tools/testing/cxl: Mock the Inject Poison mailbox command

Mock the injection of poison by storing the device:address entries in
mock_poison_list[]. Enforce a limit of 8 poison injections per memdev
device and 128 total entries for the cxl_test mock driver.

Introducing the mock_poison[] list here, makes it available for use in
the mock of Clear Poison, and the mock of Get Poison List.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/f6b7f03541eaa8c2260d3eafadd04afe3f0d7962.1681874357.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/cxl/test/mem.c

@@ -16,6 +16,9 @@
 #define DEV_SIZE SZ_2G
 #define EFFECT(x) (1U << x)
 
+#define MOCK_INJECT_DEV_MAX 8
+#define MOCK_INJECT_TEST_MAX 128
+
 static struct cxl_cel_entry mock_cel[] = {
 	{
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_SUPPORTED_LOGS),
@@ -45,6 +48,10 @@ static struct cxl_cel_entry mock_cel[] = {
 		.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),
+	},
 };
 
 /* See CXL 2.0 Table 181 Get Health Info Output Payload */
@@ -474,6 +481,7 @@ 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_DEV_MAX),
 	};
 
 	put_unaligned_le24(CXL_POISON_LIST_MAX, id.poison_list_max_mer);
@@ -895,6 +903,11 @@ 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 int mock_get_poison(struct cxl_dev_state *cxlds,
 			   struct cxl_mbox_cmd *cmd)
 {
@@ -923,6 +936,67 @@ static int mock_get_poison(struct cxl_dev_state *cxlds,
 	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 >= MOCK_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 int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
 	struct device *dev = cxlds->dev;
@@ -980,6 +1054,9 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
 	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;
 	default:
 		break;
 	}