xref: /linux/arch/powerpc/kernel/io-workarounds.c (revision 14b9f27886ce69c5f11445d107dd020f6fc5754b)
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 
16 #include <asm/io.h>
17 #include <asm/machdep.h>
18 #include <asm/pgtable.h>
19 #include <asm/ppc-pci.h>
20 #include <asm/io-workarounds.h>
21 
22 #define IOWA_MAX_BUS	8
23 
24 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
25 static unsigned int iowa_bus_count;
26 
27 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
28 {
29 	int i, j;
30 	struct resource *res;
31 	unsigned long vstart, vend;
32 
33 	for (i = 0; i < iowa_bus_count; i++) {
34 		struct iowa_bus *bus = &iowa_busses[i];
35 		struct pci_controller *phb = bus->phb;
36 
37 		if (vaddr) {
38 			vstart = (unsigned long)phb->io_base_virt;
39 			vend = vstart + phb->pci_io_size - 1;
40 			if ((vaddr >= vstart) && (vaddr <= vend))
41 				return bus;
42 		}
43 
44 		if (paddr)
45 			for (j = 0; j < 3; j++) {
46 				res = &phb->mem_resources[j];
47 				if (paddr >= res->start && paddr <= res->end)
48 					return bus;
49 			}
50 	}
51 
52 	return NULL;
53 }
54 
55 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
56 {
57 	struct iowa_bus *bus;
58 	int token;
59 
60 	token = PCI_GET_ADDR_TOKEN(addr);
61 
62 	if (token && token <= iowa_bus_count)
63 		bus = &iowa_busses[token - 1];
64 	else {
65 		unsigned long vaddr, paddr;
66 		pte_t *ptep;
67 
68 		vaddr = (unsigned long)PCI_FIX_ADDR(addr);
69 		if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
70 			return NULL;
71 
72 		ptep = find_linux_pte(init_mm.pgd, vaddr);
73 		if (ptep == NULL)
74 			paddr = 0;
75 		else
76 			paddr = pte_pfn(*ptep) << PAGE_SHIFT;
77 		bus = iowa_pci_find(vaddr, paddr);
78 
79 		if (bus == NULL)
80 			return NULL;
81 	}
82 
83 	return bus;
84 }
85 
86 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
87 {
88 	unsigned long vaddr = (unsigned long)pci_io_base + port;
89 	return iowa_pci_find(vaddr, 0);
90 }
91 
92 
93 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)		\
94 static ret iowa_##name at					\
95 {								\
96 	struct iowa_bus *bus;					\
97 	bus = iowa_##space##_find_bus(aa);			\
98 	if (bus && bus->ops && bus->ops->name)			\
99 		return bus->ops->name al;			\
100 	return __do_##name al;					\
101 }
102 
103 #define DEF_PCI_AC_NORET(name, at, al, space, aa)		\
104 static void iowa_##name at					\
105 {								\
106 	struct iowa_bus *bus;					\
107 	bus = iowa_##space##_find_bus(aa);			\
108 	if (bus && bus->ops && bus->ops->name) {		\
109 		bus->ops->name al;				\
110 		return;						\
111 	}							\
112 	__do_##name al;						\
113 }
114 
115 #include <asm/io-defs.h>
116 
117 #undef DEF_PCI_AC_RET
118 #undef DEF_PCI_AC_NORET
119 
120 static const struct ppc_pci_io __devinitconst iowa_pci_io = {
121 
122 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)	.name = iowa_##name,
123 #define DEF_PCI_AC_NORET(name, at, al, space, aa)	.name = iowa_##name,
124 
125 #include <asm/io-defs.h>
126 
127 #undef DEF_PCI_AC_RET
128 #undef DEF_PCI_AC_NORET
129 
130 };
131 
132 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
133 				  unsigned long flags, void *caller)
134 {
135 	struct iowa_bus *bus;
136 	void __iomem *res = __ioremap_caller(addr, size, flags, caller);
137 	int busno;
138 
139 	bus = iowa_pci_find(0, (unsigned long)addr);
140 	if (bus != NULL) {
141 		busno = bus - iowa_busses;
142 		PCI_SET_ADDR_TOKEN(res, busno + 1);
143 	}
144 	return res;
145 }
146 
147 /* Enable IO workaround */
148 static void __devinit io_workaround_init(void)
149 {
150 	static int io_workaround_inited;
151 
152 	if (io_workaround_inited)
153 		return;
154 	ppc_pci_io = iowa_pci_io;
155 	ppc_md.ioremap = iowa_ioremap;
156 	io_workaround_inited = 1;
157 }
158 
159 /* Register new bus to support workaround */
160 void __devinit iowa_register_bus(struct pci_controller *phb,
161 			struct ppc_pci_io *ops,
162 			int (*initfunc)(struct iowa_bus *, void *), void *data)
163 {
164 	struct iowa_bus *bus;
165 	struct device_node *np = phb->dn;
166 
167 	io_workaround_init();
168 
169 	if (iowa_bus_count >= IOWA_MAX_BUS) {
170 		pr_err("IOWA:Too many pci bridges, "
171 		       "workarounds disabled for %s\n", np->full_name);
172 		return;
173 	}
174 
175 	bus = &iowa_busses[iowa_bus_count];
176 	bus->phb = phb;
177 	bus->ops = ops;
178 	bus->private = data;
179 
180 	if (initfunc)
181 		if ((*initfunc)(bus, data))
182 			return;
183 
184 	iowa_bus_count++;
185 
186 	pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
187 }
188 
189