powerpc/mm: move __find_linux_pte() out of hugetlbpage.c

__find_linux_pte() is the only function in hugetlbpage.c
which is compiled in regardless on CONFIG_HUGETLBPAGE

This patch moves it in pgtable.c.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2019-04-26 05:59:41 +00:00 committed by Michael Ellerman
parent 3dea7332cc
commit 0caed4de50
2 changed files with 104 additions and 103 deletions

View File

@ -756,109 +756,6 @@ void flush_dcache_icache_hugepage(struct page *page)
#endif /* CONFIG_HUGETLB_PAGE */
/*
* We have 4 cases for pgds and pmds:
* (1) invalid (all zeroes)
* (2) pointer to next table, as normal; bottom 6 bits == 0
* (3) leaf pte for huge page _PAGE_PTE set
* (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table
*
* So long as we atomically load page table pointers we are safe against teardown,
* we can follow the address down to the the page and take a ref on it.
* This function need to be called with interrupts disabled. We use this variant
* when we have MSR[EE] = 0 but the paca->irq_soft_mask = IRQS_ENABLED
*/
pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
bool *is_thp, unsigned *hpage_shift)
{
pgd_t pgd, *pgdp;
pud_t pud, *pudp;
pmd_t pmd, *pmdp;
pte_t *ret_pte;
hugepd_t *hpdp = NULL;
unsigned pdshift = PGDIR_SHIFT;
if (hpage_shift)
*hpage_shift = 0;
if (is_thp)
*is_thp = false;
pgdp = pgdir + pgd_index(ea);
pgd = READ_ONCE(*pgdp);
/*
* Always operate on the local stack value. This make sure the
* value don't get updated by a parallel THP split/collapse,
* page fault or a page unmap. The return pte_t * is still not
* stable. So should be checked there for above conditions.
*/
if (pgd_none(pgd))
return NULL;
else if (pgd_huge(pgd)) {
ret_pte = (pte_t *) pgdp;
goto out;
} else if (is_hugepd(__hugepd(pgd_val(pgd))))
hpdp = (hugepd_t *)&pgd;
else {
/*
* Even if we end up with an unmap, the pgtable will not
* be freed, because we do an rcu free and here we are
* irq disabled
*/
pdshift = PUD_SHIFT;
pudp = pud_offset(&pgd, ea);
pud = READ_ONCE(*pudp);
if (pud_none(pud))
return NULL;
else if (pud_huge(pud)) {
ret_pte = (pte_t *) pudp;
goto out;
} else if (is_hugepd(__hugepd(pud_val(pud))))
hpdp = (hugepd_t *)&pud;
else {
pdshift = PMD_SHIFT;
pmdp = pmd_offset(&pud, ea);
pmd = READ_ONCE(*pmdp);
/*
* A hugepage collapse is captured by pmd_none, because
* it mark the pmd none and do a hpte invalidate.
*/
if (pmd_none(pmd))
return NULL;
if (pmd_trans_huge(pmd) || pmd_devmap(pmd)) {
if (is_thp)
*is_thp = true;
ret_pte = (pte_t *) pmdp;
goto out;
}
/*
* pmd_large check below will handle the swap pmd pte
* we need to do both the check because they are config
* dependent.
*/
if (pmd_huge(pmd) || pmd_large(pmd)) {
ret_pte = (pte_t *) pmdp;
goto out;
} else if (is_hugepd(__hugepd(pmd_val(pmd))))
hpdp = (hugepd_t *)&pmd;
else
return pte_offset_kernel(&pmd, ea);
}
}
if (!hpdp)
return NULL;
ret_pte = hugepte_offset(*hpdp, ea, pdshift);
pdshift = hugepd_shift(*hpdp);
out:
if (hpage_shift)
*hpage_shift = pdshift;
return ret_pte;
}
EXPORT_SYMBOL_GPL(__find_linux_pte);
int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{

View File

@ -30,6 +30,7 @@
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/hugetlb.h>
static inline int is_exec_fault(void)
{
@ -299,3 +300,106 @@ unsigned long vmalloc_to_phys(void *va)
return __pa(pfn_to_kaddr(pfn)) + offset_in_page(va);
}
EXPORT_SYMBOL_GPL(vmalloc_to_phys);
/*
* We have 4 cases for pgds and pmds:
* (1) invalid (all zeroes)
* (2) pointer to next table, as normal; bottom 6 bits == 0
* (3) leaf pte for huge page _PAGE_PTE set
* (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table
*
* So long as we atomically load page table pointers we are safe against teardown,
* we can follow the address down to the the page and take a ref on it.
* This function need to be called with interrupts disabled. We use this variant
* when we have MSR[EE] = 0 but the paca->irq_soft_mask = IRQS_ENABLED
*/
pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
bool *is_thp, unsigned *hpage_shift)
{
pgd_t pgd, *pgdp;
pud_t pud, *pudp;
pmd_t pmd, *pmdp;
pte_t *ret_pte;
hugepd_t *hpdp = NULL;
unsigned pdshift = PGDIR_SHIFT;
if (hpage_shift)
*hpage_shift = 0;
if (is_thp)
*is_thp = false;
pgdp = pgdir + pgd_index(ea);
pgd = READ_ONCE(*pgdp);
/*
* Always operate on the local stack value. This make sure the
* value don't get updated by a parallel THP split/collapse,
* page fault or a page unmap. The return pte_t * is still not
* stable. So should be checked there for above conditions.
*/
if (pgd_none(pgd))
return NULL;
else if (pgd_huge(pgd)) {
ret_pte = (pte_t *) pgdp;
goto out;
} else if (is_hugepd(__hugepd(pgd_val(pgd))))
hpdp = (hugepd_t *)&pgd;
else {
/*
* Even if we end up with an unmap, the pgtable will not
* be freed, because we do an rcu free and here we are
* irq disabled
*/
pdshift = PUD_SHIFT;
pudp = pud_offset(&pgd, ea);
pud = READ_ONCE(*pudp);
if (pud_none(pud))
return NULL;
else if (pud_huge(pud)) {
ret_pte = (pte_t *) pudp;
goto out;
} else if (is_hugepd(__hugepd(pud_val(pud))))
hpdp = (hugepd_t *)&pud;
else {
pdshift = PMD_SHIFT;
pmdp = pmd_offset(&pud, ea);
pmd = READ_ONCE(*pmdp);
/*
* A hugepage collapse is captured by pmd_none, because
* it mark the pmd none and do a hpte invalidate.
*/
if (pmd_none(pmd))
return NULL;
if (pmd_trans_huge(pmd) || pmd_devmap(pmd)) {
if (is_thp)
*is_thp = true;
ret_pte = (pte_t *) pmdp;
goto out;
}
/*
* pmd_large check below will handle the swap pmd pte
* we need to do both the check because they are config
* dependent.
*/
if (pmd_huge(pmd) || pmd_large(pmd)) {
ret_pte = (pte_t *) pmdp;
goto out;
} else if (is_hugepd(__hugepd(pmd_val(pmd))))
hpdp = (hugepd_t *)&pmd;
else
return pte_offset_kernel(&pmd, ea);
}
}
if (!hpdp)
return NULL;
ret_pte = hugepte_offset(*hpdp, ea, pdshift);
pdshift = hugepd_shift(*hpdp);
out:
if (hpage_shift)
*hpage_shift = pdshift;
return ret_pte;
}
EXPORT_SYMBOL_GPL(__find_linux_pte);