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

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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: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f6ea2483c2c389567b007945948f704d18cfaeea.1598862623.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2020-08-31 08:30:43 +00:00 committed by Michael Ellerman
parent 542db12a9c
commit 175a999915
2 changed files with 16 additions and 8 deletions
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18
arch/powerpc/include/asm/nohash/32/pgtable.h
View File

@ -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;

6
arch/powerpc/mm/pgtable.c
View File

@ -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;
}