From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hubbard Subject: [PATCH v2 15/18] powerpc: book3s64: convert to pin_longterm_pages() and put_user_page() Date: Sun, 3 Nov 2019 13:18:10 -0800 Message-ID: <20191103211813.213227-16-jhubbard@nvidia.com> References: <20191103211813.213227-1-jhubbard@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20191103211813.213227-1-jhubbard@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman List-Id: dri-devel@lists.freedesktop.org 1. Convert from get_user_pages(FOLL_LONGTERM) to pin_longterm_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). In this case, do so via put_user_pages_dirty_lock(). That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] 3. Release each page in mem->hpages[] (instead of mem->hpas[]), because that is the array that pin_longterm_pages() filled in. This is more accurate and should be a little safer from a maintenance point of view. [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Signed-off-by: John Hubbard --- arch/powerpc/mm/book3s64/iommu_api.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s6= 4/iommu_api.c index 56cc84520577..69d79cb50d47 100644 --- a/arch/powerpc/mm/book3s64/iommu_api.c +++ b/arch/powerpc/mm/book3s64/iommu_api.c @@ -103,9 +103,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, uns= igned long ua, for (entry =3D 0; entry < entries; entry +=3D chunk) { unsigned long n =3D min(entries - entry, chunk); =20 - ret =3D get_user_pages(ua + (entry << PAGE_SHIFT), n, - FOLL_WRITE | FOLL_LONGTERM, - mem->hpages + entry, NULL); + ret =3D pin_longterm_pages(ua + (entry << PAGE_SHIFT), n, + FOLL_WRITE, mem->hpages + entry, NULL); if (ret =3D=3D n) { pinned +=3D n; continue; @@ -167,9 +166,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, uns= igned long ua, return 0; =20 free_exit: - /* free the reference taken */ - for (i =3D 0; i < pinned; i++) - put_page(mem->hpages[i]); + /* free the references taken */ + put_user_pages(mem->hpages, pinned); =20 vfree(mem->hpas); kfree(mem); @@ -212,10 +210,9 @@ static void mm_iommu_unpin(struct mm_iommu_table_group= _mem_t *mem) if (!page) continue; =20 - if (mem->hpas[i] & MM_IOMMU_TABLE_GROUP_PAGE_DIRTY) - SetPageDirty(page); + put_user_pages_dirty_lock(&mem->hpages[i], 1, + MM_IOMMU_TABLE_GROUP_PAGE_DIRTY); =20 - put_page(page); mem->hpas[i] =3D 0; } } --=20 2.23.0