xref: /openbmc/linux/arch/sh/drivers/pci/common.c (revision 9cfc5c90)
1 #include <linux/pci.h>
2 #include <linux/interrupt.h>
3 #include <linux/timer.h>
4 #include <linux/kernel.h>
5 
6 /*
7  * These functions are used early on before PCI scanning is done
8  * and all of the pci_dev and pci_bus structures have been created.
9  */
10 static struct pci_dev *fake_pci_dev(struct pci_channel *hose,
11 	int top_bus, int busnr, int devfn)
12 {
13 	static struct pci_dev dev;
14 	static struct pci_bus bus;
15 
16 	dev.bus = &bus;
17 	dev.sysdata = hose;
18 	dev.devfn = devfn;
19 	bus.number = busnr;
20 	bus.sysdata = hose;
21 	bus.ops = hose->pci_ops;
22 
23 	if(busnr != top_bus)
24 		/* Fake a parent bus structure. */
25 		bus.parent = &bus;
26 	else
27 		bus.parent = NULL;
28 
29 	return &dev;
30 }
31 
32 #define EARLY_PCI_OP(rw, size, type)					\
33 int __init early_##rw##_config_##size(struct pci_channel *hose,		\
34 	int top_bus, int bus, int devfn, int offset, type value)	\
35 {									\
36 	return pci_##rw##_config_##size(				\
37 		fake_pci_dev(hose, top_bus, bus, devfn),		\
38 		offset, value);						\
39 }
40 
41 EARLY_PCI_OP(read, byte, u8 *)
42 EARLY_PCI_OP(read, word, u16 *)
43 EARLY_PCI_OP(read, dword, u32 *)
44 EARLY_PCI_OP(write, byte, u8)
45 EARLY_PCI_OP(write, word, u16)
46 EARLY_PCI_OP(write, dword, u32)
47 
48 int __init pci_is_66mhz_capable(struct pci_channel *hose,
49 				int top_bus, int current_bus)
50 {
51 	u32 pci_devfn;
52 	unsigned short vid;
53 	int cap66 = -1;
54 	u16 stat;
55 
56 	printk(KERN_INFO "PCI: Checking 66MHz capabilities...\n");
57 
58 	for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
59 		if (PCI_FUNC(pci_devfn))
60 			continue;
61 		if (early_read_config_word(hose, top_bus, current_bus,
62 					   pci_devfn, PCI_VENDOR_ID, &vid) !=
63 		    PCIBIOS_SUCCESSFUL)
64 			continue;
65 		if (vid == 0xffff)
66 			continue;
67 
68 		/* check 66MHz capability */
69 		if (cap66 < 0)
70 			cap66 = 1;
71 		if (cap66) {
72 			early_read_config_word(hose, top_bus, current_bus,
73 					       pci_devfn, PCI_STATUS, &stat);
74 			if (!(stat & PCI_STATUS_66MHZ)) {
75 				printk(KERN_DEBUG
76 				       "PCI: %02x:%02x not 66MHz capable.\n",
77 				       current_bus, pci_devfn);
78 				cap66 = 0;
79 				break;
80 			}
81 		}
82 	}
83 
84 	return cap66 > 0;
85 }
86 
87 static void pcibios_enable_err(unsigned long __data)
88 {
89 	struct pci_channel *hose = (struct pci_channel *)__data;
90 
91 	del_timer(&hose->err_timer);
92 	printk(KERN_DEBUG "PCI: re-enabling error IRQ.\n");
93 	enable_irq(hose->err_irq);
94 }
95 
96 static void pcibios_enable_serr(unsigned long __data)
97 {
98 	struct pci_channel *hose = (struct pci_channel *)__data;
99 
100 	del_timer(&hose->serr_timer);
101 	printk(KERN_DEBUG "PCI: re-enabling system error IRQ.\n");
102 	enable_irq(hose->serr_irq);
103 }
104 
105 void pcibios_enable_timers(struct pci_channel *hose)
106 {
107 	if (hose->err_irq) {
108 		init_timer(&hose->err_timer);
109 		hose->err_timer.data = (unsigned long)hose;
110 		hose->err_timer.function = pcibios_enable_err;
111 	}
112 
113 	if (hose->serr_irq) {
114 		init_timer(&hose->serr_timer);
115 		hose->serr_timer.data = (unsigned long)hose;
116 		hose->serr_timer.function = pcibios_enable_serr;
117 	}
118 }
119 
120 /*
121  * A simple handler for the regular PCI status errors, called from IRQ
122  * context.
123  */
124 unsigned int pcibios_handle_status_errors(unsigned long addr,
125 					  unsigned int status,
126 					  struct pci_channel *hose)
127 {
128 	unsigned int cmd = 0;
129 
130 	if (status & PCI_STATUS_REC_MASTER_ABORT) {
131 		printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n", addr);
132 		cmd |= PCI_STATUS_REC_MASTER_ABORT;
133 	}
134 
135 	if (status & PCI_STATUS_REC_TARGET_ABORT) {
136 		printk(KERN_DEBUG "PCI: target abort: ");
137 		pcibios_report_status(PCI_STATUS_REC_TARGET_ABORT |
138 				      PCI_STATUS_SIG_TARGET_ABORT |
139 				      PCI_STATUS_REC_MASTER_ABORT, 1);
140 		printk("\n");
141 
142 		cmd |= PCI_STATUS_REC_TARGET_ABORT;
143 	}
144 
145 	if (status & (PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY)) {
146 		printk(KERN_DEBUG "PCI: parity error detected: ");
147 		pcibios_report_status(PCI_STATUS_PARITY |
148 				      PCI_STATUS_DETECTED_PARITY, 1);
149 		printk("\n");
150 
151 		cmd |= PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY;
152 
153 		/* Now back off of the IRQ for awhile */
154 		if (hose->err_irq) {
155 			disable_irq_nosync(hose->err_irq);
156 			hose->err_timer.expires = jiffies + HZ;
157 			add_timer(&hose->err_timer);
158 		}
159 	}
160 
161 	return cmd;
162 }
163