// SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2021 Intel Corporation. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include "core.h" #include "trace.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_dev 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); static int cxl_dvsec_mem_range_valid(struct cxl_dev_state *cxlds, int id) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); int d = cxlds->cxl_dvsec; bool valid = false; int rc, i; u32 temp; if (id > CXL_DVSEC_RANGE_MAX) return -EINVAL; /* Check MEM INFO VALID bit first, give up after 1s */ i = 1; do { rc = pci_read_config_dword(pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(id), &temp); if (rc) return rc; valid = FIELD_GET(CXL_DVSEC_MEM_INFO_VALID, temp); if (valid) break; msleep(1000); } while (i--); if (!valid) { dev_err(&pdev->dev, "Timeout awaiting memory range %d valid after 1s.\n", id); return -ETIMEDOUT; } return 0; } static int cxl_dvsec_mem_range_active(struct cxl_dev_state *cxlds, int id) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); int d = cxlds->cxl_dvsec; bool active = false; int rc, i; u32 temp; if (id > CXL_DVSEC_RANGE_MAX) return -EINVAL; /* Check MEM ACTIVE bit, up to 60s timeout by default */ for (i = media_ready_timeout; i; i--) { rc = pci_read_config_dword( pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(id), &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; } return 0; } /* * 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; int rc, i, hdm_count; u64 md_status; u16 cap; rc = pci_read_config_word(pdev, d + CXL_DVSEC_CAP_OFFSET, &cap); if (rc) return rc; hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap); for (i = 0; i < hdm_count; i++) { rc = cxl_dvsec_mem_range_valid(cxlds, i); if (rc) return rc; } for (i = 0; i < hdm_count; i++) { rc = cxl_dvsec_mem_range_active(cxlds, i); if (rc) return rc; } 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 pci_dev *pdev, int d) { u32 val; int rc; /* * 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); } /* 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_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); } int cxl_dvsec_rr_decode(struct device *dev, int d, struct cxl_endpoint_dvsec_info *info) { struct pci_dev *pdev = to_pci_dev(dev); int hdm_count, rc, i, ranges = 0; 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; 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(pdev, d); 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. */ rc = pci_read_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, &ctrl); if (rc) return rc; info->mem_enabled = FIELD_GET(CXL_DVSEC_MEM_ENABLE, ctrl); if (!info->mem_enabled) return 0; 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; if (!size) { info->dvsec_range[i] = (struct range) { .start = 0, .end = CXL_RESOURCE_NONE, }; continue; } 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 }; ranges++; } info->ranges = ranges; return 0; } EXPORT_SYMBOL_NS_GPL(cxl_dvsec_rr_decode, CXL); /** * cxl_hdm_decode_init() - Setup HDM decoding for the endpoint * @cxlds: Device state * @cxlhdm: Mapped HDM decoder Capability * @info: Cached DVSEC range registers info * * Try to enable the endpoint's HDM Decoder Capability */ int 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 = 0; if (hdm) 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 || (!hdm && info->mem_enabled)) return devm_cxl_enable_mem(&port->dev, cxlds); else if (!hdm) return -ENODEV; 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 -ENODEV; } 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 && info->mem_enabled) { dev_err(dev, "Range register decodes outside platform defined CXL ranges.\n"); return -ENXIO; } /* * 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 0; rc = devm_cxl_enable_hdm(&port->dev, cxlhdm); if (rc) return rc; return devm_cxl_enable_mem(&port->dev, cxlds); } 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 #define CDAT_DOE_REQ(entry_handle) cpu_to_le32 \ (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 int cxl_cdat_get_length(struct device *dev, struct pci_doe_mb *doe_mb, size_t *length) { __le32 request = CDAT_DOE_REQ(0); __le32 response[2]; int rc; rc = pci_doe(doe_mb, PCI_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS, &request, sizeof(request), &response, sizeof(response)); if (rc < 0) { dev_err(dev, "DOE failed: %d", rc); return rc; } if (rc < sizeof(response)) return -EIO; *length = le32_to_cpu(response[1]); dev_dbg(dev, "CDAT length %zu\n", *length); return 0; } static int cxl_cdat_read_table(struct device *dev, struct pci_doe_mb *doe_mb, struct cdat_doe_rsp *rsp, size_t *length) { size_t received, remaining = *length; unsigned int entry_handle = 0; union cdat_data *data; __le32 saved_dw = 0; do { __le32 request = CDAT_DOE_REQ(entry_handle); int rc; rc = pci_doe(doe_mb, PCI_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS, &request, sizeof(request), rsp, sizeof(*rsp) + remaining); if (rc < 0) { dev_err(dev, "DOE failed: %d", rc); return rc; } if (rc < sizeof(*rsp)) return -EIO; data = (union cdat_data *)rsp->data; received = rc - sizeof(*rsp); if (entry_handle == 0) { if (received != sizeof(data->header)) return -EIO; } else { if (received < sizeof(data->entry) || received != le16_to_cpu(data->entry.length)) return -EIO; } /* Get the CXL table access header entry handle */ entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, le32_to_cpu(rsp->doe_header)); /* * Table Access Response Header overwrote the last DW of * previous entry, so restore that DW */ rsp->doe_header = saved_dw; remaining -= received; rsp = (void *)rsp + received; saved_dw = rsp->doe_header; } while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY); /* Length in CDAT header may exceed concatenation of CDAT entries */ *length -= remaining; return 0; } static unsigned char cdat_checksum(void *buf, size_t size) { unsigned char sum, *data = buf; size_t i; for (sum = 0, i = 0; i < size; i++) sum += data[i]; return sum; } /** * 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 device *uport = port->uport_dev; struct device *dev = &port->dev; struct pci_doe_mb *doe_mb; struct pci_dev *pdev = NULL; struct cxl_memdev *cxlmd; struct cdat_doe_rsp *buf; size_t table_length, length; int rc; if (is_cxl_memdev(uport)) { struct device *host; cxlmd = to_cxl_memdev(uport); host = cxlmd->dev.parent; if (dev_is_pci(host)) pdev = to_pci_dev(host); } else if (dev_is_pci(uport)) { pdev = to_pci_dev(uport); } if (!pdev) return; doe_mb = pci_find_doe_mailbox(pdev, PCI_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS); if (!doe_mb) { dev_dbg(dev, "No CDAT mailbox\n"); return; } port->cdat_available = true; if (cxl_cdat_get_length(dev, doe_mb, &length)) { dev_dbg(dev, "No CDAT length\n"); return; } /* * The begin of the CDAT buffer needs space for additional 4 * bytes for the DOE header. Table data starts afterwards. */ buf = devm_kzalloc(dev, sizeof(*buf) + length, GFP_KERNEL); if (!buf) goto err; table_length = length; rc = cxl_cdat_read_table(dev, doe_mb, buf, &length); if (rc) goto err; if (table_length != length) dev_warn(dev, "Malformed CDAT table length (%zu:%zu), discarding trailing data\n", table_length, length); if (cdat_checksum(buf->data, length)) goto err; port->cdat.table = buf->data; port->cdat.length = length; return; err: /* Don't leave table data allocated on error */ devm_kfree(dev, buf); dev_err(dev, "Failed to read/validate CDAT.\n"); } EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL); static void __cxl_handle_cor_ras(struct cxl_dev_state *cxlds, void __iomem *ras_base) { void __iomem *addr; u32 status; if (!ras_base) return; addr = ras_base + CXL_RAS_CORRECTABLE_STATUS_OFFSET; status = readl(addr); if (status & CXL_RAS_CORRECTABLE_STATUS_MASK) { writel(status & CXL_RAS_CORRECTABLE_STATUS_MASK, addr); trace_cxl_aer_correctable_error(cxlds->cxlmd, status); } } static void cxl_handle_endpoint_cor_ras(struct cxl_dev_state *cxlds) { return __cxl_handle_cor_ras(cxlds, cxlds->regs.ras); } /* CXL spec rev3.0 8.2.4.16.1 */ static void header_log_copy(void __iomem *ras_base, u32 *log) { void __iomem *addr; u32 *log_addr; int i, log_u32_size = CXL_HEADERLOG_SIZE / sizeof(u32); addr = ras_base + CXL_RAS_HEADER_LOG_OFFSET; log_addr = log; for (i = 0; i < log_u32_size; i++) { *log_addr = readl(addr); log_addr++; addr += sizeof(u32); } } /* * Log the state of the RAS status registers and prepare them to log the * next error status. Return 1 if reset needed. */ static bool __cxl_handle_ras(struct cxl_dev_state *cxlds, void __iomem *ras_base) { u32 hl[CXL_HEADERLOG_SIZE_U32]; void __iomem *addr; u32 status; u32 fe; if (!ras_base) return false; addr = ras_base + CXL_RAS_UNCORRECTABLE_STATUS_OFFSET; status = readl(addr); if (!(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK)) return false; /* If multiple errors, log header points to first error from ctrl reg */ if (hweight32(status) > 1) { void __iomem *rcc_addr = ras_base + CXL_RAS_CAP_CONTROL_OFFSET; fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK, readl(rcc_addr))); } else { fe = status; } header_log_copy(ras_base, hl); trace_cxl_aer_uncorrectable_error(cxlds->cxlmd, status, fe, hl); writel(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK, addr); return true; } static bool cxl_handle_endpoint_ras(struct cxl_dev_state *cxlds) { return __cxl_handle_ras(cxlds, cxlds->regs.ras); } #ifdef CONFIG_PCIEAER_CXL static void cxl_dport_map_rch_aer(struct cxl_dport *dport) { struct cxl_rcrb_info *ri = &dport->rcrb; void __iomem *dport_aer = NULL; resource_size_t aer_phys; struct device *host; if (dport->rch && ri->aer_cap) { host = dport->reg_map.host; aer_phys = ri->aer_cap + ri->base; dport_aer = devm_cxl_iomap_block(host, aer_phys, sizeof(struct aer_capability_regs)); } dport->regs.dport_aer = dport_aer; } static void cxl_dport_map_regs(struct cxl_dport *dport) { struct cxl_register_map *map = &dport->reg_map; struct device *dev = dport->dport_dev; if (!map->component_map.ras.valid) dev_dbg(dev, "RAS registers not found\n"); else if (cxl_map_component_regs(map, &dport->regs.component, BIT(CXL_CM_CAP_CAP_ID_RAS))) dev_dbg(dev, "Failed to map RAS capability.\n"); if (dport->rch) cxl_dport_map_rch_aer(dport); } static void cxl_disable_rch_root_ints(struct cxl_dport *dport) { void __iomem *aer_base = dport->regs.dport_aer; struct pci_host_bridge *bridge; u32 aer_cmd_mask, aer_cmd; if (!aer_base) return; bridge = to_pci_host_bridge(dport->dport_dev); /* * Disable RCH root port command interrupts. * CXL 3.0 12.2.1.1 - RCH Downstream Port-detected Errors * * This sequence may not be necessary. CXL spec states disabling * the root cmd register's interrupts is required. But, PCI spec * shows these are disabled by default on reset. */ if (bridge->native_aer) { aer_cmd_mask = (PCI_ERR_ROOT_CMD_COR_EN | PCI_ERR_ROOT_CMD_NONFATAL_EN | PCI_ERR_ROOT_CMD_FATAL_EN); aer_cmd = readl(aer_base + PCI_ERR_ROOT_COMMAND); aer_cmd &= ~aer_cmd_mask; writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND); } } void cxl_setup_parent_dport(struct device *host, struct cxl_dport *dport) { struct device *dport_dev = dport->dport_dev; if (dport->rch) { struct pci_host_bridge *host_bridge = to_pci_host_bridge(dport_dev); if (host_bridge->native_aer) dport->rcrb.aer_cap = cxl_rcrb_to_aer(dport_dev, dport->rcrb.base); } dport->reg_map.host = host; cxl_dport_map_regs(dport); if (dport->rch) cxl_disable_rch_root_ints(dport); } EXPORT_SYMBOL_NS_GPL(cxl_setup_parent_dport, CXL); static void cxl_handle_rdport_cor_ras(struct cxl_dev_state *cxlds, struct cxl_dport *dport) { return __cxl_handle_cor_ras(cxlds, dport->regs.ras); } static bool cxl_handle_rdport_ras(struct cxl_dev_state *cxlds, struct cxl_dport *dport) { return __cxl_handle_ras(cxlds, dport->regs.ras); } /* * Copy the AER capability registers using 32 bit read accesses. * This is necessary because RCRB AER capability is MMIO mapped. Clear the * status after copying. * * @aer_base: base address of AER capability block in RCRB * @aer_regs: destination for copying AER capability */ static bool cxl_rch_get_aer_info(void __iomem *aer_base, struct aer_capability_regs *aer_regs) { int read_cnt = sizeof(struct aer_capability_regs) / sizeof(u32); u32 *aer_regs_buf = (u32 *)aer_regs; int n; if (!aer_base) return false; /* Use readl() to guarantee 32-bit accesses */ for (n = 0; n < read_cnt; n++) aer_regs_buf[n] = readl(aer_base + n * sizeof(u32)); writel(aer_regs->uncor_status, aer_base + PCI_ERR_UNCOR_STATUS); writel(aer_regs->cor_status, aer_base + PCI_ERR_COR_STATUS); return true; } /* Get AER severity. Return false if there is no error. */ static bool cxl_rch_get_aer_severity(struct aer_capability_regs *aer_regs, int *severity) { if (aer_regs->uncor_status & ~aer_regs->uncor_mask) { if (aer_regs->uncor_status & PCI_ERR_ROOT_FATAL_RCV) *severity = AER_FATAL; else *severity = AER_NONFATAL; return true; } if (aer_regs->cor_status & ~aer_regs->cor_mask) { *severity = AER_CORRECTABLE; return true; } return false; } static void cxl_handle_rdport_errors(struct cxl_dev_state *cxlds) { struct pci_dev *pdev = to_pci_dev(cxlds->dev); struct aer_capability_regs aer_regs; struct cxl_dport *dport; struct cxl_port *port; int severity; port = cxl_pci_find_port(pdev, &dport); if (!port) return; put_device(&port->dev); if (!cxl_rch_get_aer_info(dport->regs.dport_aer, &aer_regs)) return; if (!cxl_rch_get_aer_severity(&aer_regs, &severity)) return; pci_print_aer(pdev, severity, &aer_regs); if (severity == AER_CORRECTABLE) cxl_handle_rdport_cor_ras(cxlds, dport); else cxl_handle_rdport_ras(cxlds, dport); } #else static void cxl_handle_rdport_errors(struct cxl_dev_state *cxlds) { } #endif void cxl_cor_error_detected(struct pci_dev *pdev) { struct cxl_dev_state *cxlds = pci_get_drvdata(pdev); struct device *dev = &cxlds->cxlmd->dev; scoped_guard(device, dev) { if (!dev->driver) { dev_warn(&pdev->dev, "%s: memdev disabled, abort error handling\n", dev_name(dev)); return; } if (cxlds->rcd) cxl_handle_rdport_errors(cxlds); cxl_handle_endpoint_cor_ras(cxlds); } } EXPORT_SYMBOL_NS_GPL(cxl_cor_error_detected, CXL); pci_ers_result_t cxl_error_detected(struct pci_dev *pdev, pci_channel_state_t state) { struct cxl_dev_state *cxlds = pci_get_drvdata(pdev); struct cxl_memdev *cxlmd = cxlds->cxlmd; struct device *dev = &cxlmd->dev; bool ue; scoped_guard(device, dev) { if (!dev->driver) { dev_warn(&pdev->dev, "%s: memdev disabled, abort error handling\n", dev_name(dev)); return PCI_ERS_RESULT_DISCONNECT; } if (cxlds->rcd) cxl_handle_rdport_errors(cxlds); /* * A frozen channel indicates an impending reset which is fatal to * CXL.mem operation, and will likely crash the system. On the off * chance the situation is recoverable dump the status of the RAS * capability registers and bounce the active state of the memdev. */ ue = cxl_handle_endpoint_ras(cxlds); } switch (state) { case pci_channel_io_normal: if (ue) { device_release_driver(dev); return PCI_ERS_RESULT_NEED_RESET; } return PCI_ERS_RESULT_CAN_RECOVER; case pci_channel_io_frozen: dev_warn(&pdev->dev, "%s: frozen state error detected, disable CXL.mem\n", dev_name(dev)); device_release_driver(dev); return PCI_ERS_RESULT_NEED_RESET; case pci_channel_io_perm_failure: dev_warn(&pdev->dev, "failure state error detected, request disconnect\n"); return PCI_ERS_RESULT_DISCONNECT; } return PCI_ERS_RESULT_NEED_RESET; } EXPORT_SYMBOL_NS_GPL(cxl_error_detected, CXL); static int cxl_flit_size(struct pci_dev *pdev) { if (cxl_pci_flit_256(pdev)) return 256; return 68; } /** * cxl_pci_get_latency - calculate the link latency for the PCIe link * @pdev: PCI device * * return: calculated latency or 0 for no latency * * CXL Memory Device SW Guide v1.0 2.11.4 Link latency calculation * Link latency = LinkPropagationLatency + FlitLatency + RetimerLatency * LinkProgationLatency is negligible, so 0 will be used * RetimerLatency is assumed to be negligible and 0 will be used * FlitLatency = FlitSize / LinkBandwidth * FlitSize is defined by spec. CXL rev3.0 4.2.1. * 68B flit is used up to 32GT/s. >32GT/s, 256B flit size is used. * The FlitLatency is converted to picoseconds. */ long cxl_pci_get_latency(struct pci_dev *pdev) { long bw; bw = pcie_link_speed_mbps(pdev); if (bw < 0) return 0; bw /= BITS_PER_BYTE; return cxl_flit_size(pdev) * MEGA / bw; } static int __cxl_endpoint_decoder_reset_detected(struct device *dev, void *data) { struct cxl_port *port = data; struct cxl_decoder *cxld; struct cxl_hdm *cxlhdm; void __iomem *hdm; u32 ctrl; if (!is_endpoint_decoder(dev)) return 0; cxld = to_cxl_decoder(dev); if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0) return 0; cxlhdm = dev_get_drvdata(&port->dev); hdm = cxlhdm->regs.hdm_decoder; ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); return !FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl); } bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port) { return device_for_each_child(&port->dev, port, __cxl_endpoint_decoder_reset_detected); } EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, CXL);