cxl/test: Update mock dev array before calling platform_device_add()

CXL test environment hits the following error sometimes.

 cxl_mem mem9: endpoint7 failed probe

All mock memdevs are platform firmware devices added by cxl_test module,
and cxl_test module also provides a platform device driver for them to
create a memdev device to CXL subsystem. cxl_test module uses
cxl_rcd/mem_single/mem arrays to store different types of mock memdevs.
CXL drivers calls registered mock functions for a mock memdev by
checking if a given memdev is in these arrays.

When cxl_test module adds these mock memdevs, it always calls
platform_device_add() before adding them to a suitable mock memdev
array. However, there is a small window where CXL drivers calls mock
function for a added memdev before it added to a mock memdev array. In
above case, cxl endpoint driver considers a added memdev was not a mock
memdev, then calling devm_cxl_endpoint_decoders_setup() for it rather
than mock_endpoint_decoders_setup().

An appropriate solution is that adding a new mock device to a mock
device array before calling platform_device_add() for it. It can
guarantee the new mock device is visible to CXL subsystem.

This patch introduces a new helped called cxl_mock_platform_device_add()
to handle the issue, and uses the function for all mock devices addition.

Fixes: 3a2b97b3210b ("cxl/test: Improve init-order fidelity relative to real-world systems")
Signed-off-by: Li Ming <ming.li@zohomail.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260520121457.234404-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

1 files changed, 43 insertions, 62 deletions

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 418669927fb0..296516eecfd6 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1523,6 +1523,23 @@ static void mock_companion(struct acpi_device *adev, struct device *dev)
 #define SZ_64G (SZ_32G * 2)
 #endif
 
+static int cxl_mock_platform_device_add(struct platform_device *pdev,
+					struct platform_device **ppdev)
+{
+	int rc;
+
+	if (ppdev)
+		*ppdev = pdev;
+	rc = platform_device_add(pdev);
+	if (rc) {
+		platform_device_put(pdev);
+		if (ppdev)
+			*ppdev = NULL;
+	}
+
+	return rc;
+}
+
 static __init int cxl_rch_topo_init(void)
 {
 	int rc, i;
@@ -1537,13 +1554,10 @@ static __init int cxl_rch_topo_init(void)
 			goto err_bridge;
 
 		mock_companion(adev, &pdev->dev);
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_rch[i]);
+		if (rc)
 			goto err_bridge;
-		}
 
-		cxl_rch[i] = pdev;
 		mock_pci_bus[idx].bridge = &pdev->dev;
 		rc = sysfs_create_link(&pdev->dev.kobj, &pdev->dev.kobj,
 				       "firmware_node");
@@ -1595,13 +1609,10 @@ static __init int cxl_single_topo_init(void)
 			goto err_bridge;
 
 		mock_companion(adev, &pdev->dev);
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_hb_single[i]);
+		if (rc)
 			goto err_bridge;
-		}
 
-		cxl_hb_single[i] = pdev;
 		mock_pci_bus[i + NR_CXL_HOST_BRIDGES].bridge = &pdev->dev;
 		rc = sysfs_create_link(&pdev->dev.kobj, &pdev->dev.kobj,
 				       "physical_node");
@@ -1620,12 +1631,9 @@ static __init int cxl_single_topo_init(void)
 			goto err_port;
 		pdev->dev.parent = &bridge->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_root_single[i]);
+		if (rc)
 			goto err_port;
-		}
-		cxl_root_single[i] = pdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cxl_swu_single); i++) {
@@ -1638,12 +1646,9 @@ static __init int cxl_single_topo_init(void)
 			goto err_uport;
 		pdev->dev.parent = &root_port->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_swu_single[i]);
+		if (rc)
 			goto err_uport;
-		}
-		cxl_swu_single[i] = pdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cxl_swd_single); i++) {
@@ -1657,12 +1662,9 @@ static __init int cxl_single_topo_init(void)
 			goto err_dport;
 		pdev->dev.parent = &uport->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_swd_single[i]);
+		if (rc)
 			goto err_dport;
-		}
-		cxl_swd_single[i] = pdev;
 	}
 
 	return 0;
@@ -1735,12 +1737,9 @@ static int cxl_mem_init(void)
 		pdev->dev.parent = &dport->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_mem[i]);
+		if (rc)
 			goto err_mem;
-		}
-		cxl_mem[i] = pdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cxl_mem_single); i++) {
@@ -1753,12 +1752,9 @@ static int cxl_mem_init(void)
 		pdev->dev.parent = &dport->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_mem_single[i]);
+		if (rc)
 			goto err_single;
-		}
-		cxl_mem_single[i] = pdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cxl_rcd); i++) {
@@ -1772,12 +1768,9 @@ static int cxl_mem_init(void)
 		pdev->dev.parent = &rch->dev;
 		set_dev_node(&pdev->dev, i % 2);
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_rcd[i]);
+		if (rc)
 			goto err_rcd;
-		}
-		cxl_rcd[i] = pdev;
 	}
 
 	return 0;
@@ -1869,13 +1862,10 @@ static __init int cxl_test_init(void)
 			goto err_bridge;
 
 		mock_companion(adev, &pdev->dev);
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_host_bridge[i]);
+		if (rc)
 			goto err_bridge;
-		}
 
-		cxl_host_bridge[i] = pdev;
 		mock_pci_bus[i].bridge = &pdev->dev;
 		rc = sysfs_create_link(&pdev->dev.kobj, &pdev->dev.kobj,
 				       "physical_node");
@@ -1893,12 +1883,9 @@ static __init int cxl_test_init(void)
 			goto err_port;
 		pdev->dev.parent = &bridge->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_root_port[i]);
+		if (rc)
 			goto err_port;
-		}
-		cxl_root_port[i] = pdev;
 	}
 
 	BUILD_BUG_ON(ARRAY_SIZE(cxl_switch_uport) != ARRAY_SIZE(cxl_root_port));
@@ -1911,12 +1898,9 @@ static __init int cxl_test_init(void)
 			goto err_uport;
 		pdev->dev.parent = &root_port->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_uport[i]);
+		if (rc)
 			goto err_uport;
-		}
-		cxl_switch_uport[i] = pdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(cxl_switch_dport); i++) {
@@ -1929,12 +1913,9 @@ static __init int cxl_test_init(void)
 			goto err_dport;
 		pdev->dev.parent = &uport->dev;
 
-		rc = platform_device_add(pdev);
-		if (rc) {
-			platform_device_put(pdev);
+		rc = cxl_mock_platform_device_add(pdev, &cxl_switch_dport[i]);
+		if (rc)
 			goto err_dport;
-		}
-		cxl_switch_dport[i] = pdev;
 	}
 
 	rc = cxl_single_topo_init();
@@ -1953,9 +1934,9 @@ static __init int cxl_test_init(void)
 	acpi0017_mock.dev.bus = &platform_bus_type;
 	cxl_acpi->dev.groups = cxl_acpi_groups;
 
-	rc = platform_device_add(cxl_acpi);
+	rc = cxl_mock_platform_device_add(cxl_acpi, NULL);
 	if (rc)
-		goto err_root;
+		goto err_rch;
 
 	rc = cxl_mem_init();
 	if (rc)