// SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2021 Intel Corporation. All rights reserved. */ #include #include #include #include #include #include #include "cxl.h" static struct acpi_table_header *acpi_cedt; /* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */ #define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways) #define CFMWS_INTERLEAVE_GRANULARITY(x) ((x)->granularity + 8) static unsigned long cfmws_to_decoder_flags(int restrictions) { unsigned long flags = 0; if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) flags |= CXL_DECODER_F_TYPE2; if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) flags |= CXL_DECODER_F_TYPE3; if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) flags |= CXL_DECODER_F_RAM; if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM) flags |= CXL_DECODER_F_PMEM; if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED) flags |= CXL_DECODER_F_LOCK; return flags; } static int cxl_acpi_cfmws_verify(struct device *dev, struct acpi_cedt_cfmws *cfmws) { int expected_len; if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) { dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n"); return -EINVAL; } if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) { dev_err(dev, "CFMWS Base HPA not 256MB aligned\n"); return -EINVAL; } if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) { dev_err(dev, "CFMWS Window Size not 256MB aligned\n"); return -EINVAL; } expected_len = struct_size((cfmws), interleave_targets, CFMWS_INTERLEAVE_WAYS(cfmws)); if (cfmws->header.length < expected_len) { dev_err(dev, "CFMWS length %d less than expected %d\n", cfmws->header.length, expected_len); return -EINVAL; } if (cfmws->header.length > expected_len) dev_dbg(dev, "CFMWS length %d greater than expected %d\n", cfmws->header.length, expected_len); return 0; } static void cxl_add_cfmws_decoders(struct device *dev, struct cxl_port *root_port) { struct acpi_cedt_cfmws *cfmws; struct cxl_decoder *cxld; acpi_size len, cur = 0; void *cedt_subtable; unsigned long flags; int rc; len = acpi_cedt->length - sizeof(*acpi_cedt); cedt_subtable = acpi_cedt + 1; while (cur < len) { struct acpi_cedt_header *c = cedt_subtable + cur; if (c->type != ACPI_CEDT_TYPE_CFMWS) { cur += c->length; continue; } cfmws = cedt_subtable + cur; if (cfmws->header.length < sizeof(*cfmws)) { dev_warn_once(dev, "CFMWS entry skipped:invalid length:%u\n", cfmws->header.length); cur += c->length; continue; } rc = cxl_acpi_cfmws_verify(dev, cfmws); if (rc) { dev_err(dev, "CFMWS range %#llx-%#llx not registered\n", cfmws->base_hpa, cfmws->base_hpa + cfmws->window_size - 1); cur += c->length; continue; } flags = cfmws_to_decoder_flags(cfmws->restrictions); cxld = devm_cxl_add_decoder(dev, root_port, CFMWS_INTERLEAVE_WAYS(cfmws), cfmws->base_hpa, cfmws->window_size, CFMWS_INTERLEAVE_WAYS(cfmws), CFMWS_INTERLEAVE_GRANULARITY(cfmws), CXL_DECODER_EXPANDER, flags); if (IS_ERR(cxld)) { dev_err(dev, "Failed to add decoder for %#llx-%#llx\n", cfmws->base_hpa, cfmws->base_hpa + cfmws->window_size - 1); } else { dev_dbg(dev, "add: %s range %#llx-%#llx\n", dev_name(&cxld->dev), cfmws->base_hpa, cfmws->base_hpa + cfmws->window_size - 1); } cur += c->length; } } static struct acpi_cedt_chbs *cxl_acpi_match_chbs(struct device *dev, u32 uid) { struct acpi_cedt_chbs *chbs, *chbs_match = NULL; acpi_size len, cur = 0; void *cedt_subtable; len = acpi_cedt->length - sizeof(*acpi_cedt); cedt_subtable = acpi_cedt + 1; while (cur < len) { struct acpi_cedt_header *c = cedt_subtable + cur; if (c->type != ACPI_CEDT_TYPE_CHBS) { cur += c->length; continue; } chbs = cedt_subtable + cur; if (chbs->header.length < sizeof(*chbs)) { dev_warn_once(dev, "CHBS entry skipped: invalid length:%u\n", chbs->header.length); cur += c->length; continue; } if (chbs->uid != uid) { cur += c->length; continue; } if (chbs_match) { dev_warn_once(dev, "CHBS entry skipped: duplicate UID:%u\n", uid); cur += c->length; continue; } chbs_match = chbs; cur += c->length; } return chbs_match ? chbs_match : ERR_PTR(-ENODEV); } static resource_size_t get_chbcr(struct acpi_cedt_chbs *chbs) { return IS_ERR(chbs) ? CXL_RESOURCE_NONE : chbs->base; } struct cxl_walk_context { struct device *dev; struct pci_bus *root; struct cxl_port *port; int error; int count; }; static int match_add_root_ports(struct pci_dev *pdev, void *data) { struct cxl_walk_context *ctx = data; struct pci_bus *root_bus = ctx->root; struct cxl_port *port = ctx->port; int type = pci_pcie_type(pdev); struct device *dev = ctx->dev; u32 lnkcap, port_num; int rc; if (pdev->bus != root_bus) return 0; if (!pci_is_pcie(pdev)) return 0; if (type != PCI_EXP_TYPE_ROOT_PORT) return 0; if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP, &lnkcap) != PCIBIOS_SUCCESSFUL) return 0; /* TODO walk DVSEC to find component register base */ port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap); rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE); if (rc) { ctx->error = rc; return rc; } ctx->count++; dev_dbg(dev, "add dport%d: %s\n", port_num, dev_name(&pdev->dev)); return 0; } static struct cxl_dport *find_dport_by_dev(struct cxl_port *port, struct device *dev) { struct cxl_dport *dport; device_lock(&port->dev); list_for_each_entry(dport, &port->dports, list) if (dport->dport == dev) { device_unlock(&port->dev); return dport; } device_unlock(&port->dev); return NULL; } static struct acpi_device *to_cxl_host_bridge(struct device *dev) { struct acpi_device *adev = to_acpi_device(dev); if (!acpi_pci_find_root(adev->handle)) return NULL; if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0) return adev; return NULL; } /* * A host bridge is a dport to a CFMWS decode and it is a uport to the * dport (PCIe Root Ports) in the host bridge. */ static int add_host_bridge_uport(struct device *match, void *arg) { struct acpi_device *bridge = to_cxl_host_bridge(match); struct cxl_port *root_port = arg; struct device *host = root_port->dev.parent; struct acpi_pci_root *pci_root; struct cxl_walk_context ctx; struct cxl_decoder *cxld; struct cxl_dport *dport; struct cxl_port *port; if (!bridge) return 0; dport = find_dport_by_dev(root_port, match); if (!dport) { dev_dbg(host, "host bridge expected and not found\n"); return -ENODEV; } port = devm_cxl_add_port(host, match, dport->component_reg_phys, root_port); if (IS_ERR(port)) return PTR_ERR(port); dev_dbg(host, "%s: add: %s\n", dev_name(match), dev_name(&port->dev)); /* * Note that this lookup already succeeded in * to_cxl_host_bridge(), so no need to check for failure here */ pci_root = acpi_pci_find_root(bridge->handle); ctx = (struct cxl_walk_context){ .dev = host, .root = pci_root->bus, .port = port, }; pci_walk_bus(pci_root->bus, match_add_root_ports, &ctx); if (ctx.count == 0) return -ENODEV; if (ctx.error) return ctx.error; /* TODO: Scan CHBCR for HDM Decoder resources */ /* * In the single-port host-bridge case there are no HDM decoders * in the CHBCR and a 1:1 passthrough decode is implied. */ if (ctx.count == 1) { cxld = devm_cxl_add_passthrough_decoder(host, port); if (IS_ERR(cxld)) return PTR_ERR(cxld); dev_dbg(host, "add: %s\n", dev_name(&cxld->dev)); } return 0; } static int add_host_bridge_dport(struct device *match, void *arg) { int rc; acpi_status status; unsigned long long uid; struct acpi_cedt_chbs *chbs; struct cxl_port *root_port = arg; struct device *host = root_port->dev.parent; struct acpi_device *bridge = to_cxl_host_bridge(match); if (!bridge) return 0; status = acpi_evaluate_integer(bridge->handle, METHOD_NAME__UID, NULL, &uid); if (status != AE_OK) { dev_err(host, "unable to retrieve _UID of %s\n", dev_name(match)); return -ENODEV; } chbs = cxl_acpi_match_chbs(host, uid); if (IS_ERR(chbs)) dev_dbg(host, "No CHBS found for Host Bridge: %s\n", dev_name(match)); rc = cxl_add_dport(root_port, match, uid, get_chbcr(chbs)); if (rc) { dev_err(host, "failed to add downstream port: %s\n", dev_name(match)); return rc; } dev_dbg(host, "add dport%llu: %s\n", uid, dev_name(match)); return 0; } static int add_root_nvdimm_bridge(struct device *match, void *data) { struct cxl_decoder *cxld; struct cxl_port *root_port = data; struct cxl_nvdimm_bridge *cxl_nvb; struct device *host = root_port->dev.parent; if (!is_root_decoder(match)) return 0; cxld = to_cxl_decoder(match); if (!(cxld->flags & CXL_DECODER_F_PMEM)) return 0; cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port); if (IS_ERR(cxl_nvb)) { dev_dbg(host, "failed to register pmem\n"); return PTR_ERR(cxl_nvb); } dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev), dev_name(&cxl_nvb->dev)); return 1; } static int cxl_acpi_probe(struct platform_device *pdev) { int rc; acpi_status status; struct cxl_port *root_port; struct device *host = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(host); root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL); if (IS_ERR(root_port)) return PTR_ERR(root_port); dev_dbg(host, "add: %s\n", dev_name(&root_port->dev)); status = acpi_get_table(ACPI_SIG_CEDT, 0, &acpi_cedt); if (ACPI_FAILURE(status)) return -ENXIO; rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_dport); if (rc) goto out; cxl_add_cfmws_decoders(host, root_port); /* * Root level scanned with host-bridge as dports, now scan host-bridges * for their role as CXL uports to their CXL-capable PCIe Root Ports. */ rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_uport); if (rc) goto out; if (IS_ENABLED(CONFIG_CXL_PMEM)) rc = device_for_each_child(&root_port->dev, root_port, add_root_nvdimm_bridge); out: acpi_put_table(acpi_cedt); if (rc < 0) return rc; return 0; } static const struct acpi_device_id cxl_acpi_ids[] = { { "ACPI0017", 0 }, { "", 0 }, }; MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids); static struct platform_driver cxl_acpi_driver = { .probe = cxl_acpi_probe, .driver = { .name = KBUILD_MODNAME, .acpi_match_table = cxl_acpi_ids, }, }; module_platform_driver(cxl_acpi_driver); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(CXL);