// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com> * Loongson PCH MSI support */ #define pr_fmt(fmt) "pch-msi: " fmt #include <linux/irqchip.h> #include <linux/msi.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_pci.h> #include <linux/pci.h> #include <linux/slab.h> struct pch_msi_data { struct mutex msi_map_lock; phys_addr_t doorbell; u32 irq_first; /* The vector number that MSIs starts */ u32 num_irqs; /* The number of vectors for MSIs */ unsigned long *msi_map; }; static void pch_msi_mask_msi_irq(struct irq_data *d) { pci_msi_mask_irq(d); irq_chip_mask_parent(d); } static void pch_msi_unmask_msi_irq(struct irq_data *d) { irq_chip_unmask_parent(d); pci_msi_unmask_irq(d); } static struct irq_chip pch_msi_irq_chip = { .name = "PCH PCI MSI", .irq_mask = pch_msi_mask_msi_irq, .irq_unmask = pch_msi_unmask_msi_irq, .irq_ack = irq_chip_ack_parent, .irq_set_affinity = irq_chip_set_affinity_parent, }; static int pch_msi_allocate_hwirq(struct pch_msi_data *priv, int num_req) { int first; mutex_lock(&priv->msi_map_lock); first = bitmap_find_free_region(priv->msi_map, priv->num_irqs, get_count_order(num_req)); if (first < 0) { mutex_unlock(&priv->msi_map_lock); return -ENOSPC; } mutex_unlock(&priv->msi_map_lock); return priv->irq_first + first; } static void pch_msi_free_hwirq(struct pch_msi_data *priv, int hwirq, int num_req) { int first = hwirq - priv->irq_first; mutex_lock(&priv->msi_map_lock); bitmap_release_region(priv->msi_map, first, get_count_order(num_req)); mutex_unlock(&priv->msi_map_lock); } static void pch_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) { struct pch_msi_data *priv = irq_data_get_irq_chip_data(data); msg->address_hi = upper_32_bits(priv->doorbell); msg->address_lo = lower_32_bits(priv->doorbell); msg->data = data->hwirq; } static struct msi_domain_info pch_msi_domain_info = { .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, .chip = &pch_msi_irq_chip, }; static struct irq_chip middle_irq_chip = { .name = "PCH MSI", .irq_mask = irq_chip_mask_parent, .irq_unmask = irq_chip_unmask_parent, .irq_ack = irq_chip_ack_parent, .irq_set_affinity = irq_chip_set_affinity_parent, .irq_compose_msi_msg = pch_msi_compose_msi_msg, }; static int pch_msi_parent_domain_alloc(struct irq_domain *domain, unsigned int virq, int hwirq) { struct irq_fwspec fwspec; fwspec.fwnode = domain->parent->fwnode; fwspec.param_count = 1; fwspec.param[0] = hwirq; return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); } static int pch_msi_middle_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) { struct pch_msi_data *priv = domain->host_data; int hwirq, err, i; hwirq = pch_msi_allocate_hwirq(priv, nr_irqs); if (hwirq < 0) return hwirq; for (i = 0; i < nr_irqs; i++) { err = pch_msi_parent_domain_alloc(domain, virq + i, hwirq + i); if (err) goto err_hwirq; irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, &middle_irq_chip, priv); } return 0; err_hwirq: pch_msi_free_hwirq(priv, hwirq, nr_irqs); irq_domain_free_irqs_parent(domain, virq, i - 1); return err; } static void pch_msi_middle_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs) { struct irq_data *d = irq_domain_get_irq_data(domain, virq); struct pch_msi_data *priv = irq_data_get_irq_chip_data(d); irq_domain_free_irqs_parent(domain, virq, nr_irqs); pch_msi_free_hwirq(priv, d->hwirq, nr_irqs); } static const struct irq_domain_ops pch_msi_middle_domain_ops = { .alloc = pch_msi_middle_domain_alloc, .free = pch_msi_middle_domain_free, }; static int pch_msi_init_domains(struct pch_msi_data *priv, struct device_node *node, struct irq_domain *parent) { struct irq_domain *middle_domain, *msi_domain; middle_domain = irq_domain_create_linear(of_node_to_fwnode(node), priv->num_irqs, &pch_msi_middle_domain_ops, priv); if (!middle_domain) { pr_err("Failed to create the MSI middle domain\n"); return -ENOMEM; } middle_domain->parent = parent; irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS); msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node), &pch_msi_domain_info, middle_domain); if (!msi_domain) { pr_err("Failed to create PCI MSI domain\n"); irq_domain_remove(middle_domain); return -ENOMEM; } return 0; } static int pch_msi_init(struct device_node *node, struct device_node *parent) { struct pch_msi_data *priv; struct irq_domain *parent_domain; struct resource res; int ret; parent_domain = irq_find_host(parent); if (!parent_domain) { pr_err("Failed to find the parent domain\n"); return -ENXIO; } priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; mutex_init(&priv->msi_map_lock); ret = of_address_to_resource(node, 0, &res); if (ret) { pr_err("Failed to allocate resource\n"); goto err_priv; } priv->doorbell = res.start; if (of_property_read_u32(node, "loongson,msi-base-vec", &priv->irq_first)) { pr_err("Unable to parse MSI vec base\n"); ret = -EINVAL; goto err_priv; } if (of_property_read_u32(node, "loongson,msi-num-vecs", &priv->num_irqs)) { pr_err("Unable to parse MSI vec number\n"); ret = -EINVAL; goto err_priv; } priv->msi_map = bitmap_alloc(priv->num_irqs, GFP_KERNEL); if (!priv->msi_map) { ret = -ENOMEM; goto err_priv; } pr_debug("Registering %d MSIs, starting at %d\n", priv->num_irqs, priv->irq_first); ret = pch_msi_init_domains(priv, node, parent_domain); if (ret) goto err_map; return 0; err_map: kfree(priv->msi_map); err_priv: kfree(priv); return ret; } IRQCHIP_DECLARE(pch_msi, "loongson,pch-msi-1.0", pch_msi_init);