x86-32: use brk segment for allocating initial kernel pagetable

Impact: use new interface instead of previous ad hoc implementation

Rather than having special purpose init_pg_table_start/end variables
to delimit the kernel pagetable built by head_32.S, just use the brk
mechanism to extend the bss for the new pagetable.

This patch removes init_pg_table_start/end and pg0, defines __brk_base
(which is page-aligned and immediately follows _end), initializes
the brk region to start there, and uses it for the 32-bit pagetable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 0 insertions, 4 deletions

diff --git a/arch/x86/kernel/vmlinux_32.lds.S b/arch/x86/kernel/vmlinux_32.lds.S
index 27e44aa21585..1063fbe93c73 100644
--- a/arch/x86/kernel/vmlinux_32.lds.S
+++ b/arch/x86/kernel/vmlinux_32.lds.S
@@ -196,10 +196,6 @@ SECTIONS
         __brk_limit = . ;
 
         _end = . ;
-
-        /* This is where the kernel creates the early boot page tables */
-        . = ALIGN(PAGE_SIZE);
-        pg0 = . ;
   }
 
   /* Sections to be discarded */