1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2016 Broadcom 4 */ 5 6 #include <linux/device.h> 7 #include <linux/io.h> 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/pci.h> 11 #include <linux/pci-ecam.h> 12 #include <linux/slab.h> 13 14 /* 15 * On 64-bit systems, we do a single ioremap for the whole config space 16 * since we have enough virtual address range available. On 32-bit, we 17 * ioremap the config space for each bus individually. 18 */ 19 static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT); 20 21 /* 22 * Create a PCI config space window 23 * - reserve mem region 24 * - alloc struct pci_config_window with space for all mappings 25 * - ioremap the config space 26 */ 27 struct pci_config_window *pci_ecam_create(struct device *dev, 28 struct resource *cfgres, struct resource *busr, 29 const struct pci_ecam_ops *ops) 30 { 31 unsigned int bus_shift = ops->bus_shift; 32 struct pci_config_window *cfg; 33 unsigned int bus_range, bus_range_max, bsz; 34 struct resource *conflict; 35 int err; 36 37 if (busr->start > busr->end) 38 return ERR_PTR(-EINVAL); 39 40 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 41 if (!cfg) 42 return ERR_PTR(-ENOMEM); 43 44 /* ECAM-compliant platforms need not supply ops->bus_shift */ 45 if (!bus_shift) 46 bus_shift = PCIE_ECAM_BUS_SHIFT; 47 48 cfg->parent = dev; 49 cfg->ops = ops; 50 cfg->busr.start = busr->start; 51 cfg->busr.end = busr->end; 52 cfg->busr.flags = IORESOURCE_BUS; 53 cfg->bus_shift = bus_shift; 54 bus_range = resource_size(&cfg->busr); 55 bus_range_max = resource_size(cfgres) >> bus_shift; 56 if (bus_range > bus_range_max) { 57 bus_range = bus_range_max; 58 cfg->busr.end = busr->start + bus_range - 1; 59 dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n", 60 cfgres, &cfg->busr, busr); 61 } 62 bsz = 1 << bus_shift; 63 64 cfg->res.start = cfgres->start; 65 cfg->res.end = cfgres->end; 66 cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; 67 cfg->res.name = "PCI ECAM"; 68 69 conflict = request_resource_conflict(&iomem_resource, &cfg->res); 70 if (conflict) { 71 err = -EBUSY; 72 dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n", 73 &cfg->res, conflict->name, conflict); 74 goto err_exit; 75 } 76 77 if (per_bus_mapping) { 78 cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL); 79 if (!cfg->winp) 80 goto err_exit_malloc; 81 } else { 82 cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz); 83 if (!cfg->win) 84 goto err_exit_iomap; 85 } 86 87 if (ops->init) { 88 err = ops->init(cfg); 89 if (err) 90 goto err_exit; 91 } 92 dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr); 93 return cfg; 94 95 err_exit_iomap: 96 dev_err(dev, "ECAM ioremap failed\n"); 97 err_exit_malloc: 98 err = -ENOMEM; 99 err_exit: 100 pci_ecam_free(cfg); 101 return ERR_PTR(err); 102 } 103 EXPORT_SYMBOL_GPL(pci_ecam_create); 104 105 void pci_ecam_free(struct pci_config_window *cfg) 106 { 107 int i; 108 109 if (per_bus_mapping) { 110 if (cfg->winp) { 111 for (i = 0; i < resource_size(&cfg->busr); i++) 112 if (cfg->winp[i]) 113 iounmap(cfg->winp[i]); 114 kfree(cfg->winp); 115 } 116 } else { 117 if (cfg->win) 118 iounmap(cfg->win); 119 } 120 if (cfg->res.parent) 121 release_resource(&cfg->res); 122 kfree(cfg); 123 } 124 EXPORT_SYMBOL_GPL(pci_ecam_free); 125 126 static int pci_ecam_add_bus(struct pci_bus *bus) 127 { 128 struct pci_config_window *cfg = bus->sysdata; 129 unsigned int bsz = 1 << cfg->bus_shift; 130 unsigned int busn = bus->number; 131 phys_addr_t start; 132 133 if (!per_bus_mapping) 134 return 0; 135 136 if (busn < cfg->busr.start || busn > cfg->busr.end) 137 return -EINVAL; 138 139 busn -= cfg->busr.start; 140 start = cfg->res.start + busn * bsz; 141 142 cfg->winp[busn] = pci_remap_cfgspace(start, bsz); 143 if (!cfg->winp[busn]) 144 return -ENOMEM; 145 146 return 0; 147 } 148 149 static void pci_ecam_remove_bus(struct pci_bus *bus) 150 { 151 struct pci_config_window *cfg = bus->sysdata; 152 unsigned int busn = bus->number; 153 154 if (!per_bus_mapping || busn < cfg->busr.start || busn > cfg->busr.end) 155 return; 156 157 busn -= cfg->busr.start; 158 if (cfg->winp[busn]) { 159 iounmap(cfg->winp[busn]); 160 cfg->winp[busn] = NULL; 161 } 162 } 163 164 /* 165 * Function to implement the pci_ops ->map_bus method 166 */ 167 void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn, 168 int where) 169 { 170 struct pci_config_window *cfg = bus->sysdata; 171 unsigned int bus_shift = cfg->ops->bus_shift; 172 unsigned int devfn_shift = cfg->ops->bus_shift - 8; 173 unsigned int busn = bus->number; 174 void __iomem *base; 175 u32 bus_offset, devfn_offset; 176 177 if (busn < cfg->busr.start || busn > cfg->busr.end) 178 return NULL; 179 180 busn -= cfg->busr.start; 181 if (per_bus_mapping) { 182 base = cfg->winp[busn]; 183 busn = 0; 184 } else 185 base = cfg->win; 186 187 if (cfg->ops->bus_shift) { 188 bus_offset = (busn & PCIE_ECAM_BUS_MASK) << bus_shift; 189 devfn_offset = (devfn & PCIE_ECAM_DEVFN_MASK) << devfn_shift; 190 where &= PCIE_ECAM_REG_MASK; 191 192 return base + (bus_offset | devfn_offset | where); 193 } 194 195 return base + PCIE_ECAM_OFFSET(busn, devfn, where); 196 } 197 EXPORT_SYMBOL_GPL(pci_ecam_map_bus); 198 199 /* ECAM ops */ 200 const struct pci_ecam_ops pci_generic_ecam_ops = { 201 .pci_ops = { 202 .add_bus = pci_ecam_add_bus, 203 .remove_bus = pci_ecam_remove_bus, 204 .map_bus = pci_ecam_map_bus, 205 .read = pci_generic_config_read, 206 .write = pci_generic_config_write, 207 } 208 }; 209 EXPORT_SYMBOL_GPL(pci_generic_ecam_ops); 210 211 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) 212 /* ECAM ops for 32-bit access only (non-compliant) */ 213 const struct pci_ecam_ops pci_32b_ops = { 214 .pci_ops = { 215 .add_bus = pci_ecam_add_bus, 216 .remove_bus = pci_ecam_remove_bus, 217 .map_bus = pci_ecam_map_bus, 218 .read = pci_generic_config_read32, 219 .write = pci_generic_config_write32, 220 } 221 }; 222 223 /* ECAM ops for 32-bit read only (non-compliant) */ 224 const struct pci_ecam_ops pci_32b_read_ops = { 225 .pci_ops = { 226 .add_bus = pci_ecam_add_bus, 227 .remove_bus = pci_ecam_remove_bus, 228 .map_bus = pci_ecam_map_bus, 229 .read = pci_generic_config_read32, 230 .write = pci_generic_config_write, 231 } 232 }; 233 #endif 234