microblaze: Highmem support

The first highmem implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 11 insertions, 13 deletions

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 3267cc5065d5..86ae27871f41 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -159,20 +159,18 @@ config XILINX_UNCACHED_SHADOW
           The feature requires the design to define the RAM memory controller
           window to be twice as large as the actual physical memory.
 
-config HIGHMEM_START_BOOL
-        bool "Set high memory pool address"
-        depends on ADVANCED_OPTIONS && HIGHMEM
-        help
-          This option allows you to set the base address of the kernel virtual
-          area used to map high memory pages.  This can be useful in
-          optimizing the layout of kernel virtual memory.
-
-          Say N here unless you know what you are doing.
-
-config HIGHMEM_START
-        hex "Virtual start address of high memory pool" if HIGHMEM_START_BOOL
+config HIGHMEM
+        bool "High memory support"
         depends on MMU
-        default "0xfe000000"
+        help
+          The address space of Microblaze processors is only 4 Gigabytes large
+          and it has to accommodate user address space, kernel address
+          space as well as some memory mapped IO. That means that, if you
+          have a large amount of physical memory and/or IO, not all of the
+          memory can be "permanently mapped" by the kernel. The physical
+          memory that is not permanently mapped is called "high memory".
+
+          If unsure, say n.
 
 config LOWMEM_SIZE_BOOL
         bool "Set maximum low memory"