On Fri, Jun 07, 2013 at 06:56:00PM +0200, Michael Holzheu wrote:
> From: Jan Willeke <willeke at de.ibm.com>
>
> This patch introduces the s390 specific way to map pages from oldmem.
> The memory area below OLDMEM_SIZE is mapped with offset OLDMEM_BASE.
> The other old memory is mapped directly.
>
If we get rid of swap logic in copy_oldmem_page(), quite some amount
of code can be cleaned up. One has to spcial case only zfcpdump to
read from HSA memory.
Anyway sounds like a s390 specific cleanup in a separate series.
Thanks
Vivek
> Signed-off-by: Jan Willeke <willeke at de.ibm.com>
> Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
> ---
> arch/s390/kernel/crash_dump.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
> index a17f8d4..12ccc3c 100644
> --- a/arch/s390/kernel/crash_dump.c
> +++ b/arch/s390/kernel/crash_dump.c
> @@ -56,6 +56,32 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
> }
>
> /*
> + * Remap "oldmem"
> + *
> + * For the kdump reserved memory this functions performs a swap operation:
> + * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
> + */
> +int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
> + unsigned long pfn, unsigned long size, pgprot_t prot)
> +{
> + unsigned long size_old;
> + int rc;
> +
> + if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
> + size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
> + rc = remap_pfn_range(vma, from,
> + pfn + (OLDMEM_BASE >> PAGE_SHIFT),
> + size_old, prot);
> + if (rc || size == size_old)
> + return rc;
> + size -= size_old;
> + from += size_old;
> + pfn += size_old >> PAGE_SHIFT;
> + }
> + return remap_pfn_range(vma, from, pfn, size, prot);
> +}
> +
> +/*
> * Copy memory from old kernel
> */
> int copy_from_oldmem(void *dest, void *src, size_t count)
> --
> 1.8.1.6
