diff options
Diffstat (limited to 'drivers/cxl/core/region.c')
| -rw-r--r-- | drivers/cxl/core/region.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index b2fd67fcebfb..f822de44bee0 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2238,6 +2238,130 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev) } EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL); +struct cxl_poison_context { + struct cxl_port *port; + enum cxl_decoder_mode mode; + u64 offset; +}; + +static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd, + struct cxl_poison_context *ctx) +{ + struct cxl_dev_state *cxlds = cxlmd->cxlds; + u64 offset, length; + int rc = 0; + + /* + * Collect poison for the remaining unmapped resources + * after poison is collected by committed endpoints. + * + * Knowing that PMEM must always follow RAM, get poison + * for unmapped resources based on the last decoder's mode: + * ram: scan remains of ram range, then any pmem range + * pmem: scan remains of pmem range + */ + + if (ctx->mode == CXL_DECODER_RAM) { + offset = ctx->offset; + length = resource_size(&cxlds->ram_res) - offset; + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); + if (rc == -EFAULT) + rc = 0; + if (rc) + return rc; + } + if (ctx->mode == CXL_DECODER_PMEM) { + offset = ctx->offset; + length = resource_size(&cxlds->dpa_res) - offset; + if (!length) + return 0; + } else if (resource_size(&cxlds->pmem_res)) { + offset = cxlds->pmem_res.start; + length = resource_size(&cxlds->pmem_res); + } else { + return 0; + } + + return cxl_mem_get_poison(cxlmd, offset, length, NULL); +} + +static int poison_by_decoder(struct device *dev, void *arg) +{ + struct cxl_poison_context *ctx = arg; + struct cxl_endpoint_decoder *cxled; + struct cxl_memdev *cxlmd; + u64 offset, length; + int rc = 0; + + if (!is_endpoint_decoder(dev)) + return rc; + + cxled = to_cxl_endpoint_decoder(dev); + 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; + length = cxled->skip; + rc = cxl_mem_get_poison(cxlmd, offset, length, NULL); + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) + rc = 0; + if (rc) + return rc; + } + + offset = cxled->dpa_res->start; + length = cxled->dpa_res->end - offset + 1; + rc = cxl_mem_get_poison(cxlmd, offset, length, cxled->cxld.region); + if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM) + rc = 0; + if (rc) + return rc; + + /* Iterate until commit_end is reached */ + if (cxled->cxld.id == ctx->port->commit_end) { + ctx->offset = cxled->dpa_res->end + 1; + ctx->mode = cxled->mode; + return 1; + } + + return 0; +} + +int cxl_get_poison_by_endpoint(struct cxl_port *port) +{ + struct cxl_poison_context ctx; + int rc = 0; + + rc = down_read_interruptible(&cxl_region_rwsem); + if (rc) + return rc; + + ctx = (struct cxl_poison_context) { + .port = port + }; + + rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder); + if (rc == 1) + rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport), &ctx); + + up_read(&cxl_region_rwsem); + return rc; +} + static struct lock_class_key cxl_pmem_region_key; static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr) |