From: Richard Cheng Date: Wed, 27 May 2026 09:03:32 +0000 (+0800) Subject: cxl/test: Enforce PMD alignment for volatile mock regions X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d40745cd06f35095a7b2925ea3217bf7ef764832;p=thirdparty%2Fkernel%2Fstable.git cxl/test: Enforce PMD alignment for volatile mock regions cxl_test allocates synthetic CFMWS HPA windows from a gen_pool with SZ_256M alignment. On arm64 with CONFIG_ARM64_64K_PAGES=y and CONFIG_PGTABLE_LEVELS=3, PMD_SIZE is 512M, so every CXL region carved from a volatile window inherits a non-PMD-aligned start, and cxl_dax_region_probe() -> alloc_dax_region() fails: """ cxl_dax_region dax_region1: probe with driver cxl_dax_region failed with error -12 """ Enforce that every volatile mock CFMWS is PMD-aligned in both start and size Reviewed-by: Dave Jiang Acked-by: Kai-Heng Feng Signed-off-by: Richard Cheng Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260527090332.30002-1-icheng@nvidia.com Signed-off-by: Dave Jiang --- diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index 296516eecfd6..4281d34cd0e7 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -318,7 +318,7 @@ static struct { .restrictions = ACPI_CEDT_CFMWS_RESTRICT_HOSTONLYMEM | ACPI_CEDT_CFMWS_RESTRICT_VOLATILE, .qtg_id = FAKE_QTG_ID, - .window_size = SZ_256M, + .window_size = SZ_256M > PMD_SIZE ? SZ_256M : PMD_SIZE, }, .target = { 3 }, }, @@ -495,9 +495,12 @@ static int populate_cedt(void) for (i = cfmws_start; i <= cfmws_end; i++) { struct acpi_cedt_cfmws *window = mock_cfmws[i]; + int align = SZ_256M; cfmws_elc_update(window, i); - res = alloc_mock_res(window->window_size, SZ_256M); + if (window->restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) + align = max_t(int, SZ_256M, PMD_SIZE); + res = alloc_mock_res(window->window_size, align); if (!res) return -ENOMEM; window->base_hpa = res->range.start; @@ -1819,6 +1822,12 @@ static __init int cxl_test_init(void) int rc, i; struct range mappable; + if (!IS_ALIGNED(mock_auto_region_size, PMD_SIZE)) { + pr_err_once("mock_auto_region_size %d must be PMD-aligned\n", + mock_auto_region_size); + return -EINVAL; + } + cxl_acpi_test(); cxl_core_test(); cxl_mem_test();