1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/pci.h> 3 #include <linux/interrupt.h> 4 #include <linux/timer.h> 5 #include <linux/kernel.h> 6 7 /* 8 * These functions are used early on before PCI scanning is done 9 * and all of the pci_dev and pci_bus structures have been created. 10 */ 11 static struct pci_dev *fake_pci_dev(struct pci_channel *hose, 12 int top_bus, int busnr, int devfn) 13 { 14 static struct pci_dev dev; 15 static struct pci_bus bus; 16 17 dev.bus = &bus; 18 dev.sysdata = hose; 19 dev.devfn = devfn; 20 bus.number = busnr; 21 bus.sysdata = hose; 22 bus.ops = hose->pci_ops; 23 24 if(busnr != top_bus) 25 /* Fake a parent bus structure. */ 26 bus.parent = &bus; 27 else 28 bus.parent = NULL; 29 30 return &dev; 31 } 32 33 #define EARLY_PCI_OP(rw, size, type) \ 34 int __init early_##rw##_config_##size(struct pci_channel *hose, \ 35 int top_bus, int bus, int devfn, int offset, type value) \ 36 { \ 37 return pci_##rw##_config_##size( \ 38 fake_pci_dev(hose, top_bus, bus, devfn), \ 39 offset, value); \ 40 } 41 42 EARLY_PCI_OP(read, byte, u8 *) 43 EARLY_PCI_OP(read, word, u16 *) 44 EARLY_PCI_OP(read, dword, u32 *) 45 EARLY_PCI_OP(write, byte, u8) 46 EARLY_PCI_OP(write, word, u16) 47 EARLY_PCI_OP(write, dword, u32) 48 49 int __init pci_is_66mhz_capable(struct pci_channel *hose, 50 int top_bus, int current_bus) 51 { 52 u32 pci_devfn; 53 u16 vid; 54 int cap66 = -1; 55 u16 stat; 56 int ret; 57 58 pr_info("PCI: Checking 66MHz capabilities...\n"); 59 60 for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) { 61 if (PCI_FUNC(pci_devfn)) 62 continue; 63 ret = early_read_config_word(hose, top_bus, current_bus, 64 pci_devfn, PCI_VENDOR_ID, &vid); 65 if (ret != PCIBIOS_SUCCESSFUL) 66 continue; 67 if (PCI_POSSIBLE_ERROR(vid)) 68 continue; 69 70 /* check 66MHz capability */ 71 if (cap66 < 0) 72 cap66 = 1; 73 if (cap66) { 74 early_read_config_word(hose, top_bus, current_bus, 75 pci_devfn, PCI_STATUS, &stat); 76 if (!(stat & PCI_STATUS_66MHZ)) { 77 printk(KERN_DEBUG 78 "PCI: %02x:%02x not 66MHz capable.\n", 79 current_bus, pci_devfn); 80 cap66 = 0; 81 break; 82 } 83 } 84 } 85 86 return cap66 > 0; 87 } 88 89 static void pcibios_enable_err(struct timer_list *t) 90 { 91 struct pci_channel *hose = from_timer(hose, t, err_timer); 92 93 del_timer(&hose->err_timer); 94 printk(KERN_DEBUG "PCI: re-enabling error IRQ.\n"); 95 enable_irq(hose->err_irq); 96 } 97 98 static void pcibios_enable_serr(struct timer_list *t) 99 { 100 struct pci_channel *hose = from_timer(hose, t, serr_timer); 101 102 del_timer(&hose->serr_timer); 103 printk(KERN_DEBUG "PCI: re-enabling system error IRQ.\n"); 104 enable_irq(hose->serr_irq); 105 } 106 107 void pcibios_enable_timers(struct pci_channel *hose) 108 { 109 if (hose->err_irq) { 110 timer_setup(&hose->err_timer, pcibios_enable_err, 0); 111 } 112 113 if (hose->serr_irq) { 114 timer_setup(&hose->serr_timer, pcibios_enable_serr, 0); 115 } 116 } 117 118 /* 119 * A simple handler for the regular PCI status errors, called from IRQ 120 * context. 121 */ 122 unsigned int pcibios_handle_status_errors(unsigned long addr, 123 unsigned int status, 124 struct pci_channel *hose) 125 { 126 unsigned int cmd = 0; 127 128 if (status & PCI_STATUS_REC_MASTER_ABORT) { 129 printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n", addr); 130 cmd |= PCI_STATUS_REC_MASTER_ABORT; 131 } 132 133 if (status & PCI_STATUS_REC_TARGET_ABORT) { 134 printk(KERN_DEBUG "PCI: target abort: "); 135 pcibios_report_status(PCI_STATUS_REC_TARGET_ABORT | 136 PCI_STATUS_SIG_TARGET_ABORT | 137 PCI_STATUS_REC_MASTER_ABORT, 1); 138 pr_cont("\n"); 139 140 cmd |= PCI_STATUS_REC_TARGET_ABORT; 141 } 142 143 if (status & (PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY)) { 144 printk(KERN_DEBUG "PCI: parity error detected: "); 145 pcibios_report_status(PCI_STATUS_PARITY | 146 PCI_STATUS_DETECTED_PARITY, 1); 147 pr_cont("\n"); 148 149 cmd |= PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY; 150 151 /* Now back off of the IRQ for awhile */ 152 if (hose->err_irq) { 153 disable_irq_nosync(hose->err_irq); 154 hose->err_timer.expires = jiffies + HZ; 155 add_timer(&hose->err_timer); 156 } 157 } 158 159 return cmd; 160 } 161