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linux-next/arch/mips/kernel/crash_dump.c
Joe Perches 7178d2cdd9 mips: Convert pr_warning to pr_warn
Use the much more common pr_warn instead of pr_warning
with the goal of removing pr_warning eventually.

Other miscellanea:

o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
Cc: linux-mips <linux-mips@linux-mips.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/7935/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:44:51 +01:00

67 lines
1.7 KiB
C

#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/crash_dump.h>
#include <asm/uaccess.h>
#include <linux/slab.h>
static void *kdump_buf_page;
/**
* 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.
*
* Calling copy_to_user() in atomic context is not desirable. Hence first
* copying the data to a pre-allocated kernel page and then copying to user
* space in non-atomic context.
*/
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 = kmap_atomic_pfn(pfn);
if (!userbuf) {
memcpy(buf, (vaddr + offset), csize);
kunmap_atomic(vaddr);
} else {
if (!kdump_buf_page) {
pr_warn("Kdump: Kdump buffer page not allocated\n");
return -EFAULT;
}
copy_page(kdump_buf_page, vaddr);
kunmap_atomic(vaddr);
if (copy_to_user(buf, (kdump_buf_page + offset), csize))
return -EFAULT;
}
return csize;
}
static int __init kdump_buf_page_init(void)
{
int ret = 0;
kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!kdump_buf_page) {
pr_warn("Kdump: Failed to allocate kdump buffer page\n");
ret = -ENOMEM;
}
return ret;
}
arch_initcall(kdump_buf_page_init);