From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, etnaviv@lists.freedesktop.org,
dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-media@vger.kernel.org, linux-kselftest@vger.kernel.org,
David Hildenbrand <david@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
John Hubbard <jhubbard@nvidia.com>, Peter Xu <peterx@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>, Nadav Amit <namit@vmware.com>,
Vlastimil Babka <vbabka@suse.cz>,
Matthew Wilcox <willy@infradead.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Muchun Song <songmuchun@bytedance.com>,
Lucas Stach <l.stach@pengutronix.de>,
David Airlie <airlied@gmail.com>,
Oded Gabbay <ogabbay@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Russell King <linux+etnaviv@armlinux.org.uk>,
Christian Gmeiner <christian.gmeiner@gmail.com>
Subject: [PATCH RFC 14/19] drm/etnaviv: remove FOLL_FORCE usage
Date: Mon, 7 Nov 2022 17:17:35 +0100 [thread overview]
Message-ID: <20221107161740.144456-15-david@redhat.com> (raw)
In-Reply-To: <20221107161740.144456-1-david@redhat.com>
GUP now supports reliable R/O long-term pinning in COW mappings, such
that we break COW early. MAP_SHARED VMAs only use the shared zeropage so
far in one corner case (DAXFS file with holes), which can be ignored
because GUP does not support long-term pinning in fsdax (see
check_vma_flags()).
commit cd5297b0855f ("drm/etnaviv: Use FOLL_FORCE for userptr")
documents that FOLL_FORCE | FOLL_WRITE was really only used for reliable
R/O pinning.
Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required
for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop
using FOLL_FORCE, which is really only for debugger access.
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: David Airlie <airlied@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
drivers/gpu/drm/etnaviv/etnaviv_gem.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index cc386f8a7116..efe2240945d0 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -638,6 +638,7 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj)
struct page **pvec = NULL;
struct etnaviv_gem_userptr *userptr = &etnaviv_obj->userptr;
int ret, pinned = 0, npages = etnaviv_obj->base.size >> PAGE_SHIFT;
+ unsigned int gup_flags = FOLL_LONGTERM;
might_lock_read(¤t->mm->mmap_lock);
@@ -648,14 +649,15 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj)
if (!pvec)
return -ENOMEM;
+ if (!userptr->ro)
+ gup_flags |= FOLL_WRITE;
+
do {
unsigned num_pages = npages - pinned;
uint64_t ptr = userptr->ptr + pinned * PAGE_SIZE;
struct page **pages = pvec + pinned;
- ret = pin_user_pages_fast(ptr, num_pages,
- FOLL_WRITE | FOLL_FORCE | FOLL_LONGTERM,
- pages);
+ ret = pin_user_pages_fast(ptr, num_pages, gup_flags, pages);
if (ret < 0) {
unpin_user_pages(pvec, pinned);
kvfree(pvec);
--
2.38.1
next prev parent reply other threads:[~2022-11-07 16:21 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-07 16:17 [PATCH RFC 00/19] mm/gup: remove FOLL_FORCE usage from drivers (reliable R/O long-term pinning) David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 01/19] selftests/vm: anon_cow: prepare for non-anonymous COW tests David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 02/19] selftests/vm: cow: basic COW tests for non-anonymous pages David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 03/19] selftests/vm: cow: R/O long-term pinning reliability tests for non-anon pages David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 04/19] mm: add early FAULT_FLAG_UNSHARE consistency checks David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 05/19] mm: add early FAULT_FLAG_WRITE " David Hildenbrand
2022-11-07 19:03 ` Nadav Amit
2022-11-07 19:27 ` David Hildenbrand
2022-11-07 19:50 ` Nadav Amit
2022-11-07 16:17 ` [PATCH RFC 06/19] mm: rework handling in do_wp_page() based on private vs. shared mappings David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 07/19] mm: don't call vm_ops->huge_fault() in wp_huge_pmd()/wp_huge_pud() for private mappings David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 08/19] mm: extend FAULT_FLAG_UNSHARE support to anything in a COW mapping David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 09/19] mm/gup: reliable R/O long-term pinning in COW mappings David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 10/19] RDMA/umem: remove FOLL_FORCE usage David Hildenbrand
2022-11-14 8:30 ` Leon Romanovsky
2022-11-07 16:17 ` [PATCH RFC 11/19] RDMA/usnic: " David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 12/19] RDMA/siw: " David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 13/19] media: videobuf-dma-sg: " David Hildenbrand
2022-11-07 16:17 ` David Hildenbrand [this message]
2022-11-07 16:17 ` [PATCH RFC 15/19] media: pci/ivtv: " David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 16/19] mm/frame-vector: " David Hildenbrand
2022-11-08 4:45 ` Tomasz Figa
2022-11-08 9:40 ` David Hildenbrand
2022-11-22 12:25 ` Hans Verkuil
2022-11-22 12:38 ` David Hildenbrand
2022-11-22 14:07 ` Hans Verkuil
2022-11-22 15:03 ` David Hildenbrand
2022-11-22 17:33 ` Linus Torvalds
2022-11-07 16:17 ` [PATCH RFC 17/19] drm/exynos: " David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 18/19] RDMA/hw/qib/qib_user_pages: " David Hildenbrand
2022-11-07 16:17 ` [PATCH RFC 19/19] habanalabs: " David Hildenbrand
2022-11-07 21:25 ` Oded Gabbay
2022-11-07 17:27 ` [PATCH RFC 00/19] mm/gup: remove FOLL_FORCE usage from drivers (reliable R/O long-term pinning) Linus Torvalds
2022-11-08 9:29 ` David Hildenbrand
2022-11-14 6:03 ` Christoph Hellwig
2022-11-14 8:07 ` David Hildenbrand
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