Re: [Xen-devel] [Patch] ARCH_HAS_DEV_MEM patch for Xwindow onIA64machine

[Akio Takebe <takebe_akio@jp.fujitsu.com>]

Hi, Jan

>>>> Jun Kamada <kama@jp.fujitsu.com> 04.07.07 13:43 >>>
>>We would like to support Xwindow on IA64 by remapping machine address to
>>pseudo physical address at PCI device initialization (pci_acpi_scan_root()
>>in arch/ia64/pci/pci.c) but at "mmap /dev/mem" systemcall.
>>With the new scheme, we need no longer the archtecture specific memory
>>operations described above.
>
>You only talk about X - isn't it possible that there are other users of this
> interface?
>
Yes, you're right.
But if the following kama's patches are applied,
Xen-ia64 use drivers/char/mem.c. 
So drivers/xen/char/mem.c will not be needed by Xen-ia64.
http://lists.xensource.com/archives/html/xen-ia64-devel/2007-06/msg00167.html

>Also,
>
>>--- a/drivers/xen/Kconfig	Thu Jun 21 15:12:20 2007 +0900
>>+++ b/drivers/xen/Kconfig	Thu Jun 21 15:13:21 2007 +0900
>>@@ -273,4 +273,8 @@ config XEN_SMPBOOT
>> 	default y
>> 	depends on SMP
>> 
>>+config XEN_DEVMEM
>>+	bool
>>+	default y
>>+
>> endif
>
>This seems pretty useless unless ia64 doesn't use drivers/xen/Kconfig (which
>would be a mistake I think).
Please see the following patch.
http://lists.xensource.com/archives/html/xen-ia64-devel/2007-06/msg00169.html

Currently drviers/xen/char is built by all archtecture.
But if the above kama's patche is applied, it is not built by ia64.

diff -r a55f2df725a2 -r f3d513b91dea linux-2.6-xen-sparse/arch/ia64/Kconfig
--- a/linux-2.6-xen-sparse/arch/ia64/Kconfig	Wed Jun 13 12:28:14 2007 +0900
+++ b/linux-2.6-xen-sparse/arch/ia64/Kconfig	Wed Jun 13 12:35:24 2007 +0900
@@ -582,6 +582,9 @@ if XEN
 if XEN
 config XEN_SMPBOOT
 	default n
+
+config XEN_DEVMEM
+	default n
 endif
 
 source "drivers/xen/Kconfig"

Best Regards,

Akio Takebe