drivers/pci/msi/msi.c | 33 +++++++++++++++++++++++++++++++++ drivers/pci/pci.c | 5 ----- include/linux/pci.h | 3 ++- 3 files changed, 35 insertions(+), 6 deletions(-)
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@ti.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V4: New patch
---
drivers/pci/msi/msi.c | 33 +++++++++++++++++++++++++++++++++
drivers/pci/pci.c | 5 -----
include/linux/pci.h | 3 ++-
3 files changed, 35 insertions(+), 6 deletions(-)
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -341,6 +341,31 @@ void pci_restore_msi_state(struct pci_de
}
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)
{
@@ -884,6 +909,10 @@ static int __pci_enable_msi_range(struct
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);
@@ -927,6 +956,10 @@ static int __pci_enable_msix_range(struc
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);
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2024,11 +2024,6 @@ static void pcim_release(struct device *
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);
--- 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;
On Wed, Dec 15, 2021 at 06:16:44PM +0100, Thomas Gleixner wrote: > 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@ti.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > --- > V4: New patch Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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;
On Wed, Dec 15, 2021 at 06:19:49PM +0100, Thomas Gleixner wrote: > 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> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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