1 files changed, 186 insertions, 42 deletions

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index faeb5d9d7a7a..33083a522fd1 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -9,10 +9,13 @@
 #include <linux/list.h>
 #include <linux/pci.h>
 #include <linux/pci-doe.h>
+#include <linux/aer.h>
 #include <linux/io.h>
 #include "cxlmem.h"
 #include "cxlpci.h"
 #include "cxl.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/cxl.h>
 
 /**
  * DOC: cxl pci
@@ -276,35 +279,22 @@ static int cxl_pci_setup_mailbox(struct cxl_dev_state *cxlds)
 
 static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
 {
-	void __iomem *addr;
-	int bar = map->barno;
 	struct device *dev = &pdev->dev;
-	resource_size_t offset = map->block_offset;
-
-	/* Basic sanity check that BAR is big enough */
-	if (pci_resource_len(pdev, bar) < offset) {
-		dev_err(dev, "BAR%d: %pr: too small (offset: %pa)\n", bar,
-			&pdev->resource[bar], &offset);
-		return -ENXIO;
-	}
 
-	addr = pci_iomap(pdev, bar, 0);
-	if (!addr) {
+	map->base = ioremap(map->resource, map->max_size);
+	if (!map->base) {
 		dev_err(dev, "failed to map registers\n");
 		return -ENOMEM;
 	}
 
-	dev_dbg(dev, "Mapped CXL Memory Device resource bar %u @ %pa\n",
-		bar, &offset);
-
-	map->base = addr + map->block_offset;
+	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
 	return 0;
 }
 
 static void cxl_unmap_regblock(struct pci_dev *pdev,
 			       struct cxl_register_map *map)
 {
-	pci_iounmap(pdev, map->base - map->block_offset);
+	iounmap(map->base);
 	map->base = NULL;
 }
 
@@ -324,6 +314,9 @@ static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
 			return -ENXIO;
 		}
 
+		if (!comp_map->ras.valid)
+			dev_dbg(dev, "RAS registers not found\n");
+
 		dev_dbg(dev, "Set up component registers\n");
 		break;
 	case CXL_REGLOC_RBI_MEMDEV:
@@ -347,27 +340,6 @@ static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
 	return 0;
 }
 
-static int cxl_map_regs(struct cxl_dev_state *cxlds, struct cxl_register_map *map)
-{
-	struct device *dev = cxlds->dev;
-	struct pci_dev *pdev = to_pci_dev(dev);
-
-	switch (map->reg_type) {
-	case CXL_REGLOC_RBI_COMPONENT:
-		cxl_map_component_regs(pdev, &cxlds->regs.component, map);
-		dev_dbg(dev, "Mapping component registers...\n");
-		break;
-	case CXL_REGLOC_RBI_MEMDEV:
-		cxl_map_device_regs(pdev, &cxlds->regs.device_regs, map);
-		dev_dbg(dev, "Probing device registers...\n");
-		break;
-	default:
-		break;
-	}
-
-	return 0;
-}
-
 static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
 			  struct cxl_register_map *map)
 {
@@ -418,6 +390,11 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds)
 			continue;
 		}
 
+		if (!pci_request_config_region_exclusive(pdev, off,
+							 PCI_DOE_CAP_SIZEOF,
+							 dev_name(dev)))
+			pci_err(pdev, "Failed to exclude DOE registers\n");
+
 		if (xa_insert(&cxlds->doe_mbs, off, doe_mb, GFP_KERNEL)) {
 			dev_err(dev, "xa_insert failed to insert MB @ %x\n",
 				off);
@@ -428,6 +405,20 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds)
 	}
 }
 
+/*
+ * Assume that any RCIEP that emits the CXL memory expander class code
+ * is an RCD
+ */
+static bool is_cxl_restricted(struct pci_dev *pdev)
+{
+	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
+}
+
+static void disable_aer(void *pdev)
+{
+	pci_disable_pcie_error_reporting(pdev);
+}
+
 static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct cxl_register_map map;
@@ -449,7 +440,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	cxlds = cxl_dev_state_create(&pdev->dev);
 	if (IS_ERR(cxlds))
 		return PTR_ERR(cxlds);
+	pci_set_drvdata(pdev, cxlds);
 
+	cxlds->rcd = is_cxl_restricted(pdev);
 	cxlds->serial = pci_get_dsn(pdev);
 	cxlds->cxl_dvsec = pci_find_dvsec_capability(
 		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
@@ -461,7 +454,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		return rc;
 
-	rc = cxl_map_regs(cxlds, &map);
+	rc = cxl_map_device_regs(&pdev->dev, &cxlds->regs.device_regs, &map);
 	if (rc)
 		return rc;
 
@@ -474,10 +467,15 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
 
-	cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map);
+	cxlds->component_reg_phys = map.resource;
 
 	devm_cxl_pci_create_doe(cxlds);
 
+	rc = cxl_map_component_regs(&pdev->dev, &cxlds->regs.component,
+				    &map, BIT(CXL_CM_CAP_CAP_ID_RAS));
+	if (rc)
+		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
+
 	rc = cxl_pci_setup_mailbox(cxlds);
 	if (rc)
 		return rc;
@@ -498,8 +496,13 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (IS_ERR(cxlmd))
 		return PTR_ERR(cxlmd);
 
-	if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM))
-		rc = devm_cxl_add_nvdimm(&pdev->dev, cxlmd);
+	if (cxlds->regs.ras) {
+		pci_enable_pcie_error_reporting(pdev);
+		rc = devm_add_action_or_reset(&pdev->dev, disable_aer, pdev);
+		if (rc)
+			return rc;
+	}
+	pci_save_state(pdev);
 
 	return rc;
 }
@@ -511,10 +514,151 @@ static const struct pci_device_id cxl_mem_pci_tbl[] = {
 };
 MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl);
 
+/* CXL spec rev3.0 8.2.4.16.1 */
+static void header_log_copy(struct cxl_dev_state *cxlds, u32 *log)
+{
+	void __iomem *addr;
+	u32 *log_addr;
+	int i, log_u32_size = CXL_HEADERLOG_SIZE / sizeof(u32);
+
+	addr = cxlds->regs.ras + 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_report_and_clear(struct cxl_dev_state *cxlds)
+{
+	struct cxl_memdev *cxlmd = cxlds->cxlmd;
+	struct device *dev = &cxlmd->dev;
+	u32 hl[CXL_HEADERLOG_SIZE_U32];
+	void __iomem *addr;
+	u32 status;
+	u32 fe;
+
+	if (!cxlds->regs.ras)
+		return false;
+
+	addr = cxlds->regs.ras + 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) {
+		addr = cxlds->regs.ras + CXL_RAS_CAP_CONTROL_OFFSET;
+		fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK, readl(addr)));
+	} else {
+		fe = status;
+	}
+
+	header_log_copy(cxlds, hl);
+	trace_cxl_aer_uncorrectable_error(dev, status, fe, hl);
+	writel(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK, addr);
+
+	return true;
+}
+
+static 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;
+
+	/*
+	 * 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_report_and_clear(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;
+}
+
+static pci_ers_result_t cxl_slot_reset(struct pci_dev *pdev)
+{
+	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
+	struct cxl_memdev *cxlmd = cxlds->cxlmd;
+	struct device *dev = &cxlmd->dev;
+
+	dev_info(&pdev->dev, "%s: restart CXL.mem after slot reset\n",
+		 dev_name(dev));
+	pci_restore_state(pdev);
+	if (device_attach(dev) <= 0)
+		return PCI_ERS_RESULT_DISCONNECT;
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void cxl_error_resume(struct pci_dev *pdev)
+{
+	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
+	struct cxl_memdev *cxlmd = cxlds->cxlmd;
+	struct device *dev = &cxlmd->dev;
+
+	dev_info(&pdev->dev, "%s: error resume %s\n", dev_name(dev),
+		 dev->driver ? "successful" : "failed");
+}
+
+static void cxl_cor_error_detected(struct pci_dev *pdev)
+{
+	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
+	struct cxl_memdev *cxlmd = cxlds->cxlmd;
+	struct device *dev = &cxlmd->dev;
+	void __iomem *addr;
+	u32 status;
+
+	if (!cxlds->regs.ras)
+		return;
+
+	addr = cxlds->regs.ras + 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(dev, status);
+	}
+}
+
+static const struct pci_error_handlers cxl_error_handlers = {
+	.error_detected	= cxl_error_detected,
+	.slot_reset	= cxl_slot_reset,
+	.resume		= cxl_error_resume,
+	.cor_error_detected	= cxl_cor_error_detected,
+};
+
 static struct pci_driver cxl_pci_driver = {
 	.name			= KBUILD_MODNAME,
 	.id_table		= cxl_mem_pci_tbl,
 	.probe			= cxl_pci_probe,
+	.err_handler		= &cxl_error_handlers,
 	.driver	= {
 		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
 	},