+ x86-mm-drop-unused-max_physaddr_bits.patch added to -mm tree

+ x86-mm-drop-unused-max_physaddr_bits.patch added to -mm tree

[akpm]

The patch titled
     Subject: x86/mm: drop unused MAX_PHYSADDR_BITS
has been added to the -mm tree.  Its filename is
     x86-mm-drop-unused-max_physaddr_bits.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/x86-mm-drop-unused-max_physaddr_bits.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/x86-mm-drop-unused-max_physaddr_bits.patch

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------------------------------------------------------
From: Arvind Sankar <nivedita@alum.mit.edu>
Subject: x86/mm: drop unused MAX_PHYSADDR_BITS

Patch series "Drop unused MAX_PHYSADDR_BITS".

This #define is not used anywhere, and has the wrong value on x86_64.

I tried digging into the history a bit, but it seems to have been unused
0even in the initial merge of sparsemem in v2.6.13, when it was first
defined.


This patch (of 3):

The macro is not used anywhere, and has an incorrect value (going by the
comment) on x86_64 since commit
  c898faf91b3e ("x86: 46 bit physical address support on 64 bits")

To avoid confusion, just remove the definition.

Link: http://lkml.kernel.org/r/20200723231544.17274-1-nivedita@alum.mit.edu
Link: http://lkml.kernel.org/r/20200723231544.17274-2-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/include/asm/sparsemem.h |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/arch/x86/include/asm/sparsemem.h~x86-mm-drop-unused-max_physaddr_bits
+++ a/arch/x86/include/asm/sparsemem.h
@@ -10,24 +10,20 @@
  *    field of the struct page
  *
  * SECTION_SIZE_BITS		2^n: size of each section
- * MAX_PHYSADDR_BITS		2^n: max size of physical address space
- * MAX_PHYSMEM_BITS		2^n: how much memory we can have in that space
+ * MAX_PHYSMEM_BITS		2^n: max size of physical address space
  *
  */
 
 #ifdef CONFIG_X86_32
 # ifdef CONFIG_X86_PAE
 #  define SECTION_SIZE_BITS	29
-#  define MAX_PHYSADDR_BITS	36
 #  define MAX_PHYSMEM_BITS	36
 # else
 #  define SECTION_SIZE_BITS	26
-#  define MAX_PHYSADDR_BITS	32
 #  define MAX_PHYSMEM_BITS	32
 # endif
 #else /* CONFIG_X86_32 */
 # define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */
-# define MAX_PHYSADDR_BITS	(pgtable_l5_enabled() ? 52 : 44)
 # define MAX_PHYSMEM_BITS	(pgtable_l5_enabled() ? 52 : 46)
 #endif
 
_

Patches currently in -mm which might be from nivedita@alum.mit.edu are

x86-mm-drop-unused-max_physaddr_bits.patch
sh-mm-drop-unused-max_physaddr_bits.patch
sparc-drop-unused-max_physaddr_bits.patch