powerpc/mm: Fix 40x and 8xx vs. _PAGE_SPECIAL

The test to check whether we have _PAGE_SPECIAL defined is broken,
since we always define it, just not always to a meaninful value :-)

That broke 8xx and 40x under some circumstances.

This fixes it by adding _PAGE_SPECIAL for both of these since they
had a free PTE bit, and removing the condition around advertising
it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 2 insertions, 5 deletions

diff --git a/arch/powerpc/include/asm/pte-40x.h b/arch/powerpc/include/asm/pte-40x.h
index 6c3e1f4378d4..ec0b0b0d1df9 100644
--- a/arch/powerpc/include/asm/pte-40x.h
+++ b/arch/powerpc/include/asm/pte-40x.h
@@ -43,6 +43,7 @@
 #define _PAGE_NO_CACHE  0x004   /* I: caching is inhibited */
 #define _PAGE_WRITETHRU 0x008   /* W: caching is write-through */
 #define _PAGE_USER      0x010   /* matches one of the zone permission bits */
+#define _PAGE_SPECIAL   0x020   /* software: Special page */
 #define _PAGE_RW        0x040   /* software: Writes permitted */
 #define _PAGE_DIRTY     0x080   /* software: dirty page */
 #define _PAGE_HWWRITE   0x100   /* hardware: Dirty & RW, set in exception */
diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
index 94e979718dcf..dd5ea95fe61e 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -32,6 +32,7 @@
 #define _PAGE_FILE      0x0002  /* when !present: nonlinear file mapping */
 #define _PAGE_NO_CACHE  0x0002  /* I: cache inhibit */
 #define _PAGE_SHARED    0x0004  /* No ASID (context) compare */
+#define _PAGE_SPECIAL   0x0008  /* SW entry, forced to 0 by the TLB miss */
 
 /* These five software bits must be masked out when the entry is loaded
  * into the TLB.
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c3b65076a263..f2b370180a09 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -25,9 +25,6 @@
 #ifndef _PAGE_WRITETHRU
 #define _PAGE_WRITETHRU 0
 #endif
-#ifndef _PAGE_SPECIAL
-#define _PAGE_SPECIAL   0
-#endif
 #ifndef _PAGE_4K_PFN
 #define _PAGE_4K_PFN            0
 #endif
@@ -179,7 +176,5 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
 #define HAVE_PAGE_AGP
 
 /* Advertise support for _PAGE_SPECIAL */
-#ifdef _PAGE_SPECIAL
 #define __HAVE_ARCH_PTE_SPECIAL
-#endif