1/*
  2 *  linux/arch/m68knommu/mm/init.c
  3 *
  4 *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
  5 *                      Kenneth Albanowski <kjahds@kjahds.com>,
  6 *  Copyright (C) 2000  Lineo, Inc.  (www.lineo.com) 
  7 *
  8 *  Based on:
  9 *
 10 *  linux/arch/m68k/mm/init.c
 11 *
 12 *  Copyright (C) 1995  Hamish Macdonald
 13 *
 14 *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
 15 *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
 16 */
 17
 18#include <linux/signal.h>
 19#include <linux/sched.h>
 20#include <linux/kernel.h>
 21#include <linux/errno.h>
 22#include <linux/string.h>
 23#include <linux/types.h>
 24#include <linux/ptrace.h>
 25#include <linux/mman.h>
 26#include <linux/mm.h>
 27#include <linux/swap.h>
 28#include <linux/init.h>
 29#include <linux/highmem.h>
 30#include <linux/pagemap.h>
 31#include <linux/bootmem.h>
 32#include <linux/gfp.h>
 33
 34#include <asm/setup.h>
 35#include <asm/segment.h>
 36#include <asm/page.h>
 37#include <asm/pgtable.h>
 38#include <asm/system.h>
 39#include <asm/machdep.h>
 40
 41/*
 42 * ZERO_PAGE is a special page that is used for zero-initialized
 43 * data and COW.
 44 */
 45void *empty_zero_page;
 46
 47extern unsigned long memory_start;
 48extern unsigned long memory_end;
 49
 50/*
 51 * paging_init() continues the virtual memory environment setup which
 52 * was begun by the code in arch/head.S.
 53 * The parameters are pointers to where to stick the starting and ending
 54 * addresses of available kernel virtual memory.
 55 */
 56void __init paging_init(void)
 57{
 58	/*
 59	 * Make sure start_mem is page aligned, otherwise bootmem and
 60	 * page_alloc get different views of the world.
 61	 */
 62	unsigned long end_mem   = memory_end & PAGE_MASK;
 63	unsigned long zones_size[MAX_NR_ZONES] = {0, };
 64
 65	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
 66	memset(empty_zero_page, 0, PAGE_SIZE);
 67
 68	/*
 69	 * Set up SFC/DFC registers (user data space).
 70	 */
 71	set_fs (USER_DS);
 72
 73	zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 74	free_area_init(zones_size);
 75}
 76
 77void __init mem_init(void)
 78{
 79	int codek = 0, datak = 0, initk = 0;
 80	unsigned long tmp;
 81	extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 82	extern unsigned int _ramend, _rambase;
 83	unsigned long len = _ramend - _rambase;
 84	unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 85	unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 86
 87	pr_debug("Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 88
 89	end_mem &= PAGE_MASK;
 90	high_memory = (void *) end_mem;
 91
 92	start_mem = PAGE_ALIGN(start_mem);
 93	max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
 94
 95	/* this will put all memory onto the freelists */
 96	totalram_pages = free_all_bootmem();
 97
 98	codek = (&_etext - &_stext) >> 10;
 99	datak = (&_ebss - &_sdata) >> 10;
100	initk = (&__init_begin - &__init_end) >> 10;
101
102	tmp = nr_free_pages() << PAGE_SHIFT;
103	printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
104	       tmp >> 10,
105	       len >> 10,
106	       codek,
107	       datak
108	       );
109}
110
111
112#ifdef CONFIG_BLK_DEV_INITRD
113void free_initrd_mem(unsigned long start, unsigned long end)
114{
115	int pages = 0;
116	for (; start < end; start += PAGE_SIZE) {
117		ClearPageReserved(virt_to_page(start));
118		init_page_count(virt_to_page(start));
119		free_page(start);
120		totalram_pages++;
121		pages++;
122	}
123	pr_notice("Freeing initrd memory: %luk freed\n",
124		  pages * (PAGE_SIZE / 1024));
125}
126#endif
127
128void free_initmem(void)
129{
130#ifdef CONFIG_RAMKERNEL
131	unsigned long addr;
132	extern char __init_begin, __init_end;
133	/*
134	 * The following code should be cool even if these sections
135	 * are not page aligned.
136	 */
137	addr = PAGE_ALIGN((unsigned long)(&__init_begin));
138	/* next to check that the page we free is not a partial page */
139	for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
140		ClearPageReserved(virt_to_page(addr));
141		init_page_count(virt_to_page(addr));
142		free_page(addr);
143		totalram_pages++;
144	}
145	pr_notice("Freeing unused kernel memory: %luk freed (0x%x - 0x%x)\n",
146			(addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
147			(int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
148			(int)(addr - PAGE_SIZE));
149#endif
150}
151