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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?frQgayI/FnZuVb6uB3F7gZPuJMar87qmddGDCXBcaUl2PZ42BSjWN62KUoRA?= =?us-ascii?Q?HM5U9uq8jGpTCpmQElW/0JHyatkin2M1mNnPlm67h6Ul8c3sCrvoifWhBnmE?= =?us-ascii?Q?JLT5aq1ngNBOY8xJFL6/IyZNwI+00ovIL7y2YlvwHulGWKIzQPOmqWFx2vZE?= =?us-ascii?Q?6Yvrf/dXa+IBRo7hYVVKaLV38J8Q3QSo+ciYyPbi5HHvV5RzfVRWguJASGcb?= =?us-ascii?Q?qiyiBeTfWRU0RZBhUH7+zUU00oBynndGcYF33lVqOMmFkIODgDnAFEc7cn+U?= =?us-ascii?Q?BOHrPa8mionxbnhcXcop2Lg6hGsQaYaQmK7TuIdGp+fbgFngVXxRectF72UG?= =?us-ascii?Q?OdI1D/b5lqADwOlPesrlQLEvZkx5QCpWOyGYmDrohkQiXdfVKvBx0rEKlQCm?= =?us-ascii?Q?NO8TnGJoYn1jSs1Hxghb+pQ/v3pN4yp4NkHub1yQ7Fl0Cf8UkOMrrY+kT2n0?= =?us-ascii?Q?cUGVSLdxb3EEwZH6HHyQXa1ZuuRJH2ug9wN73BBAlE2bveRRxiyZbtonuAHe?= =?us-ascii?Q?DpXUbhOPDyA1H3bc9m67+Z9brfYCVt82hAha77+3vmd7zYfIkLKf/qIny80P?= =?us-ascii?Q?CqyDMyUugWAZ082W/ijJpCR1jSC/WezgW8NOasGANVf/jMOam8QEcthLkCk6?= =?us-ascii?Q?XzbljEMQR8WZow+2m+rx3JGMoH4RT3/F0JOBg27T6Zfychcb7JeslDalauOJ?= =?us-ascii?Q?z0jEl2MWaZhtY471RCAPeAGLxVknNQnfIUGAxse4uotdWPxVUr3rrs+vAbdZ?= =?us-ascii?Q?cVtWkdgCUPIpBYn1UfRjAXgyP8QQnP2Sq0ldYBs2FhrA6RtNELMaLxw5PxCB?= =?us-ascii?Q?YaxY7B/0RQ9Ku/gsNqg32zAUSatdsTJqrUYahvLXBSTcWaHMUXQO6dbNm37y?= =?us-ascii?Q?UFg/QdSG8acjU7twWOEoKpiv61uK7Vt7oD8gYNemIybjAarSgVtuBrUH7hna?= =?us-ascii?Q?t87EV4fONtwXRy2OCjcvh6271lBh3IDU2CtbDDELF4n4RNocKweBXfDNgmcZ?= =?us-ascii?Q?SZB7g7mo3U/TV7+ymWmQ1pYXq+dVHSoQ1EwXEhnVc2r7yq0Y6A5qTuQqYsa/?= =?us-ascii?Q?z736o4vfOD9Xw7KaZp+kabZQ/9rxVypIaox5ksBn1PTRU9tadnvMTCPKLfzs?= =?us-ascii?Q?o1rqP+ZFftLPxH++jgZ/Wb/aHLxip+hSx7xKNkBC01q0GSrnfQdfI9hc03qw?= =?us-ascii?Q?t6d4CHYiP94t6o9uDXcHMoFtcMjXel45KQHptVfXFr1XGiCGZ0Sh1i+/xkha?= =?us-ascii?Q?tcUWw6VjdGstOAJ50IxM7EBSdezpp8aBtq4Vouk+3T6lYMzZjXlNKrwDnr7U?= =?us-ascii?Q?Tf8GRF8I+K2f4qchgklhkgZZCr+2kgIUZ+ABLQA2bwK0mc7j542yYgBlmXri?= =?us-ascii?Q?7nS09xQPNFTeZU8vrh3va6xTceKTLDIHN8dDOaKOAnlbtlfTwikyMnGWvtWH?= =?us-ascii?Q?vr39A+xg9ytmvMjdoR/aYTLy8FXHZlOC7s0qpnblJpM9QfQXqhl5W8fNaCmA?= =?us-ascii?Q?LJC0NfCwS+a0MNwKcc1NnR6zNHtPWnoy1YrkCk770+rAOZPmcH56liSK7brS?= =?us-ascii?Q?jojXsEHuFT7eWH8F6ShZtU+P8Uc+ApDZgTI2tE6S89TzWwiPDV4jlqMoi+8D?= =?us-ascii?Q?HSUMfU3fDuZiJAfkt3fyqexoKrXik2r9JN0tIGkLxjfWYkgRVwPjRbKR4b+z?= =?us-ascii?Q?gaVJ5nH9YiuzY/RGRfHTMWgDM/x9dm0RCzpR2s7csCbdeu91Sfs0BuAfdXtw?= =?us-ascii?Q?DdfIlB5tdg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c8980fb9-aea4-4a58-4221-08deeecfe375 X-MS-Exchange-CrossTenant-AuthSource: MW2PR12MB2380.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Jul 2026 06:49:40.4490 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: gDuPgUBGx+BUAp9mp+2vr8AFhZvkTmdIE9oGnW11B2Shx/4IEfLJV24cQh6wko/EMNT2ldVJCku/Ezd0jucOwg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA5PPFB2BF91BC0 The kernel now allows committed zero-size HDM decoders so BIOS can lock empty decoders; cxl_test needs to exercise that path. Add a mock_zero_size_decoders module parameter (default off). When set, the special endpoints under host-bridge0 (cxl_mem.0 and cxl_mem.4) commit decoders 1 and 2 as zero-size + locked above the decoder[0] auto-region, mirrored on the parent switch and host bridge. The mocks take a real zero-size DPA reservation, like enumeration of real hardware, so commit_end lands on a zero-size decoder and the reservation, poison-by-endpoint, and teardown paths all run. Signed-off-by: Vishal Aslot Signed-off-by: Richard Cheng Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Reviewed-by: Alison Schofield --- Changelog: v7 -> v8: - No change. v6->v7: - Rebase onto cxl/for-7.3/cxl-type2-test. - Integrate mock_zero_size_decoders with special-topology parameter validation and reject its incompatible use with fail_autoassemble. v5->v6: - Reword a mock comment, no functional change. v4->v5: - Mirror the v5 core semantics: mock zero-size decoders take a real zero-size DPA reservation via devm_cxl_dpa_reserve() so dpa_res/hdm_end/cxled->part match real hardware enumeration and the poison-by-endpoint walk reaches commit_end. - Set cxled->state = CXL_DECODER_STATE_AUTO to match init_hdm_decoder()'s fall-through (undoes the v2 switch to MANUAL). - cxld_registry_restore(): reserve unconditionally for enabled endpoint decoders; enabled now implies reserved, sized or not. v3->v4: - No change. v2->v3: - Gate the zero-size + locked decoder injection behind a new mock_zero_size_decoders module parameter (default off). v2 applied it unconditionally on the host-bridge0 auto-region endpoints, which the region test suite reuses, regressing 7 of 17 cxl unit tests; defaulting off leaves the shared topology untouched. v1->v2: - Replace second_decoder(), third_decoder() with a single match_decoder_by_index() helper, so all lookups share one matcher. - Use DEFINE_RANGE() for the empty range instead of an open-coded struct. - Set cxled->state = CXL_DECODER_STATE_MANUAL rather than STATE_AUTO. - Set CXL_DECODER_F_LOCK on the mock zero-size decoders to model the BIOS-burns-slots case. --- tools/testing/cxl/test/cxl.c | 109 ++++++++++++++++++++++++++++++----- 1 file changed, 94 insertions(+), 15 deletions(-) diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index 8ab2ce1262f3..fff2004a08c8 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -18,6 +18,7 @@ static int interleave_arithmetic; static bool extended_linear_cache; static bool fail_autoassemble; static bool type2_test; +static bool mock_zero_size_decoders; #define FAKE_QTG_ID 42 @@ -872,14 +873,13 @@ static int cxld_registry_restore(struct cxl_decoder *cxld, cxld_copy(cxld, &td->cxled.cxld); cxled->state = td->cxled.state; cxled->skip = td->cxled.skip; - if (range_len(&td->dpa_range)) { - rc = devm_cxl_dpa_reserve(cxled, td->dpa_range.start, - range_len(&td->dpa_range), - td->cxled.skip); - if (rc) { - init_disabled_mock_decoder(cxld); - return rc; - } + /* enabled endpoint decoders hold a reservation, sized or not */ + rc = devm_cxl_dpa_reserve(cxled, td->dpa_range.start, + range_len(&td->dpa_range), + td->cxled.skip); + if (rc) { + init_disabled_mock_decoder(cxld); + return rc; } port->commit_end = cxld->id; } @@ -1072,16 +1072,49 @@ static void default_mock_decoder(struct cxl_decoder *cxld) WARN_ON_ONCE(!cxld_registry_new(cxld)); } -static int first_decoder(struct device *dev, const void *data) +static int match_decoder_by_index(struct device *dev, const void *data) { + int target_id = *(const int *)data; struct cxl_decoder *cxld; if (!is_switch_decoder(dev)) return 0; cxld = to_cxl_decoder(dev); - if (cxld->id == 0) - return 1; - return 0; + return cxld->id == target_id; +} + +/* + * Mock a committed, locked, empty decoder + * (CXL r4.0 8.2.4.20.12). Gated by the mock_zero_size_decoders module + * param so the default cxl_test topology, shared by the region test + * suite, is left undisturbed. + */ +static void size_zero_mock_decoder_ep(struct cxl_decoder *cxld, u64 base) +{ + struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(&cxld->dev); + + cxld->hpa_range = DEFINE_RANGE(base, base - 1); + cxld->interleave_ways = 2; + cxld->interleave_granularity = 4096; + cxld->target_type = CXL_DECODER_HOSTONLYMEM; + cxld->flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK; + cxled->state = CXL_DECODER_STATE_AUTO; + /* decoder[0] reserved [0, size/2), empty decoders sit at that watermark */ + devm_cxl_dpa_reserve(cxled, mock_auto_region_size / 2, 0, 0); + cxld->commit = mock_decoder_commit; + cxld->reset = mock_decoder_reset; +} + +static void size_zero_mock_decoder_sw(struct cxl_decoder *cxld, u64 base, + int level) +{ + cxld->flags = CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK; + cxld->target_type = CXL_DECODER_HOSTONLYMEM; + cxld->interleave_ways = level == 0 ? 2 : 1; + cxld->interleave_granularity = 4096; + cxld->hpa_range = DEFINE_RANGE(base, base - 1); + cxld->commit = mock_decoder_commit; + cxld->reset = mock_decoder_reset; } enum cxld_init_type { @@ -1114,7 +1147,7 @@ static enum cxld_init_type get_decoder_init_type(struct cxl_decoder *cxld, * See 'cxl list -BMPu -m cxl_mem.0,cxl_mem.4' */ if (!is_endpoint_decoder(&cxld->dev) || !hb0 || pdev->id % 4 || - pdev->id > 4 || cxld->id > 0) + pdev->id > 4 || cxld->id > (mock_zero_size_decoders ? 2 : 0)) return MOCK_DECODER_INIT_DEFAULT; return type2_test ? MOCK_DECODER_INIT_TYPE2_AUTO : @@ -1147,6 +1180,7 @@ static void mock_init_hdm_type2_cxled(struct cxl_endpoint_decoder *cxled, struct cxl_port *root_port; struct device *dev; u64 base; + int id = 0; base = window->base_hpa; cxld->hpa_range = (struct range) { @@ -1172,7 +1206,7 @@ static void mock_init_hdm_type2_cxled(struct cxl_endpoint_decoder *cxled, */ dport = port->parent_dport; root_port = dport->port; - dev = device_find_child(&root_port->dev, NULL, first_decoder); + dev = device_find_child(&root_port->dev, &id, match_decoder_by_index); /* * Ancestor ports are guaranteed to be enumerated before * @port, and all ports have at least one decoder. @@ -1232,6 +1266,20 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled, base = window->base_hpa; if (extended_linear_cache) base += mock_auto_region_size; + + /* + * With mock_zero_size_decoders, decoders 1 and 2 of the special + * endpoints mock committed, locked, empty decoders above the + * decoder[0] auto-region (CXL r4.0 8.2.4.20.12). commit_end then + * points at a zero-size decoder, exercising the zero-size + * reservation and poison-by-endpoint code paths. + */ + if (cxld->id == 1 || cxld->id == 2) { + size_zero_mock_decoder_ep(cxld, base); + port->commit_end = cxld->id; + WARN_ON_ONCE(!cxld_registry_new(cxld)); + return; + } cxld->hpa_range = (struct range) { .start = base, .end = base + mock_auto_region_size - 1, @@ -1255,9 +1303,11 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled, */ iter = port; for (i = 0; i < 2; i++) { + int id = 0; + dport = iter->parent_dport; iter = dport->port; - dev = device_find_child(&iter->dev, NULL, first_decoder); + dev = device_find_child(&iter->dev, &id, match_decoder_by_index); /* * Ancestor ports are guaranteed to be enumerated before * @port, and all ports have at least one decoder. @@ -1307,6 +1357,26 @@ static void mock_init_hdm_type3_cxled(struct cxl_endpoint_decoder *cxled, cxld_registry_update(cxld); put_device(dev); + + if (!mock_zero_size_decoders) + continue; + + /* + * Mirror the endpoint: commit the next two switch decoders + * as zero-size + locked so the empty-decoder layout extends + * end-to-end through the switch and host bridge. + */ + for (id = 1; id <= 2; id++) { + dev = device_find_child(&iter->dev, &id, + match_decoder_by_index); + if (WARN_ON(!dev)) + continue; + cxld = to_cxl_decoder(dev); + size_zero_mock_decoder_sw(cxld, base, i); + iter->commit_end = id; + cxld_registry_update(cxld); + put_device(dev); + } } } @@ -2085,6 +2155,12 @@ static bool __init have_multiple_modparms(void) count++; if (type2_test) count++; + if (mock_zero_size_decoders) + count++; + + /* Zero-size decoders require decoder[0] to preserve commit order. */ + if (fail_autoassemble && mock_zero_size_decoders) + return true; return count > 1; } @@ -2493,6 +2569,9 @@ module_param(fail_autoassemble, bool, 0444); MODULE_PARM_DESC(fail_autoassemble, "Simulate missing member of an auto-region"); module_param(type2_test, bool, 0444); MODULE_PARM_DESC(type2_test, "Enable type 2 support testing"); +module_param(mock_zero_size_decoders, bool, 0444); +MODULE_PARM_DESC(mock_zero_size_decoders, + "Mock committed, locked, empty decoders under host-bridge0"); module_init(cxl_test_init); module_exit(cxl_test_exit); MODULE_LICENSE("GPL v2"); -- 2.43.0