1 files changed, 425 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-loongarch-avec.c b/drivers/irqchip/irq-loongarch-avec.c
new file mode 100644
index 000000000000..0f6e465dd309
--- /dev/null
+++ b/drivers/irqchip/irq-loongarch-avec.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Loongson Technologies, Inc.
+ */
+
+#include <linux/cpuhotplug.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/msi.h>
+#include <linux/radix-tree.h>
+#include <linux/spinlock.h>
+
+#include <asm/loongarch.h>
+#include <asm/setup.h>
+
+#include "irq-msi-lib.h"
+#include "irq-loongson.h"
+
+#define VECTORS_PER_REG		64
+#define IRR_VECTOR_MASK		0xffUL
+#define IRR_INVALID_MASK	0x80000000UL
+#define AVEC_MSG_OFFSET		0x100000
+
+#ifdef CONFIG_SMP
+struct pending_list {
+	struct list_head	head;
+};
+
+static struct cpumask intersect_mask;
+static DEFINE_PER_CPU(struct pending_list, pending_list);
+#endif
+
+static DEFINE_PER_CPU(struct irq_desc * [NR_VECTORS], irq_map);
+
+struct avecintc_chip {
+	raw_spinlock_t		lock;
+	struct fwnode_handle	*fwnode;
+	struct irq_domain	*domain;
+	struct irq_matrix	*vector_matrix;
+	phys_addr_t		msi_base_addr;
+};
+
+static struct avecintc_chip loongarch_avec;
+
+struct avecintc_data {
+	struct list_head	entry;
+	unsigned int		cpu;
+	unsigned int		vec;
+	unsigned int		prev_cpu;
+	unsigned int		prev_vec;
+	unsigned int		moving;
+};
+
+static inline void avecintc_ack_irq(struct irq_data *d)
+{
+}
+
+static inline void avecintc_mask_irq(struct irq_data *d)
+{
+}
+
+static inline void avecintc_unmask_irq(struct irq_data *d)
+{
+}
+
+#ifdef CONFIG_SMP
+static inline void pending_list_init(int cpu)
+{
+	struct pending_list *plist = per_cpu_ptr(&pending_list, cpu);
+
+	INIT_LIST_HEAD(&plist->head);
+}
+
+static void avecintc_sync(struct avecintc_data *adata)
+{
+	struct pending_list *plist;
+
+	if (cpu_online(adata->prev_cpu)) {
+		plist = per_cpu_ptr(&pending_list, adata->prev_cpu);
+		list_add_tail(&adata->entry, &plist->head);
+		adata->moving = 1;
+		mp_ops.send_ipi_single(adata->prev_cpu, ACTION_CLEAR_VECTOR);
+	}
+}
+
+static int avecintc_set_affinity(struct irq_data *data, const struct cpumask *dest, bool force)
+{
+	int cpu, ret, vector;
+	struct avecintc_data *adata;
+
+	scoped_guard(raw_spinlock, &loongarch_avec.lock) {
+		adata = irq_data_get_irq_chip_data(data);
+
+		if (adata->moving)
+			return -EBUSY;
+
+		if (cpu_online(adata->cpu) && cpumask_test_cpu(adata->cpu, dest))
+			return 0;
+
+		cpumask_and(&intersect_mask, dest, cpu_online_mask);
+
+		ret = irq_matrix_alloc(loongarch_avec.vector_matrix, &intersect_mask, false, &cpu);
+		if (ret < 0)
+			return ret;
+
+		vector = ret;
+		adata->cpu = cpu;
+		adata->vec = vector;
+		per_cpu_ptr(irq_map, adata->cpu)[adata->vec] = irq_data_to_desc(data);
+		avecintc_sync(adata);
+	}
+
+	irq_data_update_effective_affinity(data, cpumask_of(cpu));
+
+	return IRQ_SET_MASK_OK;
+}
+
+static int avecintc_cpu_online(unsigned int cpu)
+{
+	if (!loongarch_avec.vector_matrix)
+		return 0;
+
+	guard(raw_spinlock)(&loongarch_avec.lock);
+
+	irq_matrix_online(loongarch_avec.vector_matrix);
+
+	pending_list_init(cpu);
+
+	return 0;
+}
+
+static int avecintc_cpu_offline(unsigned int cpu)
+{
+	struct pending_list *plist = per_cpu_ptr(&pending_list, cpu);
+
+	if (!loongarch_avec.vector_matrix)
+		return 0;
+
+	guard(raw_spinlock)(&loongarch_avec.lock);
+
+	if (!list_empty(&plist->head))
+		pr_warn("CPU#%d vector is busy\n", cpu);
+
+	irq_matrix_offline(loongarch_avec.vector_matrix);
+
+	return 0;
+}
+
+void complete_irq_moving(void)
+{
+	struct pending_list *plist = this_cpu_ptr(&pending_list);
+	struct avecintc_data *adata, *tdata;
+	int cpu, vector, bias;
+	uint64_t isr;
+
+	guard(raw_spinlock)(&loongarch_avec.lock);
+
+	list_for_each_entry_safe(adata, tdata, &plist->head, entry) {
+		cpu = adata->prev_cpu;
+		vector = adata->prev_vec;
+		bias = vector / VECTORS_PER_REG;
+		switch (bias) {
+		case 0:
+			isr = csr_read64(LOONGARCH_CSR_ISR0);
+			break;
+		case 1:
+			isr = csr_read64(LOONGARCH_CSR_ISR1);
+			break;
+		case 2:
+			isr = csr_read64(LOONGARCH_CSR_ISR2);
+			break;
+		case 3:
+			isr = csr_read64(LOONGARCH_CSR_ISR3);
+			break;
+		}
+
+		if (isr & (1UL << (vector % VECTORS_PER_REG))) {
+			mp_ops.send_ipi_single(cpu, ACTION_CLEAR_VECTOR);
+			continue;
+		}
+		list_del(&adata->entry);
+		irq_matrix_free(loongarch_avec.vector_matrix, cpu, vector, false);
+		this_cpu_write(irq_map[vector], NULL);
+		adata->moving = 0;
+		adata->prev_cpu = adata->cpu;
+		adata->prev_vec = adata->vec;
+	}
+}
+#endif
+
+static void avecintc_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
+{
+	struct avecintc_data *adata = irq_data_get_irq_chip_data(d);
+
+	msg->address_hi = 0x0;
+	msg->address_lo = (loongarch_avec.msi_base_addr | (adata->vec & 0xff) << 4)
+			  | ((cpu_logical_map(adata->cpu & 0xffff)) << 12);
+	msg->data = 0x0;
+}
+
+static struct irq_chip avec_irq_controller = {
+	.name			= "AVECINTC",
+	.irq_ack		= avecintc_ack_irq,
+	.irq_mask		= avecintc_mask_irq,
+	.irq_unmask		= avecintc_unmask_irq,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= avecintc_set_affinity,
+#endif
+	.irq_compose_msi_msg	= avecintc_compose_msi_msg,
+};
+
+static void avecintc_irq_dispatch(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct irq_desc *d;
+
+	chained_irq_enter(chip, desc);
+
+	while (true) {
+		unsigned long vector = csr_read64(LOONGARCH_CSR_IRR);
+		if (vector & IRR_INVALID_MASK)
+			break;
+
+		vector &= IRR_VECTOR_MASK;
+
+		d = this_cpu_read(irq_map[vector]);
+		if (d) {
+			generic_handle_irq_desc(d);
+		} else {
+			spurious_interrupt();
+			pr_warn("Unexpected IRQ occurs on CPU#%d [vector %ld]\n", smp_processor_id(), vector);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int avecintc_alloc_vector(struct irq_data *irqd, struct avecintc_data *adata)
+{
+	int cpu, ret;
+
+	guard(raw_spinlock_irqsave)(&loongarch_avec.lock);
+
+	ret = irq_matrix_alloc(loongarch_avec.vector_matrix, cpu_online_mask, false, &cpu);
+	if (ret < 0)
+		return ret;
+
+	adata->prev_cpu = adata->cpu = cpu;
+	adata->prev_vec = adata->vec = ret;
+	per_cpu_ptr(irq_map, adata->cpu)[adata->vec] = irq_data_to_desc(irqd);
+
+	return 0;
+}
+
+static int avecintc_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *arg)
+{
+	for (unsigned int i = 0; i < nr_irqs; i++) {
+		struct irq_data *irqd = irq_domain_get_irq_data(domain, virq + i);
+		struct avecintc_data *adata = kzalloc(sizeof(*adata), GFP_KERNEL);
+		int ret;
+
+		if (!adata)
+			return -ENOMEM;
+
+		ret = avecintc_alloc_vector(irqd, adata);
+		if (ret < 0) {
+			kfree(adata);
+			return ret;
+		}
+
+		irq_domain_set_info(domain, virq + i, virq + i, &avec_irq_controller,
+				    adata, handle_edge_irq, NULL, NULL);
+		irqd_set_single_target(irqd);
+		irqd_set_affinity_on_activate(irqd);
+	}
+
+	return 0;
+}
+
+static void avecintc_free_vector(struct irq_data *irqd, struct avecintc_data *adata)
+{
+	guard(raw_spinlock_irqsave)(&loongarch_avec.lock);
+
+	per_cpu(irq_map, adata->cpu)[adata->vec] = NULL;
+	irq_matrix_free(loongarch_avec.vector_matrix, adata->cpu, adata->vec, false);
+
+#ifdef CONFIG_SMP
+	if (!adata->moving)
+		return;
+
+	per_cpu(irq_map, adata->prev_cpu)[adata->prev_vec] = NULL;
+	irq_matrix_free(loongarch_avec.vector_matrix, adata->prev_cpu, adata->prev_vec, false);
+	list_del_init(&adata->entry);
+#endif
+}
+
+static void avecintc_domain_free(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs)
+{
+	for (unsigned int i = 0; i < nr_irqs; i++) {
+		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
+
+		if (d) {
+			struct avecintc_data *adata = irq_data_get_irq_chip_data(d);
+
+			avecintc_free_vector(d, adata);
+			irq_domain_reset_irq_data(d);
+			kfree(adata);
+		}
+	}
+}
+
+static const struct irq_domain_ops avecintc_domain_ops = {
+	.alloc		= avecintc_domain_alloc,
+	.free		= avecintc_domain_free,
+	.select		= msi_lib_irq_domain_select,
+};
+
+static int __init irq_matrix_init(void)
+{
+	loongarch_avec.vector_matrix = irq_alloc_matrix(NR_VECTORS, 0, NR_VECTORS);
+	if (!loongarch_avec.vector_matrix)
+		return -ENOMEM;
+
+	for (int i = 0; i < NR_LEGACY_VECTORS; i++)
+		irq_matrix_assign_system(loongarch_avec.vector_matrix, i, false);
+
+	irq_matrix_online(loongarch_avec.vector_matrix);
+
+	return 0;
+}
+
+static int __init avecintc_init(struct irq_domain *parent)
+{
+	int ret, parent_irq;
+	unsigned long value;
+
+	raw_spin_lock_init(&loongarch_avec.lock);
+
+	loongarch_avec.fwnode = irq_domain_alloc_named_fwnode("AVECINTC");
+	if (!loongarch_avec.fwnode) {
+		pr_err("Unable to allocate domain handle\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	loongarch_avec.domain = irq_domain_create_tree(loongarch_avec.fwnode,
+						       &avecintc_domain_ops, NULL);
+	if (!loongarch_avec.domain) {
+		pr_err("Unable to create IRQ domain\n");
+		ret = -ENOMEM;
+		goto out_free_handle;
+	}
+
+	parent_irq = irq_create_mapping(parent, INT_AVEC);
+	if (!parent_irq) {
+		pr_err("Failed to mapping hwirq\n");
+		ret = -EINVAL;
+		goto out_remove_domain;
+	}
+
+	ret = irq_matrix_init();
+	if (ret < 0) {
+		pr_err("Failed to init irq matrix\n");
+		goto out_remove_domain;
+	}
+	irq_set_chained_handler_and_data(parent_irq, avecintc_irq_dispatch, NULL);
+
+#ifdef CONFIG_SMP
+	pending_list_init(0);
+	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_AVECINTC_STARTING,
+				  "irqchip/loongarch/avecintc:starting",
+				  avecintc_cpu_online, avecintc_cpu_offline);
+#endif
+	value = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
+	value |= IOCSR_MISC_FUNC_AVEC_EN;
+	iocsr_write64(value, LOONGARCH_IOCSR_MISC_FUNC);
+
+	return ret;
+
+out_remove_domain:
+	irq_domain_remove(loongarch_avec.domain);
+out_free_handle:
+	irq_domain_free_fwnode(loongarch_avec.fwnode);
+out:
+	return ret;
+}
+
+static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
+				     const unsigned long end)
+{
+	struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
+
+	loongarch_avec.msi_base_addr = pchmsi_entry->msg_address - AVEC_MSG_OFFSET;
+
+	return pch_msi_acpi_init_avec(loongarch_avec.domain);
+}
+
+static inline int __init acpi_cascade_irqdomain_init(void)
+{
+	return acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC, pch_msi_parse_madt, 1);
+}
+
+int __init avecintc_acpi_init(struct irq_domain *parent)
+{
+	int ret = avecintc_init(parent);
+	if (ret < 0) {
+		pr_err("Failed to init IRQ domain\n");
+		return ret;
+	}
+
+	ret = acpi_cascade_irqdomain_init();
+	if (ret < 0) {
+		pr_err("Failed to init cascade IRQ domain\n");
+		return ret;
+	}
+
+	return ret;
+}