mfd: ls2kbmc: Fully convert to use managed resources

The mixing of managed and non-managed resources may lead to possible
use-after-free bugs. In this driver the problematic part is the device
functionality that may just have gone behind the functions back, e.g.,
when interrupt is being served. Fix this by switching to managed resources
for PCI.

Fixes: 91a3e1f ("mfd: ls2kbmc: Check for devm_mfd_add_devices() failure")
Fixes: d952bba ("mfd: ls2kbmc: Add Loongson-2K BMC reset function support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/20251030113735.3741913-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: andy-shev

drivers/mfd/ls2k-bmc-core.c

@@ -464,53 +464,36 @@ static int ls2k_bmc_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	resource_size_t base;
 	int ret;
 
-	ret = pci_enable_device(dev);
+	ret = pcim_enable_device(dev);
 	if (ret)
 		return ret;
 
 	ddata = devm_kzalloc(&dev->dev, sizeof(*ddata), GFP_KERNEL);
-	if (!ddata) {
-		ret = -ENOMEM;
-		goto disable_pci;
-	}
+	if (!ddata)
+		return -ENOMEM;
 
 	ddata->dev = &dev->dev;
 
 	ret = ls2k_bmc_init(ddata);
 	if (ret)
-		goto disable_pci;
+		return ret;
 
 	ret = ls2k_bmc_parse_mode(dev, &pd);
 	if (ret)
-		goto disable_pci;
+		return ret;
 
 	ls2k_bmc_cells[LS2K_BMC_DISPLAY].platform_data = &pd;
 	ls2k_bmc_cells[LS2K_BMC_DISPLAY].pdata_size = sizeof(pd);
 	base = dev->resource[0].start + LS2K_DISPLAY_RES_START;
 
 	/* Remove conflicting efifb device */
 	ret = aperture_remove_conflicting_devices(base, SZ_4M, "simple-framebuffer");
-	if (ret) {
-		dev_err(&dev->dev, "Failed to removed firmware framebuffers: %d\n", ret);
-		goto disable_pci;
-	}
-
-	ret = devm_mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
-				   ls2k_bmc_cells, ARRAY_SIZE(ls2k_bmc_cells),
-				   &dev->resource[0], 0, NULL);
 	if (ret)
-		goto disable_pci;
+		return dev_err_probe(&dev->dev, ret, "Failed to removed firmware framebuffers\n");
 
-	return 0;
-
-disable_pci:
-	pci_disable_device(dev);
-	return ret;
-}
-
-static void ls2k_bmc_remove(struct pci_dev *dev)
-{
-	pci_disable_device(dev);
+	return devm_mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
+				    ls2k_bmc_cells, ARRAY_SIZE(ls2k_bmc_cells),
+				    &dev->resource[0], 0, NULL);
 }
 
 static struct pci_device_id ls2k_bmc_devices[] = {
@@ -523,7 +506,6 @@ static struct pci_driver ls2k_bmc_driver = {
 	.name = "ls2k-bmc",
 	.id_table = ls2k_bmc_devices,
 	.probe = ls2k_bmc_probe,
-	.remove = ls2k_bmc_remove,
 };
 module_pci_driver(ls2k_bmc_driver);