tools/testing/cxl: Mock support for Get Poison List

Make mock memdevs support the Get Poison List mailbox command.
Return a fake poison error record when the get poison list command
is issued.

This supports testing the kernel tracing and cxl list capabilities
for media errors.
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/14d661ce3e3a32b7d8e76b8ecc5eb88343b3d09c.1681838292.git.alison.schofield@intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

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"
@@ -40,6 +41,10 @@ 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),
+	},
 };
 
 /* See CXL 2.0 Table 181 Get Health Info Output Payload */
@@ -471,6 +476,8 @@ static int mock_id(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 			cpu_to_le64(DEV_SIZE / CXL_CAPACITY_MULTIPLIER),
 	};
 
+	put_unaligned_le24(CXL_POISON_LIST_MAX, id.poison_list_max_mer);
+
 	if (cmd->size_out < sizeof(id))
 		return -EINVAL;
 
@@ -888,6 +895,34 @@ static int mock_health_info(struct cxl_dev_state *cxlds,
 	return 0;
 }
 
+static int mock_get_poison(struct cxl_dev_state *cxlds,
+			   struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_poison_in *pi = cmd->payload_in;
+
+	/* Mock one poison record at pi.offset for 64 bytes */
+	struct {
+		struct cxl_mbox_poison_out po;
+		struct cxl_poison_record record;
+	} __packed mock_plist = {
+		.po = {
+			.count = cpu_to_le16(1),
+		},
+		.record = {
+			.length = cpu_to_le32(1),
+			.address = cpu_to_le64(le64_to_cpu(pi->offset) +
+					       CXL_POISON_SOURCE_INJECTED),
+		},
+	};
+
+	if (cmd->size_out < sizeof(mock_plist))
+		return -EINVAL;
+
+	memcpy(cmd->payload_out, &mock_plist, sizeof(mock_plist));
+	cmd->size_out = sizeof(mock_plist);
+	return 0;
+}
+
 static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
 	struct device *dev = cxlds->dev;
@@ -942,6 +977,9 @@ 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;
 	default:
 		break;
 	}
@@ -1010,6 +1048,10 @@ 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;