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 struct pci_config_window *cfg; 32 unsigned int bus_range, bus_range_max, bsz; 33 struct resource *conflict; 34 int i, err; 35 36 if (busr->start > busr->end) 37 return ERR_PTR(-EINVAL); 38 39 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 40 if (!cfg) 41 return ERR_PTR(-ENOMEM); 42 43 cfg->parent = dev; 44 cfg->ops = ops; 45 cfg->busr.start = busr->start; 46 cfg->busr.end = busr->end; 47 cfg->busr.flags = IORESOURCE_BUS; 48 bus_range = resource_size(&cfg->busr); 49 bus_range_max = resource_size(cfgres) >> ops->bus_shift; 50 if (bus_range > bus_range_max) { 51 bus_range = bus_range_max; 52 cfg->busr.end = busr->start + bus_range - 1; 53 dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n", 54 cfgres, &cfg->busr, busr); 55 } 56 bsz = 1 << ops->bus_shift; 57 58 cfg->res.start = cfgres->start; 59 cfg->res.end = cfgres->end; 60 cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; 61 cfg->res.name = "PCI ECAM"; 62 63 conflict = request_resource_conflict(&iomem_resource, &cfg->res); 64 if (conflict) { 65 err = -EBUSY; 66 dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n", 67 &cfg->res, conflict->name, conflict); 68 goto err_exit; 69 } 70 71 if (per_bus_mapping) { 72 cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL); 73 if (!cfg->winp) 74 goto err_exit_malloc; 75 for (i = 0; i < bus_range; i++) { 76 cfg->winp[i] = 77 pci_remap_cfgspace(cfgres->start + i * bsz, 78 bsz); 79 if (!cfg->winp[i]) 80 goto err_exit_iomap; 81 } 82 } else { 83 cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz); 84 if (!cfg->win) 85 goto err_exit_iomap; 86 } 87 88 if (ops->init) { 89 err = ops->init(cfg); 90 if (err) 91 goto err_exit; 92 } 93 dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr); 94 return cfg; 95 96 err_exit_iomap: 97 dev_err(dev, "ECAM ioremap failed\n"); 98 err_exit_malloc: 99 err = -ENOMEM; 100 err_exit: 101 pci_ecam_free(cfg); 102 return ERR_PTR(err); 103 } 104 EXPORT_SYMBOL_GPL(pci_ecam_create); 105 106 void pci_ecam_free(struct pci_config_window *cfg) 107 { 108 int i; 109 110 if (per_bus_mapping) { 111 if (cfg->winp) { 112 for (i = 0; i < resource_size(&cfg->busr); i++) 113 if (cfg->winp[i]) 114 iounmap(cfg->winp[i]); 115 kfree(cfg->winp); 116 } 117 } else { 118 if (cfg->win) 119 iounmap(cfg->win); 120 } 121 if (cfg->res.parent) 122 release_resource(&cfg->res); 123 kfree(cfg); 124 } 125 EXPORT_SYMBOL_GPL(pci_ecam_free); 126 127 /* 128 * Function to implement the pci_ops ->map_bus method 129 */ 130 void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn, 131 int where) 132 { 133 struct pci_config_window *cfg = bus->sysdata; 134 unsigned int devfn_shift = cfg->ops->bus_shift - 8; 135 unsigned int busn = bus->number; 136 void __iomem *base; 137 138 if (busn < cfg->busr.start || busn > cfg->busr.end) 139 return NULL; 140 141 busn -= cfg->busr.start; 142 if (per_bus_mapping) 143 base = cfg->winp[busn]; 144 else 145 base = cfg->win + (busn << cfg->ops->bus_shift); 146 return base + (devfn << devfn_shift) + where; 147 } 148 EXPORT_SYMBOL_GPL(pci_ecam_map_bus); 149 150 /* ECAM ops */ 151 const struct pci_ecam_ops pci_generic_ecam_ops = { 152 .bus_shift = 20, 153 .pci_ops = { 154 .map_bus = pci_ecam_map_bus, 155 .read = pci_generic_config_read, 156 .write = pci_generic_config_write, 157 } 158 }; 159 EXPORT_SYMBOL_GPL(pci_generic_ecam_ops); 160 161 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) 162 /* ECAM ops for 32-bit access only (non-compliant) */ 163 const struct pci_ecam_ops pci_32b_ops = { 164 .bus_shift = 20, 165 .pci_ops = { 166 .map_bus = pci_ecam_map_bus, 167 .read = pci_generic_config_read32, 168 .write = pci_generic_config_write32, 169 } 170 }; 171 #endif 172