[RFC PATCH v4 1/2] powerpc: reserve fixmap entries for early debug

[Albert Herranz]

Add a set of entries to the fixmap table to allow usage of known
reserved virtual address space by early debug code.

The address space reserved is the top 128K of the 32-bit address
space. This allows, if required, the use of a BAT to do the mappings.

Signed-off-by: Albert Herranz <albert_herranz at yahoo.es>
---
 arch/powerpc/include/asm/fixmap.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index f1f4e23..5c2c023 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -44,6 +44,9 @@
  */
 enum fixed_addresses {
 	FIX_HOLE,
+	/* reserve the top 128K for early debugging purposes */
+	FIX_EARLY_DEBUG_TOP = FIX_HOLE,
+	FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1,
 #ifdef CONFIG_HIGHMEM
 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
 	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
-- 
1.6.3.3