[PATCH v3 6/10] PCI: wire CXL reset prepare/cleanup

[<smadhavan@nvidia.com>]

From: Srirangan Madhavan <smadhavan@nvidia.com>

Wire CXL reset preparation and cleanup into the PCI CXL reset path.
The flow now validates/offlines regions, performs teardown and cache
flushes, then releases the lock on completion or error. This keeps the
common reset_prepare flow intact while adding cxl_reset-specific quiesce logic.

Signed-off-by: Srirangan Madhavan <smadhavan@nvidia.com>
---
 drivers/pci/pci.c   | 19 ++++++++++++++++++-
 include/linux/pci.h |  2 ++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b3eb82b21c35..83fd7e75a12e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4985,10 +4985,27 @@ static int cxl_reset(struct pci_dev *dev, bool probe)
 	if (probe)
 		return 0;

+	/*
+	 * CXL-reset-specific preparation: validate memory offline,
+	 * tear down regions, flush device caches.
+	 */
+	rc = cxl_reset_prepare_device(dev);
+	if (rc)
+		return rc;
+
 	if (!pci_wait_for_pending_transaction(dev))
 		pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");

-	return cxl_reset_init(dev, dvsec);
+	rc = cxl_reset_init(dev, dvsec);
+	if (rc)
+		goto out_cleanup;
+
+	cxl_reset_cleanup_device(dev);
+	return 0;
+
+out_cleanup:
+	cxl_reset_cleanup_device(dev);
+	return rc;
 }

 static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 056eff0b1e86..d29f0bfc84b5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1465,6 +1465,8 @@ int __must_check pci_resize_resource(struct pci_dev *dev, int i, int size,
 int pci_select_bars(struct pci_dev *dev, unsigned long flags);
 bool pci_device_is_present(struct pci_dev *pdev);
 bool cxl_is_type2_device(struct pci_dev *dev);
+int cxl_reset_prepare_device(struct pci_dev *pdev);
+void cxl_reset_cleanup_device(struct pci_dev *pdev);
 void pci_ignore_hotplug(struct pci_dev *dev);
 struct pci_dev *pci_real_dma_dev(struct pci_dev *dev);
 int pci_status_get_and_clear_errors(struct pci_dev *pdev);
--
2.34.1