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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?61k/rDeXEmxDE4JjoxevaawbQfDl2zWVNVRlAtQNoOmsOM8jJN39pL4Gnubb?= =?us-ascii?Q?exNcYovLDTM0ZAxA+JKQdoE4QjKb6iPAXLIfhXmgHkXH4shmMPGWUqdQSVFQ?= =?us-ascii?Q?YUS0jRp2K0UrXUNcwZGLO1cCXYCDa2AsFHnEmYCt1w9liv/Dv/y1VktJnjRX?= =?us-ascii?Q?IvLfLbmVABtxGQZBggBltmpQTprXNJ4lt9gu1iOue+G+Xj/xWGWWaE6Gg0Lr?= =?us-ascii?Q?OwSdYW77nexABLwNt0ZdP8ARRvPPXXA9SRg04nywq8h07FJzHSntGSzWFoyN?= =?us-ascii?Q?LF5W3ClDZRyVXXY2USqcC3WOWNCzJAlKqTmd1WHWZZ0X6ETPDLciLqx4pTJP?= =?us-ascii?Q?S/LzIZrNmbcX7eVbypAqXXZ5pnld+JcCnoSbh6bzTyrBfkAGbsMrks6lpbeo?= =?us-ascii?Q?uaZ6sm4k/JWo4YRXO7NvjtdHk1KT7RB0EuHj+6TfqYsYH30VMsZqwW8y+Dms?= =?us-ascii?Q?TMPzjOhAcKObhuybQXLXxIqwrlllZTtCaM+vlwDURpJjrRG4uOKNiIEAotK3?= =?us-ascii?Q?5Jn/HDQB/7O0vGpAFQohteT6F9gbo3sB3eZFb++YoBOeSaC5vh8elV2oIBtH?= =?us-ascii?Q?1c+Oek15XdrMJQqVHvosVWGg/8qwUhcJE6YVh+8izFSzoXWHMY+/brJqf14/?= =?us-ascii?Q?OdO1OWpKnomMPNuWrT5p4D1Q2Ep5PaqIDqjY2ICvjBvA0al3YSEcQGNwrpqV?= =?us-ascii?Q?RWzQIgHA3vdravdy9TP/392wVZASi7YDoR4/IRPJxav340I/xDGaD/PZHMmG?= =?us-ascii?Q?tAKHVAyYCtCRfoBZvUfQVdBsOfF+OdNU7+kkhqZS1eUBIIXyHgYMbdm0pACy?= =?us-ascii?Q?ndrQhXAsdM6H+ceTVedZEyJ+BBYHg3xotnvShTwYHfkwLsUCtuauJoSxfXzN?= =?us-ascii?Q?R6UT9s9kUjGPRuo9+mnyHQNMlguubiDxlqRd7rUzaCbGmbmOLO+7jYHt7tGd?= =?us-ascii?Q?Pgr3UQOicQ1Ap3cGEux2Axk7lC28xQIGeunOUmzIvZy4UIUBA6JXIneMYztX?= =?us-ascii?Q?MCANTzTjwomzEcEUTWfgvulqgr7sYySv8FtNgxeXUZZYqu44E4aY73uieqFT?= =?us-ascii?Q?CtwTOdcG1mab2YboQBKFOzCGergH8Hldms2otP4FUGTo1MANRXbEYC+dR1rd?= =?us-ascii?Q?T6S146li4z6U5QY5xIooBZwdtRI2lRhdvSczxLJJBzDI7bN4e8CkfewCxhbT?= =?us-ascii?Q?5rHACgAJI/jx4839tliP5mFI81tfBG5p8Xq1shw64F1Pn3Yd3dpYIHvpVDuO?= =?us-ascii?Q?/zOzW8UR+++zXOcGS2bPvivLQwFaQ/+tZi6tFvda8wvhWauBpb8bjhr2W5+w?= =?us-ascii?Q?CGILdgRY92IsD4qiR9rGQQ5+6cIImcWq3BUTf9syfcCcypuvCk+JtHC2QYpM?= =?us-ascii?Q?LBjhgLQqn1xc1+a4zzmvfA8/BjLa/LiXbkZPdfQta7ASFH5/TFSOPkWPKQ3g?= =?us-ascii?Q?h2BR0QMcwraO8ErhxcZ2nBqsznC4fa57noeqOqg0AfZPUIknDyT1UqOB9UvW?= =?us-ascii?Q?yxEg+6kA7ZM6uzMi68XzGkfkr/wvqA3pMJHBvNE3bgKS0cLeWJWytFJ2AKu0?= =?us-ascii?Q?S2lcSz1YyenZie0a/axuqUrbZ9Jhl8DMPSagUMokHUDZNUqstpN7CYdEwnnS?= =?us-ascii?Q?rNKzV7d19fExeQMu2HT7bd2RlnKL0347Wi+X8fCI2YW3HvKwdYN4XS+hceaQ?= =?us-ascii?Q?XSPHHvCor6ltqPJcaKOZoPaHvGFalJ5/nORCn/waJl4TQ5qF?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9d8836e5-a843-4dbf-d99c-08df141e3dfe X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB6085.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Sep 2026 18:13:43.2956 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uKi39hzLdOAWmaQnJKtG0+IMbyM2cA1kzkTSkmttwJDsOVne/SNSbF4FASQmzL9IGFURWsyIuYPKpfE8P6wfcA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL4PR12MB9481 On 03.09.26 16:23:48, Alison Schofield wrote: > User region creation currently requires an interleaving root to have the > same granularity as the region. > > That rejects mixed-granularity layouts, those where the region granularity > is finer than the granularity of the interleaving root decoder. A region > granularity coarser than the root remains invalid because it produces > incorrect DPA translations. > > Allow a region granularity finer than an interleaving root and continue to > reject a coarser granularity. Validate the complete ways/granularity > relationship when the region endpoints are attached. > > For example, CXL 4.0 Section 9.13.1.1 Table 9-7 describes a 6-way region at > IGB across three host bridges as a 3-way root interleave at 2 * IGB with a > 2-way interleave at IGB below it. > > Signed-off-by: Alison Schofield > Reviewed-by: Jonathan Cameron > --- > drivers/cxl/core/region.c | 15 ++++++--------- > 1 file changed, 6 insertions(+), 9 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 5b7104a55fdd..374d8c2c32d1 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -572,16 +572,13 @@ static int set_interleave_granularity(struct cxl_region *cxlr, int val) > if (rc) > return rc; > > - /* > - * When the host-bridge is interleaved, disallow region granularity != > - * root granularity. Regions with a granularity less than the root > - * interleave result in needing multiple endpoints to support a single > - * slot in the interleave (possible to support in the future). Regions > - * with a granularity greater than the root interleave result in invalid > - * DPA translations (invalid to support). > - */ > - if (cxld->interleave_ways > 1 && val != cxld->interleave_granularity) > + /* Region granularity must not be coarser than an interleaving root's */ > + if (cxld->interleave_ways > 1 && val > cxld->interleave_granularity) { > + dev_dbg(&cxlr->dev, > + "granularity %d exceeds root decoder granularity %d\n", > + val, cxld->interleave_granularity); The spec only restricts that for Mod3 configs. Else, there is no driver support. Could that added as a comment? > return -EINVAL; > + } > > lockdep_assert_held_write(&cxl_rwsem.region); > > -- > 2.37.3 >