1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Re-map IO memory to kernel address space so that we can access it.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * These functions should only be used when it is necessary to map a
6*4882a593Smuzhiyun * physical address space into the kernel address space before ioremap()
7*4882a593Smuzhiyun * can be used, e.g. early in boot before paging_init().
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * Copyright (C) 2009 Matt Fleming
10*4882a593Smuzhiyun */
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/vmalloc.h>
13*4882a593Smuzhiyun #include <linux/ioport.h>
14*4882a593Smuzhiyun #include <linux/module.h>
15*4882a593Smuzhiyun #include <linux/mm.h>
16*4882a593Smuzhiyun #include <linux/io.h>
17*4882a593Smuzhiyun #include <linux/memblock.h>
18*4882a593Smuzhiyun #include <linux/proc_fs.h>
19*4882a593Smuzhiyun #include <asm/fixmap.h>
20*4882a593Smuzhiyun #include <asm/page.h>
21*4882a593Smuzhiyun #include <asm/addrspace.h>
22*4882a593Smuzhiyun #include <asm/cacheflush.h>
23*4882a593Smuzhiyun #include <asm/tlbflush.h>
24*4882a593Smuzhiyun #include <asm/mmu.h>
25*4882a593Smuzhiyun #include <asm/mmu_context.h>
26*4882a593Smuzhiyun #include "ioremap.h"
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun struct ioremap_map {
29*4882a593Smuzhiyun void __iomem *addr;
30*4882a593Smuzhiyun unsigned long size;
31*4882a593Smuzhiyun unsigned long fixmap_addr;
32*4882a593Smuzhiyun };
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS];
35*4882a593Smuzhiyun
ioremap_fixed_init(void)36*4882a593Smuzhiyun void __init ioremap_fixed_init(void)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun struct ioremap_map *map;
39*4882a593Smuzhiyun int i;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun for (i = 0; i < FIX_N_IOREMAPS; i++) {
42*4882a593Smuzhiyun map = &ioremap_maps[i];
43*4882a593Smuzhiyun map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i);
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun void __init __iomem *
ioremap_fixed(phys_addr_t phys_addr,unsigned long size,pgprot_t prot)48*4882a593Smuzhiyun ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun enum fixed_addresses idx0, idx;
51*4882a593Smuzhiyun struct ioremap_map *map;
52*4882a593Smuzhiyun unsigned int nrpages;
53*4882a593Smuzhiyun unsigned long offset;
54*4882a593Smuzhiyun int i, slot;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun /*
57*4882a593Smuzhiyun * Mappings have to be page-aligned
58*4882a593Smuzhiyun */
59*4882a593Smuzhiyun offset = phys_addr & ~PAGE_MASK;
60*4882a593Smuzhiyun phys_addr &= PAGE_MASK;
61*4882a593Smuzhiyun size = PAGE_ALIGN(phys_addr + size) - phys_addr;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun slot = -1;
64*4882a593Smuzhiyun for (i = 0; i < FIX_N_IOREMAPS; i++) {
65*4882a593Smuzhiyun map = &ioremap_maps[i];
66*4882a593Smuzhiyun if (!map->addr) {
67*4882a593Smuzhiyun map->size = size;
68*4882a593Smuzhiyun slot = i;
69*4882a593Smuzhiyun break;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun if (slot < 0)
74*4882a593Smuzhiyun return NULL;
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun /*
77*4882a593Smuzhiyun * Mappings have to fit in the FIX_IOREMAP area.
78*4882a593Smuzhiyun */
79*4882a593Smuzhiyun nrpages = size >> PAGE_SHIFT;
80*4882a593Smuzhiyun if (nrpages > FIX_N_IOREMAPS)
81*4882a593Smuzhiyun return NULL;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun /*
84*4882a593Smuzhiyun * Ok, go for it..
85*4882a593Smuzhiyun */
86*4882a593Smuzhiyun idx0 = FIX_IOREMAP_BEGIN + slot;
87*4882a593Smuzhiyun idx = idx0;
88*4882a593Smuzhiyun while (nrpages > 0) {
89*4882a593Smuzhiyun pgprot_val(prot) |= _PAGE_WIRED;
90*4882a593Smuzhiyun __set_fixmap(idx, phys_addr, prot);
91*4882a593Smuzhiyun phys_addr += PAGE_SIZE;
92*4882a593Smuzhiyun idx++;
93*4882a593Smuzhiyun --nrpages;
94*4882a593Smuzhiyun }
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun map->addr = (void __iomem *)(offset + map->fixmap_addr);
97*4882a593Smuzhiyun return map->addr;
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun
iounmap_fixed(void __iomem * addr)100*4882a593Smuzhiyun int iounmap_fixed(void __iomem *addr)
101*4882a593Smuzhiyun {
102*4882a593Smuzhiyun enum fixed_addresses idx;
103*4882a593Smuzhiyun struct ioremap_map *map;
104*4882a593Smuzhiyun unsigned int nrpages;
105*4882a593Smuzhiyun int i, slot;
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun slot = -1;
108*4882a593Smuzhiyun for (i = 0; i < FIX_N_IOREMAPS; i++) {
109*4882a593Smuzhiyun map = &ioremap_maps[i];
110*4882a593Smuzhiyun if (map->addr == addr) {
111*4882a593Smuzhiyun slot = i;
112*4882a593Smuzhiyun break;
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun /*
117*4882a593Smuzhiyun * If we don't match, it's not for us.
118*4882a593Smuzhiyun */
119*4882a593Smuzhiyun if (slot < 0)
120*4882a593Smuzhiyun return -EINVAL;
121*4882a593Smuzhiyun
122*4882a593Smuzhiyun nrpages = map->size >> PAGE_SHIFT;
123*4882a593Smuzhiyun
124*4882a593Smuzhiyun idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1;
125*4882a593Smuzhiyun while (nrpages > 0) {
126*4882a593Smuzhiyun __clear_fixmap(idx, __pgprot(_PAGE_WIRED));
127*4882a593Smuzhiyun --idx;
128*4882a593Smuzhiyun --nrpages;
129*4882a593Smuzhiyun }
130*4882a593Smuzhiyun
131*4882a593Smuzhiyun map->size = 0;
132*4882a593Smuzhiyun map->addr = NULL;
133*4882a593Smuzhiyun
134*4882a593Smuzhiyun return 0;
135*4882a593Smuzhiyun }
136