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From:   Alex Sierra <alex.sierra@amd.com>
To:     akpm@linux-foundation.org, Felix.Kuehling@amd.com,
        linux-mm@kvack.org, rcampbell@nvidia.com,
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Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
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Subject: [PATCH v2 05/12] drm/amdkfd: ref count init for device pages
Date:   Mon, 13 Sep 2021 11:15:57 -0500
Message-Id: <20210913161604.31981-6-alex.sierra@amd.com>
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Ref counter from device pages is init to zero during memmap init zone.
The first time a new device page is allocated to migrate data into it,
its ref counter needs to be initialized to one.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index dab290a4d19d..ffad39ffa8c6 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -220,7 +220,8 @@ svm_migrate_get_vram_page(struct svm_range *prange, unsigned long pfn)
 	page = pfn_to_page(pfn);
 	svm_range_bo_ref(prange->svm_bo);
 	page->zone_device_data = prange->svm_bo;
-	get_page(page);
+	VM_BUG_ON_PAGE(page_ref_count(page), page);
+	init_page_count(page);
 	lock_page(page);
 }
 
-- 
2.32.0