summaryrefslogtreecommitdiff
path: root/arch/m68k/mm/motorola.c
blob: 7cb72dbc2eaa78bdfeb0eaed19d2fd91b6888b39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
/*
 * linux/arch/m68k/mm/motorola.c
 *
 * Routines specific to the Motorola MMU, originally from:
 * linux/arch/m68k/init.c
 * which are Copyright (C) 1995 Hamish Macdonald
 *
 * Moved 8/20/1999 Sam Creasey
 */

#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/gfp.h>

#include <asm/setup.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/dma.h>
#ifdef CONFIG_ATARI
#include <asm/atari_stram.h>
#endif
#include <asm/sections.h>

#undef DEBUG

#ifndef mm_cachebits
/*
 * Bits to add to page descriptors for "normal" caching mode.
 * For 68020/030 this is 0.
 * For 68040, this is _PAGE_CACHE040 (cachable, copyback)
 */
unsigned long mm_cachebits;
EXPORT_SYMBOL(mm_cachebits);
#endif

/* size of memory already mapped in head.S */
extern __initdata unsigned long m68k_init_mapped_size;

extern unsigned long availmem;

static pte_t * __init kernel_page_table(void)
{
	pte_t *ptablep;

	ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);

	clear_page(ptablep);
	__flush_page_to_ram(ptablep);
	flush_tlb_kernel_page(ptablep);
	nocache_page(ptablep);

	return ptablep;
}

static pmd_t *last_pgtable __initdata = NULL;
pmd_t *zero_pgtable __initdata = NULL;

static pmd_t * __init kernel_ptr_table(void)
{
	if (!last_pgtable) {
		unsigned long pmd, last;
		int i;

		/* Find the last ptr table that was used in head.S and
		 * reuse the remaining space in that page for further
		 * ptr tables.
		 */
		last = (unsigned long)kernel_pg_dir;
		for (i = 0; i < PTRS_PER_PGD; i++) {
			if (!pgd_present(kernel_pg_dir[i]))
				continue;
			pmd = __pgd_page(kernel_pg_dir[i]);
			if (pmd > last)
				last = pmd;
		}

		last_pgtable = (pmd_t *)last;
#ifdef DEBUG
		printk("kernel_ptr_init: %p\n", last_pgtable);
#endif
	}

	last_pgtable += PTRS_PER_PMD;
	if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
		last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);

		clear_page(last_pgtable);
		__flush_page_to_ram(last_pgtable);
		flush_tlb_kernel_page(last_pgtable);
		nocache_page(last_pgtable);
	}

	return last_pgtable;
}

static void __init map_node(int node)
{
#define PTRTREESIZE (256*1024)
#define ROOTTREESIZE (32*1024*1024)
	unsigned long physaddr, virtaddr, size;
	pgd_t *pgd_dir;
	pmd_t *pmd_dir;
	pte_t *pte_dir;

	size = m68k_memory[node].size;
	physaddr = m68k_memory[node].addr;
	virtaddr = (unsigned long)phys_to_virt(physaddr);
	physaddr |= m68k_supervisor_cachemode |
		    _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
	if (CPU_IS_040_OR_060)
		physaddr |= _PAGE_GLOBAL040;

	while (size > 0) {
#ifdef DEBUG
		if (!(virtaddr & (PTRTREESIZE-1)))
			printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
				virtaddr);
#endif
		pgd_dir = pgd_offset_k(virtaddr);
		if (virtaddr && CPU_IS_020_OR_030) {
			if (!(virtaddr & (ROOTTREESIZE-1)) &&
			    size >= ROOTTREESIZE) {
#ifdef DEBUG
				printk ("[very early term]");
#endif
				pgd_val(*pgd_dir) = physaddr;
				size -= ROOTTREESIZE;
				virtaddr += ROOTTREESIZE;
				physaddr += ROOTTREESIZE;
				continue;
			}
		}
		if (!pgd_present(*pgd_dir)) {
			pmd_dir = kernel_ptr_table();
#ifdef DEBUG
			printk ("[new pointer %p]", pmd_dir);
#endif
			pgd_set(pgd_dir, pmd_dir);
		} else
			pmd_dir = pmd_offset(pgd_dir, virtaddr);

		if (CPU_IS_020_OR_030) {
			if (virtaddr) {
#ifdef DEBUG
				printk ("[early term]");
#endif
				pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
				physaddr += PTRTREESIZE;
			} else {
				int i;
#ifdef DEBUG
				printk ("[zero map]");
#endif
				zero_pgtable = kernel_ptr_table();
				pte_dir = (pte_t *)zero_pgtable;
				pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
					_PAGE_TABLE | _PAGE_ACCESSED;
				pte_val(*pte_dir++) = 0;
				physaddr += PAGE_SIZE;
				for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
					pte_val(*pte_dir++) = physaddr;
			}
			size -= PTRTREESIZE;
			virtaddr += PTRTREESIZE;
		} else {
			if (!pmd_present(*pmd_dir)) {
#ifdef DEBUG
				printk ("[new table]");
#endif
				pte_dir = kernel_page_table();
				pmd_set(pmd_dir, pte_dir);
			}
			pte_dir = pte_offset_kernel(pmd_dir, virtaddr);

			if (virtaddr) {
				if (!pte_present(*pte_dir))
					pte_val(*pte_dir) = physaddr;
			} else
				pte_val(*pte_dir) = 0;
			size -= PAGE_SIZE;
			virtaddr += PAGE_SIZE;
			physaddr += PAGE_SIZE;
		}

	}
#ifdef DEBUG
	printk("\n");
#endif
}

/*
 * paging_init() continues the virtual memory environment setup which
 * was begun by the code in arch/head.S.
 */
void __init paging_init(void)
{
	unsigned long zones_size[MAX_NR_ZONES] = { 0, };
	unsigned long min_addr, max_addr;
	unsigned long addr, size, end;
	int i;

#ifdef DEBUG
	printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
#endif

	/* Fix the cache mode in the page descriptors for the 680[46]0.  */
	if (CPU_IS_040_OR_060) {
		int i;
#ifndef mm_cachebits
		mm_cachebits = _PAGE_CACHE040;
#endif
		for (i = 0; i < 16; i++)
			pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
	}

	min_addr = m68k_memory[0].addr;
	max_addr = min_addr + m68k_memory[0].size;
	for (i = 1; i < m68k_num_memory;) {
		if (m68k_memory[i].addr < min_addr) {
			printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
				m68k_memory[i].addr, m68k_memory[i].size);
			printk("Fix your bootloader or use a memfile to make use of this area!\n");
			m68k_num_memory--;
			memmove(m68k_memory + i, m68k_memory + i + 1,
				(m68k_num_memory - i) * sizeof(struct m68k_mem_info));
			continue;
		}
		addr = m68k_memory[i].addr + m68k_memory[i].size;
		if (addr > max_addr)
			max_addr = addr;
		i++;
	}
	m68k_memoffset = min_addr - PAGE_OFFSET;
	m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;

	module_fixup(NULL, __start_fixup, __stop_fixup);
	flush_icache();

	high_memory = phys_to_virt(max_addr);

	min_low_pfn = availmem >> PAGE_SHIFT;
	max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;

	for (i = 0; i < m68k_num_memory; i++) {
		addr = m68k_memory[i].addr;
		end = addr + m68k_memory[i].size;
		m68k_setup_node(i);
		availmem = PAGE_ALIGN(availmem);
		availmem += init_bootmem_node(NODE_DATA(i),
					      availmem >> PAGE_SHIFT,
					      addr >> PAGE_SHIFT,
					      end >> PAGE_SHIFT);
	}

	/*
	 * Map the physical memory available into the kernel virtual
	 * address space. First initialize the bootmem allocator with
	 * the memory we already mapped, so map_node() has something
	 * to allocate.
	 */
	addr = m68k_memory[0].addr;
	size = m68k_memory[0].size;
	free_bootmem_node(NODE_DATA(0), availmem,
			  min(m68k_init_mapped_size, size) - (availmem - addr));
	map_node(0);
	if (size > m68k_init_mapped_size)
		free_bootmem_node(NODE_DATA(0), addr + m68k_init_mapped_size,
				  size - m68k_init_mapped_size);

	for (i = 1; i < m68k_num_memory; i++)
		map_node(i);

	flush_tlb_all();

	/*
	 * initialize the bad page table and bad page to point
	 * to a couple of allocated pages
	 */
	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);

	/*
	 * Set up SFC/DFC registers
	 */
	set_fs(KERNEL_DS);

#ifdef DEBUG
	printk ("before free_area_init\n");
#endif
	for (i = 0; i < m68k_num_memory; i++) {
		zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT;
		free_area_init_node(i, zones_size,
				    m68k_memory[i].addr >> PAGE_SHIFT, NULL);
		if (node_present_pages(i))
			node_set_state(i, N_NORMAL_MEMORY);
	}
}