[RFC 01/10] mm/gup.c: Remove redundant check for PCI P2PDMA page

From: Alistair Popple <apopple@nvidia.com>
To: linux-mm@kvack.org
Cc: david@fromorbit.com, dan.j.williams@intel.com,
	jhubbard@nvidia.com, rcampbell@nvidia.com, willy@infradead.org,
	jgg@nvidia.com, linux-fsdevel@vger.kernel.org, jack@suse.cz,
	djwong@kernel.org, hch@lst.de, david@redhat.com,
	ruansy.fnst@fujitsu.com, nvdimm@lists.linux.dev,
	linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org,
	jglisse@redhat.com, Alistair Popple <apopple@nvidia.com>
Subject: [RFC 01/10] mm/gup.c: Remove redundant check for PCI P2PDMA page
Date: Thu, 11 Apr 2024 10:57:22 +1000	[thread overview]
Message-ID: <ffd72e934eeae28639b636e1e61a9c5109808420.1712796818.git-series.apopple@nvidia.com> (raw)
In-Reply-To: <cover.fe275e9819458a4bbb9451b888cafb88af8867d4.1712796818.git-series.apopple@nvidia.com>

PCI P2PDMA pages are not mapped with pXX_devmap PTEs therefore the
check in __gup_device_huge() is redundant. Remove it

Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
 mm/gup.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 2f8a2d8..a9c8a09 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2683,11 +2683,6 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
 			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))) {
-- 
git-series 0.9.1
