diff options
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | mm/gup.c | 19 | ||||
| -rw-r--r-- | mm/hugetlb.c | 6 |
3 files changed, 23 insertions, 3 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 62a91dc1272b..6b081a8dcf88 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2958,6 +2958,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ #define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */ #define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */ +#define FOLL_PCI_P2PDMA 0x100000 /* allow returning PCI P2PDMA pages */ /* * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each @@ -123,6 +123,9 @@ retry: */ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags) { + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page))) + return NULL; + if (flags & FOLL_GET) return try_get_folio(page, refs); else if (flags & FOLL_PIN) { @@ -216,6 +219,9 @@ int __must_check try_grab_page(struct page *page, unsigned int flags) if (WARN_ON_ONCE(folio_ref_count(folio) <= 0)) return -ENOMEM; + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page))) + return -EREMOTEIO; + if (flags & FOLL_GET) folio_ref_inc(folio); else if (flags & FOLL_PIN) { @@ -631,6 +637,7 @@ retry: page = ERR_PTR(ret); goto out; } + /* * We need to make the page accessible if and only if we are going * to access its content (the FOLL_PIN case). Please see @@ -1060,6 +1067,9 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) if ((gup_flags & FOLL_LONGTERM) && vma_is_fsdax(vma)) return -EOPNOTSUPP; + if ((gup_flags & FOLL_LONGTERM) && (gup_flags & FOLL_PCI_P2PDMA)) + return -EOPNOTSUPP; + if (vma_is_secretmem(vma)) return -EFAULT; @@ -2536,6 +2546,12 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, undo_dev_pagemap(nr, nr_start, flags, pages); break; } + + if (!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page)) { + undo_dev_pagemap(nr, nr_start, flags, pages); + break; + } + SetPageReferenced(page); pages[*nr] = page; if (unlikely(try_grab_page(page, flags))) { @@ -3020,7 +3036,8 @@ static int internal_get_user_pages_fast(unsigned long start, if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM | FOLL_FORCE | FOLL_PIN | FOLL_GET | - FOLL_FAST_ONLY | FOLL_NOFAULT))) + FOLL_FAST_ONLY | FOLL_NOFAULT | + FOLL_PCI_P2PDMA))) return -EINVAL; if (gup_flags & FOLL_PIN) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 67f39550520e..582ec7554927 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6361,8 +6361,10 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, * tables. If the huge page is present, then the tail * pages must also be present. The ptl prevents the * head page and tail pages from being rearranged in - * any way. So this page must be available at this - * point, unless the page refcount overflowed: + * any way. As this is hugetlb, the pages will never + * be p2pdma or not longterm pinable. So this page + * must be available at this point, unless the page + * refcount overflowed: */ if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, flags))) { |