init.c revision 1c395176962176660bb108f90e97e1686cfe0d85 
1/* MN10300 Memory management initialisation
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12#include <linux/signal.h>
13#include <linux/sched.h>
14#include <linux/kernel.h>
15#include <linux/errno.h>
16#include <linux/string.h>
17#include <linux/types.h>
18#include <linux/ptrace.h>
19#include <linux/mman.h>
20#include <linux/fs.h>
21#include <linux/mm.h>
22#include <linux/swap.h>
23#include <linux/smp.h>
24#include <linux/init.h>
25#include <linux/initrd.h>
26#include <linux/highmem.h>
27#include <linux/pagemap.h>
28#include <linux/bootmem.h>
29#include <linux/gfp.h>
30
31#include <asm/processor.h>
32#include <asm/system.h>
33#include <asm/uaccess.h>
34#include <asm/pgtable.h>
35#include <asm/pgalloc.h>
36#include <asm/dma.h>
37#include <asm/tlb.h>
38#include <asm/sections.h>
39
40unsigned long highstart_pfn, highend_pfn;
41
42#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
43static struct vm_struct user_iomap_vm;
44#endif
45
46/*
47 * set up paging
48 */
49void __init paging_init(void)
50{
51	unsigned long zones_size[MAX_NR_ZONES] = {0,};
52	pte_t *ppte;
53	int loop;
54
55	/* main kernel space -> RAM mapping is handled as 1:1 transparent by
56	 * the MMU */
57	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
58	memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
59
60	/* load the VMALLOC area PTE table addresses into the kernel PGD */
61	ppte = kernel_vmalloc_ptes;
62	for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
63	     loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
64	     loop++
65	     ) {
66		set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
67		ppte += PAGE_SIZE / sizeof(pte_t);
68	}
69
70	/* declare the sizes of the RAM zones (only use the normal zone) */
71	zones_size[ZONE_NORMAL] =
72		contig_page_data.bdata->node_low_pfn -
73		contig_page_data.bdata->node_min_pfn;
74
75	/* pass the memory from the bootmem allocator to the main allocator */
76	free_area_init(zones_size);
77
78#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
79	/* The Atomic Operation Unit registers need to be mapped to userspace
80	 * for all processes.  The following uses vm_area_register_early() to
81	 * reserve the first page of the vmalloc area and sets the pte for that
82	 * page.
83	 *
84	 * glibc hardcodes this virtual mapping, so we're pretty much stuck with
85	 * it from now on.
86	 */
87	user_iomap_vm.flags = VM_USERMAP;
88	user_iomap_vm.size = 1 << PAGE_SHIFT;
89	vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
90	ppte = kernel_vmalloc_ptes;
91	set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
92			      PAGE_USERIO));
93#endif
94
95	local_flush_tlb_all();
96}
97
98/*
99 * transfer all the memory from the bootmem allocator to the runtime allocator
100 */
101void __init mem_init(void)
102{
103	int codesize, reservedpages, datasize, initsize;
104	int tmp;
105
106	BUG_ON(!mem_map);
107
108#define START_PFN	(contig_page_data.bdata->node_min_pfn)
109#define MAX_LOW_PFN	(contig_page_data.bdata->node_low_pfn)
110
111	max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
112	high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
113
114	/* clear the zero-page */
115	memset(empty_zero_page, 0, PAGE_SIZE);
116
117	/* this will put all low memory onto the freelists */
118	totalram_pages += free_all_bootmem();
119
120	reservedpages = 0;
121	for (tmp = 0; tmp < num_physpages; tmp++)
122		if (PageReserved(&mem_map[tmp]))
123			reservedpages++;
124
125	codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
126	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
127	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
128
129	printk(KERN_INFO
130	       "Memory: %luk/%luk available"
131	       " (%dk kernel code, %dk reserved, %dk data, %dk init,"
132	       " %ldk highmem)\n",
133	       nr_free_pages() << (PAGE_SHIFT - 10),
134	       max_mapnr << (PAGE_SHIFT - 10),
135	       codesize >> 10,
136	       reservedpages << (PAGE_SHIFT - 10),
137	       datasize >> 10,
138	       initsize >> 10,
139	       totalhigh_pages << (PAGE_SHIFT - 10));
140}
141
142/*
143 *
144 */
145void free_init_pages(char *what, unsigned long begin, unsigned long end)
146{
147	unsigned long addr;
148
149	for (addr = begin; addr < end; addr += PAGE_SIZE) {
150		ClearPageReserved(virt_to_page(addr));
151		init_page_count(virt_to_page(addr));
152		memset((void *) addr, 0xcc, PAGE_SIZE);
153		free_page(addr);
154		totalram_pages++;
155	}
156	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
157}
158
159/*
160 * recycle memory containing stuff only required for initialisation
161 */
162void free_initmem(void)
163{
164	free_init_pages("unused kernel memory",
165			(unsigned long) &__init_begin,
166			(unsigned long) &__init_end);
167}
168
169/*
170 * dispose of the memory on which the initial ramdisk resided
171 */
172#ifdef CONFIG_BLK_DEV_INITRD
173void free_initrd_mem(unsigned long start, unsigned long end)
174{
175	free_init_pages("initrd memory", start, end);
176}
177#endif
178