alistair23-linux/arch/blackfin/mm/init.c

/*
 * File:         arch/blackfin/mm/init.c
 * Based on:
 * Author:
 *
 * Created:
 * Description:
 *
 * Modified:
 *               Copyright 2004-2007 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/swap.h>
#include <linux/bootmem.h>
#include <linux/uaccess.h>
#include <asm/bfin-global.h>
#include <asm/l1layout.h>
#include "blackfin_sram.h"

/*
 * BAD_PAGE is the page that is used for page faults when linux
 * is out-of-memory. Older versions of linux just did a
 * do_exit(), but using this instead means there is less risk
 * for a process dying in kernel mode, possibly leaving a inode
 * unused etc..
 *
 * BAD_PAGETABLE is the accompanying page-table: it is initialized
 * to point to BAD_PAGE entries.
 *
 * ZERO_PAGE is a special page that is used for zero-initialized
 * data and COW.
 */
static unsigned long empty_bad_page_table;

static unsigned long empty_bad_page;

unsigned long empty_zero_page;

void show_mem(void)
{
	unsigned long i;
	int free = 0, total = 0, reserved = 0, shared = 0;

	int cached = 0;
	printk(KERN_INFO "Mem-info:\n");
	show_free_areas();
	i = max_mapnr;
	while (i-- > 0) {
		total++;
		if (PageReserved(mem_map + i))
			reserved++;
		else if (PageSwapCache(mem_map + i))
			cached++;
		else if (!page_count(mem_map + i))
			free++;
		else
			shared += page_count(mem_map + i) - 1;
	}
	printk(KERN_INFO "%d pages of RAM\n", total);
	printk(KERN_INFO "%d free pages\n", free);
	printk(KERN_INFO "%d reserved pages\n", reserved);
	printk(KERN_INFO "%d pages shared\n", shared);
	printk(KERN_INFO "%d pages swap cached\n", cached);
}

/*
 * paging_init() continues the virtual memory environment setup which
 * was begun by the code in arch/head.S.
 * The parameters are pointers to where to stick the starting and ending
 * addresses  of available kernel virtual memory.
 */
void __init paging_init(void)
{
	/*
	 * make sure start_mem is page aligned,  otherwise bootmem and
	 * page_alloc get different views og the world
	 */
	unsigned long end_mem = memory_end & PAGE_MASK;

	pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);

	/*
	 * initialize the bad page table and bad page to point
	 * to a couple of allocated pages
	 */
	empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
	empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
	memset((void *)empty_zero_page, 0, PAGE_SIZE);

	/*
	 * Set up SFC/DFC registers (user data space)
	 */
	set_fs(KERNEL_DS);

	pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
	        PAGE_ALIGN(memory_start), end_mem);

	{
		unsigned long zones_size[MAX_NR_ZONES] = { 0, };

		zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
		zones_size[ZONE_NORMAL] = 0;
#ifdef CONFIG_HIGHMEM
		zones_size[ZONE_HIGHMEM] = 0;
#endif
		free_area_init(zones_size);
	}
}

void __init mem_init(void)
{
	unsigned int codek = 0, datak = 0, initk = 0;
	unsigned int reservedpages = 0, freepages = 0;
	unsigned long tmp;
	unsigned long start_mem = memory_start;
	unsigned long end_mem = memory_end;

	end_mem &= PAGE_MASK;
	high_memory = (void *)end_mem;

	start_mem = PAGE_ALIGN(start_mem);
	max_mapnr = num_physpages = MAP_NR(high_memory);
	printk(KERN_INFO "Kernel managed physical pages: %lu\n",
		num_physpages);

	/* This will put all memory onto the freelists. */
	totalram_pages = free_all_bootmem();

	reservedpages = 0;
	for (tmp = 0; tmp < max_mapnr; tmp++)
		if (PageReserved(pfn_to_page(tmp)))
			reservedpages++;
	freepages =  max_mapnr - reservedpages;

	/* do not count in kernel image between _rambase and _ramstart */
	reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
#if (defined(CONFIG_BFIN_ICACHE) && ANOMALY_05000263)
	reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >>
				PAGE_SHIFT;
#endif

	codek = (_etext - _stext) >> 10;
	initk = (__init_end - __init_begin) >> 10;
	datak = ((_ramstart - _rambase) >> 10) - codek - initk;

	printk(KERN_INFO
	     "Memory available: %luk/%luk RAM, "
		"(%uk init code, %uk kernel code, "
		"%uk data, %uk dma, %uk reserved)\n",
		(unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
		initk, codek, datak, DMA_UNCACHED_REGION >> 10,
		(reservedpages << (PAGE_SHIFT-10)));

	/* Initialize the blackfin L1 Memory. */
	l1sram_init();
	l1_data_sram_init();
	l1_inst_sram_init();

	/* Allocate this once; never free it.  We assume this gives us a
	   pointer to the start of L1 scratchpad memory; panic if it
	   doesn't.  */
	tmp = (unsigned long)l1sram_alloc(sizeof(struct l1_scratch_task_info));
	if (tmp != (unsigned long)L1_SCRATCH_TASK_INFO) {
		printk(KERN_EMERG "mem_init(): Did not get the right address from l1sram_alloc: %08lx != %08lx\n",
			tmp, (unsigned long)L1_SCRATCH_TASK_INFO);
		panic("No L1, time to give up\n");
	}
}

static __init void free_init_pages(const char *what, unsigned long begin, unsigned long end)
{
	unsigned long addr;
	/* next to check that the page we free is not a partial page */
	for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
		ClearPageReserved(virt_to_page(addr));
		init_page_count(virt_to_page(addr));
		free_page(addr);
		totalram_pages++;
	}
	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
#ifndef CONFIG_MPU
	free_init_pages("initrd memory", start, end);
#endif
}
#endif

void __init free_initmem(void)
{
#if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
	free_init_pages("unused kernel memory",
			(unsigned long)(&__init_begin),
			(unsigned long)(&__init_end));
#endif
}