@@ -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
@@ -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
new file mode 100644
@@ -0,0 +1,241 @@
+// 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 irqreturn_t imsic_local_sync_handler(int irq, void *data)
+{
+ imsic_local_sync();
+ return IRQ_HANDLED;
+}
+
+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);
+
+ /* 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;
+
+ /* Create IMSIC IPI multiplexing */
+ virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
+ if (virq <= 0)
+ 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_local_sync_handler,
+ "riscv-imsic-lsync", imsic->global.local);
+ if (virq)
+ 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);
+
+ /* 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 = local_id >> TOPEI_ID_SHIFT;
+
+ if (local_id == IMSIC_IPI_ID) {
+#ifdef CONFIG_SMP
+ ipi_mux_process();
+#endif
+ 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();
+
+ /* 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)
+{
+ int rc;
+ struct irq_domain *domain;
+
+ /* 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;
+ }
+ 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);
+ return rc;
+ }
+
+ /*
+ * 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);
+
+ return 0;
+}
+
+static int __init imsic_early_dt_init(struct device_node *node,
+ struct device_node *parent)
+{
+ int rc;
+ struct fwnode_handle *fwnode = &node->fwnode;
+
+ /* 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);
new file mode 100644
@@ -0,0 +1,887 @@
+// 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
+
+#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_read_clear(__c, __v) \
+({ \
+ unsigned long __r; \
+ csr_write(CSR_ISELECT, __c); \
+ __r = csr_read_clear(CSR_IREG, __v); \
+ __r; \
+})
+
+#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 *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) ? true : false;
+}
+
+#define __imsic_id_read_clear_enabled(__id) \
+ __imsic_eix_read_clear((__id), false)
+#define __imsic_id_read_clear_pending(__id) \
+ __imsic_eix_read_clear((__id), true)
+
+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);
+ }
+}
+
+void imsic_local_sync(void)
+{
+ struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv);
+ struct imsic_local_config *mlocal;
+ struct imsic_vector *mvec;
+ unsigned long flags;
+ int i;
+
+ raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
+ for (i = 1; i <= imsic->global.nr_ids; i++) {
+ if (i == IMSIC_IPI_ID)
+ continue;
+
+ if (test_bit(i, lpriv->ids_enabled_bitmap))
+ __imsic_id_set_enable(i);
+ else
+ __imsic_id_clear_enable(i);
+
+ mvec = lpriv->ids_move[i];
+ lpriv->ids_move[i] = NULL;
+ if (mvec) {
+ 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]);
+ }
+
+ }
+ raw_spin_unlock_irqrestore(&lpriv->ids_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_remote_sync(unsigned int cpu)
+{
+ /*
+ * We simply inject ID synchronization IPI to a target CPU
+ * if it is not same as the 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.
+ */
+ if (cpu_online(cpu)) {
+ if (cpu != smp_processor_id())
+ __ipi_send_mask(imsic->ipi_lsync_desc, cpumask_of(cpu));
+ else
+ imsic_local_sync();
+ }
+}
+#else
+static inline void imsic_remote_sync(unsigned int cpu)
+{
+ imsic_local_sync();
+}
+#endif
+
+void imsic_vector_mask(struct imsic_vector *vec)
+{
+ struct imsic_local_priv *lpriv;
+ unsigned long flags;
+
+ lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu);
+ if (WARN_ON(&lpriv->vectors[vec->local_id] != vec))
+ return;
+
+ raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
+ bitmap_clear(lpriv->ids_enabled_bitmap, vec->local_id, 1);
+ raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
+
+ imsic_remote_sync(vec->cpu);
+}
+
+void imsic_vector_unmask(struct imsic_vector *vec)
+{
+ struct imsic_local_priv *lpriv;
+ unsigned long flags;
+
+ lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu);
+ if (WARN_ON(&lpriv->vectors[vec->local_id] != vec))
+ return;
+
+ raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
+ bitmap_set(lpriv->ids_enabled_bitmap, vec->local_id, 1);
+ raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
+
+ imsic_remote_sync(vec->cpu);
+}
+
+void imsic_vector_move(struct imsic_vector *old_vec,
+ struct imsic_vector *new_vec)
+{
+ struct imsic_local_priv *old_lpriv, *new_lpriv;
+ unsigned long flags, flags1;
+
+ if (WARN_ON(old_vec->cpu == new_vec->cpu))
+ return;
+
+ old_lpriv = per_cpu_ptr(imsic->lpriv, old_vec->cpu);
+ if (WARN_ON(&old_lpriv->vectors[old_vec->local_id] != old_vec))
+ return;
+
+ new_lpriv = per_cpu_ptr(imsic->lpriv, new_vec->cpu);
+ if (WARN_ON(&new_lpriv->vectors[new_vec->local_id] != new_vec))
+ return;
+
+ raw_spin_lock_irqsave(&old_lpriv->ids_lock, flags);
+ raw_spin_lock_irqsave(&new_lpriv->ids_lock, flags1);
+
+ /* Unmask the new vector entry */
+ if (test_bit(old_vec->local_id, old_lpriv->ids_enabled_bitmap))
+ bitmap_set(new_lpriv->ids_enabled_bitmap,
+ new_vec->local_id, 1);
+
+ /* Mask the old vector entry */
+ bitmap_clear(old_lpriv->ids_enabled_bitmap, old_vec->local_id, 1);
+
+ /*
+ * 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.
+ */
+ old_lpriv->ids_move[old_vec->local_id] = new_vec;
+
+ raw_spin_unlock_irqrestore(&new_lpriv->ids_lock, flags1);
+ raw_spin_unlock_irqrestore(&old_lpriv->ids_lock, flags);
+
+ imsic_remote_sync(old_vec->cpu);
+ imsic_remote_sync(new_vec->cpu);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+void imsic_vector_debug_show(struct seq_file *m,
+ struct imsic_vector *vec, int ind)
+{
+ unsigned int mcpu = 0, mlocal_id = 0;
+ struct imsic_local_priv *lpriv;
+ bool move_in_progress = false;
+ struct imsic_vector *mvec;
+ bool is_enabled = false;
+ unsigned long flags;
+
+ lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu);
+ if (WARN_ON(&lpriv->vectors[vec->local_id] != vec))
+ return;
+
+ raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
+ if (test_bit(vec->local_id, lpriv->ids_enabled_bitmap))
+ is_enabled = true;
+ mvec = lpriv->ids_move[vec->local_id];
+ if (mvec) {
+ move_in_progress = true;
+ mcpu = mvec->cpu;
+ mlocal_id = mvec->local_id;
+ }
+ raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
+
+ 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, "",
+ (move_in_progress) ? 1 : 0);
+ if (move_in_progress) {
+ seq_printf(m, "%*smove_cpu : %5u\n", ind, "", mcpu);
+ seq_printf(m, "%*smove_local_id : %5u\n", ind, "", mlocal_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;
+
+ 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)
+{
+ int cpu;
+ struct imsic_local_priv *lpriv;
+
+ for_each_possible_cpu(cpu) {
+ lpriv = per_cpu_ptr(imsic->lpriv, cpu);
+
+ bitmap_free(lpriv->ids_enabled_bitmap);
+ kfree(lpriv->ids_move);
+ 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->ids_lock);
+
+ /* Allocate enabled bitmap */
+ lpriv->ids_enabled_bitmap = bitmap_zalloc(global->nr_ids + 1,
+ GFP_KERNEL);
+ if (!lpriv->ids_enabled_bitmap) {
+ imsic_local_cleanup();
+ return -ENOMEM;
+ }
+
+ /* Allocate move array */
+ lpriv->ids_move = kcalloc(global->nr_ids + 1,
+ sizeof(*lpriv->ids_move), GFP_KERNEL);
+ if (!lpriv->ids_move) {
+ imsic_local_cleanup();
+ return -ENOMEM;
+ }
+
+ /* Allocate vector array */
+ lpriv->vectors = kcalloc(global->nr_ids + 1,
+ sizeof(*lpriv->vectors), GFP_KERNEL);
+ if (!lpriv->vectors) {
+ imsic_local_cleanup();
+ return -ENOMEM;
+ }
+
+ /* 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;
+}
+
+int imsic_hwirq_alloc(void)
+{
+ int ret;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&imsic->hwirqs_lock, flags);
+ ret = bitmap_find_free_region(imsic->hwirqs_used_bitmap,
+ imsic->nr_hwirqs, 0);
+ raw_spin_unlock_irqrestore(&imsic->hwirqs_lock, flags);
+
+ return ret;
+}
+
+void imsic_hwirq_free(unsigned int hwirq)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&imsic->hwirqs_lock, flags);
+ bitmap_release_region(imsic->hwirqs_used_bitmap, hwirq, 0);
+ raw_spin_unlock_irqrestore(&imsic->hwirqs_lock, flags);
+}
+
+static int __init imsic_hwirqs_init(void)
+{
+ struct imsic_global_config *global = &imsic->global;
+
+ imsic->nr_hwirqs = num_possible_cpus() * (global->nr_ids - 1);
+
+ raw_spin_lock_init(&imsic->hwirqs_lock);
+
+ imsic->hwirqs_used_bitmap = bitmap_zalloc(imsic->nr_hwirqs,
+ GFP_KERNEL);
+ if (!imsic->hwirqs_used_bitmap)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __init imsic_hwirqs_cleanup(void)
+{
+ bitmap_free(imsic->hwirqs_used_bitmap);
+}
+
+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);
+}
+
+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)
+{
+ int rc;
+ struct of_phandle_args parent;
+
+ /*
+ * 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 */
+ *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);
+ 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)
+{
+ int rc, cpu;
+ phys_addr_t base_addr;
+ void __iomem **mmios_va = NULL;
+ struct resource *mmios = NULL;
+ struct imsic_local_config *local;
+ struct imsic_global_config *global;
+ unsigned long reloff, hartid;
+ u32 i, j, index, nr_parent_irqs, nr_mmios, nr_handlers = 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 -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 HW interrupt numbers */
+ rc = imsic_hwirqs_init();
+ if (rc) {
+ pr_err("%pfwP: failed to initialize HW interrupts numbers\n",
+ fwnode);
+ 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_hwirqs_cleanup;
+ }
+
+ /* 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_hwirqs_cleanup:
+ imsic_hwirqs_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;
+}
new file mode 100644
@@ -0,0 +1,105 @@
+/* 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>
+
+/*
+ * 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_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;
+};
+
+struct imsic_local_priv {
+ /* Local state of interrupt identities */
+ raw_spinlock_t ids_lock;
+ unsigned long *ids_enabled_bitmap;
+ struct imsic_vector **ids_move;
+
+ /* 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;
+
+ /* Dummy HW interrupt numbers */
+ unsigned int nr_hwirqs;
+ raw_spinlock_t hwirqs_lock;
+ unsigned long *hwirqs_used_bitmap;
+
+ /* Per-CPU state */
+ struct imsic_local_priv __percpu *lpriv;
+
+ /* State of IRQ matrix allocator */
+ raw_spinlock_t matrix_lock;
+ struct irq_matrix *matrix;
+
+ /* IPI interrupt identity and synchronization */
+ int ipi_virq;
+ struct irq_desc *ipi_lsync_desc;
+
+ /* IRQ domains (created by platform driver) */
+ struct irq_domain *base_domain;
+ struct irq_domain *plat_domain;
+};
+
+extern struct imsic_priv *imsic;
+
+void __imsic_eix_update(unsigned long base_id,
+ unsigned long num_id, bool pend, bool val);
+
+#define __imsic_id_set_enable(__id) \
+ __imsic_eix_update((__id), 1, false, true)
+#define __imsic_id_clear_enable(__id) \
+ __imsic_eix_update((__id), 1, false, false)
+
+void imsic_local_sync(void);
+void imsic_local_delivery(bool enable);
+
+void imsic_vector_mask(struct imsic_vector *vec);
+void imsic_vector_unmask(struct imsic_vector *vec);
+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);
+
+int imsic_hwirq_alloc(void);
+void imsic_hwirq_free(unsigned int hwirq);
+
+void imsic_state_online(void);
+void imsic_state_offline(void);
+int imsic_setup_state(struct fwnode_handle *fwnode);
+
+#endif
new file mode 100644
@@ -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
+
+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
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) Let us add an early irqchip driver for RISC-V IMSIC which sets up the IMSIC state and provide IPIs. Signed-off-by: Anup Patel <apatel@ventanamicro.com> --- drivers/irqchip/Kconfig | 7 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-imsic-early.c | 241 +++++++ drivers/irqchip/irq-riscv-imsic-state.c | 887 ++++++++++++++++++++++++ drivers/irqchip/irq-riscv-imsic-state.h | 105 +++ include/linux/irqchip/riscv-imsic.h | 87 +++ 6 files changed, 1328 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