1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support PCI IO workaround
4 *
5 *  Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
6 *		       IBM, Corp.
7 *  (C) Copyright 2007-2008 TOSHIBA CORPORATION
8 */
9#undef DEBUG
10
11#include <linux/kernel.h>
12#include <linux/sched/mm.h>	/* for init_mm */
13#include <linux/pgtable.h>
14
15#include <asm/io.h>
16#include <asm/machdep.h>
17#include <asm/ppc-pci.h>
18#include <asm/io-workarounds.h>
19#include <asm/pte-walk.h>
20
21
22#define IOWA_MAX_BUS	8
23
24static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
25static unsigned int iowa_bus_count;
26
27static 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#ifdef CONFIG_PPC_INDIRECT_MMIO
56struct 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
68		vaddr = (unsigned long)PCI_FIX_ADDR(addr);
69		if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
70			return NULL;
71
72		paddr = ppc_find_vmap_phys(vaddr);
73
74		bus = iowa_pci_find(vaddr, paddr);
75
76		if (bus == NULL)
77			return NULL;
78	}
79
80	return bus;
81}
82#else /* CONFIG_PPC_INDIRECT_MMIO */
83struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
84{
85	return NULL;
86}
87#endif /* !CONFIG_PPC_INDIRECT_MMIO */
88
89#ifdef CONFIG_PPC_INDIRECT_PIO
90struct iowa_bus *iowa_pio_find_bus(unsigned long port)
91{
92	unsigned long vaddr = (unsigned long)pci_io_base + port;
93	return iowa_pci_find(vaddr, 0);
94}
95#else
96struct iowa_bus *iowa_pio_find_bus(unsigned long port)
97{
98	return NULL;
99}
100#endif
101
102#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)		\
103static ret iowa_##name at					\
104{								\
105	struct iowa_bus *bus;					\
106	bus = iowa_##space##_find_bus(aa);			\
107	if (bus && bus->ops && bus->ops->name)			\
108		return bus->ops->name al;			\
109	return __do_##name al;					\
110}
111
112#define DEF_PCI_AC_NORET(name, at, al, space, aa)		\
113static void iowa_##name at					\
114{								\
115	struct iowa_bus *bus;					\
116	bus = iowa_##space##_find_bus(aa);			\
117	if (bus && bus->ops && bus->ops->name) {		\
118		bus->ops->name al;				\
119		return;						\
120	}							\
121	__do_##name al;						\
122}
123
124#include <asm/io-defs.h>
125
126#undef DEF_PCI_AC_RET
127#undef DEF_PCI_AC_NORET
128
129static const struct ppc_pci_io iowa_pci_io = {
130
131#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)	.name = iowa_##name,
132#define DEF_PCI_AC_NORET(name, at, al, space, aa)	.name = iowa_##name,
133
134#include <asm/io-defs.h>
135
136#undef DEF_PCI_AC_RET
137#undef DEF_PCI_AC_NORET
138
139};
140
141#ifdef CONFIG_PPC_INDIRECT_MMIO
142void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
143			   pgprot_t prot, void *caller)
144{
145	struct iowa_bus *bus;
146	void __iomem *res = __ioremap_caller(addr, size, prot, caller);
147	int busno;
148
149	bus = iowa_pci_find(0, (unsigned long)addr);
150	if (bus != NULL) {
151		busno = bus - iowa_busses;
152		PCI_SET_ADDR_TOKEN(res, busno + 1);
153	}
154	return res;
155}
156#endif /* !CONFIG_PPC_INDIRECT_MMIO */
157
158bool io_workaround_inited;
159
160/* Enable IO workaround */
161static void io_workaround_init(void)
162{
163	if (io_workaround_inited)
164		return;
165	ppc_pci_io = iowa_pci_io;
166	io_workaround_inited = true;
167}
168
169/* Register new bus to support workaround */
170void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
171		       int (*initfunc)(struct iowa_bus *, void *), void *data)
172{
173	struct iowa_bus *bus;
174	struct device_node *np = phb->dn;
175
176	io_workaround_init();
177
178	if (iowa_bus_count >= IOWA_MAX_BUS) {
179		pr_err("IOWA:Too many pci bridges, "
180		       "workarounds disabled for %pOF\n", np);
181		return;
182	}
183
184	bus = &iowa_busses[iowa_bus_count];
185	bus->phb = phb;
186	bus->ops = ops;
187	bus->private = data;
188
189	if (initfunc)
190		if ((*initfunc)(bus, data))
191			return;
192
193	iowa_bus_count++;
194
195	pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);
196}
197
198