[linux.git] / arch / sh / kernel / crash_dump.c

/*
 *	crash_dump.c - Memory preserving reboot related code.
 *
 *	Created by: Hariprasad Nellitheertha ([email protected])
 *	Copyright (C) IBM Corporation, 2004. All rights reserved
 */
#include <linux/errno.h>
#include <linux/crash_dump.h>
#include <linux/io.h>
#include <asm/uaccess.h>

/**
 * copy_oldmem_page - copy one page from "oldmem"
 * @pfn: page frame number to be copied
 * @buf: target memory address for the copy; this can be in kernel address
 *	space or user address space (see @userbuf)
 * @csize: number of bytes to copy
 * @offset: offset in bytes into the page (based on pfn) to begin the copy
 * @userbuf: if set, @buf is in user address space, use copy_to_user(),
 *	otherwise @buf is in kernel address space, use memcpy().
 *
 * Copy a page from "oldmem". For this page, there is no pte mapped
 * in the current kernel. We stitch up a pte, similar to kmap_atomic.
 */
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
                               size_t csize, unsigned long offset, int userbuf)
{
	void  *vaddr;

	if (!csize)
		return 0;

	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);

	if (userbuf) {
		if (copy_to_user(buf, (vaddr + offset), csize)) {
			iounmap(vaddr);
			return -EFAULT;
		}
	} else
	memcpy(buf, (vaddr + offset), csize);

	iounmap(vaddr);
	return csize;
}
Commit	Line	Data
4d5ade5b PM	1	/*
	2	* crash_dump.c - Memory preserving reboot related code.
	3	*
	4	* Created by: Hariprasad Nellitheertha ([email protected])
	5	* Copyright (C) IBM Corporation, 2004. All rights reserved
	6	*/
4d5ade5b PM	7	#include <linux/errno.h>
	8	#include <linux/crash_dump.h>
	9	#include <linux/io.h>
	10	#include <asm/uaccess.h>
	11
	12	/**
	13	* copy_oldmem_page - copy one page from "oldmem"
	14	* @pfn: page frame number to be copied
	15	* @buf: target memory address for the copy; this can be in kernel address
	16	* space or user address space (see @userbuf)
	17	* @csize: number of bytes to copy
	18	* @offset: offset in bytes into the page (based on pfn) to begin the copy
	19	* @userbuf: if set, @buf is in user address space, use copy_to_user(),
	20	* otherwise @buf is in kernel address space, use memcpy().
	21	*
	22	* Copy a page from "oldmem". For this page, there is no pte mapped
	23	* in the current kernel. We stitch up a pte, similar to kmap_atomic.
	24	*/
	25	ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
	26	size_t csize, unsigned long offset, int userbuf)
	27	{
	28	void *vaddr;
	29
	30	if (!csize)
	31	return 0;
	32
	33	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
	34
	35	if (userbuf) {
	36	if (copy_to_user(buf, (vaddr + offset), csize)) {
	37	iounmap(vaddr);
	38	return -EFAULT;
	39	}
	40	} else
	41	memcpy(buf, (vaddr + offset), csize);
	42
	43	iounmap(vaddr);
	44	return csize;
	45	}