Merge branch 'for-6.4/cxl-poison' into for-6.4/cxl

Include the poison list and injection infrastructure from Alison for
v6.4.

Documentation/ABI/testing/debugfs-cxl

+What:		/sys/kernel/debug/cxl/memX/inject_poison
+Date:		April, 2023
+KernelVersion:	v6.4
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a Device Physical Address (DPA) is written to this
+		attribute, the memdev driver sends an inject poison command to
+		the device for the specified address. The DPA must be 64-byte
+		aligned and the length of the injected poison is 64-bytes. If
+		successful, the device returns poison when the address is
+		accessed through the CXL.mem bus. Injecting poison adds the
+		address to the device's Poison List and the error source is set
+		to Injected. In addition, the device adds a poison creation
+		event to its internal Informational Event log, updates the
+		Event Status register, and if configured, interrupts the host.
+		It is not an error to inject poison into an address that
+		already has poison present and no error is returned. The
+		inject_poison attribute is only visible for devices supporting
+		the capability.
+
+
+What:		/sys/kernel/debug/memX/clear_poison
+Date:		April, 2023
+KernelVersion:	v6.4
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a Device Physical Address (DPA) is written to this
+		attribute, the memdev driver sends a clear poison command to
+		the device for the specified address. Clearing poison removes
+		the address from the device's Poison List and writes 0 (zero)
+		for 64 bytes starting at address. It is not an error to clear
+		poison from an address that does not have poison set. If the
+		device cannot clear poison from the address, -ENXIO is returned.
+		The clear_poison attribute is only visible for devices
+		supporting the capability.

Documentation/ABI/testing/sysfs-bus-cxl

@@ -415,3 +415,17 @@ Description:
 		1), and checks that the hardware accepts the commit request.
 		Reading this value indicates whether the region is committed or
 		not.
+
+
+What:		/sys/bus/cxl/devices/memX/trigger_poison_list
+Date:		April, 2023
+KernelVersion:	v6.4
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a boolean 'true' is written to this attribute the
+		memdev driver retrieves the poison list from the device. The
+		list consists of addresses that are poisoned, or would result
+		in poison if accessed, and the source of the poison. This
+		attribute is only visible for devices supporting the
+		capability. The retrieved errors are logged as kernel
+		events when cxl_poison event tracing is enabled.

drivers/cxl/core/core.h

@@ -25,7 +25,12 @@ void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled);
 #define CXL_DAX_REGION_TYPE(x) (&cxl_dax_region_type)
 int cxl_region_init(void);
 void cxl_region_exit(void);
+int cxl_get_poison_by_endpoint(struct cxl_port *port);
 #else
+static inline int cxl_get_poison_by_endpoint(struct cxl_port *port)
+{
+	return 0;
+}
 static inline void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled)
 {
 }
@@ -64,4 +69,10 @@ int cxl_memdev_init(void);
 void cxl_memdev_exit(void);
 void cxl_mbox_init(void);
 
+enum cxl_poison_trace_type {
+	CXL_POISON_TRACE_LIST,
+	CXL_POISON_TRACE_INJECT,
+	CXL_POISON_TRACE_CLEAR,
+};
+
 #endif /* __CXL_CORE_H__ */

drivers/cxl/core/mbox.c

@@ -5,6 +5,8 @@
 #include <linux/debugfs.h>
 #include <linux/ktime.h>
 #include <linux/mutex.h>
+#include <asm/unaligned.h>
+#include <cxlpci.h>
 #include <cxlmem.h>
 #include <cxl.h>
 
@@ -61,12 +63,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
 	CXL_CMD(SET_ALERT_CONFIG, 0xc, 0, 0),
 	CXL_CMD(GET_SHUTDOWN_STATE, 0, 0x1, 0),
 	CXL_CMD(SET_SHUTDOWN_STATE, 0x1, 0, 0),
-	CXL_CMD(GET_POISON, 0x10, CXL_VARIABLE_PAYLOAD, 0),
-	CXL_CMD(INJECT_POISON, 0x8, 0, 0),
-	CXL_CMD(CLEAR_POISON, 0x48, 0, 0),
 	CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0),
-	CXL_CMD(SCAN_MEDIA, 0x11, 0, 0),
-	CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0),
 };
 
 /*
@@ -87,6 +84,9 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
  *
  * CXL_MBOX_OP_[GET_]SCAN_MEDIA: The kernel provides a native error list that
  * is kept up to date with patrol notifications and error management.
+ *
+ * CXL_MBOX_OP_[GET_,INJECT_,CLEAR_]POISON: These commands require kernel
+ * driver orchestration for safety.
  */
 static u16 cxl_disabled_raw_commands[] = {
 	CXL_MBOX_OP_ACTIVATE_FW,
@@ -95,6 +95,9 @@ static u16 cxl_disabled_raw_commands[] = {
 	CXL_MBOX_OP_SET_SHUTDOWN_STATE,
 	CXL_MBOX_OP_SCAN_MEDIA,
 	CXL_MBOX_OP_GET_SCAN_MEDIA,
+	CXL_MBOX_OP_GET_POISON,
+	CXL_MBOX_OP_INJECT_POISON,
+	CXL_MBOX_OP_CLEAR_POISON,
 };
 
 /*
@@ -119,6 +122,43 @@ static bool cxl_is_security_command(u16 opcode)
 	return false;
 }
 
+static bool cxl_is_poison_command(u16 opcode)
+{
+#define CXL_MBOX_OP_POISON_CMDS 0x43
+
+	if ((opcode >> 8) == CXL_MBOX_OP_POISON_CMDS)
+		return true;
+
+	return false;
+}
+
+static void cxl_set_poison_cmd_enabled(struct cxl_poison_state *poison,
+				       u16 opcode)
+{
+	switch (opcode) {
+	case CXL_MBOX_OP_GET_POISON:
+		set_bit(CXL_POISON_ENABLED_LIST, poison->enabled_cmds);
+		break;
+	case CXL_MBOX_OP_INJECT_POISON:
+		set_bit(CXL_POISON_ENABLED_INJECT, poison->enabled_cmds);
+		break;
+	case CXL_MBOX_OP_CLEAR_POISON:
+		set_bit(CXL_POISON_ENABLED_CLEAR, poison->enabled_cmds);
+		break;
+	case CXL_MBOX_OP_GET_SCAN_MEDIA_CAPS:
+		set_bit(CXL_POISON_ENABLED_SCAN_CAPS, poison->enabled_cmds);
+		break;
+	case CXL_MBOX_OP_SCAN_MEDIA:
+		set_bit(CXL_POISON_ENABLED_SCAN_MEDIA, poison->enabled_cmds);
+		break;
+	case CXL_MBOX_OP_GET_SCAN_MEDIA:
+		set_bit(CXL_POISON_ENABLED_SCAN_RESULTS, poison->enabled_cmds);
+		break;
+	default:
+		break;
+	}
+}
+
 static struct cxl_mem_command *cxl_mem_find_command(u16 opcode)
 {
 	struct cxl_mem_command *c;
@@ -634,13 +674,18 @@ static void cxl_walk_cel(struct cxl_dev_state *cxlds, size_t size, u8 *cel)
 		u16 opcode = le16_to_cpu(cel_entry[i].opcode);
 		struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
 
-		if (!cmd) {
+		if (!cmd && !cxl_is_poison_command(opcode)) {
 			dev_dbg(cxlds->dev,
 				"Opcode 0x%04x unsupported by driver\n", opcode);
 			continue;
 		}
 
-		set_bit(cmd->info.id, cxlds->enabled_cmds);
+		if (cmd)
+			set_bit(cmd->info.id, cxlds->enabled_cmds);
+
+		if (cxl_is_poison_command(opcode))
+			cxl_set_poison_cmd_enabled(&cxlds->poison, opcode);
+
 		dev_dbg(cxlds->dev, "Opcode 0x%04x enabled\n", opcode);
 	}
 }
@@ -994,6 +1039,7 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
 	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
 	struct cxl_mbox_identify id;
 	struct cxl_mbox_cmd mbox_cmd;
+	u32 val;
 	int rc;
 
 	mbox_cmd = (struct cxl_mbox_cmd) {
@@ -1017,6 +1063,11 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
 	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
 	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
 
+	if (test_bit(CXL_POISON_ENABLED_LIST, cxlds->poison.enabled_cmds)) {
+		val = get_unaligned_le24(id.poison_list_max_mer);
+		cxlds->poison.max_errors = min_t(u32, val, CXL_POISON_LIST_MAX);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
@@ -1107,6 +1158,91 @@ int cxl_set_timestamp(struct cxl_dev_state *cxlds)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_set_timestamp, CXL);
 
+int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
+		       struct cxl_region *cxlr)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct cxl_mbox_poison_out *po;
+	struct cxl_mbox_poison_in pi;
+	struct cxl_mbox_cmd mbox_cmd;
+	int nr_records = 0;
+	int rc;
+
+	rc = mutex_lock_interruptible(&cxlds->poison.lock);
+	if (rc)
+		return rc;
+
+	po = cxlds->poison.list_out;
+	pi.offset = cpu_to_le64(offset);
+	pi.length = cpu_to_le64(len / CXL_POISON_LEN_MULT);
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_GET_POISON,
+		.size_in = sizeof(pi),
+		.payload_in = &pi,
+		.size_out = cxlds->payload_size,
+		.payload_out = po,
+		.min_out = struct_size(po, record, 0),
+	};
+
+	do {
+		rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+		if (rc)
+			break;
+
+		for (int i = 0; i < le16_to_cpu(po->count); i++)
+			trace_cxl_poison(cxlmd, cxlr, &po->record[i],
+					 po->flags, po->overflow_ts,
+					 CXL_POISON_TRACE_LIST);
+
+		/* Protect against an uncleared _FLAG_MORE */
+		nr_records = nr_records + le16_to_cpu(po->count);
+		if (nr_records >= cxlds->poison.max_errors) {
+			dev_dbg(&cxlmd->dev, "Max Error Records reached: %d\n",
+				nr_records);
+			break;
+		}
+	} while (po->flags & CXL_POISON_FLAG_MORE);
+
+	mutex_unlock(&cxlds->poison.lock);
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_get_poison, CXL);
+
+static void free_poison_buf(void *buf)
+{
+	kvfree(buf);
+}
+
+/* Get Poison List output buffer is protected by cxlds->poison.lock */
+static int cxl_poison_alloc_buf(struct cxl_dev_state *cxlds)
+{
+	cxlds->poison.list_out = kvmalloc(cxlds->payload_size, GFP_KERNEL);
+	if (!cxlds->poison.list_out)
+		return -ENOMEM;
+
+	return devm_add_action_or_reset(cxlds->dev, free_poison_buf,
+					cxlds->poison.list_out);
+}
+
+int cxl_poison_state_init(struct cxl_dev_state *cxlds)
+{
+	int rc;
+
+	if (!test_bit(CXL_POISON_ENABLED_LIST, cxlds->poison.enabled_cmds))
+		return 0;
+
+	rc = cxl_poison_alloc_buf(cxlds);
+	if (rc) {
+		clear_bit(CXL_POISON_ENABLED_LIST, cxlds->poison.enabled_cmds);
+		return rc;
+	}
+
+	mutex_init(&cxlds->poison.lock);
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_poison_state_init, CXL);
+
 struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
 {
 	struct cxl_dev_state *cxlds;

drivers/cxl/core/memdev.c

@@ -6,6 +6,7 @@
 #include <linux/idr.h>
 #include <linux/pci.h>
 #include <cxlmem.h>
+#include "trace.h"
 #include "core.h"
 
 static DECLARE_RWSEM(cxl_memdev_rwsem);
@@ -106,6 +107,232 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(numa_node);
 
+static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	u64 offset, length;
+	int rc = 0;
+
+	/* CXL 3.0 Spec 8.2.9.8.4.1 Separate pmem and ram poison requests */
+	if (resource_size(&cxlds->pmem_res)) {
+		offset = cxlds->pmem_res.start;
+		length = resource_size(&cxlds->pmem_res);
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		if (rc)
+			return rc;
+	}
+	if (resource_size(&cxlds->ram_res)) {
+		offset = cxlds->ram_res.start;
+		length = resource_size(&cxlds->ram_res);
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		/*
+		 * Invalid Physical Address is not an error for
+		 * volatile addresses. Device support is optional.
+		 */
+		if (rc == -EFAULT)
+			rc = 0;
+	}
+	return rc;
+}
+
+int cxl_trigger_poison_list(struct cxl_memdev *cxlmd)
+{
+	struct cxl_port *port;
+	int rc;
+
+	port = dev_get_drvdata(&cxlmd->dev);
+	if (!port || !is_cxl_endpoint(port))
+		return -EINVAL;
+
+	rc = down_read_interruptible(&cxl_dpa_rwsem);
+	if (rc)
+		return rc;
+
+	if (port->commit_end == -1) {
+		/* No regions mapped to this memdev */
+		rc = cxl_get_poison_by_memdev(cxlmd);
+	} else {
+		/* Regions mapped, collect poison by endpoint */
+		rc =  cxl_get_poison_by_endpoint(port);
+	}
+	up_read(&cxl_dpa_rwsem);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_trigger_poison_list, CXL);
+
+struct cxl_dpa_to_region_context {
+	struct cxl_region *cxlr;
+	u64 dpa;
+};
+
+static int __cxl_dpa_to_region(struct device *dev, void *arg)
+{
+	struct cxl_dpa_to_region_context *ctx = arg;
+	struct cxl_endpoint_decoder *cxled;
+	u64 dpa = ctx->dpa;
+
+	if (!is_endpoint_decoder(dev))
+		return 0;
+
+	cxled = to_cxl_endpoint_decoder(dev);
+	if (!cxled->dpa_res || !resource_size(cxled->dpa_res))
+		return 0;
+
+	if (dpa > cxled->dpa_res->end || dpa < cxled->dpa_res->start)
+		return 0;
+
+	dev_dbg(dev, "dpa:0x%llx mapped in region:%s\n", dpa,
+		dev_name(&cxled->cxld.region->dev));
+
+	ctx->cxlr = cxled->cxld.region;
+
+	return 1;
+}
+
+static struct cxl_region *cxl_dpa_to_region(struct cxl_memdev *cxlmd, u64 dpa)
+{
+	struct cxl_dpa_to_region_context ctx;
+	struct cxl_port *port;
+
+	ctx = (struct cxl_dpa_to_region_context) {
+		.dpa = dpa,
+	};
+	port = dev_get_drvdata(&cxlmd->dev);
+	if (port && is_cxl_endpoint(port) && port->commit_end != -1)
+		device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region);
+
+	return ctx.cxlr;
+}
+
+static int cxl_validate_poison_dpa(struct cxl_memdev *cxlmd, u64 dpa)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	if (!resource_size(&cxlds->dpa_res)) {
+		dev_dbg(cxlds->dev, "device has no dpa resource\n");
+		return -EINVAL;
+	}
+	if (dpa < cxlds->dpa_res.start || dpa > cxlds->dpa_res.end) {
+		dev_dbg(cxlds->dev, "dpa:0x%llx not in resource:%pR\n",
+			dpa, &cxlds->dpa_res);
+		return -EINVAL;
+	}
+	if (!IS_ALIGNED(dpa, 64)) {
+		dev_dbg(cxlds->dev, "dpa:0x%llx is not 64-byte aligned\n", dpa);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct cxl_mbox_inject_poison inject;
+	struct cxl_poison_record record;
+	struct cxl_mbox_cmd mbox_cmd;
+	struct cxl_region *cxlr;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	rc = down_read_interruptible(&cxl_dpa_rwsem);
+	if (rc)
+		return rc;
+
+	rc = cxl_validate_poison_dpa(cxlmd, dpa);
+	if (rc)
+		goto out;
+
+	inject.address = cpu_to_le64(dpa);
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_INJECT_POISON,
+		.size_in = sizeof(inject),
+		.payload_in = &inject,
+	};
+	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+	if (rc)
+		goto out;
+
+	cxlr = cxl_dpa_to_region(cxlmd, dpa);
+	if (cxlr)
+		dev_warn_once(cxlds->dev,
+			      "poison inject dpa:%#llx region: %s\n", dpa,
+			      dev_name(&cxlr->dev));
+
+	record = (struct cxl_poison_record) {
+		.address = cpu_to_le64(dpa),
+		.length = cpu_to_le32(1),
+	};
+	trace_cxl_poison(cxlmd, cxlr, &record, 0, 0, CXL_POISON_TRACE_INJECT);
+out:
+	up_read(&cxl_dpa_rwsem);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_inject_poison, CXL);
+
+int cxl_clear_poison(struct cxl_memdev *cxlmd, u64 dpa)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct cxl_mbox_clear_poison clear;
+	struct cxl_poison_record record;
+	struct cxl_mbox_cmd mbox_cmd;
+	struct cxl_region *cxlr;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	rc = down_read_interruptible(&cxl_dpa_rwsem);
+	if (rc)
+		return rc;
+
+	rc = cxl_validate_poison_dpa(cxlmd, dpa);
+	if (rc)
+		goto out;
+
+	/*
+	 * In CXL 3.0 Spec 8.2.9.8.4.3, the Clear Poison mailbox command
+	 * is defined to accept 64 bytes of write-data, along with the
+	 * address to clear. This driver uses zeroes as write-data.
+	 */
+	clear = (struct cxl_mbox_clear_poison) {
+		.address = cpu_to_le64(dpa)
+	};
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_CLEAR_POISON,
+		.size_in = sizeof(clear),
+		.payload_in = &clear,
+	};
+
+	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+	if (rc)
+		goto out;
+
+	cxlr = cxl_dpa_to_region(cxlmd, dpa);
+	if (cxlr)
+		dev_warn_once(cxlds->dev, "poison clear dpa:%#llx region: %s\n",
+			      dpa, dev_name(&cxlr->dev));
+
+	record = (struct cxl_poison_record) {
+		.address = cpu_to_le64(dpa),
+		.length = cpu_to_le32(1),
+	};
+	trace_cxl_poison(cxlmd, cxlr, &record, 0, 0, CXL_POISON_TRACE_CLEAR);
+out:
+	up_read(&cxl_dpa_rwsem);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_clear_poison, CXL);
+
 static struct attribute *cxl_memdev_attributes[] = {
 	&dev_attr_serial.attr,
 	&dev_attr_firmware_version.attr,

drivers/cxl/core/region.c

@@ -2238,6 +2238,130 @@ struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
 }
 EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL);
 
+struct cxl_poison_context {
+	struct cxl_port *port;
+	enum cxl_decoder_mode mode;
+	u64 offset;
+};
+
+static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd,
+				   struct cxl_poison_context *ctx)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	u64 offset, length;
+	int rc = 0;
+
+	/*
+	 * Collect poison for the remaining unmapped resources
+	 * after poison is collected by committed endpoints.
+	 *
+	 * Knowing that PMEM must always follow RAM, get poison
+	 * for unmapped resources based on the last decoder's mode:
+	 *	ram: scan remains of ram range, then any pmem range
+	 *	pmem: scan remains of pmem range
+	 */
+
+	if (ctx->mode == CXL_DECODER_RAM) {
+		offset = ctx->offset;
+		length = resource_size(&cxlds->ram_res) - offset;
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		if (rc == -EFAULT)
+			rc = 0;
+		if (rc)
+			return rc;
+	}
+	if (ctx->mode == CXL_DECODER_PMEM) {
+		offset = ctx->offset;
+		length = resource_size(&cxlds->dpa_res) - offset;
+		if (!length)
+			return 0;
+	} else if (resource_size(&cxlds->pmem_res)) {
+		offset = cxlds->pmem_res.start;
+		length = resource_size(&cxlds->pmem_res);
+	} else {
+		return 0;
+	}
+
+	return cxl_mem_get_poison(cxlmd, offset, length, NULL);
+}
+
+static int poison_by_decoder(struct device *dev, void *arg)
+{
+	struct cxl_poison_context *ctx = arg;
+	struct cxl_endpoint_decoder *cxled;
+	struct cxl_memdev *cxlmd;
+	u64 offset, length;
+	int rc = 0;
+
+	if (!is_endpoint_decoder(dev))
+		return rc;
+
+	cxled = to_cxl_endpoint_decoder(dev);
+	if (!cxled->dpa_res || !resource_size(cxled->dpa_res))
+		return rc;
+
+	/*
+	 * Regions are only created with single mode decoders: pmem or ram.
+	 * Linux does not support mixed mode decoders. This means that
+	 * reading poison per endpoint decoder adheres to the requirement
+	 * that poison reads of pmem and ram must be separated.
+	 * CXL 3.0 Spec 8.2.9.8.4.1
+	 */
+	if (cxled->mode == CXL_DECODER_MIXED) {
+		dev_dbg(dev, "poison list read unsupported in mixed mode\n");
+		return rc;
+	}
+
+	cxlmd = cxled_to_memdev(cxled);
+	if (cxled->skip) {
+		offset = cxled->dpa_res->start - cxled->skip;
+		length = cxled->skip;
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM)
+			rc = 0;
+		if (rc)
+			return rc;
+	}
+
+	offset = cxled->dpa_res->start;
+	length = cxled->dpa_res->end - offset + 1;
+	rc = cxl_mem_get_poison(cxlmd, offset, length, cxled->cxld.region);
+	if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM)
+		rc = 0;
+	if (rc)
+		return rc;
+
+	/* Iterate until commit_end is reached */
+	if (cxled->cxld.id == ctx->port->commit_end) {
+		ctx->offset = cxled->dpa_res->end + 1;
+		ctx->mode = cxled->mode;
+		return 1;
+	}
+
+	return 0;
+}
+
+int cxl_get_poison_by_endpoint(struct cxl_port *port)
+{
+	struct cxl_poison_context ctx;
+	int rc = 0;
+
+	rc = down_read_interruptible(&cxl_region_rwsem);
+	if (rc)
+		return rc;
+
+	ctx = (struct cxl_poison_context) {
+		.port = port
+	};
+
+	rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder);
+	if (rc == 1)
+		rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport), &ctx);
+
+	up_read(&cxl_region_rwsem);
+	return rc;
+}
+
 static struct lock_class_key cxl_pmem_region_key;
 
 static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)

drivers/cxl/core/trace.c

 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright(c) 2022 Intel Corporation. All rights reserved. */
 
+#include <cxl.h>
+#include "core.h"
+
 #define CREATE_TRACE_POINTS
 #include "trace.h"
+
+static bool cxl_is_hpa_in_range(u64 hpa, struct cxl_region *cxlr, int pos)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	int gran = p->interleave_granularity;
+	int ways = p->interleave_ways;
+	u64 offset;
+
+	/* Is the hpa within this region at all */
+	if (hpa < p->res->start || hpa > p->res->end) {
+		dev_dbg(&cxlr->dev,
+			"Addr trans fail: hpa 0x%llx not in region\n", hpa);
+		return false;
+	}
+
+	/* Is the hpa in an expected chunk for its pos(-ition) */
+	offset = hpa - p->res->start;
+	offset = do_div(offset, gran * ways);
+	if ((offset >= pos * gran) && (offset < (pos + 1) * gran))
+		return true;
+
+	dev_dbg(&cxlr->dev,
+		"Addr trans fail: hpa 0x%llx not in expected chunk\n", hpa);
+
+	return false;
+}
+
+static u64 cxl_dpa_to_hpa(u64 dpa,  struct cxl_region *cxlr,
+			  struct cxl_endpoint_decoder *cxled)
+{
+	u64 dpa_offset, hpa_offset, bits_upper, mask_upper, hpa;
+	struct cxl_region_params *p = &cxlr->params;
+	int pos = cxled->pos;
+	u16 eig = 0;
+	u8 eiw = 0;
+
+	ways_to_eiw(p->interleave_ways, &eiw);
+	granularity_to_eig(p->interleave_granularity, &eig);
+
+	/*
+	 * The device position in the region interleave set was removed
+	 * from the offset at HPA->DPA translation. To reconstruct the
+	 * HPA, place the 'pos' in the offset.
+	 *
+	 * The placement of 'pos' in the HPA is determined by interleave
+	 * ways and granularity and is defined in the CXL Spec 3.0 Section
+	 * 8.2.4.19.13 Implementation Note: Device Decode Logic
+	 */
+
+	/* Remove the dpa base */
+	dpa_offset = dpa - cxl_dpa_resource_start(cxled);
+
+	mask_upper = GENMASK_ULL(51, eig + 8);
+
+	if (eiw < 8) {
+		hpa_offset = (dpa_offset & mask_upper) << eiw;
+		hpa_offset |= pos << (eig + 8);
+	} else {
+		bits_upper = (dpa_offset & mask_upper) >> (eig + 8);
+		bits_upper = bits_upper * 3;
+		hpa_offset = ((bits_upper << (eiw - 8)) + pos) << (eig + 8);
+	}
+
+	/* The lower bits remain unchanged */
+	hpa_offset |= dpa_offset & GENMASK_ULL(eig + 7, 0);
+
+	/* Apply the hpa_offset to the region base address */
+	hpa = hpa_offset + p->res->start;
+
+	if (!cxl_is_hpa_in_range(hpa, cxlr, cxled->pos))
+		return ULLONG_MAX;
+
+	return hpa;
+}
+
+u64 cxl_trace_hpa(struct cxl_region *cxlr, struct cxl_memdev *cxlmd,
+		  u64 dpa)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	struct cxl_endpoint_decoder *cxled = NULL;
+
+	for (int i = 0; i <  p->nr_targets; i++) {
+		cxled = p->targets[i];
+		if (cxlmd == cxled_to_memdev(cxled))
+			break;
+	}
+	if (!cxled || cxlmd != cxled_to_memdev(cxled))
+		return ULLONG_MAX;
+
+	return cxl_dpa_to_hpa(dpa, cxlr, cxled);
+}

drivers/cxl/core/trace.h

@@ -7,10 +7,12 @@
 #define _CXL_EVENTS_H
 
 #include <linux/tracepoint.h>
+#include <linux/pci.h>
 #include <asm-generic/unaligned.h>
 
 #include <cxl.h>
 #include <cxlmem.h>
+#include "core.h"
 
 #define CXL_RAS_UC_CACHE_DATA_PARITY	BIT(0)
 #define CXL_RAS_UC_CACHE_ADDR_PARITY	BIT(1)
@@ -600,6 +602,107 @@ TRACE_EVENT(cxl_memory_module,
 	)
 );
 
+#define show_poison_trace_type(type)			\
+	__print_symbolic(type,				\
+	{ CXL_POISON_TRACE_LIST,	"List"   },	\
+	{ CXL_POISON_TRACE_INJECT,	"Inject" },	\
+	{ CXL_POISON_TRACE_CLEAR,	"Clear"  })
+
+#define __show_poison_source(source)                          \
+	__print_symbolic(source,                              \
+		{ CXL_POISON_SOURCE_UNKNOWN,   "Unknown"  },  \
+		{ CXL_POISON_SOURCE_EXTERNAL,  "External" },  \
+		{ CXL_POISON_SOURCE_INTERNAL,  "Internal" },  \
+		{ CXL_POISON_SOURCE_INJECTED,  "Injected" },  \
+		{ CXL_POISON_SOURCE_VENDOR,    "Vendor"   })
+
+#define show_poison_source(source)			     \
+	(((source > CXL_POISON_SOURCE_INJECTED) &&	     \
+	 (source != CXL_POISON_SOURCE_VENDOR)) ? "Reserved"  \
+	 : __show_poison_source(source))
+
+#define show_poison_flags(flags)                             \
+	__print_flags(flags, "|",                            \
+		{ CXL_POISON_FLAG_MORE,      "More"     },   \
+		{ CXL_POISON_FLAG_OVERFLOW,  "Overflow"  },  \
+		{ CXL_POISON_FLAG_SCANNING,  "Scanning"  })
+
+#define __cxl_poison_addr(record)					\
+	(le64_to_cpu(record->address))
+#define cxl_poison_record_dpa(record)					\
+	(__cxl_poison_addr(record) & CXL_POISON_START_MASK)
+#define cxl_poison_record_source(record)				\
+	(__cxl_poison_addr(record)  & CXL_POISON_SOURCE_MASK)
+#define cxl_poison_record_dpa_length(record)				\
+	(le32_to_cpu(record->length) * CXL_POISON_LEN_MULT)
+#define cxl_poison_overflow(flags, time)				\
+	(flags & CXL_POISON_FLAG_OVERFLOW ? le64_to_cpu(time) : 0)
+
+u64 cxl_trace_hpa(struct cxl_region *cxlr, struct cxl_memdev *memdev, u64 dpa);
+
+TRACE_EVENT(cxl_poison,
+
+	TP_PROTO(struct cxl_memdev *cxlmd, struct cxl_region *region,
+		 const struct cxl_poison_record *record, u8 flags,
+		 __le64 overflow_ts, enum cxl_poison_trace_type trace_type),
+
+	TP_ARGS(cxlmd, region, record, flags, overflow_ts, trace_type),
+
+	TP_STRUCT__entry(
+		__string(memdev, dev_name(&cxlmd->dev))
+		__string(host, dev_name(cxlmd->dev.parent))
+		__field(u64, serial)
+		__field(u8, trace_type)
+		__string(region, region)
+		__field(u64, overflow_ts)
+		__field(u64, hpa)
+		__field(u64, dpa)
+		__field(u32, dpa_length)
+		__array(char, uuid, 16)
+		__field(u8, source)
+		__field(u8, flags)
+	    ),
+
+	TP_fast_assign(
+		__assign_str(memdev, dev_name(&cxlmd->dev));
+		__assign_str(host, dev_name(cxlmd->dev.parent));
+		__entry->serial = cxlmd->cxlds->serial;
+		__entry->overflow_ts = cxl_poison_overflow(flags, overflow_ts);
+		__entry->dpa = cxl_poison_record_dpa(record);
+		__entry->dpa_length = cxl_poison_record_dpa_length(record);
+		__entry->source = cxl_poison_record_source(record);
+		__entry->trace_type = trace_type;
+		__entry->flags = flags;
+		if (region) {
+			__assign_str(region, dev_name(&region->dev));
+			memcpy(__entry->uuid, &region->params.uuid, 16);
+			__entry->hpa = cxl_trace_hpa(region, cxlmd,
+						     __entry->dpa);
+		} else {
+			__assign_str(region, "");
+			memset(__entry->uuid, 0, 16);
+			__entry->hpa = ULLONG_MAX;
+		}
+	    ),
+
+	TP_printk("memdev=%s host=%s serial=%lld trace_type=%s region=%s "  \
+		"region_uuid=%pU hpa=0x%llx dpa=0x%llx dpa_length=0x%x "    \
+		"source=%s flags=%s overflow_time=%llu",
+		__get_str(memdev),
+		__get_str(host),
+		__entry->serial,
+		show_poison_trace_type(__entry->trace_type),
+		__get_str(region),
+		__entry->uuid,
+		__entry->hpa,
+		__entry->dpa,
+		__entry->dpa_length,
+		show_poison_source(__entry->source),
+		show_poison_flags(__entry->flags),
+		__entry->overflow_ts
+	)
+);
+
 #endif /* _CXL_EVENTS_H */
 
 #define TRACE_INCLUDE_FILE trace

drivers/cxl/cxlmem.h

@@ -145,7 +145,7 @@ struct cxl_mbox_cmd {
 	C(FWROLLBACK, -ENXIO, "rolled back to the previous active FW"),         \
 	C(FWRESET, -ENXIO, "FW failed to activate, needs cold reset"),		\
 	C(HANDLE, -ENXIO, "one or more Event Record Handles were invalid"),     \
-	C(PADDR, -ENXIO, "physical address specified is invalid"),		\
+	C(PADDR, -EFAULT, "physical address specified is invalid"),		\
 	C(POISONLMT, -ENXIO, "poison injection limit has been reached"),        \
 	C(MEDIAFAILURE, -ENXIO, "permanent issue with the media"),		\
 	C(ABORT, -ENXIO, "background cmd was aborted by device"),               \
@@ -215,6 +215,37 @@ struct cxl_event_state {
 	struct mutex log_lock;
 };
 
+/* Device enabled poison commands */
+enum poison_cmd_enabled_bits {
+	CXL_POISON_ENABLED_LIST,
+	CXL_POISON_ENABLED_INJECT,
+	CXL_POISON_ENABLED_CLEAR,
+	CXL_POISON_ENABLED_SCAN_CAPS,
+	CXL_POISON_ENABLED_SCAN_MEDIA,
+	CXL_POISON_ENABLED_SCAN_RESULTS,
+	CXL_POISON_ENABLED_MAX
+};
+
+/**
+ * struct cxl_poison_state - Driver poison state info
+ *
+ * @max_errors: Maximum media error records held in device cache
+ * @enabled_cmds: All poison commands enabled in the CEL
+ * @list_out: The poison list payload returned by device
+ * @lock: Protect reads of the poison list
+ *
+ * Reads of the poison list are synchronized to ensure that a reader
+ * does not get an incomplete list because their request overlapped
+ * (was interrupted or preceded by) another read request of the same
+ * DPA range. CXL Spec 3.0 Section 8.2.9.8.4.1
+ */
+struct cxl_poison_state {
+	u32 max_errors;
+	DECLARE_BITMAP(enabled_cmds, CXL_POISON_ENABLED_MAX);
+	struct cxl_mbox_poison_out *list_out;
+	struct mutex lock;  /* Protect reads of poison list */
+};
+
 /**
  * struct cxl_dev_state - The driver device state
  *
@@ -250,6 +281,7 @@ struct cxl_event_state {
  * @info: Cached DVSEC information about the device.
  * @serial: PCIe Device Serial Number
  * @event: event log driver state
+ * @poison: poison driver state info
  * @mbox_send: @dev specific transport for transmitting mailbox commands
  *
  * See section 8.2.9.5.2 Capacity Configuration and Label Storage for
@@ -287,6 +319,7 @@ struct cxl_dev_state {
 	u64 serial;
 
 	struct cxl_event_state event;
+	struct cxl_poison_state poison;
 
 	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
 };
@@ -535,6 +568,61 @@ struct cxl_mbox_set_timestamp_in {
 
 } __packed;
 
+/* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
+struct cxl_mbox_poison_in {
+	__le64 offset;
+	__le64 length;
+} __packed;
+
+struct cxl_mbox_poison_out {
+	u8 flags;
+	u8 rsvd1;
+	__le64 overflow_ts;
+	__le16 count;
+	u8 rsvd2[20];
+	struct cxl_poison_record {
+		__le64 address;
+		__le32 length;
+		__le32 rsvd;
+	} __packed record[];
+} __packed;
+
+/*
+ * Get Poison List address field encodes the starting
+ * address of poison, and the source of the poison.
+ */
+#define CXL_POISON_START_MASK		GENMASK_ULL(63, 6)
+#define CXL_POISON_SOURCE_MASK		GENMASK(2, 0)
+
+/* Get Poison List record length is in units of 64 bytes */
+#define CXL_POISON_LEN_MULT	64
+
+/* Kernel defined maximum for a list of poison errors */
+#define CXL_POISON_LIST_MAX	1024
+
+/* Get Poison List: Payload out flags */
+#define CXL_POISON_FLAG_MORE            BIT(0)
+#define CXL_POISON_FLAG_OVERFLOW        BIT(1)
+#define CXL_POISON_FLAG_SCANNING        BIT(2)
+
+/* Get Poison List: Poison Source */
+#define CXL_POISON_SOURCE_UNKNOWN	0
+#define CXL_POISON_SOURCE_EXTERNAL	1
+#define CXL_POISON_SOURCE_INTERNAL	2
+#define CXL_POISON_SOURCE_INJECTED	3
+#define CXL_POISON_SOURCE_VENDOR	7
+
+/* Inject & Clear Poison  CXL 3.0 Spec 8.2.9.8.4.2/3 */
+struct cxl_mbox_inject_poison {
+	__le64 address;
+};
+
+/* Clear Poison  CXL 3.0 Spec 8.2.9.8.4.3 */
+struct cxl_mbox_clear_poison {
+	__le64 address;
+	u8 write_data[CXL_POISON_LEN_MULT];
+} __packed;
+
 /**
  * struct cxl_mem_command - Driver representation of a memory device command
  * @info: Command information as it exists for the UAPI
@@ -605,6 +693,12 @@ void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds
 void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
 void cxl_mem_get_event_records(struct cxl_dev_state *cxlds, u32 status);
 int cxl_set_timestamp(struct cxl_dev_state *cxlds);
+int cxl_poison_state_init(struct cxl_dev_state *cxlds);
+int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
+		       struct cxl_region *cxlr);
+int cxl_trigger_poison_list(struct cxl_memdev *cxlmd);
+int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa);
+int cxl_clear_poison(struct cxl_memdev *cxlmd, u64 dpa);
 
 #ifdef CONFIG_CXL_SUSPEND
 void cxl_mem_active_inc(void);

drivers/cxl/mem.c

@@ -94,6 +94,26 @@ static int devm_cxl_add_endpoint(struct device *host, struct cxl_memdev *cxlmd,
 	return 0;
 }
 
+static int cxl_debugfs_poison_inject(void *data, u64 dpa)
+{
+	struct cxl_memdev *cxlmd = data;
+
+	return cxl_inject_poison(cxlmd, dpa);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_inject_fops, NULL,
+			 cxl_debugfs_poison_inject, "%llx\n");
+
+static int cxl_debugfs_poison_clear(void *data, u64 dpa)
+{
+	struct cxl_memdev *cxlmd = data;
+
+	return cxl_clear_poison(cxlmd, dpa);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_clear_fops, NULL,
+			 cxl_debugfs_poison_clear, "%llx\n");
+
 static int cxl_mem_probe(struct device *dev)
 {
 	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
@@ -117,6 +137,14 @@ static int cxl_mem_probe(struct device *dev)
 
 	dentry = cxl_debugfs_create_dir(dev_name(dev));
 	debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);
+
+	if (test_bit(CXL_POISON_ENABLED_INJECT, cxlds->poison.enabled_cmds))
+		debugfs_create_file("inject_poison", 0200, dentry, cxlmd,
+				    &cxl_poison_inject_fops);
+	if (test_bit(CXL_POISON_ENABLED_CLEAR, cxlds->poison.enabled_cmds))
+		debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
+				    &cxl_poison_clear_fops);
+
 	rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
 	if (rc)
 		return rc;
@@ -176,10 +204,53 @@ static int cxl_mem_probe(struct device *dev)
 	return devm_add_action_or_reset(dev, enable_suspend, NULL);
 }
 
+static ssize_t trigger_poison_list_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	bool trigger;
+	int rc;
+
+	if (kstrtobool(buf, &trigger) || !trigger)
+		return -EINVAL;
+
+	rc = cxl_trigger_poison_list(to_cxl_memdev(dev));
+
+	return rc ? rc : len;
+}
+static DEVICE_ATTR_WO(trigger_poison_list);
+
+static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	if (a == &dev_attr_trigger_poison_list.attr) {
+		struct device *dev = kobj_to_dev(kobj);
+
+		if (!test_bit(CXL_POISON_ENABLED_LIST,
+			      to_cxl_memdev(dev)->cxlds->poison.enabled_cmds))
+			return 0;
+	}
+	return a->mode;
+}
+
+static struct attribute *cxl_mem_attrs[] = {
+	&dev_attr_trigger_poison_list.attr,
+	NULL
+};
+
+static struct attribute_group cxl_mem_group = {
+	.attrs = cxl_mem_attrs,
+	.is_visible = cxl_mem_visible,
+};
+
+__ATTRIBUTE_GROUPS(cxl_mem);
+
 static struct cxl_driver cxl_mem_driver = {
 	.name = "cxl_mem",
 	.probe = cxl_mem_probe,
 	.id = CXL_DEVICE_MEMORY_EXPANDER,
+	.drv = {
+		.dev_groups = cxl_mem_groups,
+	},
 };
 
 module_cxl_driver(cxl_mem_driver);

drivers/cxl/pci.c

@@ -720,6 +720,10 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		return rc;
 
+	rc = cxl_poison_state_init(cxlds);
+	if (rc)
+		return rc;
+
 	rc = cxl_dev_state_identify(cxlds);
 	if (rc)
 		return rc;

include/uapi/linux/cxl_mem.h

@@ -40,19 +40,22 @@
 	___C(SET_ALERT_CONFIG, "Set Alert Configuration"),                \
 	___C(GET_SHUTDOWN_STATE, "Get Shutdown State"),                   \
 	___C(SET_SHUTDOWN_STATE, "Set Shutdown State"),                   \
-	___C(GET_POISON, "Get Poison List"),                              \
-	___C(INJECT_POISON, "Inject Poison"),                             \
-	___C(CLEAR_POISON, "Clear Poison"),                               \
+	___DEPRECATED(GET_POISON, "Get Poison List"),                     \
+	___DEPRECATED(INJECT_POISON, "Inject Poison"),                    \
+	___DEPRECATED(CLEAR_POISON, "Clear Poison"),                      \
 	___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"),         \
-	___C(SCAN_MEDIA, "Scan Media"),                                   \
-	___C(GET_SCAN_MEDIA, "Get Scan Media Results"),                   \
+	___DEPRECATED(SCAN_MEDIA, "Scan Media"),                          \
+	___DEPRECATED(GET_SCAN_MEDIA, "Get Scan Media Results"),          \
 	___C(MAX, "invalid / last command")
 
 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
+#define ___DEPRECATED(a, b) CXL_MEM_DEPRECATED_ID_##a
 enum { CXL_CMDS };
 
 #undef ___C
+#undef ___DEPRECATED
 #define ___C(a, b) { b }
+#define ___DEPRECATED(a, b) { "Deprecated " b }
 static const struct {
 	const char *name;
 } cxl_command_names[] __attribute__((__unused__)) = { CXL_CMDS };
@@ -68,6 +71,28 @@ static const struct {
  */
 
 #undef ___C
+#undef ___DEPRECATED
+#define ___C(a, b) (0)
+#define ___DEPRECATED(a, b) (1)
+
+static const __u8 cxl_deprecated_commands[]
+	__attribute__((__unused__)) = { CXL_CMDS };
+
+/*
+ * Here's how this actually breaks out:
+ * cxl_deprecated_commands[] = {
+ *	[CXL_MEM_COMMAND_ID_INVALID] = 0,
+ *	[CXL_MEM_COMMAND_ID_IDENTIFY] = 0,
+ *	...
+ *	[CXL_MEM_DEPRECATED_ID_GET_POISON] = 1,
+ *	[CXL_MEM_DEPRECATED_ID_INJECT_POISON] = 1,
+ *	[CXL_MEM_DEPRECATED_ID_CLEAR_POISON] = 1,
+ *	...
+ * };
+ */
+
+#undef ___C
+#undef ___DEPRECATED
 
 /**
  * struct cxl_command_info - Command information returned from a query.

tools/testing/cxl/config_check.c

@@ -13,4 +13,5 @@ void check(void)
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_CXL_PMEM));
 	BUILD_BUG_ON(!IS_ENABLED(CONFIG_CXL_REGION_INVALIDATION_TEST));
 	BUILD_BUG_ON(!IS_ENABLED(CONFIG_NVDIMM_SECURITY_TEST));
+	BUILD_BUG_ON(!IS_ENABLED(CONFIG_DEBUG_FS));
 }

tools/testing/cxl/test/mem.c

@@ -7,6 +7,7 @@
 #include <linux/delay.h>
 #include <linux/sizes.h>
 #include <linux/bits.h>
+#include <asm/unaligned.h>
 #include <cxlmem.h>
 
 #include "trace.h"
@@ -15,6 +16,11 @@
 #define DEV_SIZE SZ_2G
 #define EFFECT(x) (1U << x)
 
+#define MOCK_INJECT_DEV_MAX 8
+#define MOCK_INJECT_TEST_MAX 128
+
+static unsigned int poison_inject_dev_max = MOCK_INJECT_DEV_MAX;
+
 static struct cxl_cel_entry mock_cel[] = {
 	{
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_SUPPORTED_LOGS),
@@ -40,6 +46,18 @@ static struct cxl_cel_entry mock_cel[] = {
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_HEALTH_INFO),
 		.effect = cpu_to_le16(0),
 	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_POISON),
+		.effect = cpu_to_le16(0),
+	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_INJECT_POISON),
+		.effect = cpu_to_le16(0),
+	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_CLEAR_POISON),
+		.effect = cpu_to_le16(0),
+	},
 };
 
 /* See CXL 2.0 Table 181 Get Health Info Output Payload */
@@ -469,8 +487,11 @@ static int mock_id(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 			cpu_to_le64(SZ_256M / CXL_CAPACITY_MULTIPLIER),
 		.total_capacity =
 			cpu_to_le64(DEV_SIZE / CXL_CAPACITY_MULTIPLIER),
+		.inject_poison_limit = cpu_to_le16(MOCK_INJECT_TEST_MAX),
 	};
 
+	put_unaligned_le24(CXL_POISON_LIST_MAX, id.poison_list_max_mer);
+
 	if (cmd->size_out < sizeof(id))
 		return -EINVAL;
 
@@ -888,6 +909,194 @@ static int mock_health_info(struct cxl_dev_state *cxlds,
 	return 0;
 }
 
+static struct mock_poison {
+	struct cxl_dev_state *cxlds;
+	u64 dpa;
+} mock_poison_list[MOCK_INJECT_TEST_MAX];
+
+static struct cxl_mbox_poison_out *
+cxl_get_injected_po(struct cxl_dev_state *cxlds, u64 offset, u64 length)
+{
+	struct cxl_mbox_poison_out *po;
+	int nr_records = 0;
+	u64 dpa;
+
+	po = kzalloc(struct_size(po, record, poison_inject_dev_max), GFP_KERNEL);
+	if (!po)
+		return NULL;
+
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (mock_poison_list[i].cxlds != cxlds)
+			continue;
+		if (mock_poison_list[i].dpa < offset ||
+		    mock_poison_list[i].dpa > offset + length - 1)
+			continue;
+
+		dpa = mock_poison_list[i].dpa + CXL_POISON_SOURCE_INJECTED;
+		po->record[nr_records].address = cpu_to_le64(dpa);
+		po->record[nr_records].length = cpu_to_le32(1);
+		nr_records++;
+		if (nr_records == poison_inject_dev_max)
+			break;
+	}
+
+	/* Always return count, even when zero */
+	po->count = cpu_to_le16(nr_records);
+
+	return po;
+}
+
+static int mock_get_poison(struct cxl_dev_state *cxlds,
+			   struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_poison_in *pi = cmd->payload_in;
+	struct cxl_mbox_poison_out *po;
+	u64 offset = le64_to_cpu(pi->offset);
+	u64 length = le64_to_cpu(pi->length);
+	int nr_records;
+
+	po = cxl_get_injected_po(cxlds, offset, length);
+	if (!po)
+		return -ENOMEM;
+	nr_records = le16_to_cpu(po->count);
+	memcpy(cmd->payload_out, po, struct_size(po, record, nr_records));
+	cmd->size_out = struct_size(po, record, nr_records);
+	kfree(po);
+
+	return 0;
+}
+
+static bool mock_poison_dev_max_injected(struct cxl_dev_state *cxlds)
+{
+	int count = 0;
+
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (mock_poison_list[i].cxlds == cxlds)
+			count++;
+	}
+	return (count >= poison_inject_dev_max);
+}
+
+static bool mock_poison_add(struct cxl_dev_state *cxlds, u64 dpa)
+{
+	if (mock_poison_dev_max_injected(cxlds)) {
+		dev_dbg(cxlds->dev,
+			"Device poison injection limit has been reached: %d\n",
+			MOCK_INJECT_DEV_MAX);
+		return false;
+	}
+
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (!mock_poison_list[i].cxlds) {
+			mock_poison_list[i].cxlds = cxlds;
+			mock_poison_list[i].dpa = dpa;
+			return true;
+		}
+	}
+	dev_dbg(cxlds->dev,
+		"Mock test poison injection limit has been reached: %d\n",
+		MOCK_INJECT_TEST_MAX);
+
+	return false;
+}
+
+static bool mock_poison_found(struct cxl_dev_state *cxlds, u64 dpa)
+{
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (mock_poison_list[i].cxlds == cxlds &&
+		    mock_poison_list[i].dpa == dpa)
+			return true;
+	}
+	return false;
+}
+
+static int mock_inject_poison(struct cxl_dev_state *cxlds,
+			      struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_inject_poison *pi = cmd->payload_in;
+	u64 dpa = le64_to_cpu(pi->address);
+
+	if (mock_poison_found(cxlds, dpa)) {
+		/* Not an error to inject poison if already poisoned */
+		dev_dbg(cxlds->dev, "DPA: 0x%llx already poisoned\n", dpa);
+		return 0;
+	}
+	if (!mock_poison_add(cxlds, dpa))
+		return -ENXIO;
+
+	return 0;
+}
+
+static bool mock_poison_del(struct cxl_dev_state *cxlds, u64 dpa)
+{
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (mock_poison_list[i].cxlds == cxlds &&
+		    mock_poison_list[i].dpa == dpa) {
+			mock_poison_list[i].cxlds = NULL;
+			return true;
+		}
+	}
+	return false;
+}
+
+static int mock_clear_poison(struct cxl_dev_state *cxlds,
+			     struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_clear_poison *pi = cmd->payload_in;
+	u64 dpa = le64_to_cpu(pi->address);
+
+	/*
+	 * A real CXL device will write pi->write_data to the address
+	 * being cleared. In this mock, just delete this address from
+	 * the mock poison list.
+	 */
+	if (!mock_poison_del(cxlds, dpa))
+		dev_dbg(cxlds->dev, "DPA: 0x%llx not in poison list\n", dpa);
+
+	return 0;
+}
+
+static bool mock_poison_list_empty(void)
+{
+	for (int i = 0; i < MOCK_INJECT_TEST_MAX; i++) {
+		if (mock_poison_list[i].cxlds)
+			return false;
+	}
+	return true;
+}
+
+static ssize_t poison_inject_max_show(struct device_driver *drv, char *buf)
+{
+	return sysfs_emit(buf, "%u\n", poison_inject_dev_max);
+}
+
+static ssize_t poison_inject_max_store(struct device_driver *drv,
+				       const char *buf, size_t len)
+{
+	int val;
+
+	if (kstrtoint(buf, 0, &val) < 0)
+		return -EINVAL;
+
+	if (!mock_poison_list_empty())
+		return -EBUSY;
+
+	if (val <= MOCK_INJECT_TEST_MAX)
+		poison_inject_dev_max = val;
+	else
+		return -EINVAL;
+
+	return len;
+}
+
+static DRIVER_ATTR_RW(poison_inject_max);
+
+static struct attribute *cxl_mock_mem_core_attrs[] = {
+	&driver_attr_poison_inject_max.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(cxl_mock_mem_core);
+
 static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
 	struct device *dev = cxlds->dev;
@@ -942,6 +1151,15 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
 	case CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE:
 		rc = mock_passphrase_secure_erase(cxlds, cmd);
 		break;
+	case CXL_MBOX_OP_GET_POISON:
+		rc = mock_get_poison(cxlds, cmd);
+		break;
+	case CXL_MBOX_OP_INJECT_POISON:
+		rc = mock_inject_poison(cxlds, cmd);
+		break;
+	case CXL_MBOX_OP_CLEAR_POISON:
+		rc = mock_clear_poison(cxlds, cmd);
+		break;
 	default:
 		break;
 	}
@@ -1010,6 +1228,10 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
+	rc = cxl_poison_state_init(cxlds);
+	if (rc)
+		return rc;
+
 	rc = cxl_dev_state_identify(cxlds);
 	if (rc)
 		return rc;
@@ -1083,6 +1305,7 @@ static struct platform_driver cxl_mock_mem_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.dev_groups = cxl_mock_mem_groups,
+		.groups = cxl_mock_mem_core_groups,
 	},
 };