Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f4894b80 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Michael Ellerman
Browse files

powerpc/mm/radix: Use ptep_get_and_clear_full when clearing pte for full mm 



This helps us to do some optimization for application exit case, where we can
skip the DD1 style pte update sequence.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent ca94573b

arch/powerpc/include/asm/book3s/64/pgtable.h

+17 −0
Original line number Diff line number Diff line
@@ -371,6 +371,23 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, 
	return __pte(old);

}



#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL

static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,

					    unsigned long addr,

					    pte_t *ptep, int full)

{

	if (full && radix_enabled()) {

		/*

		 * Let's skip the DD1 style pte update here. We know that

		 * this is a full mm pte clear and hence can be sure there is

		 * no parallel set_pte.

		 */

		return radix__ptep_get_and_clear_full(mm, addr, ptep, full);

	}

	return ptep_get_and_clear(mm, addr, ptep);

}





static inline void pte_clear(struct mm_struct *mm, unsigned long addr,

			     pte_t * ptep)

{

arch/powerpc/include/asm/book3s/64/radix.h

+22 −1
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ static inline unsigned long radix__pte_update(struct mm_struct *mm, 


		unsigned long new_pte;



		old_pte = __radix_pte_update(ptep, ~0, 0);

		old_pte = __radix_pte_update(ptep, ~0ul, 0);

		/*

		 * new value of pte

		 */
@@ -157,6 +157,27 @@ static inline unsigned long radix__pte_update(struct mm_struct *mm, 
	return old_pte;

}



static inline pte_t radix__ptep_get_and_clear_full(struct mm_struct *mm,

						   unsigned long addr,

						   pte_t *ptep, int full)

{

	unsigned long old_pte;



	if (full) {

		/*

		 * If we are trying to clear the pte, we can skip

		 * the DD1 pte update sequence and batch the tlb flush. The

		 * tlb flush batching is done by mmu gather code. We

		 * still keep the cmp_xchg update to make sure we get

		 * correct R/C bit which might be updated via Nest MMU.

		 */

		old_pte = __radix_pte_update(ptep, ~0ul, 0);

	} else

		old_pte = radix__pte_update(mm, addr, ptep, ~0ul, 0, 0);



	return __pte(old_pte);

}



/*

 * Set the dirty and/or accessed bits atomically in a linux PTE, this

 * function doesn't need to invalidate tlb.