1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2001 Dave Engebretsen, IBM Corporation 4 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM 5 * 6 * RTAS specific routines for PCI. 7 * 8 * Based on code from pci.c, chrp_pci.c and pSeries_pci.c 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/threads.h> 13 #include <linux/pci.h> 14 #include <linux/string.h> 15 #include <linux/init.h> 16 #include <linux/pgtable.h> 17 #include <linux/of_address.h> 18 #include <linux/of_fdt.h> 19 20 #include <asm/io.h> 21 #include <asm/irq.h> 22 #include <asm/machdep.h> 23 #include <asm/pci-bridge.h> 24 #include <asm/iommu.h> 25 #include <asm/rtas.h> 26 #include <asm/mpic.h> 27 #include <asm/ppc-pci.h> 28 #include <asm/eeh.h> 29 30 /* RTAS tokens */ 31 static int read_pci_config; 32 static int write_pci_config; 33 static int ibm_read_pci_config; 34 static int ibm_write_pci_config; 35 36 static inline int config_access_valid(struct pci_dn *dn, int where) 37 { 38 if (where < 256) 39 return 1; 40 if (where < 4096 && dn->pci_ext_config_space) 41 return 1; 42 43 return 0; 44 } 45 46 int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val) 47 { 48 int returnval = -1; 49 unsigned long buid, addr; 50 int ret; 51 52 if (!pdn) 53 return PCIBIOS_DEVICE_NOT_FOUND; 54 if (!config_access_valid(pdn, where)) 55 return PCIBIOS_BAD_REGISTER_NUMBER; 56 #ifdef CONFIG_EEH 57 if (pdn->edev && pdn->edev->pe && 58 (pdn->edev->pe->state & EEH_PE_CFG_BLOCKED)) 59 return PCIBIOS_SET_FAILED; 60 #endif 61 62 addr = rtas_config_addr(pdn->busno, pdn->devfn, where); 63 buid = pdn->phb->buid; 64 if (buid) { 65 ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval, 66 addr, BUID_HI(buid), BUID_LO(buid), size); 67 } else { 68 ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size); 69 } 70 *val = returnval; 71 72 if (ret) 73 return PCIBIOS_DEVICE_NOT_FOUND; 74 75 return PCIBIOS_SUCCESSFUL; 76 } 77 78 static int rtas_pci_read_config(struct pci_bus *bus, 79 unsigned int devfn, 80 int where, int size, u32 *val) 81 { 82 struct pci_dn *pdn; 83 int ret; 84 85 *val = 0xFFFFFFFF; 86 87 pdn = pci_get_pdn_by_devfn(bus, devfn); 88 89 /* Validity of pdn is checked in here */ 90 ret = rtas_read_config(pdn, where, size, val); 91 if (*val == EEH_IO_ERROR_VALUE(size) && 92 eeh_dev_check_failure(pdn_to_eeh_dev(pdn))) 93 return PCIBIOS_DEVICE_NOT_FOUND; 94 95 return ret; 96 } 97 98 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val) 99 { 100 unsigned long buid, addr; 101 int ret; 102 103 if (!pdn) 104 return PCIBIOS_DEVICE_NOT_FOUND; 105 if (!config_access_valid(pdn, where)) 106 return PCIBIOS_BAD_REGISTER_NUMBER; 107 #ifdef CONFIG_EEH 108 if (pdn->edev && pdn->edev->pe && 109 (pdn->edev->pe->state & EEH_PE_CFG_BLOCKED)) 110 return PCIBIOS_SET_FAILED; 111 #endif 112 113 addr = rtas_config_addr(pdn->busno, pdn->devfn, where); 114 buid = pdn->phb->buid; 115 if (buid) { 116 ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr, 117 BUID_HI(buid), BUID_LO(buid), size, (ulong) val); 118 } else { 119 ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val); 120 } 121 122 if (ret) 123 return PCIBIOS_DEVICE_NOT_FOUND; 124 125 return PCIBIOS_SUCCESSFUL; 126 } 127 128 static int rtas_pci_write_config(struct pci_bus *bus, 129 unsigned int devfn, 130 int where, int size, u32 val) 131 { 132 struct pci_dn *pdn; 133 134 pdn = pci_get_pdn_by_devfn(bus, devfn); 135 136 /* Validity of pdn is checked in here. */ 137 return rtas_write_config(pdn, where, size, val); 138 } 139 140 static struct pci_ops rtas_pci_ops = { 141 .read = rtas_pci_read_config, 142 .write = rtas_pci_write_config, 143 }; 144 145 static int is_python(struct device_node *dev) 146 { 147 const char *model = of_get_property(dev, "model", NULL); 148 149 if (model && strstr(model, "Python")) 150 return 1; 151 152 return 0; 153 } 154 155 static void python_countermeasures(struct device_node *dev) 156 { 157 struct resource registers; 158 void __iomem *chip_regs; 159 volatile u32 val; 160 161 if (of_address_to_resource(dev, 0, ®isters)) { 162 printk(KERN_ERR "Can't get address for Python workarounds !\n"); 163 return; 164 } 165 166 /* Python's register file is 1 MB in size. */ 167 chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000); 168 169 /* 170 * Firmware doesn't always clear this bit which is critical 171 * for good performance - Anton 172 */ 173 174 #define PRG_CL_RESET_VALID 0x00010000 175 176 val = in_be32(chip_regs + 0xf6030); 177 if (val & PRG_CL_RESET_VALID) { 178 printk(KERN_INFO "Python workaround: "); 179 val &= ~PRG_CL_RESET_VALID; 180 out_be32(chip_regs + 0xf6030, val); 181 /* 182 * We must read it back for changes to 183 * take effect 184 */ 185 val = in_be32(chip_regs + 0xf6030); 186 printk("reg0: %x\n", val); 187 } 188 189 iounmap(chip_regs); 190 } 191 192 void __init init_pci_config_tokens(void) 193 { 194 read_pci_config = rtas_token("read-pci-config"); 195 write_pci_config = rtas_token("write-pci-config"); 196 ibm_read_pci_config = rtas_token("ibm,read-pci-config"); 197 ibm_write_pci_config = rtas_token("ibm,write-pci-config"); 198 } 199 200 unsigned long get_phb_buid(struct device_node *phb) 201 { 202 struct resource r; 203 204 if (ibm_read_pci_config == -1) 205 return 0; 206 if (of_address_to_resource(phb, 0, &r)) 207 return 0; 208 return r.start; 209 } 210 211 static int phb_set_bus_ranges(struct device_node *dev, 212 struct pci_controller *phb) 213 { 214 const __be32 *bus_range; 215 unsigned int len; 216 217 bus_range = of_get_property(dev, "bus-range", &len); 218 if (bus_range == NULL || len < 2 * sizeof(int)) { 219 return 1; 220 } 221 222 phb->first_busno = be32_to_cpu(bus_range[0]); 223 phb->last_busno = be32_to_cpu(bus_range[1]); 224 225 return 0; 226 } 227 228 int rtas_setup_phb(struct pci_controller *phb) 229 { 230 struct device_node *dev = phb->dn; 231 232 if (is_python(dev)) 233 python_countermeasures(dev); 234 235 if (phb_set_bus_ranges(dev, phb)) 236 return 1; 237 238 phb->ops = &rtas_pci_ops; 239 phb->buid = get_phb_buid(dev); 240 241 return 0; 242 } 243