linux-sg2042/arch/blackfin/mm/init.c

/*
 * File:         arch/blackfin/mm/init.c
 * Based on:
 * Author:
 *
 * Created:
 * Description:
 *
 * Modified:
 *               Copyright 2004-2006 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 <asm/bfin-global.h>
#include <asm/uaccess.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 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_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
		zones_size[ZONE_HIGHMEM] = 0;
#endif
		free_area_init(zones_size);
	}
}

void mem_init(void)
{
	unsigned int codek = 0, datak = 0, initk = 0;
	unsigned long tmp;
	unsigned int len = _ramend - _rambase;
	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 "Physical pages: %lx\n", num_physpages);

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

	codek = (_etext - _stext) >> 10;
	datak = (__bss_stop - __bss_start) >> 10;
	initk = (__init_end - __init_begin) >> 10;

	tmp = nr_free_pages() << PAGE_SHIFT;
	printk(KERN_INFO
	     "Memory available: %luk/%uk RAM, (%uk init code, %uk kernel code, %uk data, %uk dma)\n",
	     tmp >> 10, len >> 10, initk, codek, datak, DMA_UNCACHED_REGION >> 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");
	}
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
	int pages = 0;
	for (; start < end; start += PAGE_SIZE) {
		ClearPageReserved(virt_to_page(start));
		init_page_count(virt_to_page(start));
		free_page(start);
		totalram_pages++;
		pages++;
	}
	printk(KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
}
#endif

void free_initmem(void)
{
#ifdef CONFIG_RAMKERNEL
	unsigned long addr;
/*
 *	the following code should be cool even if these sections
 *	are not page aligned.
 */
	addr = PAGE_ALIGN((unsigned long)(__init_begin));
	/* next to check that the page we free is not a partial page */
	for (; addr + PAGE_SIZE < (unsigned long)(__init_end);
	     addr += PAGE_SIZE) {
		ClearPageReserved(virt_to_page(addr));
		init_page_count(virt_to_page(addr));
		free_page(addr);
		totalram_pages++;
	}
	printk(KERN_NOTICE
	       "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
	       (addr - PAGE_ALIGN((long)__init_begin)) >> 10,
	       (int)(PAGE_ALIGN((unsigned long)(__init_begin))),
	       (int)(addr - PAGE_SIZE));
#endif
}