From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
[ Upstream commit 3f35d2cf9fbc656db82579d849cc69c373b1ad0d ]
The MSI core will introduce runtime allocation of MSI related data. This
data will be devres managed and has to be set up before enabling
PCI/MSI[-X]. This would introduce an ordering issue vs. pcim_release().
The setup order is:
pcim_enable_device()
devres_alloc(pcim_release...);
...
pci_irq_alloc()
msi_setup_device_data()
devres_alloc(msi_device_data_release, ...)
and once the device is released these release functions are invoked in the
opposite order:
msi_device_data_release()
...
pcim_release()
pci_disable_msi[x]()
which is obviously wrong, because pci_disable_msi[x]() requires the MSI
data to be available to tear down the MSI[-X] interrupts.
Remove the MSI[-X] teardown from pcim_release() and add an explicit action
to be installed on the attempt of enabling PCI/MSI[-X].
This allows the MSI core data allocation to be ordered correctly in a
subsequent step.
Reported-by: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Tested-by: Nishanth Menon <nm@xxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/87tuf9rdoj.ffs@tglx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/msi.c | 33 +++++++++++++++++++++++++++++++++
drivers/pci/pci.c | 5 -----
include/linux/pci.h | 3 ++-
3 files changed, 35 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d84cf30bb2790..1093f099846eb 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -461,6 +461,31 @@ void pci_restore_msi_state(struct pci_dev *dev)
}
EXPORT_SYMBOL_GPL(pci_restore_msi_state);
+static void pcim_msi_release(void *pcidev)
+{
+ struct pci_dev *dev = pcidev;
+
+ dev->is_msi_managed = false;
+ pci_free_irq_vectors(dev);
+}
+
+/*
+ * Needs to be separate from pcim_release to prevent an ordering problem
+ * vs. msi_device_data_release() in the MSI core code.
+ */
+static int pcim_setup_msi_release(struct pci_dev *dev)
+{
+ int ret;
+
+ if (!pci_is_managed(dev) || dev->is_msi_managed)
+ return 0;
+
+ ret = devm_add_action(&dev->dev, pcim_msi_release, dev);
+ if (!ret)
+ dev->is_msi_managed = true;
+ return ret;
+}
+
static struct msi_desc *
msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
{
@@ -1029,6 +1054,10 @@ 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);
+ if (rc)
+ return rc;
+
for (;;) {
if (affd) {
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
@@ -1072,6 +1101,10 @@ 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);
+ if (rc)
+ return rc;
+
for (;;) {
if (affd) {
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 3d2fb394986a4..f3f606c232a8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2024,11 +2024,6 @@ static void pcim_release(struct device *gendev, void *res)
struct pci_devres *this = res;
int i;
- if (dev->msi_enabled)
- pci_disable_msi(dev);
- if (dev->msix_enabled)
- pci_disable_msix(dev);
-
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
if (this->region_mask & (1 << i))
pci_release_region(dev, i);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 18a75c8e615cd..e26000404e3c3 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -425,7 +425,8 @@ struct pci_dev {
unsigned int ats_enabled:1; /* Address Translation Svc */
unsigned int pasid_enabled:1; /* Process Address Space ID */
unsigned int pri_enabled:1; /* Page Request Interface */
- unsigned int is_managed:1;
+ unsigned int is_managed:1; /* Managed via devres */
+ unsigned int is_msi_managed:1; /* MSI release via devres installed */
unsigned int needs_freset:1; /* Requires fundamental reset */
unsigned int state_saved:1;
unsigned int is_physfn:1;
--
2.34.1
