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/sections.h>
 36#include <asm/segment.h>
 37#include <asm/page.h>
 38#include <asm/pgtable.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
 47/*
 48 * paging_init() continues the virtual memory environment setup which
 49 * was begun by the code in arch/head.S.
 50 * The parameters are pointers to where to stick the starting and ending
 51 * addresses of available kernel virtual memory.
 52 */
 53void __init paging_init(void)
 54{
 55	/*
 56	 * Make sure start_mem is page aligned, otherwise bootmem and
 57	 * page_alloc get different views of the world.
 58	 */
 59	unsigned long end_mem   = memory_end & PAGE_MASK;
 60	unsigned long zones_size[MAX_NR_ZONES] = {0, };
 61
 62	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
 63	memset(empty_zero_page, 0, PAGE_SIZE);
 64
 65	/*
 66	 * Set up SFC/DFC registers (user data space).
 67	 */
 68	set_fs (USER_DS);
 69
 70	zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 71	free_area_init(zones_size);
 72}
 73
 74void __init mem_init(void)
 75{
 76	int codek = 0, datak = 0, initk = 0;
 77	unsigned long tmp;
 78	unsigned long len = _ramend - _rambase;
 79	unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 80	unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 81
 82	pr_debug("Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 83
 84	end_mem &= PAGE_MASK;
 85	high_memory = (void *) end_mem;
 86
 87	start_mem = PAGE_ALIGN(start_mem);
 88	max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
 89
 90	/* this will put all memory onto the freelists */
 91	totalram_pages = free_all_bootmem();
 92
 93	codek = (_etext - _stext) >> 10;
 94	datak = (_ebss - _sdata) >> 10;
 95	initk = (__init_begin - __init_end) >> 10;
 96
 97	tmp = nr_free_pages() << PAGE_SHIFT;
 98	printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
 99	       tmp >> 10,
100	       len >> 10,
101	       codek,
102	       datak
103	       );
104}
105
106
107#ifdef CONFIG_BLK_DEV_INITRD
108void free_initrd_mem(unsigned long start, unsigned long end)
109{
110	int pages = 0;
111	for (; start < end; start += PAGE_SIZE) {
112		ClearPageReserved(virt_to_page(start));
113		init_page_count(virt_to_page(start));
114		free_page(start);
115		totalram_pages++;
116		pages++;
117	}
118	pr_notice("Freeing initrd memory: %luk freed\n",
119		  pages * (PAGE_SIZE / 1024));
120}
121#endif
122
123void free_initmem(void)
124{
125#ifdef CONFIG_RAMKERNEL
126	unsigned long addr;
127	/*
128	 * The following code should be cool even if these sections
129	 * are not page aligned.
130	 */
131	addr = PAGE_ALIGN((unsigned long) __init_begin);
132	/* next to check that the page we free is not a partial page */
133	for (; addr + PAGE_SIZE < ((unsigned long) __init_end); addr += PAGE_SIZE) {
134		ClearPageReserved(virt_to_page(addr));
135		init_page_count(virt_to_page(addr));
136		free_page(addr);
137		totalram_pages++;
138	}
139	pr_notice("Freeing unused kernel memory: %luk freed (0x%x - 0x%x)\n",
140			(addr - PAGE_ALIGN((unsigned long) __init_begin)) >> 10,
141			(int)(PAGE_ALIGN((unsigned long) __init_begin)),
142			(int)(addr - PAGE_SIZE));
143#endif
144}
145