xref: /linux/arch/m68k/mm/sun3kmap.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
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/io.h>
19 #include <asm/sun3mmu.h>
20 
21 #include "../sun3/sun3.h"
22 
23 #undef SUN3_KMAP_DEBUG
24 
25 extern void mmu_emu_map_pmeg (int context, int vaddr);
26 
27 static inline void do_page_mapin(unsigned long phys, unsigned long virt,
28 				 unsigned long type)
29 {
30 	unsigned long pte;
31 	pte_t ptep;
32 
33 	ptep = pfn_pte(phys >> PAGE_SHIFT, PAGE_KERNEL);
34 	pte = pte_val(ptep);
35 	pte |= type;
36 
37 	sun3_put_pte(virt, pte);
38 
39 #ifdef SUN3_KMAP_DEBUG
40 	pr_info("mapin:");
41 	print_pte_vaddr(virt);
42 #endif
43 
44 }
45 
46 static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
47 				 unsigned long type, int pages)
48 {
49 
50 	if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
51 		mmu_emu_map_pmeg(sun3_get_context(), virt);
52 
53 	while(pages) {
54 		do_page_mapin(phys, virt, type);
55 		phys += PAGE_SIZE;
56 		virt += PAGE_SIZE;
57 		pages--;
58 	}
59 }
60 
61 void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
62 		   unsigned long type)
63 {
64 	struct vm_struct *area;
65 	unsigned long offset, virt, ret;
66 	int pages;
67 
68 	if(!size)
69 		return NULL;
70 
71 	/* page align */
72 	offset = phys & (PAGE_SIZE-1);
73 	phys &= ~(PAGE_SIZE-1);
74 
75 	size += offset;
76 	size = PAGE_ALIGN(size);
77 	if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
78 		return NULL;
79 
80 #ifdef SUN3_KMAP_DEBUG
81 	pr_info("ioremap: got virt %p size %lx(%lx)\n", area->addr, size,
82 		area->size);
83 #endif
84 
85 	pages = size / PAGE_SIZE;
86 	virt = (unsigned long)area->addr;
87 	ret = virt + offset;
88 
89 	while(pages) {
90 		int seg_pages;
91 
92 		seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
93 		if(seg_pages > pages)
94 			seg_pages = pages;
95 
96 		do_pmeg_mapin(phys, virt, type, seg_pages);
97 
98 		pages -= seg_pages;
99 		phys += seg_pages * PAGE_SIZE;
100 		virt += seg_pages * PAGE_SIZE;
101 	}
102 
103 	return (void __iomem *)ret;
104 
105 }
106 EXPORT_SYMBOL(sun3_ioremap);
107 
108 
109 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
110 {
111 
112 	return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
113 
114 }
115 EXPORT_SYMBOL(__ioremap);
116 
117 void iounmap(void __iomem *addr)
118 {
119 	vfree((void *)(PAGE_MASK & (unsigned long)addr));
120 }
121 EXPORT_SYMBOL(iounmap);
122 
123 /* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
124  * trapping the potential read fault.  Returns 0 if the access faulted,
125  * 1 on success.
126  *
127  * This function is primarily used to check addresses on the VME bus.
128  *
129  * Mucking with the page fault handler seems a little hackish to me, but
130  * SunOS, NetBSD, and Mach all implemented this check in such a manner,
131  * so I figure we're allowed.
132  */
133 int sun3_map_test(unsigned long addr, char *val)
134 {
135 	int ret = 0;
136 
137 	__asm__ __volatile__
138 		(".globl _sun3_map_test_start\n"
139 		 "_sun3_map_test_start:\n"
140 		 "1: moveb (%2), (%0)\n"
141 		 "   moveq #1, %1\n"
142 		 "2:\n"
143 		 ".section .fixup,\"ax\"\n"
144 		 ".even\n"
145 		 "3: moveq #0, %1\n"
146 		 "   jmp 2b\n"
147 		 ".previous\n"
148 		 ".section __ex_table,\"a\"\n"
149 		 ".align 4\n"
150 		 ".long 1b,3b\n"
151 		 ".previous\n"
152 		 ".globl _sun3_map_test_end\n"
153 		 "_sun3_map_test_end:\n"
154 		 : "=a"(val), "=r"(ret)
155 		 : "a"(addr));
156 
157 	return ret;
158 }
159 EXPORT_SYMBOL(sun3_map_test);
160