1 /* init.c: memory initialisation for FRV
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 * - linux/arch/m68knommu/mm/init.c
13 * - Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, Kenneth Albanowski <kjahds@kjahds.com>,
14 * - Copyright (C) 2000 Lineo, Inc. (www.lineo.com)
15 * - linux/arch/m68k/mm/init.c
16 * - Copyright (C) 1995 Hamish Macdonald
19 #include <linux/signal.h>
20 #include <linux/sched.h>
21 #include <linux/pagemap.h>
22 #include <linux/gfp.h>
23 #include <linux/swap.h>
25 #include <linux/kernel.h>
26 #include <linux/string.h>
27 #include <linux/types.h>
28 #include <linux/bootmem.h>
29 #include <linux/highmem.h>
30 #include <linux/module.h>
32 #include <asm/setup.h>
33 #include <asm/segment.h>
35 #include <asm/pgtable.h>
36 #include <asm/mmu_context.h>
37 #include <asm/virtconvert.h>
38 #include <asm/sections.h>
44 * BAD_PAGE is the page that is used for page faults when linux
45 * is out-of-memory. Older versions of linux just did a
46 * do_exit(), but using this instead means there is less risk
47 * for a process dying in kernel mode, possibly leaving a inode
50 * BAD_PAGETABLE is the accompanying page-table: it is initialized
51 * to point to BAD_PAGE entries.
53 * ZERO_PAGE is a special page that is used for zero-initialized
56 static unsigned long empty_bad_page_table
;
57 static unsigned long empty_bad_page
;
59 unsigned long empty_zero_page
;
60 EXPORT_SYMBOL(empty_zero_page
);
62 /*****************************************************************************/
64 * paging_init() continues the virtual memory environment setup which
65 * was begun by the code in arch/head.S.
66 * The parameters are pointers to where to stick the starting and ending
67 * addresses of available kernel virtual memory.
69 void __init
paging_init(void)
71 unsigned long zones_size
[MAX_NR_ZONES
] = {0, };
73 /* allocate some pages for kernel housekeeping tasks */
74 empty_bad_page_table
= (unsigned long) alloc_bootmem_pages(PAGE_SIZE
);
75 empty_bad_page
= (unsigned long) alloc_bootmem_pages(PAGE_SIZE
);
76 empty_zero_page
= (unsigned long) alloc_bootmem_pages(PAGE_SIZE
);
78 memset((void *) empty_zero_page
, 0, PAGE_SIZE
);
81 if (num_physpages
- num_mappedpages
) {
86 pkmap_page_table
= alloc_bootmem_pages(PAGE_SIZE
);
88 pge
= swapper_pg_dir
+ pgd_index_k(PKMAP_BASE
);
89 pue
= pud_offset(pge
, PKMAP_BASE
);
90 pme
= pmd_offset(pue
, PKMAP_BASE
);
91 __set_pmd(pme
, virt_to_phys(pkmap_page_table
) | _PAGE_TABLE
);
95 /* distribute the allocatable pages across the various zones and pass them to the allocator
97 zones_size
[ZONE_NORMAL
] = max_low_pfn
- min_low_pfn
;
99 zones_size
[ZONE_HIGHMEM
] = num_physpages
- num_mappedpages
;
102 free_area_init(zones_size
);
105 /* initialise init's MMU context */
106 init_new_context(&init_task
, &init_mm
);
109 } /* end paging_init() */
111 /*****************************************************************************/
115 void __init
mem_init(void)
117 unsigned long npages
= (memory_end
- memory_start
) >> PAGE_SHIFT
;
120 unsigned long loop
, pfn
;
123 int codek
= 0, datak
= 0;
125 /* this will put all memory onto the freelists */
126 totalram_pages
= free_all_bootmem();
129 for (loop
= 0 ; loop
< npages
; loop
++)
130 if (PageReserved(&mem_map
[loop
]))
133 #ifdef CONFIG_HIGHMEM
134 for (pfn
= num_physpages
- 1; pfn
>= num_mappedpages
; pfn
--) {
135 struct page
*page
= &mem_map
[pfn
];
137 ClearPageReserved(page
);
138 init_page_count(page
);
144 codek
= ((unsigned long) &_etext
- (unsigned long) &_stext
) >> 10;
145 datak
= datapages
<< (PAGE_SHIFT
- 10);
148 codek
= (_etext
- _stext
) >> 10;
149 datak
= 0; //(__bss_stop - _sdata) >> 10;
152 tmp
= nr_free_pages() << PAGE_SHIFT
;
153 printk("Memory available: %luKiB/%luKiB RAM, %luKiB/%luKiB ROM (%dKiB kernel code, %dKiB data)\n",
155 npages
<< (PAGE_SHIFT
- 10),
156 (rom_length
> 0) ? ((rom_length
>> 10) - codek
) : 0,
162 } /* end mem_init() */
164 /*****************************************************************************/
166 * free the memory that was only required for initialisation
168 void free_initmem(void)
170 #if defined(CONFIG_RAMKERNEL) && !defined(CONFIG_PROTECT_KERNEL)
171 unsigned long start
, end
, addr
;
173 start
= PAGE_ALIGN((unsigned long) &__init_begin
); /* round up */
174 end
= ((unsigned long) &__init_end
) & PAGE_MASK
; /* round down */
176 /* next to check that the page we free is not a partial page */
177 for (addr
= start
; addr
< end
; addr
+= PAGE_SIZE
) {
178 ClearPageReserved(virt_to_page(addr
));
179 init_page_count(virt_to_page(addr
));
184 printk("Freeing unused kernel memory: %ldKiB freed (0x%lx - 0x%lx)\n",
185 (end
- start
) >> 10, start
, end
);
187 } /* end free_initmem() */
189 /*****************************************************************************/
191 * free the initial ramdisk memory
193 #ifdef CONFIG_BLK_DEV_INITRD
194 void __init
free_initrd_mem(unsigned long start
, unsigned long end
)
197 for (; start
< end
; start
+= PAGE_SIZE
) {
198 ClearPageReserved(virt_to_page(start
));
199 init_page_count(virt_to_page(start
));
204 printk("Freeing initrd memory: %dKiB freed\n", (pages
* PAGE_SIZE
) >> 10);
205 } /* end free_initrd_mem() */