Commit a6d27ea0 authored by Claudio Imbrenda's avatar Claudio Imbrenda Committed by Alexander Gordeev
Browse files

s390/mm: convert pgste locking functions to C 



Convert pgste_get_lock() and pgste_set_unlock() to C.

There is no real reasons to keep them in assembler. Having them in C
makes them more readable and maintainable, and better instructions are
used automatically when available.

Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20231205173252.62305-1-imbrenda@linux.ibm.com


Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 18564756

arch/s390/mm/pgtable.c

+10 −19
Original line number Diff line number Diff line
@@ -125,32 +125,23 @@ static inline pte_t ptep_flush_lazy(struct mm_struct *mm, 


static inline pgste_t pgste_get_lock(pte_t *ptep)

{

	unsigned long new = 0;

	unsigned long value = 0;

#ifdef CONFIG_PGSTE

	unsigned long old;



	asm(

		"	lg	%0,%2\n"

		"0:	lgr	%1,%0\n"

		"	nihh	%0,0xff7f\n"	/* clear PCL bit in old */

		"	oihh	%1,0x0080\n"	/* set PCL bit in new */

		"	csg	%0,%1,%2\n"

		"	jl	0b\n"

		: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])

		: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");

	unsigned long *ptr = (unsigned long *)(ptep + PTRS_PER_PTE);



	do {

		value = __atomic64_or_barrier(PGSTE_PCL_BIT, ptr);

	} while (value & PGSTE_PCL_BIT);

	value |= PGSTE_PCL_BIT;

#endif

	return __pgste(new);

	return __pgste(value);

}



static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)

{

#ifdef CONFIG_PGSTE

	asm(

		"	nihh	%1,0xff7f\n"	/* clear PCL bit */

		"	stg	%1,%0\n"

		: "=Q" (ptep[PTRS_PER_PTE])

		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])

		: "cc", "memory");

	barrier();

	WRITE_ONCE(*(unsigned long *)(ptep + PTRS_PER_PTE), pgste_val(pgste) & ~PGSTE_PCL_BIT);

#endif

}