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 */
fake_pci_dev(struct pci_channel * hose,int top_bus,int busnr,int devfn)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
EARLY_PCI_OP(read,byte,u8 *)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 unsigned short vid;
54 int cap66 = -1;
55 u16 stat;
56
57 pr_info("PCI: Checking 66MHz capabilities...\n");
58
59 for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
60 if (PCI_FUNC(pci_devfn))
61 continue;
62 if (early_read_config_word(hose, top_bus, current_bus,
63 pci_devfn, PCI_VENDOR_ID, &vid) !=
64 PCIBIOS_SUCCESSFUL)
65 continue;
66 if (vid == 0xffff)
67 continue;
68
69 /* check 66MHz capability */
70 if (cap66 < 0)
71 cap66 = 1;
72 if (cap66) {
73 early_read_config_word(hose, top_bus, current_bus,
74 pci_devfn, PCI_STATUS, &stat);
75 if (!(stat & PCI_STATUS_66MHZ)) {
76 printk(KERN_DEBUG
77 "PCI: %02x:%02x not 66MHz capable.\n",
78 current_bus, pci_devfn);
79 cap66 = 0;
80 break;
81 }
82 }
83 }
84
85 return cap66 > 0;
86 }
87
pcibios_enable_err(struct timer_list * t)88 static void pcibios_enable_err(struct timer_list *t)
89 {
90 struct pci_channel *hose = from_timer(hose, t, err_timer);
91
92 del_timer(&hose->err_timer);
93 printk(KERN_DEBUG "PCI: re-enabling error IRQ.\n");
94 enable_irq(hose->err_irq);
95 }
96
pcibios_enable_serr(struct timer_list * t)97 static void pcibios_enable_serr(struct timer_list *t)
98 {
99 struct pci_channel *hose = from_timer(hose, t, serr_timer);
100
101 del_timer(&hose->serr_timer);
102 printk(KERN_DEBUG "PCI: re-enabling system error IRQ.\n");
103 enable_irq(hose->serr_irq);
104 }
105
pcibios_enable_timers(struct pci_channel * hose)106 void pcibios_enable_timers(struct pci_channel *hose)
107 {
108 if (hose->err_irq) {
109 timer_setup(&hose->err_timer, pcibios_enable_err, 0);
110 }
111
112 if (hose->serr_irq) {
113 timer_setup(&hose->serr_timer, pcibios_enable_serr, 0);
114 }
115 }
116
117 /*
118 * A simple handler for the regular PCI status errors, called from IRQ
119 * context.
120 */
pcibios_handle_status_errors(unsigned long addr,unsigned int status,struct pci_channel * hose)121 unsigned int pcibios_handle_status_errors(unsigned long addr,
122 unsigned int status,
123 struct pci_channel *hose)
124 {
125 unsigned int cmd = 0;
126
127 if (status & PCI_STATUS_REC_MASTER_ABORT) {
128 printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n", addr);
129 cmd |= PCI_STATUS_REC_MASTER_ABORT;
130 }
131
132 if (status & PCI_STATUS_REC_TARGET_ABORT) {
133 printk(KERN_DEBUG "PCI: target abort: ");
134 pcibios_report_status(PCI_STATUS_REC_TARGET_ABORT |
135 PCI_STATUS_SIG_TARGET_ABORT |
136 PCI_STATUS_REC_MASTER_ABORT, 1);
137 pr_cont("\n");
138
139 cmd |= PCI_STATUS_REC_TARGET_ABORT;
140 }
141
142 if (status & (PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY)) {
143 printk(KERN_DEBUG "PCI: parity error detected: ");
144 pcibios_report_status(PCI_STATUS_PARITY |
145 PCI_STATUS_DETECTED_PARITY, 1);
146 pr_cont("\n");
147
148 cmd |= PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY;
149
150 /* Now back off of the IRQ for awhile */
151 if (hose->err_irq) {
152 disable_irq_nosync(hose->err_irq);
153 hose->err_timer.expires = jiffies + HZ;
154 add_timer(&hose->err_timer);
155 }
156 }
157
158 return cmd;
159 }
160