1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Freescale Management Complex (MC) bus driver MSI support 4 * 5 * Copyright (C) 2015-2016 Freescale Semiconductor, Inc. 6 * Author: German Rivera <German.Rivera@freescale.com> 7 * 8 */ 9 10 #include <linux/of_device.h> 11 #include <linux/of_address.h> 12 #include <linux/of_irq.h> 13 #include <linux/irq.h> 14 #include <linux/irqdomain.h> 15 #include <linux/msi.h> 16 17 #include "fsl-mc-private.h" 18 19 #ifdef GENERIC_MSI_DOMAIN_OPS 20 /* 21 * Generate a unique ID identifying the interrupt (only used within the MSI 22 * irqdomain. Combine the icid with the interrupt index. 23 */ 24 static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev, 25 struct msi_desc *desc) 26 { 27 /* 28 * Make the base hwirq value for ICID*10000 so it is readable 29 * as a decimal value in /proc/interrupts. 30 */ 31 return (irq_hw_number_t)(desc->fsl_mc.msi_index + (dev->icid * 10000)); 32 } 33 34 static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg, 35 struct msi_desc *desc) 36 { 37 arg->desc = desc; 38 arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev), 39 desc); 40 } 41 #else 42 #define fsl_mc_msi_set_desc NULL 43 #endif 44 45 static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info) 46 { 47 struct msi_domain_ops *ops = info->ops; 48 49 if (!ops) 50 return; 51 52 /* 53 * set_desc should not be set by the caller 54 */ 55 if (!ops->set_desc) 56 ops->set_desc = fsl_mc_msi_set_desc; 57 } 58 59 static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev, 60 struct fsl_mc_device_irq *mc_dev_irq) 61 { 62 int error; 63 struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev; 64 struct msi_desc *msi_desc = mc_dev_irq->msi_desc; 65 struct dprc_irq_cfg irq_cfg; 66 67 /* 68 * msi_desc->msg.address is 0x0 when this function is invoked in 69 * the free_irq() code path. In this case, for the MC, we don't 70 * really need to "unprogram" the MSI, so we just return. 71 */ 72 if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0) 73 return; 74 75 if (!owner_mc_dev) 76 return; 77 78 irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) | 79 msi_desc->msg.address_lo; 80 irq_cfg.val = msi_desc->msg.data; 81 irq_cfg.irq_num = msi_desc->irq; 82 83 if (owner_mc_dev == mc_bus_dev) { 84 /* 85 * IRQ is for the mc_bus_dev's DPRC itself 86 */ 87 error = dprc_set_irq(mc_bus_dev->mc_io, 88 MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI, 89 mc_bus_dev->mc_handle, 90 mc_dev_irq->dev_irq_index, 91 &irq_cfg); 92 if (error < 0) { 93 dev_err(&owner_mc_dev->dev, 94 "dprc_set_irq() failed: %d\n", error); 95 } 96 } else { 97 /* 98 * IRQ is for for a child device of mc_bus_dev 99 */ 100 error = dprc_set_obj_irq(mc_bus_dev->mc_io, 101 MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI, 102 mc_bus_dev->mc_handle, 103 owner_mc_dev->obj_desc.type, 104 owner_mc_dev->obj_desc.id, 105 mc_dev_irq->dev_irq_index, 106 &irq_cfg); 107 if (error < 0) { 108 dev_err(&owner_mc_dev->dev, 109 "dprc_obj_set_irq() failed: %d\n", error); 110 } 111 } 112 } 113 114 /* 115 * NOTE: This function is invoked with interrupts disabled 116 */ 117 static void fsl_mc_msi_write_msg(struct irq_data *irq_data, 118 struct msi_msg *msg) 119 { 120 struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data); 121 struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev); 122 struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev); 123 struct fsl_mc_device_irq *mc_dev_irq = 124 &mc_bus->irq_resources[msi_desc->fsl_mc.msi_index]; 125 126 msi_desc->msg = *msg; 127 128 /* 129 * Program the MSI (paddr, value) pair in the device: 130 */ 131 __fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq); 132 } 133 134 static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info) 135 { 136 struct irq_chip *chip = info->chip; 137 138 if (!chip) 139 return; 140 141 /* 142 * irq_write_msi_msg should not be set by the caller 143 */ 144 if (!chip->irq_write_msi_msg) 145 chip->irq_write_msi_msg = fsl_mc_msi_write_msg; 146 } 147 148 /** 149 * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain 150 * @np: Optional device-tree node of the interrupt controller 151 * @info: MSI domain info 152 * @parent: Parent irq domain 153 * 154 * Updates the domain and chip ops and creates a fsl-mc MSI 155 * interrupt domain. 156 * 157 * Returns: 158 * A domain pointer or NULL in case of failure. 159 */ 160 struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode, 161 struct msi_domain_info *info, 162 struct irq_domain *parent) 163 { 164 struct irq_domain *domain; 165 166 if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE))) 167 info->flags &= ~MSI_FLAG_LEVEL_CAPABLE; 168 if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) 169 fsl_mc_msi_update_dom_ops(info); 170 if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) 171 fsl_mc_msi_update_chip_ops(info); 172 173 domain = msi_create_irq_domain(fwnode, info, parent); 174 if (domain) 175 irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI); 176 177 return domain; 178 } 179 180 int fsl_mc_find_msi_domain(struct device *mc_platform_dev, 181 struct irq_domain **mc_msi_domain) 182 { 183 struct irq_domain *msi_domain; 184 struct device_node *mc_of_node = mc_platform_dev->of_node; 185 186 msi_domain = of_msi_get_domain(mc_platform_dev, mc_of_node, 187 DOMAIN_BUS_FSL_MC_MSI); 188 if (!msi_domain) { 189 pr_err("Unable to find fsl-mc MSI domain for %pOF\n", 190 mc_of_node); 191 192 return -ENOENT; 193 } 194 195 *mc_msi_domain = msi_domain; 196 return 0; 197 } 198 199 static void fsl_mc_msi_free_descs(struct device *dev) 200 { 201 struct msi_desc *desc, *tmp; 202 203 list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) { 204 list_del(&desc->list); 205 free_msi_entry(desc); 206 } 207 } 208 209 static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count) 210 211 { 212 unsigned int i; 213 int error; 214 struct msi_desc *msi_desc; 215 216 for (i = 0; i < irq_count; i++) { 217 msi_desc = alloc_msi_entry(dev, 1, NULL); 218 if (!msi_desc) { 219 dev_err(dev, "Failed to allocate msi entry\n"); 220 error = -ENOMEM; 221 goto cleanup_msi_descs; 222 } 223 224 msi_desc->fsl_mc.msi_index = i; 225 INIT_LIST_HEAD(&msi_desc->list); 226 list_add_tail(&msi_desc->list, dev_to_msi_list(dev)); 227 } 228 229 return 0; 230 231 cleanup_msi_descs: 232 fsl_mc_msi_free_descs(dev); 233 return error; 234 } 235 236 int fsl_mc_msi_domain_alloc_irqs(struct device *dev, 237 unsigned int irq_count) 238 { 239 struct irq_domain *msi_domain; 240 int error; 241 242 if (!list_empty(dev_to_msi_list(dev))) 243 return -EINVAL; 244 245 error = fsl_mc_msi_alloc_descs(dev, irq_count); 246 if (error < 0) 247 return error; 248 249 msi_domain = dev_get_msi_domain(dev); 250 if (!msi_domain) { 251 error = -EINVAL; 252 goto cleanup_msi_descs; 253 } 254 255 /* 256 * NOTE: Calling this function will trigger the invocation of the 257 * its_fsl_mc_msi_prepare() callback 258 */ 259 error = msi_domain_alloc_irqs(msi_domain, dev, irq_count); 260 261 if (error) { 262 dev_err(dev, "Failed to allocate IRQs\n"); 263 goto cleanup_msi_descs; 264 } 265 266 return 0; 267 268 cleanup_msi_descs: 269 fsl_mc_msi_free_descs(dev); 270 return error; 271 } 272 273 void fsl_mc_msi_domain_free_irqs(struct device *dev) 274 { 275 struct irq_domain *msi_domain; 276 277 msi_domain = dev_get_msi_domain(dev); 278 if (!msi_domain) 279 return; 280 281 msi_domain_free_irqs(msi_domain, dev); 282 283 if (list_empty(dev_to_msi_list(dev))) 284 return; 285 286 fsl_mc_msi_free_descs(dev); 287 } 288