uml: clean up TASK_SIZE usage

Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/include/asm-um/processor-generic.h b/include/asm-um/processor-generic.h
index 35ab6a292d63..ecf67069941a 100644
--- a/include/asm-um/processor-generic.h
+++ b/include/asm-um/processor-generic.h
@@ -94,9 +94,7 @@ static inline void mm_copy_segments(struct mm_struct *from_mm,
 /*
  * User space process size: 3GB (default).
  */
-extern unsigned long task_size;
-
-#define TASK_SIZE       (task_size)
+#define TASK_SIZE (CONFIG_TOP_ADDR & PGDIR_MASK)
 
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.