1/*
2 *  linux/arch/arm26/mm/init.c
3 *
4 *  Copyright (C) 1995-2002 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/signal.h>
11#include <linux/sched.h>
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/string.h>
15#include <linux/types.h>
16#include <linux/ptrace.h>
17#include <linux/mman.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/smp.h>
21#include <linux/init.h>
22#include <linux/initrd.h>
23#include <linux/bootmem.h>
24#include <linux/blkdev.h>
25#include <linux/pfn.h>
26
27#include <asm/segment.h>
28#include <asm/mach-types.h>
29#include <asm/dma.h>
30#include <asm/hardware.h>
31#include <asm/setup.h>
32#include <asm/tlb.h>
33
34#include <asm/map.h>
35
36
37#define TABLE_SIZE	PTRS_PER_PTE * sizeof(pte_t))
38
39struct mmu_gather mmu_gathers[NR_CPUS];
40
41extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
42extern char _stext, _text, _etext, _end, __init_begin, __init_end;
43#ifdef CONFIG_XIP_KERNEL
44extern char _endtext, _sdata;
45#endif
46extern unsigned long phys_initrd_start;
47extern unsigned long phys_initrd_size;
48
49/*
50 * The sole use of this is to pass memory configuration
51 * data from paging_init to mem_init.
52 */
53static struct meminfo meminfo __initdata = { 0, };
54
55/*
56 * empty_zero_page is a special page that is used for
57 * zero-initialized data and COW.
58 */
59struct page *empty_zero_page;
60
61void show_mem(void)
62{
63	int free = 0, total = 0, reserved = 0;
64	int shared = 0, cached = 0, slab = 0;
65	struct page *page, *end;
66
67	printk("Mem-info:\n");
68	show_free_areas();
69	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
70
71
72	page = NODE_MEM_MAP(0);
73	end  = page + NODE_DATA(0)->node_spanned_pages;
74
75	do {
76		total++;
77		if (PageReserved(page))
78			reserved++;
79		else if (PageSwapCache(page))
80			cached++;
81		else if (PageSlab(page))
82			slab++;
83		else if (!page_count(page))
84			free++;
85		else
86			shared += page_count(page) - 1;
87		page++;
88	} while (page < end);
89
90	printk("%d pages of RAM\n", total);
91	printk("%d free pages\n", free);
92	printk("%d reserved pages\n", reserved);
93	printk("%d slab pages\n", slab);
94	printk("%d pages shared\n", shared);
95	printk("%d pages swap cached\n", cached);
96}
97
98struct node_info {
99	unsigned int start;
100	unsigned int end;
101	int bootmap_pages;
102};
103
104static unsigned int __init
105find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
106{
107	unsigned int start_pfn, bootmap_pfn;
108	unsigned int start, end;
109
110	start_pfn   = PFN_UP((unsigned long)&_end);
111	bootmap_pfn = 0;
112
113	/* ARM26 machines only have one node */
114	if (mi->bank->node != 0)
115		BUG();
116
117	start = PFN_UP(mi->bank->start);
118	end   = PFN_DOWN(mi->bank->size + mi->bank->start);
119
120	if (start < start_pfn)
121		start = start_pfn;
122
123	if (end <= start)
124		BUG();
125
126	if (end - start >= bootmap_pages)
127		bootmap_pfn = start;
128	else
129		BUG();
130
131	return bootmap_pfn;
132}
133
134/*
135 * Scan the memory info structure and pull out:
136 *  - the end of memory
137 *  - the number of nodes
138 *  - the pfn range of each node
139 *  - the number of bootmem bitmap pages
140 */
141static void __init
142find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
143{
144	unsigned int memend_pfn = 0;
145
146	nodes_clear(node_online_map);
147	node_set_online(0);
148
149	np->bootmap_pages = 0;
150
151	if (mi->bank->size == 0) {
152		BUG();
153	}
154
155	/*
156	 * Get the start and end pfns for this bank
157	 */
158	np->start = PFN_UP(mi->bank->start);
159	np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
160
161	if (memend_pfn < np->end)
162		memend_pfn = np->end;
163
164	/*
165	 * Calculate the number of pages we require to
166	 * store the bootmem bitmaps.
167	 */
168	np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
169
170	/*
171	 * This doesn't seem to be used by the Linux memory
172	 * manager any more.  If we can get rid of it, we
173	 * also get rid of some of the stuff above as well.
174	 */
175	max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
176	max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
177	mi->end = memend_pfn << PAGE_SHIFT;
178
179}
180
181/*
182 * Initialise the bootmem allocator for all nodes.  This is called
183 * early during the architecture specific initialisation.
184 */
185void __init bootmem_init(struct meminfo *mi)
186{
187	struct node_info node_info;
188	unsigned int bootmap_pfn;
189	pg_data_t *pgdat = NODE_DATA(0);
190
191	find_memend_and_nodes(mi, &node_info);
192
193	bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
194
195	/*
196	 * Note that node 0 must always have some pages.
197	 */
198	if (node_info.end == 0)
199		BUG();
200
201	/*
202	 * Initialise the bootmem allocator.
203	 */
204	init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
205
206 	/*
207	 * Register all available RAM in this node with the bootmem allocator.
208	 */
209	free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
210
211        /*
212         * Register the kernel text and data with bootmem.
213         * Note: with XIP we dont register .text since
214         * its in ROM.
215         */
216#ifdef CONFIG_XIP_KERNEL
217        reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
218#else
219        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
220#endif
221
222        /*
223         * And don't forget to reserve the allocator bitmap,
224         * which will be freed later.
225         */
226        reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
227                             node_info.bootmap_pages << PAGE_SHIFT);
228
229        reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
230
231#ifdef CONFIG_BLK_DEV_INITRD
232        initrd_start = phys_initrd_start;
233        initrd_end = initrd_start + phys_initrd_size;
234
235        /* Achimedes machines only have one node, so initrd is in node 0 */
236#ifdef CONFIG_XIP_KERNEL
237	/* Only reserve initrd space if it is in RAM */
238        if(initrd_start && initrd_start < 0x03000000){
239#else
240        if(initrd_start){
241#endif
242                reserve_bootmem_node(pgdat, __pa(initrd_start),
243                                             initrd_end - initrd_start);
244	}
245#endif   /* CONFIG_BLK_DEV_INITRD */
246
247
248}
249
250/*
251 * paging_init() sets up the page tables, initialises the zone memory
252 * maps, and sets up the zero page, bad page and bad page tables.
253 */
254void __init paging_init(struct meminfo *mi)
255{
256	void *zero_page;
257	unsigned long zone_size[MAX_NR_ZONES];
258        unsigned long zhole_size[MAX_NR_ZONES];
259        struct bootmem_data *bdata;
260        pg_data_t *pgdat;
261	int i;
262
263	memcpy(&meminfo, mi, sizeof(meminfo));
264
265	/*
266	 * allocate the zero page.  Note that we count on this going ok.
267	 */
268	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
269
270	/*
271	 * initialise the page tables.
272	 */
273	memtable_init(mi);
274	flush_tlb_all();
275
276	/*
277	 * initialise the zones in node 0 (archimedes have only 1 node)
278	 */
279
280	for (i = 0; i < MAX_NR_ZONES; i++) {
281		zone_size[i]  = 0;
282		zhole_size[i] = 0;
283	}
284
285	pgdat = NODE_DATA(0);
286	bdata = pgdat->bdata;
287	zone_size[0] = bdata->node_low_pfn -
288			(bdata->node_boot_start >> PAGE_SHIFT);
289	if (!zone_size[0])
290		BUG();
291	pgdat->node_mem_map = NULL;
292	free_area_init_node(0, pgdat, zone_size,
293			bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
294
295	/*
296	 * finish off the bad pages once
297	 * the mem_map is initialised
298	 */
299	memzero(zero_page, PAGE_SIZE);
300	empty_zero_page = virt_to_page(zero_page);
301}
302
303static inline void free_area(unsigned long addr, unsigned long end, char *s)
304{
305	unsigned int size = (end - addr) >> 10;
306
307	for (; addr < end; addr += PAGE_SIZE) {
308		struct page *page = virt_to_page(addr);
309		ClearPageReserved(page);
310		init_page_count(page);
311		free_page(addr);
312		totalram_pages++;
313	}
314
315	if (size && s)
316		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
317}
318
319/*
320 * mem_init() marks the free areas in the mem_map and tells us how much
321 * memory is free.  This is done after various parts of the system have
322 * claimed their memory after the kernel image.
323 */
324void __init mem_init(void)
325{
326	unsigned int codepages, datapages, initpages;
327	pg_data_t *pgdat = NODE_DATA(0);
328	extern int sysctl_overcommit_memory;
329
330
331	/* Note: data pages includes BSS */
332#ifdef CONFIG_XIP_KERNEL
333	codepages = &_endtext - &_text;
334	datapages = &_end - &_sdata;
335#else
336	codepages = &_etext - &_text;
337	datapages = &_end - &_etext;
338#endif
339	initpages = &__init_end - &__init_begin;
340
341	high_memory = (void *)__va(meminfo.end);
342	max_mapnr   = virt_to_page(high_memory) - mem_map;
343
344	/* this will put all unused low memory onto the freelists */
345	if (pgdat->node_spanned_pages != 0)
346		totalram_pages += free_all_bootmem_node(pgdat);
347
348	num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
349
350	printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
351	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
352		"%dK data, %dK init)\n",
353		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
354		codepages >> 10, datapages >> 10, initpages >> 10);
355
356	/*
357	 * Turn on overcommit on tiny machines
358	 */
359	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
360		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
361		printk("Turning on overcommit\n");
362	}
363}
364
365void free_initmem(void){
366#ifndef CONFIG_XIP_KERNEL
367	free_area((unsigned long)(&__init_begin),
368		  (unsigned long)(&__init_end),
369		  "init");
370#endif
371}
372
373#ifdef CONFIG_BLK_DEV_INITRD
374
375static int keep_initrd;
376
377void free_initrd_mem(unsigned long start, unsigned long end)
378{
379#ifdef CONFIG_XIP_KERNEL
380	/* Only bin initrd if it is in RAM... */
381	if(!keep_initrd && start < 0x03000000)
382#else
383	if (!keep_initrd)
384#endif
385		free_area(start, end, "initrd");
386}
387
388static int __init keepinitrd_setup(char *__unused)
389{
390	keep_initrd = 1;
391	return 1;
392}
393
394__setup("keepinitrd", keepinitrd_setup);
395#endif
396