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
25static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
26static unsigned int iowa_bus_count;
27
28static 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#ifdef CONFIG_PPC_INDIRECT_MMIO
57struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
58{
59	unsigned hugepage_shift;
60	struct iowa_bus *bus;
61	int token;
62
63	token = PCI_GET_ADDR_TOKEN(addr);
64
65	if (token && token <= iowa_bus_count)
66		bus = &iowa_busses[token - 1];
67	else {
68		unsigned long vaddr, paddr;
69		pte_t *ptep;
70
71		vaddr = (unsigned long)PCI_FIX_ADDR(addr);
72		if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
73			return NULL;
74		/*
75		 * We won't find huge pages here (iomem). Also can't hit
76		 * a page table free due to init_mm
77		 */
78		ptep = __find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
79						 &hugepage_shift);
80		if (ptep == NULL)
81			paddr = 0;
82		else {
83			WARN_ON(hugepage_shift);
84			paddr = pte_pfn(*ptep) << PAGE_SHIFT;
85		}
86		bus = iowa_pci_find(vaddr, paddr);
87
88		if (bus == NULL)
89			return NULL;
90	}
91
92	return bus;
93}
94#else /* CONFIG_PPC_INDIRECT_MMIO */
95struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
96{
97	return NULL;
98}
99#endif /* !CONFIG_PPC_INDIRECT_MMIO */
100
101#ifdef CONFIG_PPC_INDIRECT_PIO
102struct iowa_bus *iowa_pio_find_bus(unsigned long port)
103{
104	unsigned long vaddr = (unsigned long)pci_io_base + port;
105	return iowa_pci_find(vaddr, 0);
106}
107#else
108struct iowa_bus *iowa_pio_find_bus(unsigned long port)
109{
110	return NULL;
111}
112#endif
113
114#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)		\
115static ret iowa_##name at					\
116{								\
117	struct iowa_bus *bus;					\
118	bus = iowa_##space##_find_bus(aa);			\
119	if (bus && bus->ops && bus->ops->name)			\
120		return bus->ops->name al;			\
121	return __do_##name al;					\
122}
123
124#define DEF_PCI_AC_NORET(name, at, al, space, aa)		\
125static void iowa_##name at					\
126{								\
127	struct iowa_bus *bus;					\
128	bus = iowa_##space##_find_bus(aa);			\
129	if (bus && bus->ops && bus->ops->name) {		\
130		bus->ops->name al;				\
131		return;						\
132	}							\
133	__do_##name al;						\
134}
135
136#include <asm/io-defs.h>
137
138#undef DEF_PCI_AC_RET
139#undef DEF_PCI_AC_NORET
140
141static const struct ppc_pci_io iowa_pci_io = {
142
143#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)	.name = iowa_##name,
144#define DEF_PCI_AC_NORET(name, at, al, space, aa)	.name = iowa_##name,
145
146#include <asm/io-defs.h>
147
148#undef DEF_PCI_AC_RET
149#undef DEF_PCI_AC_NORET
150
151};
152
153#ifdef CONFIG_PPC_INDIRECT_MMIO
154static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
155				  unsigned long flags, void *caller)
156{
157	struct iowa_bus *bus;
158	void __iomem *res = __ioremap_caller(addr, size, flags, caller);
159	int busno;
160
161	bus = iowa_pci_find(0, (unsigned long)addr);
162	if (bus != NULL) {
163		busno = bus - iowa_busses;
164		PCI_SET_ADDR_TOKEN(res, busno + 1);
165	}
166	return res;
167}
168#else /* CONFIG_PPC_INDIRECT_MMIO */
169#define iowa_ioremap NULL
170#endif /* !CONFIG_PPC_INDIRECT_MMIO */
171
172/* Enable IO workaround */
173static void io_workaround_init(void)
174{
175	static int io_workaround_inited;
176
177	if (io_workaround_inited)
178		return;
179	ppc_pci_io = iowa_pci_io;
180	ppc_md.ioremap = iowa_ioremap;
181	io_workaround_inited = 1;
182}
183
184/* Register new bus to support workaround */
185void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
186		       int (*initfunc)(struct iowa_bus *, void *), void *data)
187{
188	struct iowa_bus *bus;
189	struct device_node *np = phb->dn;
190
191	io_workaround_init();
192
193	if (iowa_bus_count >= IOWA_MAX_BUS) {
194		pr_err("IOWA:Too many pci bridges, "
195		       "workarounds disabled for %s\n", np->full_name);
196		return;
197	}
198
199	bus = &iowa_busses[iowa_bus_count];
200	bus->phb = phb;
201	bus->ops = ops;
202	bus->private = data;
203
204	if (initfunc)
205		if ((*initfunc)(bus, data))
206			return;
207
208	iowa_bus_count++;
209
210	pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
211}
212
213