xref: /openbmc/linux/arch/m68k/mm/sun3kmap.c (revision 4f3db074)
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);
162