1 /*
2  * Support PCI IO workaround
3  *
4  *  Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
5  *		       IBM, Corp.
6  *  (C) Copyright 2007-2008 TOSHIBA CORPORATION
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 #undef DEBUG
13 
14 #include <linux/kernel.h>
15 #include <linux/sched.h>	/* for init_mm */
16 
17 #include <asm/io.h>
18 #include <asm/machdep.h>
19 #include <asm/pgtable.h>
20 #include <asm/ppc-pci.h>
21 #include <asm/io-workarounds.h>
22 
23 #define IOWA_MAX_BUS	8
24 
25 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
26 static unsigned int iowa_bus_count;
27 
28 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
29 {
30 	int i, j;
31 	struct resource *res;
32 	unsigned long vstart, vend;
33 
34 	for (i = 0; i < iowa_bus_count; i++) {
35 		struct iowa_bus *bus = &iowa_busses[i];
36 		struct pci_controller *phb = bus->phb;
37 
38 		if (vaddr) {
39 			vstart = (unsigned long)phb->io_base_virt;
40 			vend = vstart + phb->pci_io_size - 1;
41 			if ((vaddr >= vstart) && (vaddr <= vend))
42 				return bus;
43 		}
44 
45 		if (paddr)
46 			for (j = 0; j < 3; j++) {
47 				res = &phb->mem_resources[j];
48 				if (paddr >= res->start && paddr <= res->end)
49 					return bus;
50 			}
51 	}
52 
53 	return NULL;
54 }
55 
56 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
57 {
58 	struct iowa_bus *bus;
59 	int token;
60 
61 	token = PCI_GET_ADDR_TOKEN(addr);
62 
63 	if (token && token <= iowa_bus_count)
64 		bus = &iowa_busses[token - 1];
65 	else {
66 		unsigned long vaddr, paddr;
67 		pte_t *ptep;
68 
69 		vaddr = (unsigned long)PCI_FIX_ADDR(addr);
70 		if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
71 			return NULL;
72 
73 		ptep = find_linux_pte(init_mm.pgd, vaddr);
74 		if (ptep == NULL)
75 			paddr = 0;
76 		else
77 			paddr = pte_pfn(*ptep) << PAGE_SHIFT;
78 		bus = iowa_pci_find(vaddr, paddr);
79 
80 		if (bus == NULL)
81 			return NULL;
82 	}
83 
84 	return bus;
85 }
86 
87 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
88 {
89 	unsigned long vaddr = (unsigned long)pci_io_base + port;
90 	return iowa_pci_find(vaddr, 0);
91 }
92 
93 
94 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)		\
95 static ret iowa_##name at					\
96 {								\
97 	struct iowa_bus *bus;					\
98 	bus = iowa_##space##_find_bus(aa);			\
99 	if (bus && bus->ops && bus->ops->name)			\
100 		return bus->ops->name al;			\
101 	return __do_##name al;					\
102 }
103 
104 #define DEF_PCI_AC_NORET(name, at, al, space, aa)		\
105 static void iowa_##name at					\
106 {								\
107 	struct iowa_bus *bus;					\
108 	bus = iowa_##space##_find_bus(aa);			\
109 	if (bus && bus->ops && bus->ops->name) {		\
110 		bus->ops->name al;				\
111 		return;						\
112 	}							\
113 	__do_##name al;						\
114 }
115 
116 #include <asm/io-defs.h>
117 
118 #undef DEF_PCI_AC_RET
119 #undef DEF_PCI_AC_NORET
120 
121 static const struct ppc_pci_io __devinitconst iowa_pci_io = {
122 
123 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)	.name = iowa_##name,
124 #define DEF_PCI_AC_NORET(name, at, al, space, aa)	.name = iowa_##name,
125 
126 #include <asm/io-defs.h>
127 
128 #undef DEF_PCI_AC_RET
129 #undef DEF_PCI_AC_NORET
130 
131 };
132 
133 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
134 				  unsigned long flags, void *caller)
135 {
136 	struct iowa_bus *bus;
137 	void __iomem *res = __ioremap_caller(addr, size, flags, caller);
138 	int busno;
139 
140 	bus = iowa_pci_find(0, (unsigned long)addr);
141 	if (bus != NULL) {
142 		busno = bus - iowa_busses;
143 		PCI_SET_ADDR_TOKEN(res, busno + 1);
144 	}
145 	return res;
146 }
147 
148 /* Enable IO workaround */
149 static void __devinit io_workaround_init(void)
150 {
151 	static int io_workaround_inited;
152 
153 	if (io_workaround_inited)
154 		return;
155 	ppc_pci_io = iowa_pci_io;
156 	ppc_md.ioremap = iowa_ioremap;
157 	io_workaround_inited = 1;
158 }
159 
160 /* Register new bus to support workaround */
161 void __devinit iowa_register_bus(struct pci_controller *phb,
162 			struct ppc_pci_io *ops,
163 			int (*initfunc)(struct iowa_bus *, void *), void *data)
164 {
165 	struct iowa_bus *bus;
166 	struct device_node *np = phb->dn;
167 
168 	io_workaround_init();
169 
170 	if (iowa_bus_count >= IOWA_MAX_BUS) {
171 		pr_err("IOWA:Too many pci bridges, "
172 		       "workarounds disabled for %s\n", np->full_name);
173 		return;
174 	}
175 
176 	bus = &iowa_busses[iowa_bus_count];
177 	bus->phb = phb;
178 	bus->ops = ops;
179 	bus->private = data;
180 
181 	if (initfunc)
182 		if ((*initfunc)(bus, data))
183 			return;
184 
185 	iowa_bus_count++;
186 
187 	pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
188 }
189 
190