Commit bd39fc81 authored by Matt Turner's avatar Matt Turner Committed by Magnus Lindholm
Browse files

alpha: Define pgprot_modify to silence tautological comparison warnings 



Alpha's pgprot_noncached, pgprot_writecombine, and pgprot_device are
all identity macros, so the generic pgprot_modify() produces
tautological self-comparisons that GCC warns about:

  include/linux/pgtable.h:1701:25: warning: self-comparison always
  evaluates to true [-Wtautological-compare]

Since all caching attributes are no-ops on Alpha, define
pgprot_modify() to simply return newprot.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
Reviewed-by: default avatarMagnus Lindholm <linmag7@gmail.com>
Link: https://lore.kernel.org/r/20260403150128.488513-1-mattst88@gmail.com


Signed-off-by: default avatarMagnus Lindholm <linmag7@gmail.com>
parent 55b22075

arch/alpha/include/asm/pgtable.h

+11 −0
Original line number Diff line number Diff line
@@ -126,6 +126,17 @@ struct vm_area_struct; 
 */

#define pgprot_noncached(prot)	(prot)



/*

 * All caching attribute macros are identity on Alpha, so the generic

 * pgprot_modify() degenerates to tautological self-comparisons.

 * Override it to just return newprot directly.

 */

#define pgprot_modify pgprot_modify

static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)

{

	return newprot;

}



/*

 * ZERO_PAGE is a global shared page that is always zero:  used

 * for zero-mapped memory areas etc..