// SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2021 Intel Corporation. All rights reserved. */ #include #include #include #include #include #include #include #include #include "cxlpci.h" #include "cxl.h" #define CXL_RCRB_SIZE SZ_8K struct cxl_cxims_data { int nr_maps; u64 xormaps[] __counted_by(nr_maps); }; static const guid_t acpi_cxl_qtg_id_guid = GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); /* * Find a targets entry (n) in the host bridge interleave list. * CXL Specification 3.0 Table 9-22 */ static int cxl_xor_calc_n(u64 hpa, struct cxl_cxims_data *cximsd, int iw, int ig) { int i = 0, n = 0; u8 eiw; /* IW: 2,4,6,8,12,16 begin building 'n' using xormaps */ if (iw != 3) { for (i = 0; i < cximsd->nr_maps; i++) n |= (hweight64(hpa & cximsd->xormaps[i]) & 1) << i; } /* IW: 3,6,12 add a modulo calculation to 'n' */ if (!is_power_of_2(iw)) { if (ways_to_eiw(iw, &eiw)) return -1; hpa &= GENMASK_ULL(51, eiw + ig); n |= do_div(hpa, 3) << i; } return n; } static struct cxl_dport *cxl_hb_xor(struct cxl_root_decoder *cxlrd, int pos) { struct cxl_cxims_data *cximsd = cxlrd->platform_data; struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd; struct cxl_decoder *cxld = &cxlsd->cxld; int ig = cxld->interleave_granularity; int iw = cxld->interleave_ways; int n = 0; u64 hpa; if (dev_WARN_ONCE(&cxld->dev, cxld->interleave_ways != cxlsd->nr_targets, "misconfigured root decoder\n")) return NULL; hpa = cxlrd->res->start + pos * ig; /* Entry (n) is 0 for no interleave (iw == 1) */ if (iw != 1) n = cxl_xor_calc_n(hpa, cximsd, iw, ig); if (n < 0) return NULL; return cxlrd->cxlsd.target[n]; } struct cxl_cxims_context { struct device *dev; struct cxl_root_decoder *cxlrd; }; static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg, const unsigned long end) { struct acpi_cedt_cxims *cxims = (struct acpi_cedt_cxims *)header; struct cxl_cxims_context *ctx = arg; struct cxl_root_decoder *cxlrd = ctx->cxlrd; struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct device *dev = ctx->dev; struct cxl_cxims_data *cximsd; unsigned int hbig, nr_maps; int rc; rc = eig_to_granularity(cxims->hbig, &hbig); if (rc) return rc; /* Does this CXIMS entry apply to the given CXL Window? */ if (hbig != cxld->interleave_granularity) return 0; /* IW 1,3 do not use xormaps and skip this parsing entirely */ if (is_power_of_2(cxld->interleave_ways)) /* 2, 4, 8, 16 way */ nr_maps = ilog2(cxld->interleave_ways); else /* 6, 12 way */ nr_maps = ilog2(cxld->interleave_ways / 3); if (cxims->nr_xormaps < nr_maps) { dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n", cxims->nr_xormaps, nr_maps); return -ENXIO; } cximsd = devm_kzalloc(dev, struct_size(cximsd, xormaps, nr_maps), GFP_KERNEL); if (!cximsd) return -ENOMEM; cximsd->nr_maps = nr_maps; memcpy(cximsd->xormaps, cxims->xormap_list, nr_maps * sizeof(*cximsd->xormaps)); cxlrd->platform_data = cximsd; return 0; } static unsigned long cfmws_to_decoder_flags(int restrictions) { unsigned long flags = CXL_DECODER_F_ENABLE; 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 rc, expected_len; unsigned int ways; if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO && cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_XOR) { dev_err(dev, "CFMWS Unknown Interleave Arithmetic: %d\n", cfmws->interleave_arithmetic); 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; } rc = eiw_to_ways(cfmws->interleave_ways, &ways); if (rc) { dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n", cfmws->interleave_ways); return -EINVAL; } expected_len = struct_size(cfmws, interleave_targets, ways); 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; } /* * Note, @dev must be the first member, see 'struct cxl_chbs_context' * and mock_acpi_table_parse_cedt() */ struct cxl_cfmws_context { struct device *dev; struct cxl_port *root_port; struct resource *cxl_res; int id; }; /** * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM * @handle: ACPI handle * @coord: performance access coordinates * @entries: number of QTG IDs to return * @qos_class: int array provided by caller to return QTG IDs * * Return: number of QTG IDs returned, or -errno for errors * * Issue QTG _DSM with accompanied bandwidth and latency data in order to get * the QTG IDs that are suitable for the performance point in order of most * suitable to least suitable. Write back array of QTG IDs and return the * actual number of QTG IDs written back. */ static int cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord, int entries, int *qos_class) { union acpi_object *out_obj, *out_buf, *obj; union acpi_object in_array[4] = { [0].integer = { ACPI_TYPE_INTEGER, coord->read_latency }, [1].integer = { ACPI_TYPE_INTEGER, coord->write_latency }, [2].integer = { ACPI_TYPE_INTEGER, coord->read_bandwidth }, [3].integer = { ACPI_TYPE_INTEGER, coord->write_bandwidth }, }; union acpi_object in_obj = { .package = { .type = ACPI_TYPE_PACKAGE, .count = 4, .elements = in_array, }, }; int count, pkg_entries, i; u16 max_qtg; int rc; if (!entries) return -EINVAL; out_obj = acpi_evaluate_dsm(handle, &acpi_cxl_qtg_id_guid, 1, 1, &in_obj); if (!out_obj) return -ENXIO; if (out_obj->type != ACPI_TYPE_PACKAGE) { rc = -ENXIO; goto out; } /* Check Max QTG ID */ obj = &out_obj->package.elements[0]; if (obj->type != ACPI_TYPE_INTEGER) { rc = -ENXIO; goto out; } max_qtg = obj->integer.value; /* It's legal to have 0 QTG entries */ pkg_entries = out_obj->package.count; if (pkg_entries <= 1) { rc = 0; goto out; } /* Retrieve QTG IDs package */ obj = &out_obj->package.elements[1]; if (obj->type != ACPI_TYPE_PACKAGE) { rc = -ENXIO; goto out; } pkg_entries = obj->package.count; count = min(entries, pkg_entries); for (i = 0; i < count; i++) { u16 qtg_id; out_buf = &obj->package.elements[i]; if (out_buf->type != ACPI_TYPE_INTEGER) { rc = -ENXIO; goto out; } qtg_id = out_buf->integer.value; if (qtg_id > max_qtg) pr_warn("QTG ID %u greater than MAX %u\n", qtg_id, max_qtg); qos_class[i] = qtg_id; } rc = count; out: ACPI_FREE(out_obj); return rc; } static int cxl_acpi_qos_class(struct cxl_port *root_port, struct access_coordinate *coord, int entries, int *qos_class) { acpi_handle handle; struct device *dev; dev = root_port->uport_dev; if (!dev_is_platform(dev)) return -ENODEV; handle = ACPI_HANDLE(dev); if (!handle) return -ENODEV; return cxl_acpi_evaluate_qtg_dsm(handle, coord, entries, qos_class); } static const struct cxl_root_ops acpi_root_ops = { .qos_class = cxl_acpi_qos_class, }; static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, const unsigned long end) { int target_map[CXL_DECODER_MAX_INTERLEAVE]; struct cxl_cfmws_context *ctx = arg; struct cxl_port *root_port = ctx->root_port; struct resource *cxl_res = ctx->cxl_res; struct cxl_cxims_context cxims_ctx; struct cxl_root_decoder *cxlrd; struct device *dev = ctx->dev; struct acpi_cedt_cfmws *cfmws; cxl_calc_hb_fn cxl_calc_hb; struct cxl_decoder *cxld; unsigned int ways, i, ig; struct resource *res; int rc; cfmws = (struct acpi_cedt_cfmws *) header; 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); return 0; } rc = eiw_to_ways(cfmws->interleave_ways, &ways); if (rc) return rc; rc = eig_to_granularity(cfmws->granularity, &ig); if (rc) return rc; for (i = 0; i < ways; i++) target_map[i] = cfmws->interleave_targets[i]; res = kzalloc(sizeof(*res), GFP_KERNEL); if (!res) return -ENOMEM; res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++); if (!res->name) goto err_name; res->start = cfmws->base_hpa; res->end = cfmws->base_hpa + cfmws->window_size - 1; res->flags = IORESOURCE_MEM; /* add to the local resource tracking to establish a sort order */ rc = insert_resource(cxl_res, res); if (rc) goto err_insert; if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) cxl_calc_hb = cxl_hb_modulo; else cxl_calc_hb = cxl_hb_xor; cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb); if (IS_ERR(cxlrd)) return 0; cxld = &cxlrd->cxlsd.cxld; cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions); cxld->target_type = CXL_DECODER_HOSTONLYMEM; cxld->hpa_range = (struct range) { .start = res->start, .end = res->end, }; cxld->interleave_ways = ways; /* * Minimize the x1 granularity to advertise support for any * valid region granularity */ if (ways == 1) ig = CXL_DECODER_MIN_GRANULARITY; cxld->interleave_granularity = ig; if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) { if (ways != 1 && ways != 3) { cxims_ctx = (struct cxl_cxims_context) { .dev = dev, .cxlrd = cxlrd, }; rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS, cxl_parse_cxims, &cxims_ctx); if (rc < 0) goto err_xormap; if (!cxlrd->platform_data) { dev_err(dev, "No CXIMS for HBIG %u\n", ig); rc = -EINVAL; goto err_xormap; } } } cxlrd->qos_class = cfmws->qtg_id; rc = cxl_decoder_add(cxld, target_map); err_xormap: if (rc) put_device(&cxld->dev); else rc = cxl_decoder_autoremove(dev, cxld); if (rc) { dev_err(dev, "Failed to add decode range: %pr", res); return rc; } dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n", dev_name(&cxld->dev), phys_to_target_node(cxld->hpa_range.start), cxld->hpa_range.start, cxld->hpa_range.end); return 0; err_insert: kfree(res->name); err_name: kfree(res); return -ENOMEM; } __mock struct acpi_device *to_cxl_host_bridge(struct device *host, 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; } /* Note, @dev is used by mock_acpi_table_parse_cedt() */ struct cxl_chbs_context { struct device *dev; unsigned long long uid; resource_size_t base; u32 cxl_version; }; static int cxl_get_chbs_iter(union acpi_subtable_headers *header, void *arg, const unsigned long end) { struct cxl_chbs_context *ctx = arg; struct acpi_cedt_chbs *chbs; if (ctx->base != CXL_RESOURCE_NONE) return 0; chbs = (struct acpi_cedt_chbs *) header; if (ctx->uid != chbs->uid) return 0; ctx->cxl_version = chbs->cxl_version; if (!chbs->base) return 0; if (chbs->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11 && chbs->length != CXL_RCRB_SIZE) return 0; ctx->base = chbs->base; return 0; } static int cxl_get_chbs(struct device *dev, struct acpi_device *hb, struct cxl_chbs_context *ctx) { unsigned long long uid; int rc; rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid); if (rc != AE_OK) { dev_err(dev, "unable to retrieve _UID\n"); return -ENOENT; } dev_dbg(dev, "UID found: %lld\n", uid); *ctx = (struct cxl_chbs_context) { .dev = dev, .uid = uid, .base = CXL_RESOURCE_NONE, .cxl_version = UINT_MAX, }; acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbs_iter, ctx); return 0; } static int add_host_bridge_dport(struct device *match, void *arg) { acpi_status rc; struct device *bridge; struct cxl_dport *dport; struct cxl_chbs_context ctx; struct acpi_pci_root *pci_root; struct cxl_port *root_port = arg; struct device *host = root_port->dev.parent; struct acpi_device *hb = to_cxl_host_bridge(host, match); if (!hb) return 0; rc = cxl_get_chbs(match, hb, &ctx); if (rc) return rc; if (ctx.cxl_version == UINT_MAX) { dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n", ctx.uid); return 0; } if (ctx.base == CXL_RESOURCE_NONE) { dev_warn(match, "CHBS invalid for Host Bridge (UID %lld)\n", ctx.uid); return 0; } pci_root = acpi_pci_find_root(hb->handle); bridge = pci_root->bus->bridge; /* * In RCH mode, bind the component regs base to the dport. In * VH mode it will be bound to the CXL host bridge's port * object later in add_host_bridge_uport(). */ if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) { dev_dbg(match, "RCRB found for UID %lld: %pa\n", ctx.uid, &ctx.base); dport = devm_cxl_add_rch_dport(root_port, bridge, ctx.uid, ctx.base); } else { dport = devm_cxl_add_dport(root_port, bridge, ctx.uid, CXL_RESOURCE_NONE); } if (IS_ERR(dport)) return PTR_ERR(dport); return 0; } /* * 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 cxl_port *root_port = arg; struct device *host = root_port->dev.parent; struct acpi_device *hb = to_cxl_host_bridge(host, match); struct acpi_pci_root *pci_root; struct cxl_dport *dport; struct cxl_port *port; struct device *bridge; struct cxl_chbs_context ctx; resource_size_t component_reg_phys; int rc; if (!hb) return 0; pci_root = acpi_pci_find_root(hb->handle); bridge = pci_root->bus->bridge; dport = cxl_find_dport_by_dev(root_port, bridge); if (!dport) { dev_dbg(host, "host bridge expected and not found\n"); return 0; } if (dport->rch) { dev_info(bridge, "host supports CXL (restricted)\n"); return 0; } rc = cxl_get_chbs(match, hb, &ctx); if (rc) return rc; if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) { dev_warn(bridge, "CXL CHBS version mismatch, skip port registration\n"); return 0; } component_reg_phys = ctx.base; if (component_reg_phys != CXL_RESOURCE_NONE) dev_dbg(match, "CHBCR found for UID %lld: %pa\n", ctx.uid, &component_reg_phys); rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus); if (rc) return rc; port = devm_cxl_add_port(host, bridge, component_reg_phys, dport); if (IS_ERR(port)) return PTR_ERR(port); dev_info(bridge, "host supports CXL\n"); 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 struct lock_class_key cxl_root_key; static void cxl_acpi_lock_reset_class(void *dev) { device_lock_reset_class(dev); } static void del_cxl_resource(struct resource *res) { kfree(res->name); kfree(res); } static void cxl_set_public_resource(struct resource *priv, struct resource *pub) { priv->desc = (unsigned long) pub; } static struct resource *cxl_get_public_resource(struct resource *priv) { return (struct resource *) priv->desc; } static void remove_cxl_resources(void *data) { struct resource *res, *next, *cxl = data; for (res = cxl->child; res; res = next) { struct resource *victim = cxl_get_public_resource(res); next = res->sibling; remove_resource(res); if (victim) { remove_resource(victim); kfree(victim); } del_cxl_resource(res); } } /** * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource * @cxl_res: A standalone resource tree where each CXL window is a sibling * * Walk each CXL window in @cxl_res and add it to iomem_resource potentially * expanding its boundaries to ensure that any conflicting resources become * children. If a window is expanded it may then conflict with a another window * entry and require the window to be truncated or trimmed. Consider this * situation: * * |-- "CXL Window 0" --||----- "CXL Window 1" -----| * |--------------- "System RAM" -------------| * * ...where platform firmware has established as System RAM resource across 2 * windows, but has left some portion of window 1 for dynamic CXL region * provisioning. In this case "Window 0" will span the entirety of the "System * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end * of that "System RAM" resource. */ static int add_cxl_resources(struct resource *cxl_res) { struct resource *res, *new, *next; for (res = cxl_res->child; res; res = next) { new = kzalloc(sizeof(*new), GFP_KERNEL); if (!new) return -ENOMEM; new->name = res->name; new->start = res->start; new->end = res->end; new->flags = IORESOURCE_MEM; new->desc = IORES_DESC_CXL; /* * Record the public resource in the private cxl_res tree for * later removal. */ cxl_set_public_resource(res, new); insert_resource_expand_to_fit(&iomem_resource, new); next = res->sibling; while (next && resource_overlaps(new, next)) { if (resource_contains(new, next)) { struct resource *_next = next->sibling; remove_resource(next); del_cxl_resource(next); next = _next; } else next->start = new->end + 1; } } return 0; } static int pair_cxl_resource(struct device *dev, void *data) { struct resource *cxl_res = data; struct resource *p; if (!is_root_decoder(dev)) return 0; for (p = cxl_res->child; p; p = p->sibling) { struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev); struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct resource res = { .start = cxld->hpa_range.start, .end = cxld->hpa_range.end, .flags = IORESOURCE_MEM, }; if (resource_contains(p, &res)) { cxlrd->res = cxl_get_public_resource(p); break; } } return 0; } static int cxl_acpi_probe(struct platform_device *pdev) { int rc; struct resource *cxl_res; struct cxl_root *cxl_root; struct cxl_port *root_port; struct device *host = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(host); struct cxl_cfmws_context ctx; device_lock_set_class(&pdev->dev, &cxl_root_key); rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class, &pdev->dev); if (rc) return rc; cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL); if (!cxl_res) return -ENOMEM; cxl_res->name = "CXL mem"; cxl_res->start = 0; cxl_res->end = -1; cxl_res->flags = IORESOURCE_MEM; cxl_root = devm_cxl_add_root(host, &acpi_root_ops); if (IS_ERR(cxl_root)) return PTR_ERR(cxl_root); root_port = &cxl_root->port; rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_dport); if (rc < 0) return rc; rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res); if (rc) return rc; ctx = (struct cxl_cfmws_context) { .dev = host, .root_port = root_port, .cxl_res = cxl_res, }; rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx); if (rc < 0) return -ENXIO; rc = add_cxl_resources(cxl_res); if (rc) return rc; /* * Populate the root decoders with their related iomem resource, * if present */ device_for_each_child(&root_port->dev, cxl_res, pair_cxl_resource); /* * 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 < 0) return rc; if (IS_ENABLED(CONFIG_CXL_PMEM)) rc = device_for_each_child(&root_port->dev, root_port, add_root_nvdimm_bridge); if (rc < 0) return rc; /* In case PCI is scanned before ACPI re-trigger memdev attach */ cxl_bus_rescan(); return 0; } static const struct acpi_device_id cxl_acpi_ids[] = { { "ACPI0017" }, { }, }; MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids); static const struct platform_device_id cxl_test_ids[] = { { "cxl_acpi" }, { }, }; MODULE_DEVICE_TABLE(platform, cxl_test_ids); static struct platform_driver cxl_acpi_driver = { .probe = cxl_acpi_probe, .driver = { .name = KBUILD_MODNAME, .acpi_match_table = cxl_acpi_ids, }, .id_table = cxl_test_ids, }; static int __init cxl_acpi_init(void) { return platform_driver_register(&cxl_acpi_driver); } static void __exit cxl_acpi_exit(void) { platform_driver_unregister(&cxl_acpi_driver); cxl_bus_drain(); } /* load before dax_hmem sees 'Soft Reserved' CXL ranges */ subsys_initcall(cxl_acpi_init); module_exit(cxl_acpi_exit); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(CXL); MODULE_IMPORT_NS(ACPI);