1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com> 4 * Loongson PCH MSI support 5 */ 6 7 #define pr_fmt(fmt) "pch-msi: " fmt 8 9 #include <linux/irqchip.h> 10 #include <linux/msi.h> 11 #include <linux/of.h> 12 #include <linux/of_address.h> 13 #include <linux/of_irq.h> 14 #include <linux/of_pci.h> 15 #include <linux/pci.h> 16 #include <linux/slab.h> 17 18 static int nr_pics; 19 20 struct pch_msi_data { 21 struct mutex msi_map_lock; 22 phys_addr_t doorbell; 23 u32 irq_first; /* The vector number that MSIs starts */ 24 u32 num_irqs; /* The number of vectors for MSIs */ 25 unsigned long *msi_map; 26 }; 27 28 static struct fwnode_handle *pch_msi_handle[MAX_IO_PICS]; 29 30 static void pch_msi_mask_msi_irq(struct irq_data *d) 31 { 32 pci_msi_mask_irq(d); 33 irq_chip_mask_parent(d); 34 } 35 36 static void pch_msi_unmask_msi_irq(struct irq_data *d) 37 { 38 irq_chip_unmask_parent(d); 39 pci_msi_unmask_irq(d); 40 } 41 42 static struct irq_chip pch_msi_irq_chip = { 43 .name = "PCH PCI MSI", 44 .irq_mask = pch_msi_mask_msi_irq, 45 .irq_unmask = pch_msi_unmask_msi_irq, 46 .irq_ack = irq_chip_ack_parent, 47 .irq_set_affinity = irq_chip_set_affinity_parent, 48 }; 49 50 static int pch_msi_allocate_hwirq(struct pch_msi_data *priv, int num_req) 51 { 52 int first; 53 54 mutex_lock(&priv->msi_map_lock); 55 56 first = bitmap_find_free_region(priv->msi_map, priv->num_irqs, 57 get_count_order(num_req)); 58 if (first < 0) { 59 mutex_unlock(&priv->msi_map_lock); 60 return -ENOSPC; 61 } 62 63 mutex_unlock(&priv->msi_map_lock); 64 65 return priv->irq_first + first; 66 } 67 68 static void pch_msi_free_hwirq(struct pch_msi_data *priv, 69 int hwirq, int num_req) 70 { 71 int first = hwirq - priv->irq_first; 72 73 mutex_lock(&priv->msi_map_lock); 74 bitmap_release_region(priv->msi_map, first, get_count_order(num_req)); 75 mutex_unlock(&priv->msi_map_lock); 76 } 77 78 static void pch_msi_compose_msi_msg(struct irq_data *data, 79 struct msi_msg *msg) 80 { 81 struct pch_msi_data *priv = irq_data_get_irq_chip_data(data); 82 83 msg->address_hi = upper_32_bits(priv->doorbell); 84 msg->address_lo = lower_32_bits(priv->doorbell); 85 msg->data = data->hwirq; 86 } 87 88 static struct msi_domain_info pch_msi_domain_info = { 89 .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | 90 MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, 91 .chip = &pch_msi_irq_chip, 92 }; 93 94 static struct irq_chip middle_irq_chip = { 95 .name = "PCH MSI", 96 .irq_mask = irq_chip_mask_parent, 97 .irq_unmask = irq_chip_unmask_parent, 98 .irq_ack = irq_chip_ack_parent, 99 .irq_set_affinity = irq_chip_set_affinity_parent, 100 .irq_compose_msi_msg = pch_msi_compose_msi_msg, 101 }; 102 103 static int pch_msi_parent_domain_alloc(struct irq_domain *domain, 104 unsigned int virq, int hwirq) 105 { 106 struct irq_fwspec fwspec; 107 108 fwspec.fwnode = domain->parent->fwnode; 109 fwspec.param_count = 1; 110 fwspec.param[0] = hwirq; 111 112 return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); 113 } 114 115 static int pch_msi_middle_domain_alloc(struct irq_domain *domain, 116 unsigned int virq, 117 unsigned int nr_irqs, void *args) 118 { 119 struct pch_msi_data *priv = domain->host_data; 120 int hwirq, err, i; 121 122 hwirq = pch_msi_allocate_hwirq(priv, nr_irqs); 123 if (hwirq < 0) 124 return hwirq; 125 126 for (i = 0; i < nr_irqs; i++) { 127 err = pch_msi_parent_domain_alloc(domain, virq + i, hwirq + i); 128 if (err) 129 goto err_hwirq; 130 131 irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, 132 &middle_irq_chip, priv); 133 } 134 135 return 0; 136 137 err_hwirq: 138 pch_msi_free_hwirq(priv, hwirq, nr_irqs); 139 irq_domain_free_irqs_parent(domain, virq, i - 1); 140 141 return err; 142 } 143 144 static void pch_msi_middle_domain_free(struct irq_domain *domain, 145 unsigned int virq, 146 unsigned int nr_irqs) 147 { 148 struct irq_data *d = irq_domain_get_irq_data(domain, virq); 149 struct pch_msi_data *priv = irq_data_get_irq_chip_data(d); 150 151 irq_domain_free_irqs_parent(domain, virq, nr_irqs); 152 pch_msi_free_hwirq(priv, d->hwirq, nr_irqs); 153 } 154 155 static const struct irq_domain_ops pch_msi_middle_domain_ops = { 156 .alloc = pch_msi_middle_domain_alloc, 157 .free = pch_msi_middle_domain_free, 158 }; 159 160 static int pch_msi_init_domains(struct pch_msi_data *priv, 161 struct irq_domain *parent, 162 struct fwnode_handle *domain_handle) 163 { 164 struct irq_domain *middle_domain, *msi_domain; 165 166 middle_domain = irq_domain_create_hierarchy(parent, 0, priv->num_irqs, 167 domain_handle, 168 &pch_msi_middle_domain_ops, 169 priv); 170 if (!middle_domain) { 171 pr_err("Failed to create the MSI middle domain\n"); 172 return -ENOMEM; 173 } 174 175 irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS); 176 177 msi_domain = pci_msi_create_irq_domain(domain_handle, 178 &pch_msi_domain_info, 179 middle_domain); 180 if (!msi_domain) { 181 pr_err("Failed to create PCI MSI domain\n"); 182 irq_domain_remove(middle_domain); 183 return -ENOMEM; 184 } 185 186 return 0; 187 } 188 189 static int pch_msi_init(phys_addr_t msg_address, int irq_base, int irq_count, 190 struct irq_domain *parent_domain, struct fwnode_handle *domain_handle) 191 { 192 int ret; 193 struct pch_msi_data *priv; 194 195 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 196 if (!priv) 197 return -ENOMEM; 198 199 mutex_init(&priv->msi_map_lock); 200 201 priv->doorbell = msg_address; 202 priv->irq_first = irq_base; 203 priv->num_irqs = irq_count; 204 205 priv->msi_map = bitmap_zalloc(priv->num_irqs, GFP_KERNEL); 206 if (!priv->msi_map) 207 goto err_priv; 208 209 pr_debug("Registering %d MSIs, starting at %d\n", 210 priv->num_irqs, priv->irq_first); 211 212 ret = pch_msi_init_domains(priv, parent_domain, domain_handle); 213 if (ret) 214 goto err_map; 215 216 pch_msi_handle[nr_pics++] = domain_handle; 217 return 0; 218 219 err_map: 220 bitmap_free(priv->msi_map); 221 err_priv: 222 kfree(priv); 223 224 return -EINVAL; 225 } 226 227 #ifdef CONFIG_OF 228 static int pch_msi_of_init(struct device_node *node, struct device_node *parent) 229 { 230 int err; 231 int irq_base, irq_count; 232 struct resource res; 233 struct irq_domain *parent_domain; 234 235 parent_domain = irq_find_host(parent); 236 if (!parent_domain) { 237 pr_err("Failed to find the parent domain\n"); 238 return -ENXIO; 239 } 240 241 if (of_address_to_resource(node, 0, &res)) { 242 pr_err("Failed to allocate resource\n"); 243 return -EINVAL; 244 } 245 246 if (of_property_read_u32(node, "loongson,msi-base-vec", &irq_base)) { 247 pr_err("Unable to parse MSI vec base\n"); 248 return -EINVAL; 249 } 250 251 if (of_property_read_u32(node, "loongson,msi-num-vecs", &irq_count)) { 252 pr_err("Unable to parse MSI vec number\n"); 253 return -EINVAL; 254 } 255 256 err = pch_msi_init(res.start, irq_base, irq_count, parent_domain, of_node_to_fwnode(node)); 257 if (err < 0) 258 return err; 259 260 return 0; 261 } 262 263 IRQCHIP_DECLARE(pch_msi, "loongson,pch-msi-1.0", pch_msi_of_init); 264 #endif 265 266 #ifdef CONFIG_ACPI 267 struct fwnode_handle *get_pch_msi_handle(int pci_segment) 268 { 269 int i; 270 271 for (i = 0; i < MAX_IO_PICS; i++) { 272 if (msi_group[i].pci_segment == pci_segment) 273 return pch_msi_handle[i]; 274 } 275 return NULL; 276 } 277 278 int __init pch_msi_acpi_init(struct irq_domain *parent, 279 struct acpi_madt_msi_pic *acpi_pchmsi) 280 { 281 int ret; 282 struct fwnode_handle *domain_handle; 283 284 domain_handle = irq_domain_alloc_fwnode(&acpi_pchmsi->msg_address); 285 ret = pch_msi_init(acpi_pchmsi->msg_address, acpi_pchmsi->start, 286 acpi_pchmsi->count, parent, domain_handle); 287 if (ret < 0) 288 irq_domain_free_fwnode(domain_handle); 289 290 return ret; 291 } 292 #endif 293