// SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2021 Intel Corporation. All rights reserved. */ #include #include #include #include #include #include #include #include #include "core.h" /** * DOC: cxl core pci * * Compute Express Link protocols are layered on top of PCIe. CXL core provides * a set of helpers for CXL interactions which occur via PCIe. */ static unsigned short media_ready_timeout = 60; module_param(media_ready_timeout, ushort, 0644); MODULE_PARM_DESC(media_ready_timeout, "seconds to wait for media ready"); struct cxl_walk_context { struct pci_bus *bus; struct cxl_port *port; int type; int error; int count; }; static int match_add_dports(struct pci_dev *pdev, void *data) { struct cxl_walk_context *ctx = data; struct cxl_port *port = ctx->port; int type = pci_pcie_type(pdev); struct cxl_register_map map; struct cxl_dport *dport; u32 lnkcap, port_num; int rc; if (pdev->bus != ctx->bus) return 0; if (!pci_is_pcie(pdev)) return 0; if (type != ctx->type) return 0; if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP, &lnkcap)) return 0; rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map); if (rc) dev_dbg(&port->dev, "failed to find component registers\n"); port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap); dport = devm_cxl_add_dport(port, &pdev->dev, port_num, map.resource); if (IS_ERR(dport)) { ctx->error = PTR_ERR(dport); return PTR_ERR(dport); } ctx->count++; return 0; } /** * devm_cxl_port_enumerate_dports - enumerate downstream ports of the upstream port * @port: cxl_port whose ->uport is the upstream of dports to be enumerated * * Returns a positive number of dports enumerated or a negative error * code. */ int devm_cxl_port_enumerate_dports(struct cxl_port *port) { struct pci_bus *bus = cxl_port_to_pci_bus(port); struct cxl_walk_context ctx; int type; if (!bus) return -ENXIO; if (pci_is_root_bus(bus)) type = PCI_EXP_TYPE_ROOT_PORT; else type = PCI_EXP_TYPE_DOWNSTREAM; ctx = (struct cxl_walk_context) { .port = port, .bus = bus, .type = type, }; pci_walk_bus(bus, match_add_dports, &ctx); if (ctx.count == 0) return -ENODEV; if (ctx.error) return ctx.error; return ctx.count; } EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL); /* * Wait up to @media_ready_timeout for the device to report memory * active. */ int cxl_await_media_ready(struct cxl_dev_state *cxlds) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); int d = cxlds->cxl_dvsec; bool active = false; u64 md_status; int rc, i; for (i = media_ready_timeout; i; i--) { u32 temp; rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp); if (rc) return rc; active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp); if (active) break; msleep(1000); } if (!active) { dev_err(&pdev->dev, "timeout awaiting memory active after %d seconds\n", media_ready_timeout); return -ETIMEDOUT; } md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET); if (!CXLMDEV_READY(md_status)) return -EIO; return 0; } EXPORT_SYMBOL_NS_GPL(cxl_await_media_ready, CXL); static int wait_for_valid(struct cxl_dev_state *cxlds) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); int d = cxlds->cxl_dvsec, rc; u32 val; /* * Memory_Info_Valid: When set, indicates that the CXL Range 1 Size high * and Size Low registers are valid. Must be set within 1 second of * deassertion of reset to CXL device. Likely it is already set by the * time this runs, but otherwise give a 1.5 second timeout in case of * clock skew. */ rc = pci_read_config_dword(pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &val); if (rc) return rc; if (val & CXL_DVSEC_MEM_INFO_VALID) return 0; msleep(1500); rc = pci_read_config_dword(pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &val); if (rc) return rc; if (val & CXL_DVSEC_MEM_INFO_VALID) return 0; return -ETIMEDOUT; } static int cxl_set_mem_enable(struct cxl_dev_state *cxlds, u16 val) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); int d = cxlds->cxl_dvsec; u16 ctrl; int rc; rc = pci_read_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, &ctrl); if (rc < 0) return rc; if ((ctrl & CXL_DVSEC_MEM_ENABLE) == val) return 1; ctrl &= ~CXL_DVSEC_MEM_ENABLE; ctrl |= val; rc = pci_write_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, ctrl); if (rc < 0) return rc; return 0; } static void clear_mem_enable(void *cxlds) { cxl_set_mem_enable(cxlds, 0); } static int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds) { int rc; rc = cxl_set_mem_enable(cxlds, CXL_DVSEC_MEM_ENABLE); if (rc < 0) return rc; if (rc > 0) return 0; return devm_add_action_or_reset(host, clear_mem_enable, cxlds); } static bool range_contains(struct range *r1, struct range *r2) { return r1->start <= r2->start && r1->end >= r2->end; } /* require dvsec ranges to be covered by a locked platform window */ static int dvsec_range_allowed(struct device *dev, void *arg) { struct range *dev_range = arg; struct cxl_decoder *cxld; if (!is_root_decoder(dev)) return 0; cxld = to_cxl_decoder(dev); if (!(cxld->flags & CXL_DECODER_F_LOCK)) return 0; if (!(cxld->flags & CXL_DECODER_F_RAM)) return 0; return range_contains(&cxld->hpa_range, dev_range); } static void disable_hdm(void *_cxlhdm) { u32 global_ctrl; struct cxl_hdm *cxlhdm = _cxlhdm; void __iomem *hdm = cxlhdm->regs.hdm_decoder; global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET); writel(global_ctrl & ~CXL_HDM_DECODER_ENABLE, hdm + CXL_HDM_DECODER_CTRL_OFFSET); } static int devm_cxl_enable_hdm(struct device *host, struct cxl_hdm *cxlhdm) { void __iomem *hdm = cxlhdm->regs.hdm_decoder; u32 global_ctrl; global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET); writel(global_ctrl | CXL_HDM_DECODER_ENABLE, hdm + CXL_HDM_DECODER_CTRL_OFFSET); return devm_add_action_or_reset(host, disable_hdm, cxlhdm); } static bool __cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm, struct cxl_endpoint_dvsec_info *info) { void __iomem *hdm = cxlhdm->regs.hdm_decoder; struct cxl_port *port = cxlhdm->port; struct device *dev = cxlds->dev; struct cxl_port *root; int i, rc, allowed; u32 global_ctrl; global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET); /* * If the HDM Decoder Capability is already enabled then assume * that some other agent like platform firmware set it up. */ if (global_ctrl & CXL_HDM_DECODER_ENABLE) { rc = devm_cxl_enable_mem(&port->dev, cxlds); if (rc) return false; return true; } root = to_cxl_port(port->dev.parent); while (!is_cxl_root(root) && is_cxl_port(root->dev.parent)) root = to_cxl_port(root->dev.parent); if (!is_cxl_root(root)) { dev_err(dev, "Failed to acquire root port for HDM enable\n"); return false; } for (i = 0, allowed = 0; info->mem_enabled && i < info->ranges; i++) { struct device *cxld_dev; cxld_dev = device_find_child(&root->dev, &info->dvsec_range[i], dvsec_range_allowed); if (!cxld_dev) { dev_dbg(dev, "DVSEC Range%d denied by platform\n", i); continue; } dev_dbg(dev, "DVSEC Range%d allowed by platform\n", i); put_device(cxld_dev); allowed++; } if (!allowed) { cxl_set_mem_enable(cxlds, 0); info->mem_enabled = 0; } /* * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base * [High,Low] when HDM operation is enabled the range register values * are ignored by the device, but the spec also recommends matching the * DVSEC Range 1,2 to HDM Decoder Range 0,1. So, non-zero info->ranges * are expected even though Linux does not require or maintain that * match. If at least one DVSEC range is enabled and allowed, skip HDM * Decoder Capability Enable. */ if (info->mem_enabled) return false; rc = devm_cxl_enable_hdm(&port->dev, cxlhdm); if (rc) return false; rc = devm_cxl_enable_mem(&port->dev, cxlds); if (rc) return false; return true; } /** * cxl_hdm_decode_init() - Setup HDM decoding for the endpoint * @cxlds: Device state * @cxlhdm: Mapped HDM decoder Capability * * Try to enable the endpoint's HDM Decoder Capability */ int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); struct cxl_endpoint_dvsec_info info = { 0 }; int hdm_count, rc, i, ranges = 0; struct device *dev = &pdev->dev; int d = cxlds->cxl_dvsec; u16 cap, ctrl; if (!d) { dev_dbg(dev, "No DVSEC Capability\n"); return -ENXIO; } rc = pci_read_config_word(pdev, d + CXL_DVSEC_CAP_OFFSET, &cap); if (rc) return rc; rc = pci_read_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, &ctrl); if (rc) return rc; if (!(cap & CXL_DVSEC_MEM_CAPABLE)) { dev_dbg(dev, "Not MEM Capable\n"); return -ENXIO; } /* * It is not allowed by spec for MEM.capable to be set and have 0 legacy * HDM decoders (values > 2 are also undefined as of CXL 2.0). As this * driver is for a spec defined class code which must be CXL.mem * capable, there is no point in continuing to enable CXL.mem. */ hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap); if (!hdm_count || hdm_count > 2) return -EINVAL; rc = wait_for_valid(cxlds); if (rc) { dev_dbg(dev, "Failure awaiting MEM_INFO_VALID (%d)\n", rc); return rc; } /* * The current DVSEC values are moot if the memory capability is * disabled, and they will remain moot after the HDM Decoder * capability is enabled. */ info.mem_enabled = FIELD_GET(CXL_DVSEC_MEM_ENABLE, ctrl); if (!info.mem_enabled) goto hdm_init; for (i = 0; i < hdm_count; i++) { u64 base, size; u32 temp; rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_SIZE_HIGH(i), &temp); if (rc) return rc; size = (u64)temp << 32; rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(i), &temp); if (rc) return rc; size |= temp & CXL_DVSEC_MEM_SIZE_LOW_MASK; rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_BASE_HIGH(i), &temp); if (rc) return rc; base = (u64)temp << 32; rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_BASE_LOW(i), &temp); if (rc) return rc; base |= temp & CXL_DVSEC_MEM_BASE_LOW_MASK; info.dvsec_range[i] = (struct range) { .start = base, .end = base + size - 1 }; if (size) ranges++; } info.ranges = ranges; /* * If DVSEC ranges are being used instead of HDM decoder registers there * is no use in trying to manage those. */ hdm_init: if (!__cxl_hdm_decode_init(cxlds, cxlhdm, &info)) { dev_err(dev, "Legacy range registers configuration prevents HDM operation.\n"); return -EBUSY; } return 0; } EXPORT_SYMBOL_NS_GPL(cxl_hdm_decode_init, CXL); #define CXL_DOE_TABLE_ACCESS_REQ_CODE 0x000000ff #define CXL_DOE_TABLE_ACCESS_REQ_CODE_READ 0 #define CXL_DOE_TABLE_ACCESS_TABLE_TYPE 0x0000ff00 #define CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA 0 #define CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE 0xffff0000 #define CXL_DOE_TABLE_ACCESS_LAST_ENTRY 0xffff #define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 static struct pci_doe_mb *find_cdat_doe(struct device *uport) { struct cxl_memdev *cxlmd; struct cxl_dev_state *cxlds; unsigned long index; void *entry; cxlmd = to_cxl_memdev(uport); cxlds = cxlmd->cxlds; xa_for_each(&cxlds->doe_mbs, index, entry) { struct pci_doe_mb *cur = entry; if (pci_doe_supports_prot(cur, PCI_DVSEC_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS)) return cur; } return NULL; } #define CDAT_DOE_REQ(entry_handle) \ (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \ CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \ FIELD_PREP(CXL_DOE_TABLE_ACCESS_TABLE_TYPE, \ CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) | \ FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle))) static void cxl_doe_task_complete(struct pci_doe_task *task) { complete(task->private); } struct cdat_doe_task { u32 request_pl; u32 response_pl[32]; struct completion c; struct pci_doe_task task; }; #define DECLARE_CDAT_DOE_TASK(req, cdt) \ struct cdat_doe_task cdt = { \ .c = COMPLETION_INITIALIZER_ONSTACK(cdt.c), \ .request_pl = req, \ .task = { \ .prot.vid = PCI_DVSEC_VENDOR_ID_CXL, \ .prot.type = CXL_DOE_PROTOCOL_TABLE_ACCESS, \ .request_pl = &cdt.request_pl, \ .request_pl_sz = sizeof(cdt.request_pl), \ .response_pl = cdt.response_pl, \ .response_pl_sz = sizeof(cdt.response_pl), \ .complete = cxl_doe_task_complete, \ .private = &cdt.c, \ } \ } static int cxl_cdat_get_length(struct device *dev, struct pci_doe_mb *cdat_doe, size_t *length) { DECLARE_CDAT_DOE_TASK(CDAT_DOE_REQ(0), t); int rc; rc = pci_doe_submit_task(cdat_doe, &t.task); if (rc < 0) { dev_err(dev, "DOE submit failed: %d", rc); return rc; } wait_for_completion(&t.c); if (t.task.rv < sizeof(u32)) return -EIO; *length = t.response_pl[1]; dev_dbg(dev, "CDAT length %zu\n", *length); return 0; } static int cxl_cdat_read_table(struct device *dev, struct pci_doe_mb *cdat_doe, struct cxl_cdat *cdat) { size_t length = cdat->length; u32 *data = cdat->table; int entry_handle = 0; do { DECLARE_CDAT_DOE_TASK(CDAT_DOE_REQ(entry_handle), t); size_t entry_dw; u32 *entry; int rc; rc = pci_doe_submit_task(cdat_doe, &t.task); if (rc < 0) { dev_err(dev, "DOE submit failed: %d", rc); return rc; } wait_for_completion(&t.c); /* 1 DW header + 1 DW data min */ if (t.task.rv < (2 * sizeof(u32))) return -EIO; /* Get the CXL table access header entry handle */ entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, t.response_pl[0]); entry = t.response_pl + 1; entry_dw = t.task.rv / sizeof(u32); /* Skip Header */ entry_dw -= 1; entry_dw = min(length / sizeof(u32), entry_dw); /* Prevent length < 1 DW from causing a buffer overflow */ if (entry_dw) { memcpy(data, entry, entry_dw * sizeof(u32)); length -= entry_dw * sizeof(u32); data += entry_dw; } } while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY); return 0; } /** * read_cdat_data - Read the CDAT data on this port * @port: Port to read data from * * This call will sleep waiting for responses from the DOE mailbox. */ void read_cdat_data(struct cxl_port *port) { struct pci_doe_mb *cdat_doe; struct device *dev = &port->dev; struct device *uport = port->uport; size_t cdat_length; int rc; cdat_doe = find_cdat_doe(uport); if (!cdat_doe) { dev_dbg(dev, "No CDAT mailbox\n"); return; } port->cdat_available = true; if (cxl_cdat_get_length(dev, cdat_doe, &cdat_length)) { dev_dbg(dev, "No CDAT length\n"); return; } port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL); if (!port->cdat.table) return; port->cdat.length = cdat_length; rc = cxl_cdat_read_table(dev, cdat_doe, &port->cdat); if (rc) { /* Don't leave table data allocated on error */ devm_kfree(dev, port->cdat.table); port->cdat.table = NULL; port->cdat.length = 0; dev_err(dev, "CDAT data read error\n"); } } EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);