[tip: irq/msi] PCI/MSI: Allocate MSI device data on first use

["tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>]

The following commit has been merged into the irq/msi branch of tip:

Commit-ID:     93296cd1325d1d9afede60202d8833011c9001f2
Gitweb:        https://git.kernel.org/tip/93296cd1325d1d9afede60202d8833011c9001f2
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Wed, 15 Dec 2021 18:19:49 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Dec 2021 22:16:38 +01:00

PCI/MSI: Allocate MSI device data on first use

Allocate MSI device data on first use, i.e. when a PCI driver invokes one
of the PCI/MSI enablement functions.

Add a wrapper function to ensure that the ordering vs. pcim_msi_release()
is correct.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/87r1adrdje.ffs@tglx

---
 drivers/pci/msi/msi.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 358b63e..369e3c5 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -366,6 +366,19 @@ static int pcim_setup_msi_release(struct pci_dev *dev)
 	return ret;
 }
 
+/*
+ * Ordering vs. devres: msi device data has to be installed first so that
+ * pcim_msi_release() is invoked before it on device release.
+ */
+static int pci_setup_msi_context(struct pci_dev *dev)
+{
+	int ret = msi_setup_device_data(&dev->dev);
+
+	if (!ret)
+		ret = pcim_setup_msi_release(dev);
+	return ret;
+}
+
 static struct msi_desc *
 msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
 {
@@ -909,7 +922,7 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
 	if (nvec > maxvec)
 		nvec = maxvec;
 
-	rc = pcim_setup_msi_release(dev);
+	rc = pci_setup_msi_context(dev);
 	if (rc)
 		return rc;
 
@@ -956,7 +969,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
 	if (WARN_ON_ONCE(dev->msix_enabled))
 		return -EINVAL;
 
-	rc = pcim_setup_msi_release(dev);
+	rc = pci_setup_msi_context(dev);
 	if (rc)
 		return rc;