summaryrefslogtreecommitdiffstats
path: root/arch/alpha/mm/init.c
blob: 91eddd8505df3d30c0e137f9cf5d5c2b8f6d53e8 (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
/*
 *  linux/arch/alpha/mm/init.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 */

/* 2.3.x zone allocator, 1999 Andrea Arcangeli <andrea@suse.de> */

#include <linux/pagemap.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h> /* max_low_pfn */
#include <linux/vmalloc.h>

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/hwrpb.h>
#include <asm/dma.h>
#include <asm/mmu_context.h>
#include <asm/console.h>
#include <asm/tlb.h>

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

extern void die_if_kernel(char *,struct pt_regs *,long);

static struct pcb_struct original_pcb;

pgd_t *
pgd_alloc(struct mm_struct *mm)
{
	pgd_t *ret, *init;

	ret = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
	init = pgd_offset(&init_mm, 0UL);
	if (ret) {
#ifdef CONFIG_ALPHA_LARGE_VMALLOC
		memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
			(PTRS_PER_PGD - USER_PTRS_PER_PGD - 1)*sizeof(pgd_t));
#else
		pgd_val(ret[PTRS_PER_PGD-2]) = pgd_val(init[PTRS_PER_PGD-2]);
#endif

		/* The last PGD entry is the VPTB self-map.  */
		pgd_val(ret[PTRS_PER_PGD-1])
		  = pte_val(mk_pte(virt_to_page(ret), PAGE_KERNEL));
	}
	return ret;
}


/*
 * BAD_PAGE is the page that is used for page faults when linux
 * is out-of-memory. Older versions of linux just did a
 * do_exit(), but using this instead means there is less risk
 * for a process dying in kernel mode, possibly leaving an inode
 * unused etc..
 *
 * BAD_PAGETABLE is the accompanying page-table: it is initialized
 * to point to BAD_PAGE entries.
 *
 * ZERO_PAGE is a special page that is used for zero-initialized
 * data and COW.
 */
pmd_t *
__bad_pagetable(void)
{
	memset((void *) EMPTY_PGT, 0, PAGE_SIZE);
	return (pmd_t *) EMPTY_PGT;
}

pte_t
__bad_page(void)
{
	memset((void *) EMPTY_PGE, 0, PAGE_SIZE);
	return pte_mkdirty(mk_pte(virt_to_page(EMPTY_PGE), PAGE_SHARED));
}

static inline unsigned long
load_PCB(struct pcb_struct *pcb)
{
	register unsigned long sp __asm__("$30");
	pcb->ksp = sp;
	return __reload_thread(pcb);
}

/* Set up initial PCB, VPTB, and other such nicities.  */

static inline void
switch_to_system_map(void)
{
	unsigned long newptbr;
	unsigned long original_pcb_ptr;

	/* Initialize the kernel's page tables.  Linux puts the vptb in
	   the last slot of the L1 page table.  */
	memset(swapper_pg_dir, 0, PAGE_SIZE);
	newptbr = ((unsigned long) swapper_pg_dir - PAGE_OFFSET) >> PAGE_SHIFT;
	pgd_val(swapper_pg_dir[1023]) =
		(newptbr << 32) | pgprot_val(PAGE_KERNEL);

	/* Set the vptb.  This is often done by the bootloader, but 
	   shouldn't be required.  */
	if (hwrpb->vptb != 0xfffffffe00000000UL) {
		wrvptptr(0xfffffffe00000000UL);
		hwrpb->vptb = 0xfffffffe00000000UL;
		hwrpb_update_checksum(hwrpb);
	}

	/* Also set up the real kernel PCB while we're at it.  */
	init_thread_info.pcb.ptbr = newptbr;
	init_thread_info.pcb.flags = 1;	/* set FEN, clear everything else */
	original_pcb_ptr = load_PCB(&init_thread_info.pcb);
	tbia();

	/* Save off the contents of the original PCB so that we can
	   restore the original console's page tables for a clean reboot.

	   Note that the PCB is supposed to be a physical address, but
	   since KSEG values also happen to work, folks get confused.
	   Check this here.  */

	if (original_pcb_ptr < PAGE_OFFSET) {
		original_pcb_ptr = (unsigned long)
			phys_to_virt(original_pcb_ptr);
	}
	original_pcb = *(struct pcb_struct *) original_pcb_ptr;
}

int callback_init_done;

void * __init
callback_init(void * kernel_end)
{
	struct crb_struct * crb;
	pgd_t *pgd;
	pmd_t *pmd;
	void *two_pages;

	/* Starting at the HWRPB, locate the CRB. */
	crb = (struct crb_struct *)((char *)hwrpb + hwrpb->crb_offset);

	if (alpha_using_srm) {
		/* Tell the console whither it is to be remapped. */
		if (srm_fixup(VMALLOC_START, (unsigned long)hwrpb))
			__halt();		/* "We're boned."  --Bender */

		/* Edit the procedure descriptors for DISPATCH and FIXUP. */
		crb->dispatch_va = (struct procdesc_struct *)
			(VMALLOC_START + (unsigned long)crb->dispatch_va
			 - crb->map[0].va);
		crb->fixup_va = (struct procdesc_struct *)
			(VMALLOC_START + (unsigned long)crb->fixup_va
			 - crb->map[0].va);
	}

	switch_to_system_map();

	/* Allocate one PGD and one PMD.  In the case of SRM, we'll need
	   these to actually remap the console.  There is an assumption
	   here that only one of each is needed, and this allows for 8MB.
	   On systems with larger consoles, additional pages will be
	   allocated as needed during the mapping process.

	   In the case of not SRM, but not CONFIG_ALPHA_LARGE_VMALLOC,
	   we need to allocate the PGD we use for vmalloc before we start
	   forking other tasks.  */

	two_pages = (void *)
	  (((unsigned long)kernel_end + ~PAGE_MASK) & PAGE_MASK);
	kernel_end = two_pages + 2*PAGE_SIZE;
	memset(two_pages, 0, 2*PAGE_SIZE);

	pgd = pgd_offset_k(VMALLOC_START);
	pgd_set(pgd, (pmd_t *)two_pages);
	pmd = pmd_offset(pgd, VMALLOC_START);
	pmd_set(pmd, (pte_t *)(two_pages + PAGE_SIZE));

	if (alpha_using_srm) {
		static struct vm_struct console_remap_vm;
		unsigned long nr_pages = 0;
		unsigned long vaddr;
		unsigned long i, j;

		/* calculate needed size */
		for (i = 0; i < crb->map_entries; ++i)
			nr_pages += crb->map[i].count;

		/* register the vm area */
		console_remap_vm.flags = VM_ALLOC;
		console_remap_vm.size = nr_pages << PAGE_SHIFT;
		vm_area_register_early(&console_remap_vm, PAGE_SIZE);

		vaddr = (unsigned long)consle_remap_vm.addr;

		/* Set up the third level PTEs and update the virtual
		   addresses of the CRB entries.  */
		for (i = 0; i < crb->map_entries; ++i) {
			unsigned long pfn = crb->map[i].pa >> PAGE_SHIFT;
			crb->map[i].va = vaddr;
			for (j = 0; j < crb->map[i].count; ++j) {
				/* Newer consoles (especially on larger
				   systems) may require more pages of
				   PTEs. Grab additional pages as needed. */
				if (pmd != pmd_offset(pgd, vaddr)) {
					memset(kernel_end, 0, PAGE_SIZE);
					pmd = pmd_offset(pgd, vaddr);
					pmd_set(pmd, (pte_t *)kernel_end);
					kernel_end += PAGE_SIZE;
				}
				set_pte(pte_offset_kernel(pmd, vaddr),
					pfn_pte(pfn, PAGE_KERNEL));
				pfn++;
				vaddr += PAGE_SIZE;
			}
		}
	}

	callback_init_done = 1;
	return kernel_end;
}


#ifndef CONFIG_DISCONTIGMEM
/*
 * paging_init() sets up the memory map.
 */
void __init paging_init(void)
{
	unsigned long zones_size[MAX_NR_ZONES] = {0, };
	unsigned long dma_pfn, high_pfn;

	dma_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
	high_pfn = max_pfn = max_low_pfn;

	if (dma_pfn >= high_pfn)
		zones_size[ZONE_DMA] = high_pfn;
	else {
		zones_size[ZONE_DMA] = dma_pfn;
		zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
	}

	/* Initialize mem_map[].  */
	free_area_init(zones_size);

	/* Initialize the kernel's ZERO_PGE. */
	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
}
#endif /* CONFIG_DISCONTIGMEM */

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
void
srm_paging_stop (void)
{
	/* Move the vptb back to where the SRM console expects it.  */
	swapper_pg_dir[1] = swapper_pg_dir[1023];
	tbia();
	wrvptptr(0x200000000UL);
	hwrpb->vptb = 0x200000000UL;
	hwrpb_update_checksum(hwrpb);

	/* Reload the page tables that the console had in use.  */
	load_PCB(&original_pcb);
	tbia();
}
#endif

#ifndef CONFIG_DISCONTIGMEM
static void __init
printk_memory_info(void)
{
	unsigned long codesize, reservedpages, datasize, initsize, tmp;
	extern int page_is_ram(unsigned long) __init;
	extern char _text, _etext, _data, _edata;
	extern char __init_begin, __init_end;

	/* printk all informations */
	reservedpages = 0;
	for (tmp = 0; tmp < max_low_pfn; tmp++)
		/*
		 * Only count reserved RAM pages
		 */
		if (page_is_ram(tmp) && PageReserved(mem_map+tmp))
			reservedpages++;

	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
	datasize =  (unsigned long) &_edata - (unsigned long) &_data;
	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

	printk("Memory: %luk/%luk available (%luk kernel code, %luk reserved, %luk data, %luk init)\n",
	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
	       max_mapnr << (PAGE_SHIFT-10),
	       codesize >> 10,
	       reservedpages << (PAGE_SHIFT-10),
	       datasize >> 10,
	       initsize >> 10);
}

void __init
mem_init(void)
{
	max_mapnr = num_physpages = max_low_pfn;
	totalram_pages += free_all_bootmem();
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

	printk_memory_info();
}
#endif /* CONFIG_DISCONTIGMEM */

void
free_reserved_mem(void *start, void *end)
{
	void *__start = start;
	for (; __start < end; __start += PAGE_SIZE) {
		ClearPageReserved(virt_to_page(__start));
		init_page_count(virt_to_page(__start));
		free_page((long)__start);
		totalram_pages++;
	}
}

void
free_initmem(void)
{
	extern char __init_begin, __init_end;

	free_reserved_mem(&__init_begin, &__init_end);
	printk ("Freeing unused kernel memory: %ldk freed\n",
		(&__init_end - &__init_begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void
free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_mem((void *)start, (void *)end);
	printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
}
#endif
OpenPOWER on IntegriCloud