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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?w2ow1BTmFSrkfqnIX+YP7Js0NHFWsv/QdOeFj7XcoN+WDWCK9tQFCQPZxVGR?= =?us-ascii?Q?rxXKZrYFlhpZXovhHUMmrsJbtYVrxJLjMWmk2qLrKHd5mem1n75Ybg9Yj1sB?= =?us-ascii?Q?mW0WJmtXXaA/7JpFi0J+sJG2PUiYPQ2UNHZBlIN8e3LCiwaZNYK5SDY7nj7d?= =?us-ascii?Q?ErcA5lO3dbv7Lx9BBQNeR9vwgs84xTOAqMChWWLMoe7viiZn6w94Pi1YJ7pq?= =?us-ascii?Q?p4K23Dq9B4Vsr5mdl8XeW2cbimWoWR72r97Qp/O9LBSaCL6oQ4wewuQWAd7p?= =?us-ascii?Q?hh79U5lo/UMB/BU15HyF0G08GejsSe3YeKd4EvuH6McZwbiJVAhr71JHWNVT?= =?us-ascii?Q?CxVlMnC+yT+OAC6alOpzhcOW3VJemD8jg9v/TdQblItFtBk7E2js5IsRzMU+?= =?us-ascii?Q?DQLfEl+SCvdD8zjrjs5l23xlmLAovDcXiYBzYcUEZb3YGZBz4R0/WjwOluFQ?= =?us-ascii?Q?I/v9F+tSYT93ZWvSbg5VmNjTr+6LvF8IfBRNtv64+IK7pbS/a9dqzgpFQcGX?= =?us-ascii?Q?hnfBqRyH49K92mPk5HJzykkQ8/sr6+x8rMQzNzOqv0YSN+zEHvC99FnhpnI2?= =?us-ascii?Q?5n5wTDEEGUv5dtHtlr9GzgOf8CICWji1iz8ULFZ4IoweciPbo1Nf4u1iRPBA?= =?us-ascii?Q?xdho+eOHGOgvrbAx7KI3VKv4h2ELmhP7flMkRZiyH9nYRG+d1ypgV81dV4zU?= =?us-ascii?Q?UPenlW9Prz3e8m7HMDIPDhYOqlblDycKsqpAgutJAkNd06dRKCTVceHc4U++?= =?us-ascii?Q?Z2i3urEiKHmTVT9VOsHjvVoI/FKaZI0DixriJORfJVskhJum9xyNppvclPE+?= =?us-ascii?Q?ctN8AdA48FujdsfbUwAvyZft2Xo3LYiWdwHU4KWS/v520EQSC9Ezs2N7s18K?= =?us-ascii?Q?XKSy+uh8ECVtWFRT7Q7ZvEtwNxoxgNllXtoUm7AuVq0HuHjkxASZ8s6wEhdN?= =?us-ascii?Q?zPwlOrWpsxfo8MOuH7GlRsBqdJOB8Jv009YqHvbhafG3/r8UIcNYsuFKpfE+?= =?us-ascii?Q?mHf+NLhJgQfku6+rBgK0emMEEA02mVfHd2ga99LpSOgs/RKsNA0wWgTaXF3w?= =?us-ascii?Q?BLQZPMO9F2uW3H98sGXfIMfT85WyneKmVLP3YupYEXKx1biIrbOSaNsVUt5C?= =?us-ascii?Q?NXje8LPfs+4V/X42Bv2ifwjJTJolOvXwc2v2Vn5hVLzOZ/a3bbMlypVx09ER?= =?us-ascii?Q?BkxdMC1Agc3yBpzDeQuQ6L8IGnZL9jU9jRClNcCL0T0MJ+naZTTNhWt4vYKd?= =?us-ascii?Q?gK/Ym3573YemyzafMOPicq7l0eKY3yQMDtRwVkeWUO7jwdJ72n9GPKnXqL5F?= =?us-ascii?Q?TBWlkEBsCneqrlIBGgGrrwCozEBkrNRJdk2qKiaZePn5AGjGdEk3TxIqGXvu?= =?us-ascii?Q?A4U4XxkYSd8DMzsFzsLIvy+rSsuP1TZlwnQc+BXNhv1DC/Q87YFlzRSAofed?= =?us-ascii?Q?Gq6f440oANo0vXxFk6Y7INIJ/CuA0CukYEFUIPxieX8n1RdU3Hh4bEA9nVPL?= =?us-ascii?Q?6IKBC6ZoFBm1HLJozRsa3faJ9qlcGfHAPTNdzJypGYle3znJPdm3NZqczIBL?= =?us-ascii?Q?5/CT1U+mNhmHz7dpsf3SFAT4YqWW8SwRVOvcRvAHKkk1tRmuWm74J1h01ajI?= =?us-ascii?Q?hPZP5+r7tSOyilY7VAxQSsSQDTb9IG6dMJ1cB6kzcgOZm4+0c0/oNt+Uaebz?= =?us-ascii?Q?3V2dmy2Cb2+ymyhDrSgDMe42ISDri9lsrO44Xa7D42NlB7F4FyIGgaC85bl9?= =?us-ascii?Q?zTRDFZ6qyw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1638d112-170f-4ab6-930e-08dec45717fc X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB2370.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jun 2026 05:39:09.1968 (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: ycknrcn9Yiu1l8b5UvRKfs3LZL95fMXkX8LPtM9fEhEul6rFVghc5u2yEH6bFGEmaLJaDS4MhP8UBkbPj7BJuQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4443 The kernel now allows committed HDM decoders of zero size so BIOS can burn slots with LOCK, cxl_test needs to exercise the patch. Add a mock_zero_size_decoders module param, When set, the special endpoint 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. commit_end then lands on a decoder with no DPA resource, exercising the new enumeration and poison-by-endpoint paths. Signed-off-by: Vishal Aslot Signed-off-by: Richard Cheng --- 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 | 83 +++++++++++++++++++++++++++++++++--- 1 file changed, 77 insertions(+), 6 deletions(-) diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index 296516eecfd6..190cb18d6932 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -17,6 +17,7 @@ static int interleave_arithmetic; static bool extended_linear_cache; static bool fail_autoassemble; +static bool mock_zero_size_decoders; #define FAKE_QTG_ID 42 @@ -1041,16 +1042,47 @@ 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 BIOS-burnt slot: a committed, locked, zero-size decoder + * (CXL r3.2 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_MANUAL; + 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; } /* @@ -1131,7 +1163,7 @@ static bool mock_init_hdm_decoder(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)) { default_mock_decoder(cxld); return false; } @@ -1145,6 +1177,20 @@ static bool mock_init_hdm_decoder(struct cxl_decoder *cxld) 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 BIOS-burnt zero-size + locked slots above the + * decoder[0] auto-region (CXL r3.2 8.2.4.20.12). commit_end then + * points at a decoder with no DPA resource, exercising the + * zero-size enumeration 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 false; + } cxld->hpa_range = (struct range) { .start = base, .end = base + mock_auto_region_size - 1, @@ -1168,9 +1214,11 @@ static bool mock_init_hdm_decoder(struct cxl_decoder *cxld) */ 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. @@ -1214,6 +1262,26 @@ static bool mock_init_hdm_decoder(struct cxl_decoder *cxld) 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 burnt-slot 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); + } } return false; @@ -2030,6 +2098,9 @@ module_param(extended_linear_cache, bool, 0444); MODULE_PARM_DESC(extended_linear_cache, "Enable extended linear cache support"); module_param(fail_autoassemble, bool, 0444); MODULE_PARM_DESC(fail_autoassemble, "Simulate missing member of an auto-region"); +module_param(mock_zero_size_decoders, bool, 0444); +MODULE_PARM_DESC(mock_zero_size_decoders, + "Mock BIOS-burnt committed zero-size locked decoders under host-bridge0"); module_init(cxl_test_init); module_exit(cxl_test_exit); MODULE_LICENSE("GPL v2"); -- 2.43.0