From: Mostafa Saleh Date: Thu, 24 Oct 2024 16:25:16 +0000 (+0000) Subject: iommu/io-pgtable-arm: Add self test for the last page in the IAS X-Git-Tag: v6.13-rc1~105^2~1^2~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d64c8053378e0e9ab61331124798688043b0dbba;p=thirdparty%2Flinux.git iommu/io-pgtable-arm: Add self test for the last page in the IAS Add a case in the selftests that can detect some bugs with concatenated page tables, where it maps the biggest supported page size at the end of the IAS, this test would fail without the previous fix. Signed-off-by: Mostafa Saleh Link: https://lore.kernel.org/r/20241024162516.2005652-3-smostafa@google.com Signed-off-by: Will Deacon --- diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index a286c5404ea70..40c1cd079f8e1 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -1394,6 +1394,23 @@ static int __init arm_lpae_run_tests(struct io_pgtable_cfg *cfg) iova += SZ_1G; } + /* + * Map/unmap the last largest supported page of the IAS, this can + * trigger corner cases in the concatednated page tables. + */ + mapped = 0; + size = 1UL << __fls(cfg->pgsize_bitmap); + iova = (1UL << cfg->ias) - size; + if (ops->map_pages(ops, iova, iova, size, 1, + IOMMU_READ | IOMMU_WRITE | + IOMMU_NOEXEC | IOMMU_CACHE, + GFP_KERNEL, &mapped)) + return __FAIL(ops, i); + if (mapped != size) + return __FAIL(ops, i); + if (ops->unmap_pages(ops, iova, size, 1, NULL) != size) + return __FAIL(ops, i); + free_io_pgtable_ops(ops); }