GNU Linux-libre 4.9.306-gnu1
[releases.git] / arch / m68k / mm / sun3kmap.c
1 /*
2  * linux/arch/m68k/mm/sun3kmap.c
3  *
4  * Copyright (C) 2002 Sam Creasey <sammy@sammy.net>
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive
8  * for more details.
9  */
10
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/vmalloc.h>
16
17 #include <asm/page.h>
18 #include <asm/pgtable.h>
19 #include <asm/io.h>
20 #include <asm/sun3mmu.h>
21
22 #undef SUN3_KMAP_DEBUG
23
24 #ifdef SUN3_KMAP_DEBUG
25 extern void print_pte_vaddr(unsigned long vaddr);
26 #endif
27
28 extern void mmu_emu_map_pmeg (int context, int vaddr);
29
30 static inline void do_page_mapin(unsigned long phys, unsigned long virt,
31                                  unsigned long type)
32 {
33         unsigned long pte;
34         pte_t ptep;
35
36         ptep = pfn_pte(phys >> PAGE_SHIFT, PAGE_KERNEL);
37         pte = pte_val(ptep);
38         pte |= type;
39
40         sun3_put_pte(virt, pte);
41
42 #ifdef SUN3_KMAP_DEBUG
43         print_pte_vaddr(virt);
44 #endif
45
46 }
47
48 static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
49                                  unsigned long type, int pages)
50 {
51
52         if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
53                 mmu_emu_map_pmeg(sun3_get_context(), virt);
54
55         while(pages) {
56                 do_page_mapin(phys, virt, type);
57                 phys += PAGE_SIZE;
58                 virt += PAGE_SIZE;
59                 pages--;
60         }
61 }
62
63 void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
64                    unsigned long type)
65 {
66         struct vm_struct *area;
67         unsigned long offset, virt, ret;
68         int pages;
69
70         if(!size)
71                 return NULL;
72
73         /* page align */
74         offset = phys & (PAGE_SIZE-1);
75         phys &= ~(PAGE_SIZE-1);
76
77         size += offset;
78         size = PAGE_ALIGN(size);
79         if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
80                 return NULL;
81
82 #ifdef SUN3_KMAP_DEBUG
83         printk("ioremap: got virt %p size %lx(%lx)\n",
84                area->addr, size, area->size);
85 #endif
86
87         pages = size / PAGE_SIZE;
88         virt = (unsigned long)area->addr;
89         ret = virt + offset;
90
91         while(pages) {
92                 int seg_pages;
93
94                 seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
95                 if(seg_pages > pages)
96                         seg_pages = pages;
97
98                 do_pmeg_mapin(phys, virt, type, seg_pages);
99
100                 pages -= seg_pages;
101                 phys += seg_pages * PAGE_SIZE;
102                 virt += seg_pages * PAGE_SIZE;
103         }
104
105         return (void __iomem *)ret;
106
107 }
108 EXPORT_SYMBOL(sun3_ioremap);
109
110
111 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
112 {
113
114         return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
115
116 }
117 EXPORT_SYMBOL(__ioremap);
118
119 void iounmap(void __iomem *addr)
120 {
121         vfree((void *)(PAGE_MASK & (unsigned long)addr));
122 }
123 EXPORT_SYMBOL(iounmap);
124
125 /* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
126  * trapping the potential read fault.  Returns 0 if the access faulted,
127  * 1 on success.
128  *
129  * This function is primarily used to check addresses on the VME bus.
130  *
131  * Mucking with the page fault handler seems a little hackish to me, but
132  * SunOS, NetBSD, and Mach all implemented this check in such a manner,
133  * so I figure we're allowed.
134  */
135 int sun3_map_test(unsigned long addr, char *val)
136 {
137         int ret = 0;
138
139         __asm__ __volatile__
140                 (".globl _sun3_map_test_start\n"
141                  "_sun3_map_test_start:\n"
142                  "1: moveb (%2), (%0)\n"
143                  "   moveq #1, %1\n"
144                  "2:\n"
145                  ".section .fixup,\"ax\"\n"
146                  ".even\n"
147                  "3: moveq #0, %1\n"
148                  "   jmp 2b\n"
149                  ".previous\n"
150                  ".section __ex_table,\"a\"\n"
151                  ".align 4\n"
152                  ".long 1b,3b\n"
153                  ".previous\n"
154                  ".globl _sun3_map_test_end\n"
155                  "_sun3_map_test_end:\n"
156                  : "=a"(val), "=r"(ret)
157                  : "a"(addr));
158
159         return ret;
160 }
161 EXPORT_SYMBOL(sun3_map_test);