x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit

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Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE just like we already do on
x86-64.  After deciphering the PTE layout it becomes clear that there are
still unused bits for 2-level and 3-level page tables that we should be
able to use.  Reusing a bit avoids stealing one bit from the swap offset.

While at it, mask the type in __swp_entry(); use some helper definitions
to make the macros easier to grasp.

Link: https://lkml.kernel.org/r/20230113171026.582290-25-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

...

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David Hildenbrand 2023-01-13 18:10:24 +01:00 • committed by Andrew Morton

parent e2858d778e

commit 93c0eac40d

3 changed files with 44 additions and 10 deletions

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26

arch/x86/include/asm/pgtable-2level.h

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26

arch/x86/include/asm/pgtable-3level.h

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2

arch/x86/include/asm/pgtable.h

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