1/*
  2 *  linux/arch/h8300/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/m68knommu/mm/init.c
 11 *  linux/arch/m68k/mm/init.c
 12 *
 13 *  Copyright (C) 1995  Hamish Macdonald
 14 *
 15 *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
 16 *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
 17 */
 18
 19#include <linux/signal.h>
 20#include <linux/sched.h>
 21#include <linux/kernel.h>
 22#include <linux/errno.h>
 23#include <linux/string.h>
 24#include <linux/types.h>
 25#include <linux/ptrace.h>
 26#include <linux/mman.h>
 27#include <linux/mm.h>
 28#include <linux/swap.h>
 29#include <linux/init.h>
 30#include <linux/highmem.h>
 31#include <linux/pagemap.h>
 32#include <linux/bootmem.h>
 33#include <linux/gfp.h>
 34
 35#include <asm/setup.h>
 36#include <asm/segment.h>
 37#include <asm/page.h>
 38#include <asm/pgtable.h>
 39#include <asm/system.h>
 40
 41#undef DEBUG
 42
 43/*
 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
 48 * unused etc..
 49 *
 50 * BAD_PAGETABLE is the accompanying page-table: it is initialized
 51 * to point to BAD_PAGE entries.
 52 *
 53 * ZERO_PAGE is a special page that is used for zero-initialized
 54 * data and COW.
 55 */
 56static unsigned long empty_bad_page_table;
 57
 58static unsigned long empty_bad_page;
 59
 60unsigned long empty_zero_page;
 61
 62extern unsigned long rom_length;
 63
 64extern unsigned long memory_start;
 65extern unsigned long memory_end;
 66
 67/*
 68 * paging_init() continues the virtual memory environment setup which
 69 * was begun by the code in arch/head.S.
 70 * The parameters are pointers to where to stick the starting and ending
 71 * addresses of available kernel virtual memory.
 72 */
 73void __init paging_init(void)
 74{
 75	/*
 76	 * Make sure start_mem is page aligned,  otherwise bootmem and
 77	 * page_alloc get different views og the world.
 78	 */
 79#ifdef DEBUG
 80	unsigned long start_mem = PAGE_ALIGN(memory_start);
 81#endif
 82	unsigned long end_mem   = memory_end & PAGE_MASK;
 83
 84#ifdef DEBUG
 85	printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
 86		start_mem, end_mem);
 87#endif
 88
 89	/*
 90	 * Initialize the bad page table and bad page to point
 91	 * to a couple of allocated pages.
 92	 */
 93	empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 94	empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 95	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 96	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 97
 98	/*
 99	 * Set up SFC/DFC registers (user data space).
100	 */
101	set_fs (USER_DS);
102
103#ifdef DEBUG
104	printk ("before free_area_init\n");
105
106	printk ("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
107		start_mem, end_mem);
108#endif
109
110	{
111		unsigned long zones_size[MAX_NR_ZONES] = {0, };
112
113		zones_size[ZONE_DMA]     = 0 >> PAGE_SHIFT;
114		zones_size[ZONE_NORMAL]  = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
115#ifdef CONFIG_HIGHMEM
116		zones_size[ZONE_HIGHMEM] = 0;
117#endif
118		free_area_init(zones_size);
119	}
120}
121
122void __init mem_init(void)
123{
124	int codek = 0, datak = 0, initk = 0;
125	/* DAVIDM look at setup memory map generically with reserved area */
126	unsigned long tmp;
127	extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
128	extern unsigned long  _ramend, _ramstart;
129	unsigned long len = &_ramend - &_ramstart;
130	unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
131	unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
132
133#ifdef DEBUG
134	printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
135#endif
136
137	end_mem &= PAGE_MASK;
138	high_memory = (void *) end_mem;
139
140	start_mem = PAGE_ALIGN(start_mem);
141	max_mapnr = num_physpages = MAP_NR(high_memory);
142
143	/* this will put all memory onto the freelists */
144	totalram_pages = free_all_bootmem();
145
146	codek = (&_etext - &_stext) >> 10;
147	datak = (&_ebss - &_sdata) >> 10;
148	initk = (&__init_begin - &__init_end) >> 10;
149
150	tmp = nr_free_pages() << PAGE_SHIFT;
151	printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
152	       tmp >> 10,
153	       len >> 10,
154	       (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
155	       rom_length >> 10,
156	       codek,
157	       datak
158	       );
159}
160
161
162#ifdef CONFIG_BLK_DEV_INITRD
163void free_initrd_mem(unsigned long start, unsigned long end)
164{
165	int pages = 0;
166	for (; start < end; start += PAGE_SIZE) {
167		ClearPageReserved(virt_to_page(start));
168		init_page_count(virt_to_page(start));
169		free_page(start);
170		totalram_pages++;
171		pages++;
172	}
173	printk ("Freeing initrd memory: %dk freed\n", pages);
174}
175#endif
176
177void
178free_initmem(void)
179{
180#ifdef CONFIG_RAMKERNEL
181	unsigned long addr;
182	extern char __init_begin, __init_end;
183/*
184 *	the following code should be cool even if these sections
185 *	are not page aligned.
186 */
187	addr = PAGE_ALIGN((unsigned long)(&__init_begin));
188	/* next to check that the page we free is not a partial page */
189	for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
190		ClearPageReserved(virt_to_page(addr));
191		init_page_count(virt_to_page(addr));
192		free_page(addr);
193		totalram_pages++;
194	}
195	printk(KERN_INFO "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
196			(addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
197			(int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
198			(int)(addr - PAGE_SIZE));
199#endif
200}
201