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 */
11static 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)					\
34int __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
42EARLY_PCI_OP(read, byte, u8 *)
43EARLY_PCI_OP(read, word, u16 *)
44EARLY_PCI_OP(read, dword, u32 *)
45EARLY_PCI_OP(write, byte, u8)
46EARLY_PCI_OP(write, word, u16)
47EARLY_PCI_OP(write, dword, u32)
48
49int __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
88static 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
97static 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
106void 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 */
121unsigned 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