From: Christophe Leroy Date: Fri, 26 Apr 2019 05:59:41 +0000 (+0000) Subject: powerpc/mm: move __find_linux_pte() out of hugetlbpage.c X-Git-Tag: Ubuntu-5.13.0-19.19~8573^2~110 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=0caed4de502c7699b7faeaea0a93b39e4f19e11a;p=mirror_ubuntu-jammy-kernel.git 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 Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 5f67e7a4d1cc..17915fc389ff 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -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) { diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index d3d61d29b4f1..9f4ccd15849f 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -30,6 +30,7 @@ #include #include #include +#include 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);