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Diffstat (limited to 'mm')
-rw-r--r--mm/gup.c45
-rw-r--r--mm/huge_memory.c19
-rw-r--r--mm/hugetlb.c23
3 files changed, 58 insertions, 29 deletions
diff --git a/mm/gup.c b/mm/gup.c
index 3b7bc2c1fd44..98aac6201e1b 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -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) {
@@ -202,17 +205,22 @@ static void gup_put_folio(struct folio *folio, int refs, unsigned int flags)
* time. Cases: please see the try_grab_folio() documentation, with
* "refs=1".
*
- * Return: true for success, or if no action was required (if neither FOLL_PIN
- * nor FOLL_GET was set, nothing is done). False for failure: FOLL_GET or
- * FOLL_PIN was set, but the page could not be grabbed.
+ * Return: 0 for success, or if no action was required (if neither FOLL_PIN
+ * nor FOLL_GET was set, nothing is done). A negative error code for failure:
+ *
+ * -ENOMEM FOLL_GET or FOLL_PIN was set, but the page could not
+ * be grabbed.
*/
-bool __must_check try_grab_page(struct page *page, unsigned int flags)
+int __must_check try_grab_page(struct page *page, unsigned int flags)
{
struct folio *folio = page_folio(page);
WARN_ON_ONCE((flags & (FOLL_GET | FOLL_PIN)) == (FOLL_GET | FOLL_PIN));
if (WARN_ON_ONCE(folio_ref_count(folio) <= 0))
- return false;
+ return -ENOMEM;
+
+ if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page)))
+ return -EREMOTEIO;
if (flags & FOLL_GET)
folio_ref_inc(folio);
@@ -232,7 +240,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags)
node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, 1);
}
- return true;
+ return 0;
}
/**
@@ -624,10 +632,12 @@ retry:
!PageAnonExclusive(page), page);
/* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */
- if (unlikely(!try_grab_page(page, flags))) {
- page = ERR_PTR(-ENOMEM);
+ ret = try_grab_page(page, flags);
+ if (unlikely(ret)) {
+ 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
@@ -960,10 +970,9 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
goto unmap;
*page = pte_page(*pte);
}
- if (unlikely(!try_grab_page(*page, gup_flags))) {
- ret = -ENOMEM;
+ ret = try_grab_page(*page, gup_flags);
+ if (unlikely(ret))
goto unmap;
- }
out:
ret = 0;
unmap:
@@ -1058,6 +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;
@@ -2534,9 +2546,15 @@ 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))) {
+ if (unlikely(try_grab_page(page, flags))) {
undo_dev_pagemap(nr, nr_start, flags, pages);
break;
}
@@ -3018,7 +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/huge_memory.c b/mm/huge_memory.c
index 811d19b5c4f6..ffbea56a8711 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1035,6 +1035,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn = pmd_pfn(*pmd);
struct mm_struct *mm = vma->vm_mm;
struct page *page;
+ int ret;
assert_spin_locked(pmd_lockptr(mm, pmd));
@@ -1066,8 +1067,9 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
if (!*pgmap)
return ERR_PTR(-EFAULT);
page = pfn_to_page(pfn);
- if (!try_grab_page(page, flags))
- page = ERR_PTR(-ENOMEM);
+ ret = try_grab_page(page, flags);
+ if (ret)
+ page = ERR_PTR(ret);
return page;
}
@@ -1193,6 +1195,7 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn = pud_pfn(*pud);
struct mm_struct *mm = vma->vm_mm;
struct page *page;
+ int ret;
assert_spin_locked(pud_lockptr(mm, pud));
@@ -1226,8 +1229,10 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
if (!*pgmap)
return ERR_PTR(-EFAULT);
page = pfn_to_page(pfn);
- if (!try_grab_page(page, flags))
- page = ERR_PTR(-ENOMEM);
+
+ ret = try_grab_page(page, flags);
+ if (ret)
+ page = ERR_PTR(ret);
return page;
}
@@ -1435,6 +1440,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
{
struct mm_struct *mm = vma->vm_mm;
struct page *page;
+ int ret;
assert_spin_locked(pmd_lockptr(mm, pmd));
@@ -1459,8 +1465,9 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) &&
!PageAnonExclusive(page), page);
- if (!try_grab_page(page, flags))
- return ERR_PTR(-ENOMEM);
+ ret = try_grab_page(page, flags);
+ if (ret)
+ return ERR_PTR(ret);
if (flags & FOLL_TOUCH)
touch_pmd(vma, addr, pmd, flags & FOLL_WRITE);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e36ca75311a5..3d9f4abec17c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6372,8 +6372,10 @@ 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))) {
@@ -7254,14 +7256,15 @@ retry:
page = pte_page(pte) +
((address & ~huge_page_mask(h)) >> PAGE_SHIFT);
/*
- * try_grab_page() should always succeed here, because: a) we
- * hold the pmd (ptl) lock, and b) we've just checked that the
- * huge pmd (head) page is present in the page tables. 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:
+ * try_grab_page() should always be able to get the page here,
+ * because: a) we hold the pmd (ptl) lock, and b) we've just
+ * checked that the huge pmd (head) page is present in the
+ * page tables. 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:
*/
- if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ if (try_grab_page(page, flags)) {
page = NULL;
goto out;
}
@@ -7299,7 +7302,7 @@ retry:
pte = huge_ptep_get((pte_t *)pud);
if (pte_present(pte)) {
page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
- if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
+ if (try_grab_page(page, flags)) {
page = NULL;
goto out;
}
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2025-01-12 02:57:47 +0000