <linux/module.h> +#include <linux/msi.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/smp.h> +#include <asm/hwcap.h> + +#define IMSIC_DISABLE_EIDELIVERY 0 +#define IMSIC_ENABLE_EIDELIVERY 1 +#define IMSIC_DISABLE_EITHRESHOLD 1 +#define IMSIC_ENABLE_EITHRESHOLD 0 + +/* + * The IMSIC driver uses 1 IPI for ID synchronization and + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the + * total number of IPIs to 8. + */ +#define IMSIC_NR_IPI 8 + +#define imsic_csr_write(__c, __v) \ +do { \ + csr_write(CSR_ISELECT, __c); \ + csr_write(CSR_IREG, __v); \ +} while (0) + +#define imsic_csr_read(__c) \ +({ \ + unsigned long __v; \ + csr_write(CSR_ISELECT, __c); \ + __v = csr_read(CSR_IREG); \ + __v; \ +}) + +#define imsic_csr_set(__c, __v) \ +do { \ + csr_write(CSR_ISELECT, __c); \ + csr_set(CSR_IREG, __v); \ +} while (0) + +#define imsic_csr_clear(__c, __v) \ +do { \ + csr_write(CSR_ISELECT, __c); \ + csr_clear(CSR_IREG, __v); \ +} while (0) + +struct imsic_priv { + /* Global configuration common for all HARTs */ + struct imsic_global_config global; + + /* Global state of interrupt identities */ + raw_spinlock_t ids_lock; + unsigned long *ids_used_bimap; + unsigned long *ids_enabled_bimap; + unsigned int *ids_target_cpu; + + /* Mask for connected CPUs */ + struct cpumask lmask; + + /* IPI interrupt identity and synchronization */ + u32 ipi_id; + int ipi_virq; + struct irq_desc *ipi_lsync_desc; + + /* IRQ domains */ + struct irq_domain *base_domain; + struct irq_domain *plat_domain; +}; + +static struct imsic_priv *imsic; +static int imsic_parent_irq; + +const struct imsic_global_config *imsic_get_global_config(void) +{ + return (imsic) ? &imsic->global : NULL; +} +EXPORT_SYMBOL_GPL(imsic_get_global_config); + +static int imsic_cpu_page_phys(unsigned int cpu, + unsigned int guest_index, + phys_addr_t *out_msi_pa) +{ + struct imsic_global_config *global; + struct imsic_local_config *local; + + global = &imsic->global; + local = per_cpu_ptr(global->local, cpu); + + if (BIT(global->guest_index_bits) <= guest_index) + return -EINVAL; + + if (out_msi_pa) + *out_msi_pa = local->msi_pa + + (guest_index * IMSIC_MMIO_PAGE_SZ); + + return 0; +} + +static int imsic_get_cpu(const struct cpumask *mask_val, bool force, + unsigned int *out_target_cpu) +{ + struct cpumask amask; + unsigned int cpu; + + cpumask_and(&amask, &imsic->lmask, mask_val); + + if (force) + cpu = cpumask_first(&amask); + else + cpu = cpumask_any_and(&amask, cpu_online_mask); + + if (cpu >= nr_cpu_ids) + return -EINVAL; + + if (out_target_cpu) + *out_target_cpu = cpu; + + return 0; +} + +static void imsic_id_set_target(unsigned int id, unsigned int target_cpu) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + imsic->ids_target_cpu[id] = target_cpu; + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); +} + +static unsigned int imsic_id_get_target(unsigned int id) +{ + unsigned int ret; + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + ret = imsic->ids_target_cpu[id]; + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); + + return ret; +} + +static void __imsic_eix_update(unsigned long base_id, + unsigned long num_id, bool pend, bool val) +{ + unsigned long i, isel, ireg; + unsigned long id = base_id, last_id = base_id + num_id; + + while (id < last_id) { + isel = id / BITS_PER_LONG; + isel *= BITS_PER_LONG / IMSIC_EIPx_BITS; + isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0; + + ireg = 0; + for (i = id & (__riscv_xlen - 1); + (id < last_id) && (i < __riscv_xlen); i++) { + ireg |= BIT(i); + id++; + } + + /* + * The IMSIC EIEx and EIPx registers are indirectly + * accessed via using ISELECT and IREG CSRs so we + * need to access these CSRs without getting preempted. + * + * All existing users of this function call this + * function with local IRQs disabled so we don't + * need to do anything special here. + */ + if (val) + imsic_csr_set(isel, ireg); + else + imsic_csr_clear(isel, ireg); + } +} + +#define __imsic_id_enable(__id) \ + __imsic_eix_update((__id), 1, false, true) +#define __imsic_id_disable(__id) \ + __imsic_eix_update((__id), 1, false, false) + +static void imsic_ids_local_sync(void) +{ + int i; + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + for (i = 1; i <= imsic->global.nr_ids; i++) { + if (imsic->ipi_id == i) + continue; + + if (test_bit(i, imsic->ids_enabled_bimap)) + __imsic_id_enable(i); + else + __imsic_id_disable(i); + } + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); +} + +static void imsic_ids_local_delivery(bool enable) +{ + if (enable) { + imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD); + imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY); + } else { + imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY); + imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD); + } +} + +#ifdef CONFIG_SMP +static irqreturn_t imsic_ids_sync_handler(int irq, void *data) +{ + imsic_ids_local_sync(); + return IRQ_HANDLED; +} + +static void imsic_ids_remote_sync(void) +{ + struct cpumask amask; + + /* + * We simply inject ID synchronization IPI to all target CPUs + * except current CPU. The ipi_send_mask() implementation of + * IPI mux will inject ID synchronization IPI only for CPUs + * that have enabled it so offline CPUs won't receive IPI. + * An offline CPU will unconditionally synchronize IDs through + * imsic_starting_cpu() when the CPU is brought up. + */ + cpumask_andnot(&amask, &imsic->lmask, cpumask_of(smp_processor_id())); + __ipi_send_mask(imsic->ipi_lsync_desc, &amask); +} +#else +#define imsic_ids_remote_sync() +#endif + +static int imsic_ids_alloc(unsigned int order) +{ + int ret; + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + ret = bitmap_find_free_region(imsic->ids_used_bimap, + imsic->global.nr_ids + 1, order); + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); + + return ret; +} + +static void imsic_ids_free(unsigned int base_id, unsigned int order) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + bitmap_release_region(imsic->ids_used_bimap, base_id, order); + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); +} + +static int __init imsic_ids_init(void) +{ + int i; + struct imsic_global_config *global = &imsic->global; + + raw_spin_lock_init(&imsic->ids_lock); + + /* Allocate used bitmap */ + imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL); + if (!imsic->ids_used_bimap) + return -ENOMEM; + + /* Allocate enabled bitmap */ + imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1, + GFP_KERNEL); + if (!imsic->ids_enabled_bimap) { + kfree(imsic->ids_used_bimap); + return -ENOMEM; + } + + /* Allocate target CPU array */ + imsic->ids_target_cpu = kcalloc(global->nr_ids + 1, + sizeof(unsigned int), GFP_KERNEL); + if (!imsic->ids_target_cpu) { + bitmap_free(imsic->ids_enabled_bimap); + bitmap_free(imsic->ids_used_bimap); + return -ENOMEM; + } + for (i = 0; i <= global->nr_ids; i++) + imsic->ids_target_cpu[i] = UINT_MAX; + + /* Reserve ID#0 because it is special and never implemented */ + bitmap_set(imsic->ids_used_bimap, 0, 1); + + return 0; +} + +static void __init imsic_ids_cleanup(void) +{ + kfree(imsic->ids_target_cpu); + bitmap_free(imsic->ids_enabled_bimap); + bitmap_free(imsic->ids_used_bimap); +} + +#ifdef CONFIG_SMP +static void imsic_ipi_send(unsigned int cpu) +{ + struct imsic_local_config *local = + per_cpu_ptr(imsic->global.local, cpu); + + writel(imsic->ipi_id, local->msi_va); +} + +static void imsic_ipi_starting_cpu(void) +{ + /* Enable IPIs for current CPU. */ + __imsic_id_enable(imsic->ipi_id); + + /* Enable virtual IPI used for IMSIC ID synchronization */ + enable_percpu_irq(imsic->ipi_virq, 0); +} + +static void imsic_ipi_dying_cpu(void) +{ + /* + * Disable virtual IPI used for IMSIC ID synchronization so + * that we don't receive ID synchronization requests. + */ + disable_percpu_irq(imsic->ipi_virq); +} + +static int __init imsic_ipi_domain_init(void) +{ + int virq; + + /* Allocate interrupt identity for IPIs */ + virq = imsic_ids_alloc(get_count_order(1)); + if (virq < 0) + return virq; + imsic->ipi_id = virq; + + /* Create IMSIC IPI multiplexing */ + virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send); + if (virq <= 0) { + imsic_ids_free(imsic->ipi_id, get_count_order(1)); + return (virq < 0) ? virq : -ENOMEM; + } + imsic->ipi_virq = virq; + + /* First vIRQ is used for IMSIC ID synchronization */ + virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler, + "riscv-imsic-lsync", imsic->global.local); + if (virq) { + imsic_ids_free(imsic->ipi_id, get_count_order(1)); + return virq; + } + irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN); + imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq); + + /* Set vIRQ range */ + riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true); + + return 0; +} + +static void __init imsic_ipi_domain_cleanup(void) +{ + if (imsic->ipi_lsync_desc) + free_percpu_irq(imsic->ipi_virq, imsic->global.local); + imsic_ids_free(imsic->ipi_id, get_count_order(1)); +} +#else +static void imsic_ipi_starting_cpu(void) +{ +} + +static void imsic_ipi_dying_cpu(void) +{ +} + +static int __init imsic_ipi_domain_init(void) +{ + /* Clear the IPI id because we are not using IPIs */ + imsic->ipi_id = 0; + return 0; +} + +static void __init imsic_ipi_domain_cleanup(void) +{ +} +#endif + +static void imsic_irq_mask(struct irq_data *d) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1); + __imsic_id_disable(d->hwirq); + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); + + imsic_ids_remote_sync(); +} + +static void imsic_irq_unmask(struct irq_data *d) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->ids_lock, flags); + bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1); + __imsic_id_enable(d->hwirq); + raw_spin_unlock_irqrestore(&imsic->ids_lock, flags); + + imsic_ids_remote_sync(); +} + +static void imsic_irq_compose_msi_msg(struct irq_data *d, + struct msi_msg *msg) +{ + struct msi_desc *desc = irq_data_get_msi_desc(d); + phys_addr_t msi_addr; + unsigned int cpu; + int err; + + cpu = imsic_id_get_target(d->hwirq); + if (WARN_ON(cpu == UINT_MAX)) + return; + + err = imsic_cpu_page_phys(cpu, 0, &msi_addr); + if (WARN_ON(err)) + return; + + msg->address_hi = upper_32_bits(msi_addr); + msg->address_lo = lower_32_bits(msi_addr); + msg->data = d->hwirq; + iommu_dma_compose_msi_msg(desc, msg); +} + +#ifdef CONFIG_SMP +static int imsic_irq_set_affinity(struct irq_data *d, + const struct cpumask *mask_val, + bool force) +{ + unsigned int target_cpu; + int rc; + + rc = imsic_get_cpu(mask_val, force, &target_cpu); + if (rc) + return rc; + + imsic_id_set_target(d->hwirq, target_cpu); + irq_data_update_effective_affinity(d, cpumask_of(target_cpu)); + + return IRQ_SET_MASK_OK; +} +#endif + +static struct irq_chip imsic_irq_base_chip = { + .name = "RISC-V IMSIC-BASE", + .irq_mask = imsic_irq_mask, + .irq_unmask = imsic_irq_unmask, +#ifdef CONFIG_SMP + .irq_set_affinity = imsic_irq_set_affinity, +#endif + .irq_compose_msi_msg = imsic_irq_compose_msi_msg, + .flags = IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_MASK_ON_SUSPEND, +}; + +static int imsic_irq_domain_alloc(struct irq_domain *domain, + unsigned int virq, + unsigned int nr_irqs, + void *args) +{ + msi_alloc_info_t *info = args; + phys_addr_t msi_addr; + int i, hwirq, err = 0; + unsigned int cpu; + + err = imsic_get_cpu(&imsic->lmask, false, &cpu); + if (err) + return err; + + err = imsic_cpu_page_phys(cpu, 0, &msi_addr); + if (err) + return err; + + hwirq = imsic_ids_alloc(get_count_order(nr_irqs)); + if (hwirq < 0) + return hwirq; + + err = iommu_dma_prepare_msi(info->desc, msi_addr); + if (err) + goto fail; + + for (i = 0; i < nr_irqs; i++) { + imsic_id_set_target(hwirq + i, cpu); + irq_domain_set_info(domain, virq + i, hwirq + i, + &imsic_irq_base_chip, imsic, + handle_simple_irq, NULL, NULL); + irq_set_noprobe(virq + i); + irq_set_affinity(virq + i, &imsic->lmask); + /* + * IMSIC does not implement irq_disable() so Linux interrupt + * subsystem will take a lazy approach for disabling an IMSIC + * interrupt. This means IMSIC 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 IMSIC interrupts. + */ + irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY); + } + + return 0; + +fail: + imsic_ids_free(hwirq, get_count_order(nr_irqs)); + return err; +} + +static void imsic_irq_domain_free(struct irq_domain *domain, + unsigned int virq, + unsigned int nr_irqs) +{ + struct irq_data *d = irq_domain_get_irq_data(domain, virq); + + imsic_ids_free(d->hwirq, get_count_order(nr_irqs)); + irq_domain_free_irqs_parent(domain, virq, nr_irqs); +} + +static const struct irq_domain_ops imsic_base_domain_ops = { + .alloc = imsic_irq_domain_alloc, + .free = imsic_irq_domain_free, +}; + +static struct irq_chip imsic_plat_irq_chip = { + .name = "RISC-V IMSIC-PLAT", +}; + +static struct msi_domain_ops imsic_plat_domain_ops = { +}; + +static struct msi_domain_info imsic_plat_domain_info = { + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS), + .ops = &imsic_plat_domain_ops, + .chip = &imsic_plat_irq_chip, +}; + +static int __init imsic_irq_domains_init(struct fwnode_handle *fwnode) +{ + /* Create Base IRQ domain */ + imsic->base_domain = irq_domain_create_tree(fwnode, + &imsic_base_domain_ops, imsic); + if (!imsic->base_domain) { + pr_err("Failed to create IMSIC base domain\n"); + return -ENOMEM; + } + irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS); + + /* Create Platform MSI domain */ + imsic->plat_domain = platform_msi_create_irq_domain(fwnode, + &imsic_plat_domain_info, + imsic->base_domain); + if (!imsic->plat_domain) { + pr_err("Failed to create IMSIC platform domain\n"); + irq_domain_remove(imsic->base_domain); + return -ENOMEM; + } + + return 0; +} + +/* + * To handle an interrupt, we read the TOPEI CSR and write zero in one + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to + * Linux interrupt number and let Linux IRQ subsystem handle it. + */ +static void imsic_handle_irq(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + irq_hw_number_t hwirq; + int err; + + chained_irq_enter(chip, desc); + + while ((hwirq = csr_swap(CSR_TOPEI, 0))) { + hwirq = hwirq >> TOPEI_ID_SHIFT; + + if (hwirq == imsic->ipi_id) { +#ifdef CONFIG_SMP + ipi_mux_process(); +#endif + continue; + } + + err = generic_handle_domain_irq(imsic->base_domain, hwirq); + if (unlikely(err)) + pr_warn_ratelimited( + "hwirq %lu mapping not found\n", hwirq); + } + + chained_irq_exit(chip, desc); +} + +static int imsic_starting_cpu(unsigned int cpu) +{ + /* Enable per-CPU parent interrupt */ + enable_percpu_irq(imsic_parent_irq, + irq_get_trigger_type(imsic_parent_irq)); + + /* Setup IPIs */ + imsic_ipi_starting_cpu(); + + /* + * Interrupts identities might have been enabled/disabled while + * this CPU was not running so sync-up local enable/disable state. + */ + imsic_ids_local_sync(); + + /* Enable local interrupt delivery */ + imsic_ids_local_delivery(true); + + return 0; +} + +static int imsic_dying_cpu(unsigned int cpu) +{ + /* Cleanup IPIs */ + imsic_ipi_dying_cpu(); + + return 0; +} + +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode, + u32 index, unsigned long *hartid) +{ + int rc; + struct fwnode_reference_args parent; + + rc = fwnode_property_get_reference_args(fwnode, + "interrupts-extended", "#interrupt-cells", + 0, index, &parent); + if (rc) + return rc; + + /* + * Skip interrupts other than external interrupts for + * current privilege level. + */ + if (parent.args[0] != RV_IRQ_EXT) + return -EINVAL; + + return riscv_fw_parent_hartid(parent.fwnode, hartid); +} + +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode, + u32 index, struct resource *res) +{ + /* + * Currently, only OF fwnode is support so extend this function + * for other types of fwnode for ACPI support. + */ + if (!is_of_node(fwnode)) + return -EINVAL; + return of_address_to_resource(to_of_node(fwnode), index, res); +} + +static int __init imsic_init(struct fwnode_handle *fwnode) +{ + int rc, cpu; + phys_addr_t base_addr; + struct irq_domain *domain; + void __iomem **mmios_va = NULL; + struct resource res, *mmios = NULL; + struct imsic_local_config *local; + struct imsic_global_config *global; + unsigned long reloff, hartid; + u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0; + + /* + * Only one IMSIC instance allowed in a platform for clean + * implementation of SMP IRQ affinity and per-CPU IPIs. + * + * This means on a multi-socket (or multi-die) platform we + * will have multiple MMIO regions for one IMSIC instance. + */ + if (imsic) { + pr_err("%pfwP: already initialized hence ignoring\n", + fwnode); + return -ENODEV; + } + + if (!riscv_isa_extension_available(NULL, SxAIA)) { + pr_err("%pfwP: AIA support not available\n", fwnode); + return -ENODEV; + } + + imsic = kzalloc(sizeof(*imsic), GFP_KERNEL); + if (!imsic) + return -ENOMEM; + global = &imsic->global; + + global->local = alloc_percpu(typeof(*(global->local))); + if (!global->local) { + rc = -ENOMEM; + goto out_free_priv; + } + + /* Find number of parent interrupts */ + nr_parent_irqs = 0; + while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid)) + nr_parent_irqs++; + if (!nr_parent_irqs) { + pr_err("%pfwP: no parent irqs available\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Find number of guest index bits in MSI address */ + rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits", + &global->guest_index_bits, 1); + if (rc) + global->guest_index_bits = 0; + i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT; + if (i < global->guest_index_bits) { + pr_err("%pfwP: guest index bits too big\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Find number of HART index bits */ + rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits", + &global->hart_index_bits, 1); + if (rc) { + /* Assume default value */ + global->hart_index_bits = __fls(nr_parent_irqs); + if (BIT(global->hart_index_bits) < nr_parent_irqs) + global->hart_index_bits++; + } + i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits; + if (i < global->hart_index_bits) { + pr_err("%pfwP: HART index bits too big\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Find number of group index bits */ + rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits", + &global->group_index_bits, 1); + if (rc) + global->group_index_bits = 0; + i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - + global->guest_index_bits - global->hart_index_bits; + if (i < global->group_index_bits) { + pr_err("%pfwP: group index bits too big\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* + * Find first bit position of group index. + * If not specified assumed the default APLIC-IMSIC configuration. + */ + rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift", + &global->group_index_shift, 1); + if (rc) + global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2; + i = global->group_index_bits + global->group_index_shift - 1; + if (i >= BITS_PER_LONG) { + pr_err("%pfwP: group index shift too big\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Find number of interrupt identities */ + rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids", + &global->nr_ids, 1); + if (rc) { + pr_err("%pfwP: number of interrupt identities not found\n", + fwnode); + goto out_free_local; + } + if ((global->nr_ids < IMSIC_MIN_ID) || + (global->nr_ids >= IMSIC_MAX_ID) || + ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) { + pr_err("%pfwP: invalid number of interrupt identities\n", + fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Find number of guest interrupt identities */ + if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids", + &global->nr_guest_ids, 1)) + global->nr_guest_ids = global->nr_ids; + if ((global->nr_guest_ids < IMSIC_MIN_ID) || + (global->nr_guest_ids >= IMSIC_MAX_ID) || + ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) { + pr_err("%pfwP: invalid number of guest interrupt identities\n", + fwnode); + rc = -EINVAL; + goto out_free_local; + } + + /* Compute base address */ + rc = imsic_get_mmio_resource(fwnode, 0, &res); + if (rc) { + pr_err("%pfwP: first MMIO resource not found\n", fwnode); + rc = -EINVAL; + goto out_free_local; + } + global->base_addr = res.start; + global->base_addr &= ~(BIT(global->guest_index_bits + + global->hart_index_bits + + IMSIC_MMIO_PAGE_SHIFT) - 1); + global->base_addr &= ~((BIT(global->group_index_bits) - 1) << + global->group_index_shift); + + /* Find number of MMIO register sets */ + while (!imsic_get_mmio_resource(fwnode, num_mmios, &res)) + num_mmios++; + + /* Allocate MMIO resource array */ + mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL); + if (!mmios) { + rc = -ENOMEM; + goto out_free_local; + } + + /* Allocate MMIO virtual address array */ + mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL); + if (!mmios_va) { + rc = -ENOMEM; + goto out_iounmap; + } + + /* Parse and map MMIO register sets */ + for (i = 0; i < num_mmios; i++) { + rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]); + if (rc) { + pr_err("%pfwP: unable to parse MMIO regset %d\n", + fwnode, i); + goto out_iounmap; + } + + base_addr = mmios[i].start; + base_addr &= ~(BIT(global->guest_index_bits + + global->hart_index_bits + + IMSIC_MMIO_PAGE_SHIFT) - 1); + base_addr &= ~((BIT(global->group_index_bits) - 1) << + global->group_index_shift); + if (base_addr != global->base_addr) { + rc = -EINVAL; + pr_err("%pfwP: address mismatch for regset %d\n", + fwnode, i); + goto out_iounmap; + } + + mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i])); + if (!mmios_va[i]) { + rc = -EIO; + pr_err("%pfwP: unable to map MMIO regset %d\n", + fwnode, i); + goto out_iounmap; + } + } + + /* Initialize interrupt identity management */ + rc = imsic_ids_init(); + if (rc) { + pr_err("%pfwP: failed to initialize interrupt management\n", + fwnode); + goto out_iounmap; + } + + /* Configure handlers for target CPUs */ + for (i = 0; i < nr_parent_irqs; i++) { + rc = imsic_get_parent_hartid(fwnode, i, &hartid); + if (rc) { + pr_warn("%pfwP: hart ID for parent irq%d not found\n", + fwnode, i); + continue; + } + + cpu = riscv_hartid_to_cpuid(hartid); + if (cpu < 0) { + pr_warn("%pfwP: invalid cpuid for parent irq%d\n", + fwnode, i); + continue; + } + + /* Find MMIO location of MSI page */ + index = num_mmios; + reloff = i * BIT(global->guest_index_bits) * + IMSIC_MMIO_PAGE_SZ; + for (j = 0; num_mmios; j++) { + if (reloff < resource_size(&mmios[j])) { + index = j; + break; + } + + /* + * MMIO region size may not be aligned to + * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ + * if holes are present. + */ + reloff -= ALIGN(resource_size(&mmios[j]), + BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ); + } + if (index >= num_mmios) { + pr_warn("%pfwP: MMIO not found for parent irq%d\n", + fwnode, i); + continue; + } + + cpumask_set_cpu(cpu, &imsic->lmask); + + local = per_cpu_ptr(global->local, cpu); + local->msi_pa = mmios[index].start + reloff; + local->msi_va = mmios_va[index] + reloff; + + nr_handlers++; + } + + /* If no CPU handlers found then can't take interrupts */ + if (!nr_handlers) { + pr_err("%pfwP: No CPU handlers found\n", fwnode); + rc = -ENODEV; + goto out_ids_cleanup; + } + + /* Find parent domain and register chained handler */ + domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), + DOMAIN_BUS_ANY); + if (!domain) { + pr_err("%pfwP: Failed to find INTC domain\n", fwnode); + rc = -ENOENT; + goto out_ids_cleanup; + } + imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT); + if (!imsic_parent_irq) { + pr_err("%pfwP: Failed to create INTC mapping\n", fwnode); + rc = -ENOENT; + goto out_ids_cleanup; + } + irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq); + + /* Initialize IPI domain */ + rc = imsic_ipi_domain_init(); + if (rc) { + pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode); + goto out_ids_cleanup; + } + + /* Initialize IRQ and MSI domains */ + rc = imsic_irq_domains_init(fwnode); + if (rc) { + pr_err("%pfwP: Failed to initialize IRQ and MSI domains\n", + fwnode); + goto out_ipi_domain_cleanup; + } + + /* + * Setup cpuhp state (must be done after setting imsic_parent_irq) + * + * Don't disable per-CPU IMSIC file when CPU goes offline + * because this affects IPI and the masking/unmasking of + * virtual IPIs is done via generic IPI-Mux + */ + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "irqchip/riscv/imsic:starting", + imsic_starting_cpu, imsic_dying_cpu); + + /* We don't need MMIO arrays anymore so let's free-up */ + kfree(mmios_va); + kfree(mmios); + + pr_info("%pfwP: hart-index-bits: %d, guest-index-bits: %d\n", + fwnode, global->hart_index_bits, global->guest_index_bits); + pr_info("%pfwP: group-index-bits: %d, group-index-shift: %d\n", + fwnode, global->group_index_bits, global->group_index_shift); + pr_info("%pfwP: mapped %d interrupts for %d CPUs at %pa\n", + fwnode, global->nr_ids, nr_handlers, &global->base_addr); + if (imsic->ipi_id) + pr_info("%pfwP: providing IPIs using interrupt %d\n", + fwnode, imsic->ipi_id); + + return 0; + +out_ipi_domain_cleanup: + imsic_ipi_domain_cleanup(); +out_ids_cleanup: + imsic_ids_cleanup(); +out_iounmap: + for (i = 0; i < num_mmios; i++) { + if (mmios_va[i]) + iounmap(mmios_va[i]); + } + kfree(mmios_va); + kfree(mmios); +out_free_local: + free_percpu(imsic->global.local); +out_free_priv: + kfree(imsic); + imsic = NULL; + return rc; +} + +static int __init imsic_dt_init(struct device_node *node, + struct device_node *parent) +{ + return imsic_init(&node->fwnode); +} +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_dt_init); diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h new file mode 100644 index 000000000000..1f6fc9a57218 --- /dev/null +++ b/include/linux/irqchip/riscv-imsic.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + */ +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H +#define __LINUX_IRQCHIP_RISCV_IMSIC_H + +#include <linux/types.h> +#include <asm/csr.h> + +#define IMSIC_MMIO_PAGE_SHIFT 12 +#define IMSIC_MMIO_PAGE_SZ (1UL << IMSIC_MMIO_PAGE_SHIFT) +#define IMSIC_MMIO_PAGE_LE 0x00 +#define IMSIC_MMIO_PAGE_BE 0x04 + +#define IMSIC_MIN_ID 63 +#define IMSIC_MAX_ID 2048 + +#define IMSIC_EIDELIVERY 0x70 + +#define IMSIC_EITHRESHOLD 0x72 + +#define IMSIC_EIP0 0x80 +#define IMSIC_EIP63 0xbf +#define IMSIC_EIPx_BITS 32 + +#define IMSIC_EIE0 0xc0 +#define IMSIC_EIE63 0xff +#define IMSIC_EIEx_BITS 32 + +#define IMSIC_FIRST IMSIC_EIDELIVERY +#define IMSIC_LAST IMSIC_EIE63 + +#define IMSIC_MMIO_SETIPNUM_LE 0x00 +#define IMSIC_MMIO_SETIPNUM_BE 0x04 + +struct imsic_local_config { + phys_addr_t msi_pa; + void __iomem *msi_va; +}; + +struct imsic_global_config { + /* + * MSI Target Address Scheme + * + * XLEN-1 12 0 + * | | | + * ------------------------------------------------------------- + * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index| 0 | + * ------------------------------------------------------------- + */ + + /* Bits representing Guest index, HART index, and Group index */ + u32 guest_index_bits; + u32 hart_index_bits; + u32 group_index_bits; + u32 group_index_shift; + + /* Global base address matching all target MSI addresses */ + phys_addr_t base_addr; + + /* Number of interrupt identities */ + u32 nr_ids; + + /* Number of guest interrupt identities */ + u32 nr_guest_ids; + + /* Per-CPU IMSIC addresses */ + struct imsic_local_config __percpu *local; +}; + +#ifdef CONFIG_RISCV_IMSIC + +extern const struct imsic_global_config *imsic_get_global_config(void); + +#else + +static inline const struct imsic_global_config *imsic_get_global_config(void) +{ + return NULL; +} + +#endif + +#endif -- 2.34.1
