[PATCH] makedumpfile: s390x: Add 2GB frame support for page table walker

[Atsushi Kumagai]

Hello Michael,

On Fri, 19 Oct 2012 18:29:12 +0200
Michael Holzheu <holzheu at linux.vnet.ibm.com> wrote:

> On s390 the zEC12 machines support 2GB frames. In order to walk page
> tables correctly add support to the page table walker function so it
> detects 2GB frames.
> 
> Signed-off-by: Heiko Carstens <heiko.carstens at de.ibm.com>
> Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>

Thank you for your work. I have a question.

> ---
>  arch/s390x.c   |    6 ++++++
>  makedumpfile.h |    1 +
>  2 files changed, 7 insertions(+)
> 
> --- a/arch/s390x.c
> +++ b/arch/s390x.c
> @@ -247,6 +247,11 @@ vtop_s390x(unsigned long vaddr)
>  			return NOT_PADDR;
>  		}
>  		table = entry & _REGION_ENTRY_ORIGIN;
> +		if ((entry & _REGION_ENTRY_LARGE) && (level == 1)) {
> +			table &= ~0x7fffffffUL;
> +			paddr = table + (vaddr & 0x7ffffffUL);
                                                 ^^^^^^^^^^^
There is 0x7ffffff(27bit) but the patch for crash uses 0x7fffffff(31bit).
Which is correct ?


Thanks
Atsushi Kumagai

> +			return paddr;
> +		}
>  		len = RSG_TABLE_LENGTH(entry);
>  		level--;
>  	}
> @@ -257,6 +262,7 @@ vtop_s390x(unsigned long vaddr)
>  	 * if no, then get the page table entry using PX index.
>  	 */
>  	if (entry & _SEGMENT_ENTRY_LARGE) {
> +		table &= ~_PAGE_BYTE_INDEX_MASK;
>  		paddr = table + (vaddr &  _PAGE_BYTE_INDEX_MASK);
>  	} else {
>  		entry = _kl_pg_table_deref_s390x(vaddr,
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -563,6 +563,7 @@ do { \
>  #define _REGION_ENTRY_TYPE_MASK	0x0c	/* region table type mask */
>  #define _REGION_ENTRY_INVALID	0x20	/* invalid region table entry */
>  #define _REGION_ENTRY_LENGTH	0x03	/* region table length */
> +#define _REGION_ENTRY_LARGE	0x400
>  #define _REGION_OFFSET_MASK	0x7ffUL	/* region/segment table offset mask */
>  
>  #define RSG_TABLE_LEVEL(x)	(((x) & _REGION_ENTRY_TYPE_MASK) >> 2)
> 
> 
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