Kernel 4.7: PAGE_GUARDED and _PAGE_NO_CACHE

[Michael Ellerman]

On Thu, 2016-06-09 at 10:48 +0200, Christian Zigotzky wrote:

> Shall I modify the workaround? Is the workaround for lack of the device 
> tree the problem?

I don't think so.

You could try this patch to try and isolate it:

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 88a5ecaa157b..ae2f2705e8a0 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -251,7 +251,7 @@ extern unsigned long ioremap_bot;
  *  PHB_IO_BASE = ISA_IO_BASE + 64K to ISA_IO_BASE + 2G, PHB IO spaces
  * IOREMAP_BASE = ISA_IO_BASE + 2G to VMALLOC_START + PGTABLE_RANGE
  */
-#define KERN_IO_START	(KERN_VIRT_START + (KERN_VIRT_SIZE >> 1))
+#define KERN_IO_START	(H_KERN_VIRT_START + (H_KERN_VIRT_SIZE >> 1))
 #define FULL_IO_SIZE	0x80000000ul
 #define  ISA_IO_BASE	(KERN_IO_START)
 #define  ISA_IO_END	(KERN_IO_START + 0x10000ul)


cheers