[PATCH] fix linux ioremap() of domain local memory

[PATCH] fix linux ioremap() of domain local memory

[Avi Kivity]

is_local_lowmem() treats its physical address input as a machine 
address; this causes agpgart to fail while calling ioremap_nocache().

X still does not load on my Athlon 64 / Via S3 Unichrome, so perhaps 
best not to apply just yet.

Signed-off-by: Avi Kivity <avi@qumranet.com>

--- xen-ioremap-fix/linux-2.6-xen-sparse/arch/i386/mm/ioremap-xen.c~ioremap	2006-06-22 20:30:20.000000000 +0300
+++ xen-ioremap-fix/linux-2.6-xen-sparse/arch/i386/mm/ioremap-xen.c	2006-06-22 20:31:09.000000000 +0300
@@ -206,13 +206,11 @@
 /*
  * Does @address reside within a non-highmem page that is local to this virtual
  * machine (i.e., not an I/O page, nor a memory page belonging to another VM).
- * See the comment that accompanies mfn_to_local_pfn() in page.h to understand
- * why this works.
  */
 static inline int is_local_lowmem(unsigned long address)
 {
 	extern unsigned long max_low_pfn;
-	return (mfn_to_local_pfn(address >> PAGE_SHIFT) < max_low_pfn);
+	return ((address >> PAGE_SHIFT) < max_low_pfn);
 }
 
 /*




-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

Re: [PATCH] fix linux ioremap() of domain local memory

[Avi Kivity]

Avi Kivity wrote:
> is_local_lowmem() treats its physical address input as a machine 
> address; this causes agpgart to fail while calling ioremap_nocache().
>
> X still does not load on my Athlon 64 / Via S3 Unichrome, so perhaps 
> best not to apply just yet.

This is bogus: ioremap_nocache() does accept machine addresses, but 
x86_64 agpgart passes it a physical address.  This is because x86_64 
lacks the address translation bits:

--- /dev/null   2006-06-25 13:08:55.714359750 +0300
+++ include/asm-x86_64/mach-xen/asm/agp.h       2006-06-25 13:15:12.000000000 +0300
@@ -0,0 +1 @@
+#include "../../../asm-i386/mach-xen/asm/agp.h"


Still locks up hard when starting up X, but now the gart table is 
remapped correctly at least.

-- 
error compiling committee.c: too many arguments to function