diff options
author | Souptick Joarder <jrdr.linux@gmail.com> | 2020-06-08 07:40:55 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-08 21:05:56 +0300 |
commit | dadbb612f6e50bbf9101c2f5d82690ce9ea4d66b (patch) | |
tree | 6395c50985da61e0b2b25ccf73947f51b81918bf /mm | |
parent | e77132e75845470065768e2205727e6be52cb7f4 (diff) |
mm/gup.c: convert to use get_user_{page|pages}_fast_only()
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to
align with pin_user_pages_fast_only().
As part of this we will get rid of write parameter. Instead caller will
pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any
existing functionality of the API.
All the callers are changed to pass FOLL_WRITE.
Also introduce get_user_page_fast_only(), and use it in a few places
that hard-code nr_pages to 1.
Updated the documentation of the API.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm]
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/gup.c | 29 |
1 files changed, 16 insertions, 13 deletions
@@ -2294,7 +2294,7 @@ pte_unmap: * to be special. * * For a futex to be placed on a THP tail page, get_futex_key requires a - * __get_user_pages_fast implementation that can pin pages. Thus it's still + * get_user_pages_fast_only implementation that can pin pages. Thus it's still * useful to have gup_huge_pmd even if we can't operate on ptes. */ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, @@ -2699,7 +2699,7 @@ static inline void gup_pgd_range(unsigned long addr, unsigned long end, #ifndef gup_fast_permitted /* - * Check if it's allowed to use __get_user_pages_fast() for the range, or + * Check if it's allowed to use get_user_pages_fast_only() for the range, or * we need to fall back to the slow version: */ static bool gup_fast_permitted(unsigned long start, unsigned long end) @@ -2811,8 +2811,14 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages, return ret; } - -/* +/** + * get_user_pages_fast_only() - pin user pages in memory + * @start: starting user address + * @nr_pages: number of pages from start to pin + * @gup_flags: flags modifying pin behaviour + * @pages: array that receives pointers to the pages pinned. + * Should be at least nr_pages long. + * * Like get_user_pages_fast() except it's IRQ-safe in that it won't fall back to * the regular GUP. * Note a difference with get_user_pages_fast: this always returns the @@ -2825,8 +2831,8 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages, * access can get ambiguous page results. If you call this function without * 'write' set, you'd better be sure that you're ok with that ambiguity. */ -int __get_user_pages_fast(unsigned long start, int nr_pages, int write, - struct page **pages) +int get_user_pages_fast_only(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages) { int nr_pinned; /* @@ -2836,10 +2842,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, * FOLL_FAST_ONLY is required in order to match the API description of * this routine: no fall back to regular ("slow") GUP. */ - unsigned int gup_flags = FOLL_GET | FOLL_FAST_ONLY; - - if (write) - gup_flags |= FOLL_WRITE; + gup_flags |= FOLL_GET | FOLL_FAST_ONLY; nr_pinned = internal_get_user_pages_fast(start, nr_pages, gup_flags, pages); @@ -2855,7 +2858,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, return nr_pinned; } -EXPORT_SYMBOL_GPL(__get_user_pages_fast); +EXPORT_SYMBOL_GPL(get_user_pages_fast_only); /** * get_user_pages_fast() - pin user pages in memory @@ -2926,8 +2929,8 @@ int pin_user_pages_fast(unsigned long start, int nr_pages, EXPORT_SYMBOL_GPL(pin_user_pages_fast); /* - * This is the FOLL_PIN equivalent of __get_user_pages_fast(). Behavior is the - * same, except that this one sets FOLL_PIN instead of FOLL_GET. + * This is the FOLL_PIN equivalent of get_user_pages_fast_only(). Behavior + * is the same, except that this one sets FOLL_PIN instead of FOLL_GET. * * The API rules are the same, too: no negative values may be returned. */ |