static int acpi_nfit_find_poison(struct acpi_nfit_desc *acpi_desc, struct nd_region_desc *ndr_desc) { struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc; struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus; struct nd_cmd_ars_status *ars_status = NULL; struct nd_cmd_ars_start *ars_start = NULL; struct nd_cmd_ars_cap *ars_cap = NULL; u64 start, len, cur, remaining; int rc; ars_cap = kzalloc(sizeof(*ars_cap), GFP_KERNEL); if (!ars_cap) return -ENOMEM; start = ndr_desc->res->start; len = ndr_desc->res->end - ndr_desc->res->start + 1; rc = ars_get_cap(nd_desc, ars_cap, start, len); if (rc) goto out; /* * If ARS is unsupported, or if the 'Persistent Memory Scrub' flag in * extended status is not set, skip this but continue initialization */ if ((ars_cap->status & 0xffff) || !(ars_cap->status >> 16 & ND_ARS_PERSISTENT)) { dev_warn(acpi_desc->dev, "ARS unsupported (status: 0x%x), won't create an error list\n", ars_cap->status); goto out; } /* * Check if a full-range ARS has been run. If so, use those results * without having to start a new ARS. */ ars_status = kzalloc(ars_cap->max_ars_out + sizeof(*ars_status), GFP_KERNEL); if (!ars_status) { rc = -ENOMEM; goto out; } rc = ars_get_status(nd_desc, ars_status); if (rc) goto out; if (ars_status->address <= start && (ars_status->address + ars_status->length >= start + len)) { rc = ars_status_process_records(nvdimm_bus, ars_status, start); goto out; }

/* * ARS_STATUS can overflow if the number of poison entries found is * greater than the maximum buffer size (ars_cap->max_ars_out) * To detect overflow, check if the length field of ars_status * is less than the length we supplied. If so, process the * error entries we got, adjust the start point, and start again */

ars_start = kzalloc(sizeof(*ars_start), GFP_KERNEL); if (!ars_start) return -ENOMEM; cur = start; remaining = len;

do { u64 done, end; rc = ars_do_start(nd_desc, ars_start, cur, remaining); if (rc) goto out; rc = ars_get_status(nd_desc, ars_status); if (rc) goto out; rc = ars_status_process_records(nvdimm_bus, ars_status, cur); if (rc) goto out; end = min(cur + remaining, ars_status->address + ars_status->length); done = end - cur; cur += done; remaining -= done; } while (remaining); out: kfree(ars_cap); kfree(ars_start); kfree(ars_status); return rc; }