[patch V4 09-02/35] PCI/MSI: Allocate MSI device data on first use

Thomas Gleixner
2021-12-15T17:19:53Z

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>
---
V4: Adopted to ensure devres ordering
---
drivers/pci/msi/msi.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -366,6 +366,19 @@ static int pcim_setup_msi_release(struct
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
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(struc
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;