The RISC-V advanced interrupt architecture (AIA) specification defines a new MSI controller called incoming message signalled interrupt controller (IMSIC) which manages MSI on per-HART (or per-CPU) basis. It also supports IPIs as software injected MSIs. (For more details refer https://github.com/riscv/riscv-aia) Add an early irqchip driver for RISC-V IMSIC which sets up the IMSIC state and provide IPIs. Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> --- drivers/irqchip/Kconfig | 7 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-imsic-early.c | 201 ++++++ drivers/irqchip/irq-riscv-imsic-state.c | 865 ++++++++++++++++++++++++ drivers/irqchip/irq-riscv-imsic-state.h | 107 +++ include/linux/cpuhotplug.h | 1 + include/linux/irqchip/riscv-imsic.h | 87 +++ 7 files changed, 1269 insertions(+) create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h create mode 100644 include/linux/irqchip/riscv-imsic.h diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index f7149d0f3d45..85f86e31c996 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -546,6 +546,13 @@ 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_IRQ_MATRIX_ALLOCATOR + 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..d714724387ce 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-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic-state.o irq-riscv-imsic-early.o obj-$(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-early.c b/drivers/irqchip/irq-riscv-imsic-early.c new file mode 100644 index 000000000000..886418ec06cb --- /dev/null +++ b/drivers/irqchip/irq-riscv-imsic-early.c @@ -0,0 +1,201 @@ +// 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/cpu.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/smp.h> + +#include "irq-riscv-imsic-state.h" + +static int imsic_parent_irq; + +#ifdef CONFIG_SMP +static void imsic_ipi_send(unsigned int cpu) +{ + struct imsic_local_config *local = per_cpu_ptr(imsic->global.local, cpu); + + writel_relaxed(IMSIC_IPI_ID, local->msi_va); +} + +static void imsic_ipi_starting_cpu(void) +{ + /* Enable IPIs for current CPU. */ + __imsic_id_set_enable(IMSIC_IPI_ID); +} + +static void imsic_ipi_dying_cpu(void) +{ + /* Disable IPIs for current CPU. */ + __imsic_id_clear_enable(IMSIC_IPI_ID); +} + +static int __init imsic_ipi_domain_init(void) +{ + int virq; + + /* Create IMSIC IPI multiplexing */ + virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send); + if (virq <= 0) + return virq < 0 ? virq : -ENOMEM; + + /* Set vIRQ range */ + riscv_ipi_set_virq_range(virq, IMSIC_NR_IPI, true); + + /* Announce that IMSIC is providing IPIs */ + pr_info("%pfwP: providing IPIs using interrupt %d\n", imsic->fwnode, IMSIC_IPI_ID); + + return 0; +} +#else +static void imsic_ipi_starting_cpu(void) { } +static void imsic_ipi_dying_cpu(void) { } +static int __init imsic_ipi_domain_init(void) { return 0; } +#endif + +/* + * 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); + int err, cpu = smp_processor_id(); + struct imsic_vector *vec; + unsigned long local_id; + + chained_irq_enter(chip, desc); + + while ((local_id = csr_swap(CSR_TOPEI, 0))) { + local_id >>= TOPEI_ID_SHIFT; + + if (local_id == IMSIC_IPI_ID) { + if (IS_ENABLED(CONFIG_SMP)) + ipi_mux_process(); + continue; + } + + if (unlikely(!imsic->base_domain)) + continue; + + vec = imsic_vector_from_local_id(cpu, local_id); + if (!vec) { + pr_warn_ratelimited("vector not found for local ID 0x%lx\n", local_id); + continue; + } + + err = generic_handle_domain_irq(imsic->base_domain, vec->hwirq); + if (unlikely(err)) + pr_warn_ratelimited("hwirq 0x%x mapping not found\n", vec->hwirq); + } + + chained_irq_exit(chip, desc); +} + +static int imsic_starting_cpu(unsigned int cpu) +{ + /* Mark per-CPU IMSIC state as online */ + imsic_state_online(); + + /* 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_local_sync_all(); + + /* Enable local interrupt delivery */ + imsic_local_delivery(true); + + return 0; +} + +static int imsic_dying_cpu(unsigned int cpu) +{ + /* Cleanup IPIs */ + imsic_ipi_dying_cpu(); + + /* Mark per-CPU IMSIC state as offline */ + imsic_state_offline(); + + return 0; +} + +static int __init imsic_early_probe(struct fwnode_handle *fwnode) +{ + struct irq_domain *domain; + int rc; + + /* 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); + return -ENOENT; + } + imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT); + if (!imsic_parent_irq) { + pr_err("%pfwP: Failed to create INTC mapping\n", fwnode); + return -ENOENT; + } + + /* Initialize IPI domain */ + rc = imsic_ipi_domain_init(); + if (rc) { + pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode); + return rc; + } + + /* Setup chained handler to the parent domain interrupt */ + irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq); + + /* + * 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_IRQ_RISCV_IMSIC_STARTING, "irqchip/riscv/imsic:starting", + imsic_starting_cpu, imsic_dying_cpu); + + return 0; +} + +static int __init imsic_early_dt_init(struct device_node *node, struct device_node *parent) +{ + struct fwnode_handle *fwnode = &node->fwnode; + int rc; + + /* Setup IMSIC state */ + rc = imsic_setup_state(fwnode); + if (rc) { + pr_err("%pfwP: failed to setup state (error %d)\n", fwnode, rc); + return rc; + } + + /* Do early setup of IPIs */ + rc = imsic_early_probe(fwnode); + if (rc) + return rc; + + /* Ensure that OF platform device gets probed */ + of_node_clear_flag(node, OF_POPULATED); + return 0; +} + +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init); diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c new file mode 100644 index 000000000000..5479f872e62b --- /dev/null +++ b/drivers/irqchip/irq-riscv-imsic-state.c @@ -0,0 +1,865 @@ +// 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/cpu.h> +#include <linux/bitmap.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/smp.h> +#include <asm/hwcap.h> + +#include "irq-riscv-imsic-state.h" + +#define IMSIC_DISABLE_EIDELIVERY 0 +#define IMSIC_ENABLE_EIDELIVERY 1 +#define IMSIC_DISABLE_EITHRESHOLD 1 +#define IMSIC_ENABLE_EITHRESHOLD 0 + +static inline void imsic_csr_write(unsigned long reg, unsigned long val) +{ + csr_write(CSR_ISELECT, reg); + csr_write(CSR_IREG, val); +} + +static inline unsigned long imsic_csr_read(unsigned long reg) +{ + csr_write(CSR_ISELECT, reg); + return csr_read(CSR_IREG); +} + +static inline unsigned long imsic_csr_read_clear(unsigned long reg, unsigned long val) +{ + csr_write(CSR_ISELECT, reg); + return csr_read_clear(CSR_IREG, val); +} + +static inline void imsic_csr_set(unsigned long reg, unsigned long val) +{ + csr_write(CSR_ISELECT, reg); + csr_set(CSR_IREG, val); +} + +static inline void imsic_csr_clear(unsigned long reg, unsigned long val) +{ + csr_write(CSR_ISELECT, reg); + csr_clear(CSR_IREG, val); +} + +struct imsic_priv *imsic; + +const struct imsic_global_config *imsic_get_global_config(void) +{ + return imsic ? &imsic->global : NULL; +} +EXPORT_SYMBOL_GPL(imsic_get_global_config); + +static bool __imsic_eix_read_clear(unsigned long id, bool pend) +{ + unsigned long isel, imask; + + isel = id / BITS_PER_LONG; + isel *= BITS_PER_LONG / IMSIC_EIPx_BITS; + isel += pend ? IMSIC_EIP0 : IMSIC_EIE0; + imask = BIT(id & (__riscv_xlen - 1)); + + return !!(imsic_csr_read_clear(isel, imask) & imask); +} + +static inline bool __imsic_id_read_clear_enabled(unsigned long id) +{ + return __imsic_eix_read_clear(id, false); +} + +static inline bool __imsic_id_read_clear_pending(unsigned long id) +{ + return __imsic_eix_read_clear(id, true); +} + +void __imsic_eix_update(unsigned long base_id, unsigned long num_id, bool pend, bool val) +{ + unsigned long id = base_id, last_id = base_id + num_id; + unsigned long i, isel, ireg; + + while (id < last_id) { + isel = id / BITS_PER_LONG; + isel *= BITS_PER_LONG / IMSIC_EIPx_BITS; + isel += pend ? IMSIC_EIP0 : IMSIC_EIE0; + + /* + * Prepare the ID mask to be programmed in the + * IMSIC EIEx and EIPx registers. These registers + * are XLEN-wide and we must not touch IDs which + * are < base_id and >= (base_id + num_id). + */ + 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); + } +} + +static void __imsic_local_sync(struct imsic_local_priv *lpriv) +{ + struct imsic_local_config *mlocal; + struct imsic_vector *vec, *mvec; + int i; + + lockdep_assert_held(&lpriv->lock); + + for_each_set_bit(i, lpriv->dirty_bitmap, imsic->global.nr_ids + 1) { + if (!i || i == IMSIC_IPI_ID) + goto skip; + vec = &lpriv->vectors[i]; + + if (READ_ONCE(vec->enable)) + __imsic_id_set_enable(i); + else + __imsic_id_clear_enable(i); + + /* + * If the ID was being moved to a new ID on some other CPU + * then we can get a MSI during the movement so check the + * ID pending bit and re-trigger the new ID on other CPU + * using MMIO write. + */ + mvec = READ_ONCE(vec->move); + WRITE_ONCE(vec->move, NULL); + if (mvec && mvec != vec) { + if (__imsic_id_read_clear_pending(i)) { + mlocal = per_cpu_ptr(imsic->global.local, mvec->cpu); + writel_relaxed(mvec->local_id, mlocal->msi_va); + } + + imsic_vector_free(&lpriv->vectors[i]); + } + +skip: + bitmap_clear(lpriv->dirty_bitmap, i, 1); + } +} + +void imsic_local_sync_all(void) +{ + struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv); + unsigned long flags; + + raw_spin_lock_irqsave(&lpriv->lock, flags); + bitmap_fill(lpriv->dirty_bitmap, imsic->global.nr_ids + 1); + __imsic_local_sync(lpriv); + raw_spin_unlock_irqrestore(&lpriv->lock, flags); +} + +void imsic_local_delivery(bool enable) +{ + if (enable) { + imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD); + imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY); + return; + } + + imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY); + imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD); +} + +#ifdef CONFIG_SMP +static void imsic_local_timer_callback(struct timer_list *timer) +{ + struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv); + unsigned long flags; + + raw_spin_lock_irqsave(&lpriv->lock, flags); + __imsic_local_sync(lpriv); + raw_spin_unlock_irqrestore(&lpriv->lock, flags); +} + +static void __imsic_remote_sync(struct imsic_local_priv *lpriv, unsigned int cpu) +{ + lockdep_assert_held(&lpriv->lock); + + /* + * The spinlock acquire/release semantics ensure that changes + * to vector enable, vector move and dirty bitmap are visible + * to the target CPU. + */ + + /* + * We schedule a timer on the target CPU if the target CPU is not + * same as the current CPU. An offline CPU will unconditionally + * synchronize IDs through imsic_starting_cpu() when the + * CPU is brought up. + */ + if (cpu_online(cpu)) { + if (cpu == smp_processor_id()) { + __imsic_local_sync(lpriv); + return; + } + + if (!timer_pending(&lpriv->timer)) { + lpriv->timer.expires = jiffies + 1; + add_timer_on(&lpriv->timer, cpu); + } + } +} +#else +static void __imsic_remote_sync(struct imsic_local_priv *lpriv, unsigned int cpu) +{ + lockdep_assert_held(&lpriv->lock); + __imsic_local_sync(lpriv); +} +#endif + +void imsic_vector_mask(struct imsic_vector *vec) +{ + struct imsic_local_priv *lpriv; + + lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu); + if (WARN_ON_ONCE(&lpriv->vectors[vec->local_id] != vec)) + return; + + /* + * This function is called through Linux irq subsystem with + * irqs disabled so no need to save/restore irq flags. + */ + + raw_spin_lock(&lpriv->lock); + + WRITE_ONCE(vec->enable, false); + bitmap_set(lpriv->dirty_bitmap, vec->local_id, 1); + __imsic_remote_sync(lpriv, vec->cpu); + + raw_spin_unlock(&lpriv->lock); +} + +void imsic_vector_unmask(struct imsic_vector *vec) +{ + struct imsic_local_priv *lpriv; + + lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu); + if (WARN_ON_ONCE(&lpriv->vectors[vec->local_id] != vec)) + return; + + /* + * This function is called through Linux irq subsystem with + * irqs disabled so no need to save/restore irq flags. + */ + + raw_spin_lock(&lpriv->lock); + + WRITE_ONCE(vec->enable, true); + bitmap_set(lpriv->dirty_bitmap, vec->local_id, 1); + __imsic_remote_sync(lpriv, vec->cpu); + + raw_spin_unlock(&lpriv->lock); +} + +static bool imsic_vector_move_update(struct imsic_local_priv *lpriv, struct imsic_vector *vec, + bool new_enable, struct imsic_vector *new_move) +{ + unsigned long flags; + bool enabled; + + raw_spin_lock_irqsave(&lpriv->lock, flags); + + /* Update enable and move details */ + enabled = READ_ONCE(vec->enable); + WRITE_ONCE(vec->enable, new_enable); + WRITE_ONCE(vec->move, new_move); + + /* Mark the vector as dirty and synchronize */ + bitmap_set(lpriv->dirty_bitmap, vec->local_id, 1); + __imsic_remote_sync(lpriv, vec->cpu); + + raw_spin_unlock_irqrestore(&lpriv->lock, flags); + + return enabled; +} + +void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec) +{ + struct imsic_local_priv *old_lpriv, *new_lpriv; + bool enabled; + + if (WARN_ON_ONCE(old_vec->cpu == new_vec->cpu)) + return; + + old_lpriv = per_cpu_ptr(imsic->lpriv, old_vec->cpu); + if (WARN_ON_ONCE(&old_lpriv->vectors[old_vec->local_id] != old_vec)) + return; + + new_lpriv = per_cpu_ptr(imsic->lpriv, new_vec->cpu); + if (WARN_ON_ONCE(&new_lpriv->vectors[new_vec->local_id] != new_vec)) + return; + + /* + * Move and re-trigger the new vector based on the pending + * state of the old vector because we might get a device + * interrupt on the old vector while device was being moved + * to the new vector. + */ + enabled = imsic_vector_move_update(old_lpriv, old_vec, false, new_vec); + imsic_vector_move_update(new_lpriv, new_vec, enabled, new_vec); +} + +#ifdef CONFIG_GENERIC_IRQ_DEBUGFS +void imsic_vector_debug_show(struct seq_file *m, struct imsic_vector *vec, int ind) +{ + struct imsic_local_priv *lpriv; + struct imsic_vector *mvec; + bool is_enabled; + + lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu); + if (WARN_ON_ONCE(&lpriv->vectors[vec->local_id] != vec)) + return; + + is_enabled = imsic_vector_isenabled(vec); + mvec = imsic_vector_get_move(vec); + + seq_printf(m, "%*starget_cpu : %5u\n", ind, "", vec->cpu); + seq_printf(m, "%*starget_local_id : %5u\n", ind, "", vec->local_id); + seq_printf(m, "%*sis_reserved : %5u\n", ind, "", + (vec->local_id <= IMSIC_IPI_ID) ? 1 : 0); + seq_printf(m, "%*sis_enabled : %5u\n", ind, "", is_enabled ? 1 : 0); + seq_printf(m, "%*sis_move_pending : %5u\n", ind, "", mvec ? 1 : 0); + if (mvec) { + seq_printf(m, "%*smove_cpu : %5u\n", ind, "", mvec->cpu); + seq_printf(m, "%*smove_local_id : %5u\n", ind, "", mvec->local_id); + } +} + +void imsic_vector_debug_show_summary(struct seq_file *m, int ind) +{ + irq_matrix_debug_show(m, imsic->matrix, ind); +} +#endif + +struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id) +{ + struct imsic_local_priv *lpriv = per_cpu_ptr(imsic->lpriv, cpu); + + if (!lpriv || imsic->global.nr_ids < local_id) + return NULL; + + return &lpriv->vectors[local_id]; +} + +struct imsic_vector *imsic_vector_alloc(unsigned int hwirq, const struct cpumask *mask) +{ + struct imsic_vector *vec = NULL; + struct imsic_local_priv *lpriv; + unsigned long flags; + unsigned int cpu; + int local_id; + + raw_spin_lock_irqsave(&imsic->matrix_lock, flags); + local_id = irq_matrix_alloc(imsic->matrix, mask, false, &cpu); + raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags); + if (local_id < 0) + return NULL; + + lpriv = per_cpu_ptr(imsic->lpriv, cpu); + vec = &lpriv->vectors[local_id]; + vec->hwirq = hwirq; + vec->enable = false; + vec->move = NULL; + + return vec; +} + +void imsic_vector_free(struct imsic_vector *vec) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->matrix_lock, flags); + vec->hwirq = UINT_MAX; + irq_matrix_free(imsic->matrix, vec->cpu, vec->local_id, false); + raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags); +} + +static void __init imsic_local_cleanup(void) +{ + struct imsic_local_priv *lpriv; + int cpu; + + for_each_possible_cpu(cpu) { + lpriv = per_cpu_ptr(imsic->lpriv, cpu); + + bitmap_free(lpriv->dirty_bitmap); + kfree(lpriv->vectors); + } + + free_percpu(imsic->lpriv); +} + +static int __init imsic_local_init(void) +{ + struct imsic_global_config *global = &imsic->global; + struct imsic_local_priv *lpriv; + struct imsic_vector *vec; + int cpu, i; + + /* Allocate per-CPU private state */ + imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv)); + if (!imsic->lpriv) + return -ENOMEM; + + /* Setup per-CPU private state */ + for_each_possible_cpu(cpu) { + lpriv = per_cpu_ptr(imsic->lpriv, cpu); + + raw_spin_lock_init(&lpriv->lock); + + /* Allocate dirty bitmap */ + lpriv->dirty_bitmap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL); + if (!lpriv->dirty_bitmap) + goto fail_local_cleanup; + +#ifdef CONFIG_SMP + /* Setup lazy timer for synchronization */ + timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED); +#endif + + /* Allocate vector array */ + lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors), + GFP_KERNEL); + if (!lpriv->vectors) + goto fail_local_cleanup; + + /* Setup vector array */ + for (i = 0; i <= global->nr_ids; i++) { + vec = &lpriv->vectors[i]; + vec->cpu = cpu; + vec->local_id = i; + vec->hwirq = UINT_MAX; + } + } + + return 0; + +fail_local_cleanup: + imsic_local_cleanup(); + return -ENOMEM; +} + +void imsic_state_online(void) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->matrix_lock, flags); + irq_matrix_online(imsic->matrix); + raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags); +} + +void imsic_state_offline(void) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&imsic->matrix_lock, flags); + irq_matrix_offline(imsic->matrix); + raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags); + +#ifdef CONFIG_SMP + struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv); + + raw_spin_lock_irqsave(&lpriv->lock, flags); + WARN_ON_ONCE(try_to_del_timer_sync(&lpriv->timer) < 0); + raw_spin_unlock_irqrestore(&lpriv->lock, flags); +#endif +} + +static int __init imsic_matrix_init(void) +{ + struct imsic_global_config *global = &imsic->global; + + raw_spin_lock_init(&imsic->matrix_lock); + imsic->matrix = irq_alloc_matrix(global->nr_ids + 1, + 0, global->nr_ids + 1); + if (!imsic->matrix) + return -ENOMEM; + + /* Reserve ID#0 because it is special and never implemented */ + irq_matrix_assign_system(imsic->matrix, 0, false); + + /* Reserve IPI ID because it is special and used internally */ + irq_matrix_assign_system(imsic->matrix, IMSIC_IPI_ID, false); + + return 0; +} + +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode, + u32 index, unsigned long *hartid) +{ + struct of_phandle_args parent; + int rc; + + /* + * Currently, only OF fwnode is supported so extend this + * function for ACPI support. + */ + if (!is_of_node(fwnode)) + return -EINVAL; + + rc = of_irq_parse_one(to_of_node(fwnode), 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_of_parent_hartid(parent.np, hartid); +} + +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode, + u32 index, struct resource *res) +{ + /* + * Currently, only OF fwnode is supported so extend this + * function 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_parse_fwnode(struct fwnode_handle *fwnode, + struct imsic_global_config *global, + u32 *nr_parent_irqs, + u32 *nr_mmios) +{ + unsigned long hartid; + struct resource res; + int rc; + u32 i; + + /* + * Currently, only OF fwnode is supported so extend this + * function for ACPI support. + */ + if (!is_of_node(fwnode)) + return -EINVAL; + + *nr_parent_irqs = 0; + *nr_mmios = 0; + + /* Find number of parent interrupts */ + 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); + return -EINVAL; + } + + /* Find number of guest index bits in MSI address */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,guest-index-bits", + &global->guest_index_bits); + if (rc) + global->guest_index_bits = 0; + + /* Find number of HART index bits */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,hart-index-bits", + &global->hart_index_bits); + 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++; + } + + /* Find number of group index bits */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,group-index-bits", + &global->group_index_bits); + if (rc) + global->group_index_bits = 0; + + /* + * Find first bit position of group index. + * If not specified assumed the default APLIC-IMSIC configuration. + */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,group-index-shift", + &global->group_index_shift); + if (rc) + global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2; + + /* Find number of interrupt identities */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,num-ids", + &global->nr_ids); + if (rc) { + pr_err("%pfwP: number of interrupt identities not found\n", fwnode); + return rc; + } + + /* Find number of guest interrupt identities */ + rc = of_property_read_u32(to_of_node(fwnode), "riscv,num-guest-ids", + &global->nr_guest_ids); + if (rc) + global->nr_guest_ids = global->nr_ids; + + /* Sanity check guest index bits */ + i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT; + if (i < global->guest_index_bits) { + pr_err("%pfwP: guest index bits too big\n", fwnode); + return -EINVAL; + } + + /* Sanity check 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); + return -EINVAL; + } + + /* Sanity check group index bits */ + 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); + return -EINVAL; + } + + /* Sanity check group index shift */ + 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); + return -EINVAL; + } + + /* Sanity check number of interrupt identities */ + 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); + return -EINVAL; + } + + /* Sanity check number of guest interrupt identities */ + 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); + return -EINVAL; + } + + /* Compute base address */ + rc = imsic_get_mmio_resource(fwnode, 0, &res); + if (rc) { + pr_err("%pfwP: first MMIO resource not found\n", fwnode); + return -EINVAL; + } + 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, *nr_mmios, &res)) + (*nr_mmios)++; + + return 0; +} + +int __init imsic_setup_state(struct fwnode_handle *fwnode) +{ + u32 i, j, index, nr_parent_irqs, nr_mmios, nr_handlers = 0; + struct imsic_global_config *global; + struct imsic_local_config *local; + void __iomem **mmios_va = NULL; + struct resource *mmios = NULL; + unsigned long reloff, hartid; + phys_addr_t base_addr; + int rc, cpu; + + /* + * 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 -EALREADY; + } + + 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; + imsic->fwnode = fwnode; + global = &imsic->global; + + global->local = alloc_percpu(typeof(*global->local)); + if (!global->local) { + rc = -ENOMEM; + goto out_free_priv; + } + + /* Parse IMSIC fwnode */ + rc = imsic_parse_fwnode(fwnode, global, &nr_parent_irqs, &nr_mmios); + if (rc) + goto out_free_local; + + /* Allocate MMIO resource array */ + mmios = kcalloc(nr_mmios, sizeof(*mmios), GFP_KERNEL); + if (!mmios) { + rc = -ENOMEM; + goto out_free_local; + } + + /* Allocate MMIO virtual address array */ + mmios_va = kcalloc(nr_mmios, sizeof(*mmios_va), GFP_KERNEL); + if (!mmios_va) { + rc = -ENOMEM; + goto out_iounmap; + } + + /* Parse and map MMIO register sets */ + for (i = 0; i < nr_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 local (or per-CPU )state */ + rc = imsic_local_init(); + if (rc) { + pr_err("%pfwP: failed to initialize local state\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 = nr_mmios; + reloff = i * BIT(global->guest_index_bits) * + IMSIC_MMIO_PAGE_SZ; + for (j = 0; nr_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 >= nr_mmios) { + pr_warn("%pfwP: MMIO not found for parent irq%d\n", fwnode, i); + continue; + } + + 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_local_cleanup; + } + + /* Initialize matrix allocator */ + rc = imsic_matrix_init(); + if (rc) { + pr_err("%pfwP: failed to create matrix allocator\n", fwnode); + goto out_local_cleanup; + } + + /* We don't need MMIO arrays anymore so let's free-up */ + kfree(mmios_va); + kfree(mmios); + + return 0; + +out_local_cleanup: + imsic_local_cleanup(); +out_iounmap: + for (i = 0; i < nr_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; +} diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h new file mode 100644 index 000000000000..8ec9649d0d01 --- /dev/null +++ b/drivers/irqchip/irq-riscv-imsic-state.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * Copyright (C) 2022 Ventana Micro Systems Inc. + */ + +#ifndef _IRQ_RISCV_IMSIC_STATE_H +#define _IRQ_RISCV_IMSIC_STATE_H + +#include <linux/irqchip/riscv-imsic.h> +#include <linux/irqdomain.h> +#include <linux/fwnode.h> +#include <linux/timer.h> + +#define IMSIC_IPI_ID 1 +#define IMSIC_NR_IPI 8 + +struct imsic_vector { + /* Fixed details of the vector */ + unsigned int cpu; + unsigned int local_id; + /* Details saved by driver in the vector */ + unsigned int hwirq; + /* Details accessed using local lock held */ + bool enable; + struct imsic_vector *move; +}; + +struct imsic_local_priv { + /* Local lock to protect vector enable/move variables and dirty bitmap */ + raw_spinlock_t lock; + + /* Local dirty bitmap for synchronization */ + unsigned long *dirty_bitmap; + +#ifdef CONFIG_SMP + /* Local timer for synchronization */ + struct timer_list timer; +#endif + + /* Local vector table */ + struct imsic_vector *vectors; +}; + +struct imsic_priv { + /* Device details */ + struct fwnode_handle *fwnode; + + /* Global configuration common for all HARTs */ + struct imsic_global_config global; + + /* Per-CPU state */ + struct imsic_local_priv __percpu *lpriv; + + /* State of IRQ matrix allocator */ + raw_spinlock_t matrix_lock; + struct irq_matrix *matrix; + + /* IRQ domains (created by platform driver) */ + struct irq_domain *base_domain; +}; + +extern struct imsic_priv *imsic; + +void __imsic_eix_update(unsigned long base_id, unsigned long num_id, bool pend, bool val); + +static inline void __imsic_id_set_enable(unsigned long id) +{ + __imsic_eix_update(id, 1, false, true); +} + +static inline void __imsic_id_clear_enable(unsigned long id) +{ + __imsic_eix_update(id, 1, false, false); +} + +void imsic_local_sync_all(void); +void imsic_local_delivery(bool enable); + +void imsic_vector_mask(struct imsic_vector *vec); +void imsic_vector_unmask(struct imsic_vector *vec); + +static inline bool imsic_vector_isenabled(struct imsic_vector *vec) +{ + return READ_ONCE(vec->enable); +} + +static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *vec) +{ + return READ_ONCE(vec->move); +} + +void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec); + +struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id); + +struct imsic_vector *imsic_vector_alloc(unsigned int hwirq, const struct cpumask *mask); +void imsic_vector_free(struct imsic_vector *vector); + +void imsic_vector_debug_show(struct seq_file *m, struct imsic_vector *vec, int ind); +void imsic_vector_debug_show_summary(struct seq_file *m, int ind); + +void imsic_state_online(void); +void imsic_state_offline(void); +int imsic_setup_state(struct fwnode_handle *fwnode); + +#endif diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 172d0a743e5d..39d36183d9fc 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -146,6 +146,7 @@ enum cpuhp_state { CPUHP_AP_IRQ_MIPS_GIC_STARTING, CPUHP_AP_IRQ_LOONGARCH_STARTING, CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING, + CPUHP_AP_IRQ_RISCV_IMSIC_STARTING, CPUHP_AP_ARM_MVEBU_COHERENCY, CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING, CPUHP_AP_PERF_X86_STARTING, diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h new file mode 100644 index 000000000000..faf0b800b1b0 --- /dev/null +++ b/include/linux/irqchip/riscv-imsic.h @@ -0,0 +1,87 @@ +/* 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 <linux/bitops.h> +#include <asm/csr.h> + +#define IMSIC_MMIO_PAGE_SHIFT 12 +#define IMSIC_MMIO_PAGE_SZ BIT(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 + +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
