diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 14:16:54 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-14 13:11:15 +0100 |
| commit | 162434e7f58b21f0b6c9cc5fb02222cd7d9064cc (patch) | |
| tree | adf014fd36b800345ea4abfb27961de4b9677f92 /arch/x86/include/asm/sparsemem.h | |
| parent | c65e774fb3f6af212641538694b9778ff9ab4300 (diff) | |
x86/mm: Make MAX_PHYSADDR_BITS and MAX_PHYSMEM_BITS dynamic
For boot-time switching between paging modes, we need to be able to
adjust size of physical address space at runtime.
As part of making physical address space size variable, we have to make
X86_5LEVEL dependent on SPARSEMEM_VMEMMAP. !SPARSEMEM_VMEMMAP
configuration doesn't build with variable MAX_PHYSMEM_BITS.
For !SPARSEMEM_VMEMMAP SECTIONS_WIDTH depends on MAX_PHYSMEM_BITS:
SECTIONS_WIDTH
SECTIONS_SHIFT
MAX_PHYSMEM_BITS
And SECTIONS_WIDTH is used on pre-processor stage, it doesn't work if it's
dyncamic. See include/linux/page-flags-layout.h.
Effect on kernel image size:
text data bss dec hex filename
8628393 4734340 1368064 14730797 e0c62d vmlinux.before
8628892 4734340 1368064 14731296 e0c820 vmlinux.after
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214111656.88514-8-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/sparsemem.h')
| -rw-r--r-- | arch/x86/include/asm/sparsemem.h | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h index 4fc1e9d3c43e..4617a2bf123c 100644 --- a/arch/x86/include/asm/sparsemem.h +++ b/arch/x86/include/asm/sparsemem.h @@ -27,13 +27,8 @@ # endif #else /* CONFIG_X86_32 */ # define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */ -# ifdef CONFIG_X86_5LEVEL -# define MAX_PHYSADDR_BITS 52 -# define MAX_PHYSMEM_BITS 52 -# else -# define MAX_PHYSADDR_BITS 44 -# define MAX_PHYSMEM_BITS 46 -# endif +# define MAX_PHYSADDR_BITS (pgtable_l5_enabled ? 52 : 44) +# define MAX_PHYSMEM_BITS (pgtable_l5_enabled ? 52 : 46) #endif #endif /* CONFIG_SPARSEMEM */ |