diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2023-01-24 21:34:26 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-10 01:51:44 +0100 |
| commit | d64e2dbc33a109a37ad4f5c18945c324345fe873 (patch) | |
| tree | 7eb9c0df30e45d1b1ee0083264a90ba31d347f1c /mm/huge_memory.c | |
| parent | mm/gup: move try_grab_page() to mm/internal.h (diff) | |
| download | linux-d64e2dbc33a109a37ad4f5c18945c324345fe873.tar.xz linux-d64e2dbc33a109a37ad4f5c18945c324345fe873.zip | |
mm/gup: simplify the external interface functions and consolidate invariants
The GUP family of functions have a complex, but fairly well defined, set
of invariants for their arguments. Currently these are sprinkled about,
sometimes in duplicate through many functions.
Internally we don't follow all the invariants that the external interface
has to follow, so place these checks directly at the exported interface.
This ensures the internal functions never reach a violated invariant.
Remove the duplicated invariant checks.
The end result is to make these functions fully internal:
__get_user_pages_locked()
internal_get_user_pages_fast()
__gup_longterm_locked()
And all the other functions call directly into one of these.
Link: https://lkml.kernel.org/r/5-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1d6977dc6b31..1343a7d88299 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1042,11 +1042,6 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, assert_spin_locked(pmd_lockptr(mm, pmd)); - /* FOLL_GET and FOLL_PIN are mutually exclusive. */ - if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == - (FOLL_PIN | FOLL_GET))) - return NULL; - if (flags & FOLL_WRITE && !pmd_write(*pmd)) return NULL; @@ -1205,11 +1200,6 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, if (flags & FOLL_WRITE && !pud_write(*pud)) return NULL; - /* FOLL_GET and FOLL_PIN are mutually exclusive. */ - if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == - (FOLL_PIN | FOLL_GET))) - return NULL; - if (pud_present(*pud) && pud_devmap(*pud)) /* pass */; else |