diff options
Diffstat (limited to 'arch/powerpc/kernel/crash_dump.c')
| -rw-r--r-- | arch/powerpc/kernel/crash_dump.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c index 5337ab75978..87effa3f21a 100644 --- a/arch/powerpc/kernel/crash_dump.c +++ b/arch/powerpc/kernel/crash_dump.c @@ -16,6 +16,7 @@ #include <asm/kdump.h> #include <asm/lmb.h> #include <asm/firmware.h> +#include <asm/uaccess.h> #ifdef DEBUG #include <asm/udbg.h> @@ -71,3 +72,38 @@ static int __init parse_savemaxmem(char *p) return 0; } __setup("savemaxmem=", parse_savemaxmem); + +/* + * 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, 0); + + if (userbuf) { + if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) { + iounmap(vaddr); + return -EFAULT; + } + } else + memcpy(buf, (vaddr + offset), csize); + + iounmap(vaddr); + return csize; +} |