diff options
| author | Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> | 2009-02-27 13:27:38 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-03-14 17:23:47 -0700 |
| commit | ccf3fe02e35f4abca2589f99022cc25084bbd8ae (patch) | |
| tree | 3bcf329116b8c689b4da1bb1a0d87bb587d3f3c7 /arch/x86/kernel/head_32.S | |
| parent | 5368a2be34b96fda9c05d79424fa63a73ead04ed (diff) | |
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>
Diffstat (limited to 'arch/x86/kernel/head_32.S')
| -rw-r--r-- | arch/x86/kernel/head_32.S | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index c32ca19d591..db6652710e9 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -167,7 +167,7 @@ num_subarch_entries = (. - subarch_entries) / 4 /* * Initialize page tables. This creates a PDE and a set of page * tables, which are located immediately beyond _end. The variable - * init_pg_tables_end is set up to point to the first "safe" location. + * _brk_end is set up to point to the first "safe" location. * Mappings are created both at virtual address 0 (identity mapping) * and PAGE_OFFSET for up to _end+sizeof(page tables)+INIT_MAP_BEYOND_END. * @@ -190,8 +190,7 @@ default_entry: xorl %ebx,%ebx /* %ebx is kept at zero */ - movl $pa(pg0), %edi - movl %edi, pa(init_pg_tables_start) + movl $pa(__brk_base), %edi movl $pa(swapper_pg_pmd), %edx movl $PTE_IDENT_ATTR, %eax 10: @@ -216,7 +215,8 @@ default_entry: cmpl %ebp,%eax jb 10b 1: - movl %edi,pa(init_pg_tables_end) + addl $__PAGE_OFFSET, %edi + movl %edi, pa(_brk_end) shrl $12, %eax movl %eax, pa(max_pfn_mapped) @@ -227,8 +227,7 @@ default_entry: page_pde_offset = (__PAGE_OFFSET >> 20); - movl $pa(pg0), %edi - movl %edi, pa(init_pg_tables_start) + movl $pa(__brk_base), %edi movl $pa(swapper_pg_dir), %edx movl $PTE_IDENT_ATTR, %eax 10: @@ -249,7 +248,8 @@ page_pde_offset = (__PAGE_OFFSET >> 20); leal (INIT_MAP_BEYOND_END+PTE_IDENT_ATTR)(%edi),%ebp cmpl %ebp,%eax jb 10b - movl %edi,pa(init_pg_tables_end) + addl $__PAGE_OFFSET, %edi + movl %edi, pa(_brk_end) shrl $12, %eax movl %eax, pa(max_pfn_mapped) |