Re: [PATCH] KVM: s390: Fix to clear PTE when discarding a swapped page

Re: [PATCH] KVM: s390: Fix to clear PTE when discarding a swapped page

[kernel test robot]

Hi Gautam,

kernel test robot noticed the following build warnings:

[auto build test WARNING on s390/features]
[also build test WARNING on linus/master v6.17-rc7 next-20250926]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gautam-Gala/KVM-s390-Fix-to-clear-PTE-when-discarding-a-swapped-page/20250924-201847
base:   https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git features
patch link:    https://lore.kernel.org/r/20250924121707.145350-1-ggala%40linux.ibm.com
patch subject: [PATCH] KVM: s390: Fix to clear PTE when discarding a swapped page
config: s390-defconfig (https://download.01.org/0day-ci/archive/20250928/202509280003.NWFBhwme-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project cafc064fc7a96b3979a023ddae1da2b499d6c954)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250928/202509280003.NWFBhwme-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509280003.NWFBhwme-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from arch/s390/boot/als.c:9:
   In file included from arch/s390/include/asm/sclp.h:26:
   In file included from arch/s390/include/asm/chpid.h:10:
   In file included from arch/s390/include/asm/cio.h:10:
   In file included from arch/s390/include/asm/dma-types.h:7:
   In file included from include/linux/io.h:12:
   In file included from arch/s390/include/asm/io.h:15:
>> arch/s390/include/asm/pgtable.h:2065:48: warning: passing 'unsigned long *' to parameter of type 'long *' converts between pointers to integer types with different sign [-Wpointer-sign]
    2065 |                 value = __atomic64_or_barrier(PGSTE_PCL_BIT, ptr);
         |                                                              ^~~
   arch/s390/include/asm/atomic_ops.h:161:1: note: passing argument to parameter 'ptr' here
     161 | __ATOMIC64_OPS(__atomic64_or,  "ogr")
         | ^
   arch/s390/include/asm/atomic_ops.h:157:2: note: expanded from macro '__ATOMIC64_OPS'
     157 |         __ATOMIC64_OP(op_name##_barrier, op_string)
         |         ^
   arch/s390/include/asm/atomic_ops.h:141:53: note: expanded from macro '__ATOMIC64_OP'
     141 | static __always_inline long op_name(long val, long *ptr)                \
         |                                                     ^
   1 warning generated.


vim +2065 arch/s390/include/asm/pgtable.h

  2057	
  2058	static inline pgste_t pgste_get_lock(pte_t *ptep)
  2059	{
  2060		unsigned long value = 0;
  2061	#ifdef CONFIG_PGSTE
  2062		unsigned long *ptr = (unsigned long *)(ptep + PTRS_PER_PTE);
  2063	
  2064		do {
> 2065			value = __atomic64_or_barrier(PGSTE_PCL_BIT, ptr);
  2066		} while (value & PGSTE_PCL_BIT);
  2067		value |= PGSTE_PCL_BIT;
  2068	#endif
  2069		return __pgste(value);
  2070	}
  2071	

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