Commit 175a9999 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/8xx: Refactor calculation of number of entries per PTE in page tables 



On 8xx, the number of entries occupied by a PTE in the page tables
depends on the size of the page. At the time being, this calculation
is done in two places: in pte_update() and in set_huge_pte_at()

Refactor this calculation into a helper called
number_of_cells_per_pte(). For the time being, the val param is
unused. It will be used by following patch.

Instead of opencoding is_hugepd(), use hugepd_ok() with a forward
declaration.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f6ea2483c2c389567b007945948f704d18cfaeea.1598862623.git.christophe.leroy@csgroup.eu
parent 542db12a

arch/powerpc/include/asm/nohash/32/pgtable.h

+12 −6
Original line number Diff line number Diff line
@@ -227,6 +227,17 @@ static inline void pmd_clear(pmd_t *pmdp) 
 */

#ifdef CONFIG_PPC_8xx

static pmd_t *pmd_off(struct mm_struct *mm, unsigned long addr);

static int hugepd_ok(hugepd_t hpd);



static int number_of_cells_per_pte(pmd_t *pmd, pte_basic_t val, int huge)

{

	if (!huge)

		return PAGE_SIZE / SZ_4K;

	else if (hugepd_ok(*((hugepd_t *)pmd)))

		return 1;

	else

		return SZ_512K / SZ_4K;

}



static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,

				     unsigned long clr, unsigned long set, int huge)
@@ -237,12 +248,7 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p 
	int num, i;

	pmd_t *pmd = pmd_off(mm, addr);



	if (!huge)

		num = PAGE_SIZE / SZ_4K;

	else if ((pmd_val(*pmd) & _PMD_PAGE_MASK) != _PMD_PAGE_8M)

		num = SZ_512K / SZ_4K;

	else

		num = 1;

	num = number_of_cells_per_pte(pmd, new, huge);



	for (i = 0; i < num; i++, entry++, new += SZ_4K)

		*entry = new;

arch/powerpc/mm/pgtable.c

+4 −2
Original line number Diff line number Diff line
@@ -266,8 +266,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_ 
	pmd_t *pmd = pmd_off(mm, addr);

	pte_basic_t val;

	pte_basic_t *entry = &ptep->pte;

	int num = is_hugepd(*((hugepd_t *)pmd)) ? 1 : SZ_512K / SZ_4K;

	int i;

	int num, i;



	/*

	 * Make sure hardware valid bit is not set. We don't do
@@ -280,6 +279,9 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_ 
	pte = set_pte_filter(pte);



	val = pte_val(pte);



	num = number_of_cells_per_pte(pmd, val, 1);



	for (i = 0; i < num; i++, entry++, val += SZ_4K)

		*entry = val;

}

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