summaryrefslogtreecommitdiffstats
path: root/arch/m68k/mm/memory.c
blob: a226668f20c329413a70cd3a207707d012838ee3 (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
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
/*
 *  linux/arch/m68k/mm/memory.c
 *
 *  Copyright (C) 1995  Hamish Macdonald
 */

#include <linux/config.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pagemap.h>

#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/machdep.h>


/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from
   struct page instead of separately kmalloced struct.  Stolen from
   arch/sparc/mm/srmmu.c ... */

typedef struct list_head ptable_desc;
static LIST_HEAD(ptable_list);

#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru))
#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru))
#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index)

#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t))

void __init init_pointer_table(unsigned long ptable)
{
	ptable_desc *dp;
	unsigned long page = ptable & PAGE_MASK;
	unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE);

	dp = PD_PTABLE(page);
	if (!(PD_MARKBITS(dp) & mask)) {
		PD_MARKBITS(dp) = 0xff;
		list_add(dp, &ptable_list);
	}

	PD_MARKBITS(dp) &= ~mask;
#ifdef DEBUG
	printk("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
#endif

	/* unreserve the page so it's possible to free that page */
	PD_PAGE(dp)->flags &= ~(1 << PG_reserved);
	init_page_count(PD_PAGE(dp));

	return;
}

pmd_t *get_pointer_table (void)
{
	ptable_desc *dp = ptable_list.next;
	unsigned char mask = PD_MARKBITS (dp);
	unsigned char tmp;
	unsigned int off;

	/*
	 * For a pointer table for a user process address space, a
	 * table is taken from a page allocated for the purpose.  Each
	 * page can hold 8 pointer tables.  The page is remapped in
	 * virtual address space to be noncacheable.
	 */
	if (mask == 0) {
		void *page;
		ptable_desc *new;

		if (!(page = (void *)get_zeroed_page(GFP_KERNEL)))
			return NULL;

		flush_tlb_kernel_page(page);
		nocache_page(page);

		new = PD_PTABLE(page);
		PD_MARKBITS(new) = 0xfe;
		list_add_tail(new, dp);

		return (pmd_t *)page;
	}

	for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE)
		;
	PD_MARKBITS(dp) = mask & ~tmp;
	if (!PD_MARKBITS(dp)) {
		/* move to end of list */
		list_move_tail(dp, &ptable_list);
	}
	return (pmd_t *) (page_address(PD_PAGE(dp)) + off);
}

int free_pointer_table (pmd_t *ptable)
{
	ptable_desc *dp;
	unsigned long page = (unsigned long)ptable & PAGE_MASK;
	unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE);

	dp = PD_PTABLE(page);
	if (PD_MARKBITS (dp) & mask)
		panic ("table already free!");

	PD_MARKBITS (dp) |= mask;

	if (PD_MARKBITS(dp) == 0xff) {
		/* all tables in page are free, free page */
		list_del(dp);
		cache_page((void *)page);
		free_page (page);
		return 1;
	} else if (ptable_list.next != dp) {
		/*
		 * move this descriptor to the front of the list, since
		 * it has one or more free tables.
		 */
		list_move(dp, &ptable_list);
	}
	return 0;
}

#ifdef DEBUG_INVALID_PTOV
int mm_inv_cnt = 5;
#endif

#ifndef CONFIG_SINGLE_MEMORY_CHUNK
/*
 * The following two routines map from a physical address to a kernel
 * virtual address and vice versa.
 */
unsigned long mm_vtop(unsigned long vaddr)
{
	int i=0;
	unsigned long voff = (unsigned long)vaddr - PAGE_OFFSET;

	do {
		if (voff < m68k_memory[i].size) {
#ifdef DEBUGPV
			printk ("VTOP(%p)=%lx\n", vaddr,
				m68k_memory[i].addr + voff);
#endif
			return m68k_memory[i].addr + voff;
		}
		voff -= m68k_memory[i].size;
	} while (++i < m68k_num_memory);

	/* As a special case allow `__pa(high_memory)'.  */
	if (voff == 0)
		return m68k_memory[i-1].addr + m68k_memory[i-1].size;

	return -1;
}
#endif

#ifndef CONFIG_SINGLE_MEMORY_CHUNK
unsigned long mm_ptov (unsigned long paddr)
{
	int i = 0;
	unsigned long poff, voff = PAGE_OFFSET;

	do {
		poff = paddr - m68k_memory[i].addr;
		if (poff < m68k_memory[i].size) {
#ifdef DEBUGPV
			printk ("PTOV(%lx)=%lx\n", paddr, poff + voff);
#endif
			return poff + voff;
		}
		voff += m68k_memory[i].size;
	} while (++i < m68k_num_memory);

#ifdef DEBUG_INVALID_PTOV
	if (mm_inv_cnt > 0) {
		mm_inv_cnt--;
		printk("Invalid use of phys_to_virt(0x%lx) at 0x%p!\n",
			paddr, __builtin_return_address(0));
	}
#endif
	return -1;
}
#endif

/* invalidate page in both caches */
static inline void clear040(unsigned long paddr)
{
	asm volatile (
		"nop\n\t"
		".chip 68040\n\t"
		"cinvp %%bc,(%0)\n\t"
		".chip 68k"
		: : "a" (paddr));
}

/* invalidate page in i-cache */
static inline void cleari040(unsigned long paddr)
{
	asm volatile (
		"nop\n\t"
		".chip 68040\n\t"
		"cinvp %%ic,(%0)\n\t"
		".chip 68k"
		: : "a" (paddr));
}

/* push page in both caches */
/* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */
static inline void push040(unsigned long paddr)
{
	asm volatile (
		"nop\n\t"
		".chip 68040\n\t"
		"cpushp %%bc,(%0)\n\t"
		".chip 68k"
		: : "a" (paddr));
}

/* push and invalidate page in both caches, must disable ints
 * to avoid invalidating valid data */
static inline void pushcl040(unsigned long paddr)
{
	unsigned long flags;

	local_irq_save(flags);
	push040(paddr);
	if (CPU_IS_060)
		clear040(paddr);
	local_irq_restore(flags);
}

/*
 * 040: Hit every page containing an address in the range paddr..paddr+len-1.
 * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s).
 * Hit every page until there is a page or less to go. Hit the next page,
 * and the one after that if the range hits it.
 */
/* ++roman: A little bit more care is required here: The CINVP instruction
 * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning
 * and the end of the region must be treated differently if they are not
 * exactly at the beginning or end of a page boundary. Else, maybe too much
 * data becomes invalidated and thus lost forever. CPUSHP does what we need:
 * it invalidates the page after pushing dirty data to memory. (Thanks to Jes
 * for discovering the problem!)
 */
/* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set
 * the DPI bit in the CACR; would it cause problems with temporarily changing
 * this?). So we have to push first and then additionally to invalidate.
 */


/*
 * cache_clear() semantics: Clear any cache entries for the area in question,
 * without writing back dirty entries first. This is useful if the data will
 * be overwritten anyway, e.g. by DMA to memory. The range is defined by a
 * _physical_ address.
 */

void cache_clear (unsigned long paddr, int len)
{
    if (CPU_IS_040_OR_060) {
	int tmp;

	/*
	 * We need special treatment for the first page, in case it
	 * is not page-aligned. Page align the addresses to work
	 * around bug I17 in the 68060.
	 */
	if ((tmp = -paddr & (PAGE_SIZE - 1))) {
	    pushcl040(paddr & PAGE_MASK);
	    if ((len -= tmp) <= 0)
		return;
	    paddr += tmp;
	}
	tmp = PAGE_SIZE;
	paddr &= PAGE_MASK;
	while ((len -= tmp) >= 0) {
	    clear040(paddr);
	    paddr += tmp;
	}
	if ((len += tmp))
	    /* a page boundary gets crossed at the end */
	    pushcl040(paddr);
    }
    else /* 68030 or 68020 */
	asm volatile ("movec %/cacr,%/d0\n\t"
		      "oriw %0,%/d0\n\t"
		      "movec %/d0,%/cacr"
		      : : "i" (FLUSH_I_AND_D)
		      : "d0");
#ifdef CONFIG_M68K_L2_CACHE
    if(mach_l2_flush)
	mach_l2_flush(0);
#endif
}


/*
 * cache_push() semantics: Write back any dirty cache data in the given area,
 * and invalidate the range in the instruction cache. It needs not (but may)
 * invalidate those entries also in the data cache. The range is defined by a
 * _physical_ address.
 */

void cache_push (unsigned long paddr, int len)
{
    if (CPU_IS_040_OR_060) {
	int tmp = PAGE_SIZE;

	/*
         * on 68040 or 68060, push cache lines for pages in the range;
	 * on the '040 this also invalidates the pushed lines, but not on
	 * the '060!
	 */
	len += paddr & (PAGE_SIZE - 1);

	/*
	 * Work around bug I17 in the 68060 affecting some instruction
	 * lines not being invalidated properly.
	 */
	paddr &= PAGE_MASK;

	do {
	    push040(paddr);
	    paddr += tmp;
	} while ((len -= tmp) > 0);
    }
    /*
     * 68030/68020 have no writeback cache. On the other hand,
     * cache_push is actually a superset of cache_clear (the lines
     * get written back and invalidated), so we should make sure
     * to perform the corresponding actions. After all, this is getting
     * called in places where we've just loaded code, or whatever, so
     * flushing the icache is appropriate; flushing the dcache shouldn't
     * be required.
     */
    else /* 68030 or 68020 */
	asm volatile ("movec %/cacr,%/d0\n\t"
		      "oriw %0,%/d0\n\t"
		      "movec %/d0,%/cacr"
		      : : "i" (FLUSH_I)
		      : "d0");
#ifdef CONFIG_M68K_L2_CACHE
    if(mach_l2_flush)
	mach_l2_flush(1);
#endif
}

#ifndef CONFIG_SINGLE_MEMORY_CHUNK
int mm_end_of_chunk (unsigned long addr, int len)
{
	int i;

	for (i = 0; i < m68k_num_memory; i++)
		if (m68k_memory[i].addr + m68k_memory[i].size == addr + len)
			return 1;
	return 0;
}
#endif