diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2025-02-03 20:24:06 -0800 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2025-02-04 13:48:18 -0700 |
| commit | 188e9529a606f35c57e34cf860b99bc2b191b5f4 (patch) | |
| tree | a457cf60c1a62cf6b7f90d8f814698e4a930b89f | |
| parent | 2014c95afecee3e76ca4a56956a936e23283f05b (diff) | |
cxl: Remove the CXL_DECODER_MIXED mistake
CXL_DECODER_MIXED is a safety mechanism introduced for the case where
platform firmware has programmed an endpoint decoder that straddles a
DPA partition boundary. While the kernel is careful to only allocate DPA
capacity within a single partition there is no guarantee that platform
firmware, or anything that touched the device before the current kernel,
gets that right.
However, __cxl_dpa_reserve() will never get to the CXL_DECODER_MIXED
designation because of the way it tracks partition boundaries. A
request_resource() that spans ->ram_res and ->pmem_res fails with the
following signature:
__cxl_dpa_reserve: cxl_port endpoint15: decoder15.0: failed to reserve allocation
CXL_DECODER_MIXED is dead defensive programming after the driver has
already given up on the device. It has never offered any protection in
practice, just delete it.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Tested-by: Alejandro Lucero <alucerop@amd.com>
Link: https://patch.msgid.link/173864304660.668823.17000888505587850279.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
| -rw-r--r-- | drivers/cxl/core/hdm.c | 6 | ||||
| -rw-r--r-- | drivers/cxl/core/region.c | 12 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 4 |
3 files changed, 4 insertions, 18 deletions
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 50e6a45b30ba..b7f6a2d69f78 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -332,9 +332,9 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, else if (resource_contains(&cxlds->ram_res, res)) cxled->mode = CXL_DECODER_RAM; else { - dev_warn(dev, "decoder%d.%d: %pr mixed mode not supported\n", - port->id, cxled->cxld.id, cxled->dpa_res); - cxled->mode = CXL_DECODER_MIXED; + dev_warn(dev, "decoder%d.%d: %pr does not map any partition\n", + port->id, cxled->cxld.id, res); + cxled->mode = CXL_DECODER_NONE; } port->hdm_end++; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index e8d11a988fd9..34aa3d45fafa 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2738,18 +2738,6 @@ static int poison_by_decoder(struct device *dev, void *arg) if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) return rc; - /* - * Regions are only created with single mode decoders: pmem or ram. - * Linux does not support mixed mode decoders. This means that - * reading poison per endpoint decoder adheres to the requirement - * that poison reads of pmem and ram must be separated. - * CXL 3.0 Spec 8.2.9.8.4.1 - */ - if (cxled->mode == CXL_DECODER_MIXED) { - dev_dbg(dev, "poison list read unsupported in mixed mode\n"); - return rc; - } - cxlmd = cxled_to_memdev(cxled); if (cxled->skip) { offset = cxled->dpa_res->start - cxled->skip; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index bbbaa0d0a670..9fd1524ed150 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -380,7 +380,6 @@ enum cxl_decoder_mode { CXL_DECODER_NONE, CXL_DECODER_RAM, CXL_DECODER_PMEM, - CXL_DECODER_MIXED, CXL_DECODER_DEAD, }; @@ -390,10 +389,9 @@ static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode) [CXL_DECODER_NONE] = "none", [CXL_DECODER_RAM] = "ram", [CXL_DECODER_PMEM] = "pmem", - [CXL_DECODER_MIXED] = "mixed", }; - if (mode >= CXL_DECODER_NONE && mode <= CXL_DECODER_MIXED) + if (mode >= CXL_DECODER_NONE && mode < CXL_DECODER_DEAD) return names[mode]; return "mixed"; } |