xref: /openbmc/linux/arch/m68k/mm/sun3kmap.c (revision e2c75e76)
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 	pr_info("mapin:");
44 	print_pte_vaddr(virt);
45 #endif
46 
47 }
48 
49 static inline void do_pmeg_mapin(unsigned long phys, unsigned long virt,
50 				 unsigned long type, int pages)
51 {
52 
53 	if(sun3_get_segmap(virt & ~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
54 		mmu_emu_map_pmeg(sun3_get_context(), virt);
55 
56 	while(pages) {
57 		do_page_mapin(phys, virt, type);
58 		phys += PAGE_SIZE;
59 		virt += PAGE_SIZE;
60 		pages--;
61 	}
62 }
63 
64 void __iomem *sun3_ioremap(unsigned long phys, unsigned long size,
65 		   unsigned long type)
66 {
67 	struct vm_struct *area;
68 	unsigned long offset, virt, ret;
69 	int pages;
70 
71 	if(!size)
72 		return NULL;
73 
74 	/* page align */
75 	offset = phys & (PAGE_SIZE-1);
76 	phys &= ~(PAGE_SIZE-1);
77 
78 	size += offset;
79 	size = PAGE_ALIGN(size);
80 	if((area = get_vm_area(size, VM_IOREMAP)) == NULL)
81 		return NULL;
82 
83 #ifdef SUN3_KMAP_DEBUG
84 	pr_info("ioremap: got virt %p size %lx(%lx)\n", area->addr, size,
85 		area->size);
86 #endif
87 
88 	pages = size / PAGE_SIZE;
89 	virt = (unsigned long)area->addr;
90 	ret = virt + offset;
91 
92 	while(pages) {
93 		int seg_pages;
94 
95 		seg_pages = (SUN3_PMEG_SIZE - (virt & SUN3_PMEG_MASK)) / PAGE_SIZE;
96 		if(seg_pages > pages)
97 			seg_pages = pages;
98 
99 		do_pmeg_mapin(phys, virt, type, seg_pages);
100 
101 		pages -= seg_pages;
102 		phys += seg_pages * PAGE_SIZE;
103 		virt += seg_pages * PAGE_SIZE;
104 	}
105 
106 	return (void __iomem *)ret;
107 
108 }
109 EXPORT_SYMBOL(sun3_ioremap);
110 
111 
112 void __iomem *__ioremap(unsigned long phys, unsigned long size, int cache)
113 {
114 
115 	return sun3_ioremap(phys, size, SUN3_PAGE_TYPE_IO);
116 
117 }
118 EXPORT_SYMBOL(__ioremap);
119 
120 void iounmap(void __iomem *addr)
121 {
122 	vfree((void *)(PAGE_MASK & (unsigned long)addr));
123 }
124 EXPORT_SYMBOL(iounmap);
125 
126 /* sun3_map_test(addr, val) -- Reads a byte from addr, storing to val,
127  * trapping the potential read fault.  Returns 0 if the access faulted,
128  * 1 on success.
129  *
130  * This function is primarily used to check addresses on the VME bus.
131  *
132  * Mucking with the page fault handler seems a little hackish to me, but
133  * SunOS, NetBSD, and Mach all implemented this check in such a manner,
134  * so I figure we're allowed.
135  */
136 int sun3_map_test(unsigned long addr, char *val)
137 {
138 	int ret = 0;
139 
140 	__asm__ __volatile__
141 		(".globl _sun3_map_test_start\n"
142 		 "_sun3_map_test_start:\n"
143 		 "1: moveb (%2), (%0)\n"
144 		 "   moveq #1, %1\n"
145 		 "2:\n"
146 		 ".section .fixup,\"ax\"\n"
147 		 ".even\n"
148 		 "3: moveq #0, %1\n"
149 		 "   jmp 2b\n"
150 		 ".previous\n"
151 		 ".section __ex_table,\"a\"\n"
152 		 ".align 4\n"
153 		 ".long 1b,3b\n"
154 		 ".previous\n"
155 		 ".globl _sun3_map_test_end\n"
156 		 "_sun3_map_test_end:\n"
157 		 : "=a"(val), "=r"(ret)
158 		 : "a"(addr));
159 
160 	return ret;
161 }
162 EXPORT_SYMBOL(sun3_map_test);
163